solas explainatory

1 10/01/2012

SOLAS Consolidated Edition 2009

with Explanatory Notes

(Res. MSC.281(85))

Applicable to Passenger and Cargo Ships of all Sizes

& Dry Cargo Ships with Length => 80 m

with keels laid on or after 1st January, 2009

KEY TO COLOUR CODES and FONTS USED IN THIS DOCUMENT SOLAS Consolidated Edition 2009; Current SOLAS text Resolution MSC.281(85); Current Explanatory Notes (EN) Regulation 2.9 (ref. SLF 52/17/6 - Norway); Proposed changes to SOLAS text with ref. Regulation 4.3 (ref. SLF 52/3/3 - Germany) Proposed changes to EN (with ref.) Regulation 4.1 (ref. SLF 52/17/6 - Norway) Proposed changes to footnotes (with ref.) [Coordinator’s Note:] Guidance and suggested minor changes MSC Circulars MSC Circulars referred to in the text Round 1/2 Discussion: Co-ordinator’s comments on Round 1/2 Q1A Round 2 questions Q1B Round 3 questions for discussion at SLF53 Agreed Regulatory Text Changes Changes to SOLAS agreed in SLF53/WP.6 Agreed EN Text Changes Changes to EN text agreed in SLF 53/WP.6 Rejected Regulatory Text Changes Changes to SOLAS rejected at SLF 53 Rejected EN Text Changes Changes to EN text rejected at SLF 53 Q1C Round 4 questions for 2011 CG Q1D Questions for discussion at SLF53 Proposed Regulatory Text Changes Changes to SOLAS proposed by 2011 CG Proposed EN Text Changes Changes to EN text proposed by 2011 CG NFA No Further Action – leave text unchanged

2 10/01/2012

UPDATES TO SOLAS 2009 AMENDMENTS

To simplify the task of discussing and agreeing updates to the SOLAS regulations, this document includes the full text of the SOLAS Consolidated Edition 2009 in black Ariel 11 font and the explanatory notes from Resolution MSC.281(85) in red Ariel 11 italic font. Any MSC Circulars referred to in the regulations or explanatory notes are also included in black Times New Roman 11 font. Most of the text is in Word though some sections containing complex formulae and figures use Adobe .pdf and cannot be edited. Changes to be discussed by this CG, including suggestions for possible amendments to SOLAS 2009, are shown in blue and are taken largely from SLF 51/3/2 to 51/3/7 and 52/17/1 to 52/17/6 (see Table 1 below). Proposed amendments to the explanatory notes taken from the above papers are highlighted in green and proposed amendments to the footnotes are highlighted in turquoise (see in particular SLF 52/WP.5, Agenda Item 14). Each proposed change to the regulations, EN or footnotes is inserted into the text at the relevant point with a space for questions and comments. Some minor suggestions for changing the text are highlighted in yellow for consideration by the CG (see Regs 13.11.1, 15.4, 15.5.1 & 35-1.2.3, for example). Changes needed to the 2009 Consolidated text already agreed in MSC.269(85) are similarly highlighted. Ref. Date By Subject Status SLF 51/3/2 10/04/08 Sweden+US SDS CG report for possible future

improvements to SOLAS Ch II-1 regulations; includes the following Reg 1 - Application; para 1.3.4 Reg 5-1 - Information to the master para. 3 para. 4 Reg 7 - Index A; para 2 para. 6 Reg 7-1 - Calculation of factor pi;

para 1 para. 1.2 Reg 7-2 - Calculation of factor si; para 2 para. 4 para. 4.1.1 paras 5.2 and 5.3 Reg 8 - Clarify N formula; paras 3.2-3.5 Reg 9 - Double bottoms; para. 8 Reg 12 - s = 1 fwd of collision bhd proposed new para. Reg17 - WT integrity above bhd dk

para. 3 Reg 22 - Clarify heading Reg 24 - Clarify heading Reg 35-1 - Mods may be needed

For this CG to consider

3 10/01/2012

Ref. Date By Subject Status SLF 51/3/3

29/04/08 Germany Status of the Explanatory Notes (proposal to make some mandatory)

Not confirmed. Germany reserves position. (Ref. 51/17/3.21)

SLF 51/3/4

09/05/08 IACS Reg 12.5.1 Requirements for pipes piercing collision bulkheads

For this CG to consider (Ref.51/17/Annex 3)

SLF 51/3/5

09/05/08 IACS Reg 9.3 - Interpretation of DB height Not accepted (Ref. 51/WP.1para 6)

SLF 51/3/6

22/05/08 China Reg 5-1/3 and /4 - Proposed mods to EN for trim range and critical KG/GM curves

Accepted EN already amended

SLF 51/3/7

23/05/08 Norway Reg 13.4; main or aux mchy separated by longitudinal bhd

Accepted EN amended

SLF 51/17

28/08/08 Secretariat Report from SLF 51 to MSC85 covering Agenda Item 3; see paras 3.1 – 3.22

SLF 52/17/1

26/10/09 Germany Reg 7-2 - Uniform application of cross-flooding provisions


SLF 52/17/2

26/10/09 Germany Reg 19 - Damage control information “

SLF 52/17/3

19/11/09 Finland Reg 7-1 - Enhancement to EN “

SLF 52/17/4

20/11/09 Norway Proposes amendments to the following Reg 5-1 - Information to Master Reg 7 - Index A; mod 7.1 .2 & add 7.3 Reg 4 - footnote Regs 5-1.3, 5-1.4 and 7.2 EN Regs 7.1 and 7.2 EN

“

SLF 52/17/5

20/11/09 Norway These are comments on SLF 51/3/2:- Reg 1 - Application; para 1.3.4 Reg 7 - Index A, 1 free surface; para 6 Reg 7-1 - Calc of factor pi; paras 1 &1.2 Reg 7-2 - Calc of factor si; para 4 Reg 8 - Keep text for N; para 3.2 to .5 Reg 35-1 - Clarify L & N; paras 3.2 .4 .9

“

SLF 52/17/6

20/11/09 Norway Further proposed amendments to:- Reg 2 - Definitions in paras 9 and 13 Reg 4 - General; para 1 Reg 5 - Intact Stability; para 1 Reg 5-1- Stability info to master; para 4 Reg 7-2 - Calculation of factor si; para 2 Reg 8 - Consistent use of L; factor si Reg 12 - New para for si = 1; collsn bhd Reg 17 - WT integrity; para 3 and EN Reg 20 - should not be limited to pax ships; para 1 – add “ship to be upright etc”; propose to add heel tolerance.

“

4 10/01/2012

Ref. Date By Subject Status MSC 85/23/1

18/06/08 UK Reg 4 - proposal to delete footnote .4 and update references to remaining footnotes such as .6 & .7 as necessary


SLF 52/ WP.5/ 14.2

29/1/10 S-C Reg 4 – Germany requests footnotes .6 and .7 to be considered for deletion

“

Res. MSC. 269(85)

Adopted 4/12/08

MSC Part A reg 2 ; new para 27 Part B-1 reg 5; change to heading ; new sentence in para 1

Not in 2009 Consolidated Ed. Highlighted in yellow in this doc

Rpt of CSSF WG v04

June ‘10 CLIA/CSSF* Reg 4 – MARPOL to be excluded from Part B-1 damage Reg. 7-2.5.3, delete “at each boundary” Reg. 2.11; additional text Reg. 5-1.3/4 EN2; text changes Reg. 7.2; mods to 52/17/4 proposals Reg. 7.5; change to centreline text Reg. 7.7; EN 1 extra text – valve size Reg. 7.7; EN2 clarification – pipe area Reg. 7-1; addition to 52/17/3 – diagram Reg. 7-1.1.2 EN 12 – as for 7.7 EN1 Reg. 7-2.2 EN 1-4; various mods. Reg. 7-2.5.2.2 EN 1,2&5; horiz Esc R Reg. 9.2; additional text + diagram Reg 17.1; remove “sliding”

For this CG to Consider in R2 “ “ “

Table 1

Papers containing proposed changes to SOLAS 2009 regulations, footnotes and

Explanatory Notes

* The working group of the CSSF has identified a number of smaller corrections and additions to SOLAS2009 II-1 and the corresponding explanatory notes. Only those proposals are presented in this paper which have supported by a clear majority of the working group members. In addition some topics have been identified, where no consensus could be reached, but which are worth to be further discussed in the ISCG and at the SDS working group during SLF53.

5 10/01/2012

SOLAS Regulations as amended on 1/1/2009 This document contains the amendments to the old SOLAS Chapter II-1 Parts A, B and B-1 which have been completely replaced by the following regulations now incorporated into the SOLAS Consolidated Edition 2009. Regulations shown in red have EN.

CONTENTS

Part A - General Regulation 1 ...................................................................................................Application Regulation 2 ....................................................................................................Definitions Regulation 3 ........................................................Definitions Relating to parts C, D and E Part B - Subdivision and stability Regulation 4 ....................................................................................................General Part B-1 - Stability Regulation 5 .............................................................................Intact stability information Regulation 5-1 .....................................Stability information to be supplied to the master Regulation 6 ..........................................................................Required subdivision index R Regulation 7 …......................................................................Attained subdivision index A Regulation 7-1 ............................................................................Calculation of the factor pi Regulation 7-2 ............................................................................Calculation of the factor si Regulation 7-3 …..............................................................................................Permeability Regulation 8 ...............................Special requirements concerning passenger ship stability Regulation 8-1 ..............................System capabilities and operational information after a flooding casualty on passenger ships Part B-2 - Subdivision, watertight and weathertight Integrity Regulation 9 ....Double bottoms in passenger ships and cargo ships other than tankers Regulation 10 ...........................................................Construction of watertight bulkheads Regulation 11 …...............................................Initial testing of watertight bulkheads etc Regulation 12 …...........................Peak and machinery space bulkheads, shaft tunnels, etc Regulation 13 …………..Openings in watertight bulkheads below the bulkhead deck in passenger ships Regulation 13-1..........Openings in watertight bulkheads and internal decks in cargo ships Regulation 14 ........Passenger ships carrying goods vehicles and accompanying personnel Regulation 15 .........Openings in the shell plating below the bulkhead deck of passengers ships and the freeboard deck of cargo ships Regulation 15-1 ............................................................External openings in cargo ships Regulation 16 ...............Construction and initial tests of watertight doors, sidescuttles etc Regulation 16-1 ....................Construction and initial tests of watertight decks, trunks etc Regulation 17 ....Internal watertight integrity of passenger ships above the bulkhead deck Regulation 17-1 …………Integrity of the hull and superstructure, damage prevention and control on ro-ro passenger ships

6 10/01/2012

Part B-3 - Subdivision load line assignment for passenger ships Regulation 18 ....Assigning, marking and recording of subdivision load lines for passenger ships Part B-4 - Stability management Regulation 19 .........................................................................Damage Control Information Regulation 20 ...................... ..................................................Loading of [passenger] Ships [See Q53 – proposal to delete “Passenger” rejected by WG at SLF 53. But now see Q53D] Regulation 21 ....................Periodical operation and inspection of watertight doors, etc., in passenger ships Regulation 22 ..............Prevention and control of water ingress, etc. [in passenger ships and cargo ships] – [Clarification proposed in SLF 51/3/2, rejected by SLF 53 WG. NFA] Regulation 22-1 ......Flooding detection systems for passenger ships carrying 36 or more persons constructed on or after 1/7/2010 Regulation 23 ..............................................Special requirements for ro-ro passenger ships Regulation 24 ...............................[ Additional measures for the] [Additional requirements for] prevention and control of water ingress, etc., in cargo ships [only] – [Ref. SLF 51/3/2, also see Reg. 22; “Additional measures etc… agreed by SLF 53 WG but “only” rejected; new US proposal in blue for approval at SLF 54] [see Q58D] Regulation 25 ………......Water level detectors on single hold cargo ships other than bulk

carriers Part C – Machinery installations Regulation 35-1 .....................................................................Bilge Pumping Arrangements Associated MSC Resolutions included in the text below for easy reference Adoption of Amendments to the International Convention for the Safety of Life at Sea, 1974, as amended (Ref. Resolution MSC.216(82), adopted on 8th October, 2006) Recommendation on a Standard Method for Evaluating Cross-Flooding Arrangements (Ref. Resolution MSC.245(83), adopted on 12th October, 2007) Adoption of Amendments to the International Convention for the Safety of Life at Sea, 1974, as amended (Ref. Resolution MSC.269(85), adopted on 4th December, 2008) [Amendments not included in SOLAS Consolidated Edition 2009 but highlighted thus in this document] Explanatory Notes to the SOLAS Chapter II-1 Subdivision and Damage Stability Regulations (Ref. Resolution MSC.281(85), adopted on 4th December, 2008)

7 10/01/2012

Associated MSC Circulars included in the text below for easy reference Guidance Notes on the Integrity of Flooding Boundaries above the Bulkhead Deck of Passenger Ships (Ref. MSC/Circ.541, dated 19th July, 1990) Unified Interpretation regarding Timber Deck Cargo in the Context of Damage Stability Requirements (Ref. MSC/Circ.998, dated 25th July, 2001) Unified Interpretations to SOLAS II-1 Part B-1 Regulation 5 regarding Stability Information for Passenger and Cargo Ships (Lightweight Check) (Ref. MSC/Circ.1158, dated 24th May, 2005) Unified Interpretations to SOLAS Chapter II-1 Regulation12 regarding Bow Doors and the Extension of the Collision Bulkhead. (Ref. MSC.1/Circ.1211, dated 25th May, 2006) Performance Standards for the Systems and Services to Remain Operational on Passenger Ships for Safe Return to Port and Orderly Evacuation and Abandonment after a Casualty (Ref. MSC.1/Circ.1214, dated 15th December, 2006) Guidelines for Damage Control Plans and Information to the Master. (Ref. MSC.1/Circ.1245, dated 29th October, 2007) Interpretation of Alterations and Modifications of a Major Character (Ref. MSC.1/Circ.1246, dated 29th October, 2007, which supersedes MSC/Circ.650). Guidelines for Flooding Detection Systems on Passenger Ships. (Ref. MSC.1/Circ.1291, adopted on 9th December, 2008) Guidelines for the Drainage of Fire-Fighting Water from Closed Vehicle and Ro-Ro Spaces and Special Category Spaces of Passenger and Cargo Ships. (Ref. MSC.1/Circ.1320, dated 11th June, 2009) Guidance for watertight doors on passenger ships which may be opened during navigation. (Ref. MSC.1/Circ.1380, dated 10th December, 2010)

8 10/01/2012

RESOLUTION MSC.281(85)

(adopted on 4 December 2008)

EXPLANATORY NOTES TO THE SOLAS CHAPER II-1 SUBDIVISION AND DAMAGE STABILITY REGULATIONS

THE MARITIME SAFETY COMMITTEE, RECALLING Article 28(b) of the Convention on the International Maritime Organization concerning the function of the Committee, RECALLING ALSO that, by resolution MSC.216(82), it adopted the regulations on subdivision and damage stability as contained in SOLAS chapter II-1 which are based on the probabilistic concept, using the probability if survival after collision as a measure of ships’ safety in a damage condition, NOTING that, at the eighty-second session, it approved Interim Explanatory Notes to the SOLAS chapter II-1 subdivision and damage stability regulations (MSC.1/Circ.1226), to assist Administrations in the uniform interpretation and application of the aforementioned subdivision and damage stability regulations. BEING DESIROUS that definitive Explanatory Notes should be adopted when more experience in the application of the aforementioned subdivision and damage stability regulations and the Interim Explanatory Notes had been gained, RECOGNIZING that the appropriate application of the Explanatory Notes is essential for ensuring the uniform application of the SOLAS chapter II-1 subdivision and damage stabilioty regulations, HAVING CONSIDERED, at its eighty-fifth session, the recommendations made by the Sub-Committee on Stability and Load Lines and on Fishing Vessels Safety at its fifty-first session, 1. ADOPTS the Explanatory Notes to the SOLAS chapter II-1 subdivision and damage stability regulations set out in the Annex to the present resolution; 2. URGES Governments and all parties concerned to utilize the Explanatory Notes when applying the SOLAS chapter II-1 subdivision and damage stability regulations adopted by resolution MSC.216(82).

9 10/01/2012

EXPLANATORY NOTES TO THE SOLAS CHAPTER II-1 SUBDIVISION AND DAMAGE STABILITY REGULATIONS

Contents

Part A - INTRODUCTION

Part B - GUIDANCE ON INDIVIDUAL SOLAS CHAPTER II-1 SUBDIVISION AND DAMAGE STABILITY REGULATIONS

Regulation 1 Application Regulation 2 Definitions Regulation 4 General Regulation 5 Intact stability information Regulation 5-1 Stability information to be supplied to the master Regulation 6 Required subdivision index R Regulation 7 Attained subdivision index A Regulation 7-1 Calculation of the factor pi Regulation 7-2 Calculation of the factor si Regulation 7-3 Permeability Regulation 8 Special requirements concerning passenger ship stability Regulation 8-1 System capabilities and operational information after a flooding casualty

on passenger ships Regulation 9 Double bottoms in passenger ships and cargo ships other than tankers Regulation 10 Construction of watertight bulkheads Regulation 12 Peak and machinery space bulkheads, shaft tunnels, etc. Regulation 13 Openings in watertight bulkheads below the bulkhead deck in passenger

ships Regulation 13-1 Openings in watertight bulkheads and internal decks in cargo ships Regulation 15 Openings in the shell plating below the bulkhead deck of passenger

ships and the free board deck of cargo ships Regulation 15-1 External openings in cargo ships Regulation 16 Construction and initial tests of watertight doors, sidescuttles, etc. Regulation 17 Internal watertight integrity of passenger ships above the bulkhead deck Appendix Guidelines for the preparation of subdivision and damage stability

calculations

10 10/01/2012

PART A

INTRODUCTION

1 The harmonized SOLAS regulations on subdivision and damage stability, as contained in revised SOLAS chapter II-1 are based on a probabilistic concept which uses the probability of survival after collision as a measure of ships’ safety in a damaged condition. This probability is referred to as the “attained subdivision index A” in the regulations. This can be considered an objective measure of ship safety and, ideally, there would be no need to supplement this index by any deterministic requirements.

2 The philosophy behind the probabilistic concept is that two different ships with the same attained index are of equal safety and, therefore, there is no need for special treatment of specific parts of the ship, even if they are able to survive different damages. The only areas which are given special attention in these regulations are the forward and bottom regions which are dealt with by special subdivision rules provided for the cases of ramming and grounding.

3 Only a few deterministic elements, which were necessary to make the concept practicable, have been included. It was also necessary to include a deterministic “minor damage” on top of the probabilistic regulations for passenger ships to avoid ships being designed with what might be perceived as unacceptably vulnerable spots in some part of their length.

4 It is easily recognized that there are many factors that will affect the final consequences of hull damage to the ship. These factors are random and their influence is different for ships with different characteristics. For example, it would seem obvious that in ships of similar size carrying different amounts of cargo, damages of similar extents may lead to different results because of differences in the range of permeability and draught during service. The mass and velocity of the ramming ship is obviously another random variable.

5 Due to this, the effect of a three-dimensional damage to a ship with given watertight subdivision depends on the following circumstances:

.1 which particular space or group of adjacent spaces is flooded;

.2 the draught, trim and intact metacentric height at the time of damage;

.3 the permeability of affected spaces at the time of damage;

.4 the sea state at the time of damage; and

.5 other factors, such as possible heeling moments due to unsymmetrical weights.

6 Some of these circumstances are interdependent and the relationship between them and their effects may vary in different cases. Additionally, the effect of hull strength on penetration will obviously have some effect on the results for a given ship. Since the location and size of the damage is random, it is not possible to state which part of the

11 10/01/2012

ship becomes flooded. However, the probability of flooding a given space can be determined if the probability of occurrence of certain damages is known from experience, that is, damage statistics. The probability of flooding a space is then equal to the probability of occurrence of all such damages which just open the considered space to the sea. 7 For these reasons and because of mathematical complexity as well as insufficient data, it would not be practicable to make an exact or direct assessment of their effect on the probability that a particular ship will survive a random damage if it occurs. However, accepting some approximations or qualitative judgments, a logical treatment may be achieved by using the probability approach as the basis of a comparative method for the assessment and regulation of ship safety.

8 It may be demonstrated by means of probability theory that the probability of ship survival should be calculated as a sum of probabilities of its survival after flooding each single compartment, each group of two, three, etc., adjacent compartments multiplied, respectively, by the probabilities of occurrence of such damages as lead to the flooding of the corresponding compartment or group of compartments.

9 If the probability of occurrence for each of the damage scenarios the ship could be subjected to is calculated and then combined with the probability of surviving each of these damages with the ship loaded in the most probable loading conditions, we can determine the attained index A as a measure for the ship’s ability to sustain a collision damage.

10 It follows that the probability that a ship will remain afloat without sinking or capsizing as a result of an arbitrary collision in a given longitudinal position can be broken down to:

.1 the probability that the longitudinal centre of damage occurs in just the region of the ship under consideration;

.2 the probability that this damage has a longitudinal extent that only includes spaces between the transverse watertight bulkheads found in this region;

.3 the probability that the damage has a vertical extent that will flood only the spaces below a given horizontal boundary, such as a watertight deck;

.4 the probability that the damage has a transverse penetration not greater than the distance to a given longitudinal boundary; and

.5 the probability that the watertight integrity and the stability throughout the flooding sequence is sufficient to avoid capsizing or sinking.

11 The first three of these factors are solely dependent on the watertight arrangement of the ship, while the last two depend on the ship’s shape. The last factor also depends on the actual loading condition. By grouping these probabilities, calculation of the probability of survival, or attained index A, have been formulated to include the following probabilities:

.1 the probability of flooding each single compartment and each possible group of two or more adjacent compartments; and

12 10/01/2012

.2 the probability that the stability after flooding a compartment or a group of two or more adjacent compartments will be sufficient to prevent capsizing or dangerous heeling due to loss of stability or to heeling moments in intermediate or final stages of flooding.

12 This concept allows a rule requirement to be applied by requiring a minimum value of A for a particular ship. This minimum value is referred to as the “required subdivision index R” in the present regulations and can be made dependent on ship size, number of passengers or other factors legislators might consider important.

13 Evidence of compliance with the rules then simply becomes:

A ≥ R

As explained above, the attained subdivision index A is determined by a formula for the entire probability as the sum of the products for each compartment or group of compartments of the probability that a space is flooded, multiplied by the probability that the ship will not capsize or sink due to flooding of the considered space. In other words, the general formula for the attained index can be given in the form:

A = Σpi.si

Subscript “i” represents the damage zone (group of compartments) under consideration within the watertight subdivision of the ship. The subdivision is viewed in the longitudinal direction, starting with the aftmost zone/compartment.

The value of “pi” represents the probability that only the zone “i” under consideration will be flooded, disregarding any horizontal subdivision, but taking transverse subdivision into account. Longitudinal subdivision within the zone will result in additional flooding scenarios, each with their own probability of occurrence.

The value of “si” represents the probability of survival after flooding the zone “i” under consideration.

14 Although the ideas outlined above are very simple, their practical application in an exact manner would give rise to several difficulties if a mathematically perfect method was to be developed. As pointed out above, an extensive but still incomplete description of the damage will include its longitudinal and vertical location as well as its longitudinal, vertical and transverse extent. Apart from the difficulties in handling such a five-dimensional random variable, it is impossible to determine its probability distribution very accurately with the presently available damage statistics. Similar limitations are true for the variables and physical relationships involved in the calculation of the probability that a ship will not capsize or sink during intermediate stages or in the final stage of flooding.

15 A close approximation of the available statistics would result in extremely numerous and complicated computations. In order to make the concept practicable, extensive simplifications are necessary. Although it is not possible to calculate the exact probability of survival on such a simplified basis, it has still been possible to develop a useful comparative measure of the merits of the longitudinal, transverse and horizontal subdivision of the ship.

13 10/01/2012

RESOLUTION MSC.216(82)

(adopted on 8 December 2006)

ADOPTION OF AMENDMENTS TO THE INTERNATIONAL CONVENTION FOR

THE SAFETY OF LIFE AT SEA, 1974, AS AMENDED

THE MARITIME SAFETY COMMITTEE,

RECALLING Article 28(b) of the Convention on the International Maritime Organization concerning the functions of the Committee,

RECALLING FURTHER article VIII(b) of the International Convention for the Safety of Life at Sea (SOLAS), 1974 (hereinafter referred to as “the Convention”), concerning the amendment procedure applicable to the Annex to the Convention, other than to the provisions of chapter I thereof,

HAVING CONSIDERED, at its eighty-second session, amendments to the Convention, proposed and circulated in accordance with article VIII(b)(i) thereof,

1. ADOPTS, in accordance with article VIII(b)(iv) of the Convention, amendments to the Convention, the text of which is set out in Annexes 1, 2 and 3 to the present resolution; 2. DETERMINES, in accordance with article VIII(b)(vi)(2)(bb) of the Convention, that:

(a) the said amendments, set out in Annex 1, shall be deemed to have been accepted on 1 January 2008;

(b) the said amendments, set out in Annex 2, shall be deemed to have been

accepted on 1 July 2008; and (c) the said amendments, set out in Annex 3, shall be deemed to have been

accepted on 1 January 2010, unless, prior to those dates, more than one third of the Contracting Governments to the Convention or Contracting Governments the combined merchant fleets of which constitute not less than 50% of the gross tonnage of the world’s merchant fleet, have notified their objections to the amendments;

3. INVITES SOLAS Contracting Governments to note that, in accordance with article VIII(b)(vii)(2) of the Convention:

(a) the amendments, set out in Annex 1, shall enter into force on 1 July 2008;

14 10/01/2012

(b) the amendments, set out in Annex 2, shall enter into force on 1 January

2009; and (c) the amendments, set out in Annex 3, shall enter into force on 1

July 2010, upon their acceptance in accordance with paragraph 2 above;

4. REQUESTS the Secretary-General, in conformity with article VIII(b)(v) of the Convention, to transmit certified copies of the present resolution and the text of the amendments contained in Annexes 1, 2 and 3 to all Contracting Governments to the Convention; 5. FURTHER REQUESTS the Secretary-General to transmit copies of this resolution and its Annexes 1, 2 and 3 to Members of the Organization, which are not Contracting Governments to the Convention.

15 10/01/2012

ANNEX 2

AMENDMENTS TO THE INTERNATIONAL CONVENTION FOR THE SAFETY OF LIFE AT SEA, 1974, AS AMENDED

CHAPTER II-1 CONSTRUCTION -STRUCTURE, SUBDIVISION AND STABILITY,

MACHINERY AND ELECTRICAL INSTALLATIONS The existing text of parts A, B and B-1 of the chapter is replaced by the following:

(Extracts from SOLAS Consolidated Edition 2009)

Part A General

Regulation 1 Application 1.1 Unless expressly provided otherwise, this chapter shall apply to ships the keels of which are laid or which are at a similar stage of construction on or after 1 January 2009. 1.2 For the purpose of this chapter, the term a similar stage of construction means

the stage at which:

.1 construction identifiable with a specific ship begins; and

.2 assembly of that ship has commenced comprising at least 50 tonnes or one per cent of the estimated mass of all structural material, whichever is less.

1.3 For the purpose of this chapter:

.1 the expression ships constructed means ships the keels of which are laid or which are at a similar stage of construction;

.2 the expression all ships means ships constructed before, on or after 1 January 2009;

.3 a cargo ship, whenever built, which is converted to a passenger ship shall be treated as a passenger ship constructed on the date on which such a conversion commences;

.4 the expression alterations and modifications of a major character means, in the context of cargo ship subdivision and stability, any modification to the construction which affects the level of subdivision of that ship. Where a cargo ship is subject to such modification, it shall be demonstrated that the A/R ratio calculated for the ship after such modifications is not less than the A/R ratio calculated for the ship before the modification.

16 10/01/2012

However, in those cases where the ship’s A/R ratio before modification is equal to or greater than unity, it is only necessary that the ship after modification has an A value which is not less than R, calculated for the modified ship. [Q1]

Regulation 1.1.3.4 (ref. SLF 51/3/2 – US and Sweden) This provision, regarding cargo ship subdivision and damage stability in the context of alterations and modifications of a major character, is not currently in line with the principles recently agreed to at SLF 50 and approved at MSC 83 in new MSC.1/Circ.1246 (which superseded MSC/Circ.650). This provision should be revised to reflect the principles in MSC.1/Circ.1246 (see SLF 50/19, paragraph 3.17.2) [Coordinator’s Note: MSC.1/Circ.1246 is included below for easy reference]. Regulation 1.1.3.4 (ref. SLF 52/17/5 - Norway) Document SLF 51/3/2 contains a proposal that the paragraph should be revised to reflect the principles in MSC.1/Circ.1246. This Administration agrees that a revision is appropriate. The intended application of paragraph 1.3.4 appears to be unclear. Any ship constructed from 1 January 2009 onwards must comply fully with the revised chapter according to its type and length at all times, not just an A/R evaluation. All older ships are still subject to compliance with regulations 1.3.1 in the previous version of chapter II-1 (and MSC.1/Circ.1246 if adopted by the Administration). In this chapter the expression “major character” is only used for a very limited purpose in paragraph 3. Paragraph 2 on new regulation 1 lists applicable standards for ships constructed before 1 January 2009. Since the damage stability requirements in resolutions MSC.19(58) and MSC.47(66) are included in that list, it would seem inappropriate to apply the provisions of the new chapter in cases where an existing ship continues to comply fully with those provisions after a conversion. For the time being it seems that the only contingency needed in paragraph 1.3.4 with respect to stability is where a dry cargo ship of less than 80 m in length (L) is lengthened beyond that limit. It is proposed that the application of MSC.1/Circ.1246 is limited to ships constructed before 1 January 2009 and that a separate circular be developed to cover ships constructed from 1 January 2009 onwards. It is also proposed that a footnote with reference to MSC.1/Circ.1246 be added to paragraph 3 to cover existing ships. R1.3.4 Alterations and modifications of a major character R1.3 Q1. Norway suggests that Regulation 1.3.4 is currently unclear in its

application; the only situation it needs to cover is when a S2009 cargo ship is lengthened beyond 80 m(L). Norway proposes that a new MSC Circular is needed for ships constructed after 1/1/2009 and that MSC.1/Circ.1246 should only apply to existing ships built before 1/1/2009. A footnote should be added to Regulation 1.3 stating that for ships constructed before 1/1/2009 MSC.1/Circ.1246 should be applied. Do you agree with these proposals?

17 10/01/2012

Yes

China, Finland, Germany, Japan, MI, Norway, Italy, Spain, Denmark, UK, US, Sweden

No

Comments / Alternative Proposals / Suggested wording for footnote?:- US: We fully agree with the principles associated with Norway’s proposals. However, we think it would be better to delete regulation 1.1.3.4 completely. This is because for cargo ships built on or after 1 January 2009 there should not be an A/R standard applied (i.e. “Any ship constructed from 1 January 2009 onwards must comply fully with the revised chapter according to its type and length at all times, not just an A/R evaluation.”). This reflects the same principle applied in MSC.1/Circ.1246 (i.e. if constructed on or after 1 July 1998 the ship is never considered an ‘existing cargo ship’). If regulation 1.1.3.4 is deleted, the existing EN for regulation 1.3 (now only addressing passenger ships) could be expanded to indicate: • Application of MSC.1/Circ.1246 is limited to cargo ships constructed before 1 January 2009. • a cargo ship constructed on or after 1 January 2009 of less than 80 m in length that is later

lengthened beyond that limit must fully comply with the damage stability regulations according to its type and length.

Note: this should also eliminate the need for a footnote regarding MSC.1/Circ.1246. Round 1 Discussion: Although there is strong support for Norway’s proposal it would seem that the US’ suggestions may provide the best solution. Q1A. Recognising that Reg. 1.1.3.4 may be misleading do you support the US proposal to delete it altogether and change EN 1.3 as highlighted below?:-

Regulation 1.3

.1 If a passenger ship built before 1 January 2009 undergoes alterations or modifications of major character, it may still remain under the damage stability regulations applicable to ships built before 1 January 2009, except in the case of a cargo ship being converted to a passenger ship.

.2 Application of MSC.1/Circ.1246 is limited to cargo ships constructed before 1 January 2009 .3 A cargo ship constructed on or after 1 January 2009 of less than 80 m in length that is later lengthened beyond that limit must fully comply with the damage stability regulations according to its type and length. Yes

MI, Germany, China, Finland, US, Italy, Japan, RINA (see comment 1), France (with comment), Norway, CLIA, UK, Denmark

No

RINA (see comment 2), Sweden

Comments / Alternative Proposals?:- MI: Agree deletion of Reg. 1.1.3.4 and change EN 1.3 as proposed by the US. RINA: 1. We would support the deletion of 1.1.3.4 as the definitions to alteration and modifications of a major character for cargo and passenger ships are included in regulation 1.3. 2. With regard to the proposal to amend EN 1.3 we would comment as follows:

• 1.3.1 The inclusion of this text conflicts with that in Regulation 1.3. The A/R ratio calculated for the ship after modifications is not less than the A/R ratio calculated for the ship before the modification, is in general, applicable to ships which have their

18 10/01/2012

damage stability assessed in accordance with a deterministic method. It would then follow that all such ships, when modified, should meet the requirements of MSC.1/Circ.1246.

• 1.3.2 If the rationale in 1.3.1 is accepted then MSC.1/Circ.1246 will need to be revised

to address alteration and modifications of a major character for passenger and cargo ships which have been assessed against deterministic damage stability calculations.

France: US proposal is in line with present explanatory notes. Round 2 Discussion: Although there is a large majority in support of the US proposal to delete regulation 1.1.3.4 and expand EN 1.3, Sweden is opposed and RINA has doubts about the amendments to the EN. Regarding RINA’s comments - our understanding of MSC.1/Circ.1246 is that it was written to cover the situation where a cargo ship built before damage stability regulations were introduced into SOLAS90 Part B-1 on 1st February, 1992 underwent major alterations. Prior to that date cargo ships were not required to comply with any damage stability standards (except ILLC, Reg. 27) so we cannot agree with the RINA statement that such ships would necessarily have had their damage stability assessed against a deterministic standard. For this reason Circ.1246 is specifically addressing cargo ships only and requires new calculations of A/R to be carried out “before and after” major modification to ensure that whatever safety level the vessel had beforehand was either not reduced (if A was <=R) or become less than one (if A was > R). We therefore believe that the proposed amendments to the EN do make sense as written. Q1B (for SLF53 WG). Can we accept the US proposal to delete Part A Reg. 1.1.3.4 and amend EN 1.3 as shown under Q1A (above)? Yes

Proposal accepted by SLF53 WG

No

Are there any further comments?:- No further discussion in 2011 CG. Q1. Recommend acceptance at SLF54

Ref. T1/2.04 MSC.1/Circ.1246

29 October 2007

INTERPRETATION OF ALTERATIONS AND MODIFICATIONS OF A MAJOR CHARACTER

1. The Maritime Safety Committee, at its sixty-third session (16-25 May 1994), noted that the Sub-Committee on Stability and Load Lines and on Fishing Vessels Safety (SLF), in considering a definition of the term “modification of a major character” in the context of Chapter II-1 of the 1974 SOLAS Convention, had decided that it should be sufficient to relate the modification, whatever its nature and extent, to its effect on the level of subdivision of the ship. The Committee, therefore, agreed to the following interpretation of alterations and modifications of a major character proposed by the SLF Sub-Committee:

19 10/01/2012

. “Where an existing cargo ship is subject to any modification which affects the level of subdivision of that ship, it should be demonstrated that the A/R ratio calculated for the ship after such modifications is not less than the A/R ratio calculated for the ship before the modification. However, in those cases where the ship’s A/R ratio before modification is equal to or greater than unity, it is only necessary to demonstrate that the ship after such modification has an ’A’ value which is not less than ’R’, calculated for the modified ship.”

2. The Maritime Safety Committee, at its eighty-third session (3-12 October 2007), considered a definition of the term “existing cargo ship” in the context of the above interpretation and, following a proposal by the SLF Sub-Committee at its fiftieth session, agreed that, in the context of this circular, an existing cargo ship means:

.1. a cargo ship constructed before 1 February 1992, regardless of length; and

.2. a cargo ship constructed before 1 July 1998, below or equal to 100 m in length.

3. Notwithstanding the above, a cargo ship should not be considered an existing cargo ship if it was:

.1 constructed between 1 February 1992 and 30 June 1998, and lengthened from below to above 100 m; and

.2 constructed on or after 1 July 1998.

4. Member Governments are invited to take account of the above interpretation when applying the relevant provisions of Chapter II-1 of the 1974 SOLAS Convention.

5. This circular supersedes MSC/Circ.650

2 Unless expressly provided otherwise, for ships constructed before 1 January 2009, the Administration shall ensure that the requirements which are applicable under chapter II-1 of the International Convention for the Safety of Life at Sea, 1974, as amended by resolutions MSC.1(XLV), MSC.6(48), MSC.11(55), MSC.12(56), MSC.13(57), MSC.19(58), MSC.26(60), MSC.27(61), Resolution 1 of the 1995 SOLAS Conference, MSC.47(66), MSC.57(67), MSC.65(68), MSC.69(69), MSC.99(73), MSC.134(76), MSC.151(78) and MSC.170(79) are complied with.

3 All ships which undergo repairs, alterations, modifications and outfitting related thereto shall continue to comply with at least the requirements previously applicable to these ships. Such ships, if constructed before the date on which any relevant amendments enter into force, shall, as a rule, comply with the requirements for ships constructed on or after that date to at least the same extent as they did before undergoing such repairs, alterations, modifications or outfitting. Repairs, alterations and modifications of a major character and outfitting related thereto shall meet the requirements for ships constructed on or after the date on which any relevant amendments enter into force, in so far as the Administration deems reasonable and practicable.

Regulation 1.3

.1 If a passenger ship built before 1 January 2009 undergoes alterations or

20 10/01/2012

modifications of major character, it may still remain under the damage stability regulations applicable to ships built before 1 January 2009, except in the case of a cargo ship being converted to a passenger ship.

.2 Application of MSC.1/Circ.1246 is limited to cargo ships constructed before 1 January 2009 .3 A cargo ship constructed on or after 1 January 2009 of less than 80 m in length that is later lengthened beyond that limit must fully comply with the damage stability regulations according to its type and length . [Co-ordinator’s Note: See Q1B for a proposal to modify this EN, which was accepted by the WG at SLF 53] 4 The Administration of a State may, if it considers that the sheltered nature and conditions of the voyage are such as to render the application of any specific requirements of this chapter unreasonable or unnecessary, exempt from those requirements individual ships or classes of ships entitled to fly the flag of that State which, in the course of their voyage, do not proceed more than 20 miles from the nearest land.

5 In the case of passenger ships which are employed in special trades for the carriage of large numbers of special trade passengers, such as the pilgrim trade, the Administration of the State whose flag such ships are entitled to fly, if satisfied that it is impracticable to enforce compliance with the requirements of this chapter, may exempt such ships from those requirements, provided that they comply fully with the provisions of:

.1 the rules annexed to the Special Trade Passenger Ships Agreement, 1971; and

.2 the rules annexed to the Protocol on Space Requirements for Special Trade Passenger Ships, 1973.

Regulation 2 Definitions

For the purpose of this chapter, unless expressly provided otherwise:

1 Subdivision length (Ls) of the ship is the greatest projected moulded length of that part of the ship at or below deck or decks limiting the vertical extent of flooding with the ship at the deepest subdivision draught.

Regulation 2.1

Subdivision length (Ls) – Different examples of Ls showing the buoyant hull and the reserve buoyancy are provided in the figures below. The limiting deck for the reserve buoyancy may be partially watertight. The maximum possible vertical extent of damage above the baseline is ds + 12.5 metres.

21 10/01/2012

2 Mid-length is the mid-point of the subdivision length of the ship.

[Coordinator’s Note post SLF 53 – WG agreed that R2.2 can now be deleted so all subsequent Reg. numbers need adjusting and cross-references checked]. [Q2]

22 10/01/2012

[Coordinator’s Note for SLF 54 – see Q66D for a proposal to move the definition of “amidships” from R2.26 to R2.2, thereby removing the need to alter the numbering. There was an 11-1 majority in favour – to be finally agreed at SLF 54.] 2 Amidship is at the middle of the length (L). [Proposal to move Reg. 2.26 to Reg.

2.2 to replace deleted definition of “mid length”.] [Q66 – see under 2.26, below]

3 2 Aft terminal is the aft limit of the subdivision length.

4 3 Forward terminal is the forward limit of the subdivision length. 5 4 Length (L) is the length as defined in the International Convention on Load Lines in force.

6 5 Freeboard deck is the deck as defined in the International Convention on Load Lines in force.

Regulation 2.6 2.5

Freeboard deck – See Explanatory Notes for regulation 13-1* for the treatment of a stepped freeboard deck with regard to watertightness and construction requirements. * References to regulations in these Guidelines are to regulations of SOLAS chapter II-1, unless expressly provided otherwise. 7 6 Forward perpendicular is the forward perpendicular as defined in the International Convention on Load Lines in force.

8 7 Breadth (B) is the greatest moulded breadth of the ship at or below the deepest subdivision draught.

9 8 Draught (d) is the vertical distance from the keel line at mid-length amidships [Q2] to the waterline in question.

Regulation 2.9 (ref. SLF 52/17/6 - Norway) The definition of draught was transferred from the previous chapter. Since the calculations in old part B-1 were to be carried out at even keel the longitudinal position of “mid-length” had no practical implication, but this is no longer the case. The revised chapter requires that additional calculations must be carried out at ds and dp if the anticipated operational trim range exceeds +/-0.5% of Ls. According to its definition the aft terminal of the subdivision length Ls can be located a substantial distance aft of the aft perpendicular according to the load line length (L) and the aft terminal of the conventional length between perpendiculars (LBP) often preferred by yards and designers. The latter is normally referred to in the ship’s hydrostatic particulars. As a result the mid-length draught at Ls will often differ from the draught at the load line mark and from the longitudinal reference point assumed in the stability manual for trimmed waterlines. The nominal value of a trim measured over Ls will then also differ from the trims assumed in the stability booklet. This inconsistency should be rectified. Ls is primarily a calculation parameter used in Part B-1 and can easily be replaced in

23 10/01/2012

other contexts where consistency with intact stability calculations is important. Since practices on the definitions of LBP may vary it is proposed as a compromise that “draught” in the regulations is referred to length (L) in the future by amending paragraphs 9 and 13 as follows:

Draught (d) is the vertical distance from the keel line at mid-length on length (L) to the waterline in question.

R2.2 Definition of mid-length R2.9 Definition of draught Q2. Do you agree with the underlined addition to the definition of draught? Yes

Japan, MI, Norway, Spain, Denmark, US, Sweden

No

China, Finland, Germany, CLIA, Italy, UK

Comments / Alternative Proposals?:- China: Regarding definition of draught: The draught (dl, dp and ds) used in the calculation of Index A should be the same for all trims. Mean draught cannot achieve this. However, correspondent draft (i.e. the draught corresponding to level trim) under a constant displacement doesn’t vary with the floating status. Therefore China proposes to revise paragraph 9 as follows:

“9 draught (d) is the vertical distance from the keel line to the waterline at level trim.” This revision implies that 3 draughts (dl, dp and ds) defined in paragraph 10, 11 and 12 should be determined at level trim. And this also can resolve the problems mentioned by Norway. Finland: Prefer to add “on length (LBP)” to avoid differences between Ls and L (Load Line). All stability documents are done to refer length between perpendiculars including also input data in stability loading computer. Clear definition of LBP is needed to insert under reg. 2. Germany: We prefer that “LBP” (length between perpendiculars) shall be used as this is a preferable approach to address this important information to the crew and to ensure “operational compliance”. At the same time a clear definition of LBP is needed. CLIA: No need. Lg is OK! Italy: Length between perpendiculars “LBP” is preferable for operational purpose. Spain: We can accept the proposal, but, in that case we think that more modifications (as proposed in other parts of this document) are needed. We think that all of these changes should be evaluated jointly:

- Regulation 2.2 (Mid-length definition) should be deleted or changed. - The trim definition and the limits should be adjusted also (according proposal contained

in Q3): Clarification: In S2009 trim is the difference between the draught forward and the draught aft, where the draughts are measured at the forward and aft terminals respectively, disregarding any rake of keel. If the draught definition is changed, then the new draught is the vertical distance at mid-length on length (L), but it is not equal to the average of draught forward and the draught aft, measured at the forward and aft terminals. In other words, d ≠ Aft/Fore draught ± Trim / 2. That is why we agree with proposal of Norway (see Q3).

- To be consequent, trim limits should be changed accordingly. It should be referred to +/-0.5% of L (instead of Ls).

24 10/01/2012

- As per Norway proposal (SLF 52/17/6), for consistency Ls should then be replaced by the load line length L in other regulations.

US: However, isn’t the mid-length of L already defined as “amidships”? Suggest changing to: “Draught (d) is the vertical distance from the keel line at amidships to the waterline in question.” Also, not sure if the definition of “mid-length” is now needed; is it used anywhere other than in the definition of draught? Round 1 Discussion: The current definition of draught (d) is that it is the vertical distance from the keel line at mid-length (defined in Reg 2.2 as the mid-point of the subdivision length, Ls) to the waterline in question. Norway is concerned that there may be some confusion between the draughts and trims used in the damage stability calculations and those in the intact stability as used in the Stability Book. The aft terminal on Ls can differ considerably from the AP on L or LBP. Norway proposes to solve this by specifying that draught “d” be measured at the mid-length “on length (L)”. For consistency they propose a similar amendment in the definition of trim (Reg. 2.13 – see Q3). A problem with Norway’s proposal is that the term “mid-length” is already defined in 2.2 relative to Ls. The current trim definition refers to the aft and forward terminals, also relative to Ls. So “mid-length” referring to L, as proposed, could be confusing. The US suggests that there is already a definition for amidships at the middle of the length (L) (See Reg. 2.26) and proposes to use this in a new definition (above). Spain and the US question whether the Reg. 2.2 definition of mid-length is needed at all. China tries to avoid the problem by removing all references to amidships or mid-length but there may be a problem here with rake of keel vessels where the midships reference point for draught needs to be defined. Several correspondents express a preference for use of LBP. If LBP is the same as L (is there a difference?) and we use the US proposal then it seems we could reach agreement. The remaining question then would be whether to remove Reg 2.2 altogether and re-number the remaining regulations or just leave it there serving no purpose. Q2A. Recognising that Norway has identified a possible source of confusion over the definition of draught in Reg 2.9 and also that we need consistency throughout in the use of L and Ls, can we accept the US’ proposed revision of 2.9 as follows?:- “Draught (d) is the vertical distance from the keel line at amidships to the waterline in question.” Yes

MI, US, Japan, RINA, Norway (but with comment), CLIA, UK (with comment), Sweden

No

Germany, Finland (with comment), Italy (with comment), France (with comments), Denmark

Comments / If “Yes” should we delete existing regulation 2.2 which is not used anywhere else and re-number the remaining regulations (cross-referencing checks will be needed) / Alternatives? MI: Agree (to delete Reg 2.2 etc ). Germany: No, we still prefer LBP and the corresponding trim and draft. China: Draught at amidships equals to mean draft which may be have multiple value as it varies with trim. In order not produce multiple draught, correspondent draught, or draught at LCF, of ds, dp and dl should be used in damage stability calculation. Therefore China would like to suggest a slight change to the wording proposed by US as follows: “Draught (d) is the correspondent draught which is the vertical distance from the keel line at

25 10/01/2012

amidships to the waterline in question.” Finland: All delivery documents (draught and trim) related to stability are based on LBP. Also software in loading computers is based on LBP. Crew are familiar with LBP (between perpendiculars). US: Yes [delete Reg. 2.2 and renumber the rest]. Italy: LBP is preferred. Stability manuals are referring to LBP, which is not the same as L (which is defined in the Load Line Convention). RINA: Agree that regulation 2.2 could be deleted. France: A common reference must be used for all stability documents. When ship is trimmed, draft will be different depending on mid-length definition, for a given waterline, but this will not influence calculation results. So France proposes to measure the draft at mid length between design perpendiculars which seems to be the current practice. A way may be to modify reg 2.2 and 2.9 as follows : 2 Reference point is the mid-point of design length between points where are calculated fore and aft drafts reported in stability documents. 9 Draught (d) is the vertical distance from the keel line at reference point to the waterline in question. Norway: Yes, but 2.2 should rather be harmonized with ICLL-66, i.e. “Amidships is the middle of the length (L)”. The mean draught will then be measured in the same longitudinal location as the load line mark. Our proposal was based on the anticipation that it may prove difficult to agree on a universal definition of LBP that will be enforceable due to different local traditions and practices on designer level. UK: The use of “mid-length” was needed for the old regulations where the assumed distribution density of damage location centre was not uniform, whereas the harmonised regulations assumed that the factor “a” to be uniformly distributed, therefore this definition is no longer needed. Should the above said distribution function be modified in the future to account for historical changes to come, there is no guarantee that “mid-length” to mark a bi-linear function might be employed. Round 2 Discussion: It seems that the UK has provided us with a very good reason to delete Reg. 2.2. China’s proposal to define “d” as draught at LCF (correspondent draught) would seem to be difficult to apply as LCF varies with draught – but perhaps we have not understood the proposal correctly? We also don’t quite understand Norway’s comment as the definition they quote - “Amidships is the middle of the length (L)” – is already included as Reg. 2.26. Several members still prefer to use “LBP” rather than “L”. It seems that we could probably all agree to the US proposal - “Draught (d) is the vertical distance from the keel line at amidships to the waterline in question.” – with amidships as defined in Reg. 2.26 and with Reg. 2.2 deleted if only we could agree that “LBP” and “L” are the same. The advantage of using “L” from the ICLL is that it is very clearly defined, with diagrams and explanations, even covering raked keel vessels (ref. Res. MSC.143(77) Reg. 3) . We have already referred the definition of forward perpendicular (Reg. 2.7) to the ICLL definition and our definition of amidships in Reg. 2.26 is the same as in the ICLL. The ICLL definition of “perpendiculars” (Ref. MSC.143 reg. 3.2) reads:- “The forward and after perpendiculars shall be taken at the forward and after ends of the length (L). The forward perpendicular shall coincide with the foreside of the stem on the waterline on

26 10/01/2012

which the length is measured.” We don’t really understand why, as Italy and many others state, “Stability manuals are referring to LBP, which is not the same as L (which is defined in the Load Line Convention).” Maybe it is something to do with the A.P. definition – azipods, for example? Perhaps we should discuss this at SLF 53 and if we cannot agree that L is the same as LBP we may need to revise the definitions of Regs. 2.2 and 2.9 as proposed by France. Q2B (for SLF53 WG). Can we agree that L as defined in ICLL is the same as LBP as commonly used in industry? Consistency needed with Reg. 2.13 on trim (see Q3). Yes

No

Comments / If “yes” can we then agree to the US’ proposed revision of Reg. 2.9, the deletion of Reg. 2.2 and the consequent re-numbering of Regs. 2.3 to 2.26? / Alternatives? After discussion, the US’ proposals were agreed to by the SLF 53 WG. Q2. Recommend acceptance at SLF54 but the re-numbering may not be necessary

(see Q66). 10 9 Deepest subdivision draught (ds) is the waterline which corresponds to the summer load line draught of the ship. 11 10 Light service draught (dl) is the service draught corresponding to the lightest anticipated loading and associated tankage, including, however, such ballast as may be necessary for stability and/or immersion. Passenger ships should include the full complement of passengers and crew on board. [Coordinator’s Note:- New question for SLF53 WG: For ro-pax ships do we include full passengers but no cars? It does not seem logical as most ro-ro passengers come with their cars.] [Coordinator’s Note post SLF 53 – we can’t recall what was decided in WG3 – therefore guess that no clarification is necessary].

Regulation 2.11 2.10 Light service draught (dl) – The light service draught (dl) represents the lower draught limit of the minimum required GM (or maximum allowable KG) curve. It corresponds, in general, to the ballast arrival condition with 10% consumables for cargo ships. For passenger ships, it corresponds, in general, to the arrival condition with 10% consumables, a full complement of passengers and crew and their effects, and ballast as necessary for stability and trim. The 10% arrival condition is not necessarily the specific condition that must be used for all ships, but represents, in general, a suitable lower limit for all loading conditions. This is understood to not include docking conditions or other non-voyage conditions.

R2.11 EN Comments received from CLIA/CCSF between round 1 and 2:

During ballast water exchange procedures it might happen that the resulting draught will be lower than the light service draught dl. It should be made clear that such temporary conditions are not to be used for the definition of the light service draught. Additional explanation: Any conditions, which result to a lower draught as the 10% arrival conditions due to ballast water exchange procedures, are not to be taken as dl

27 10/01/2012

Coordinator’s Comments: If we accept this addition to the EN, we would suggest slight improvements to the wording for clarity:- Any conditions, which result [to] [in] a [lower] draught [as] [lower than] the 10% arrival conditions due to ballast water exchange procedures, are not to be taken as dl. CG Member’s Comments?:- MI: No objection to this addition to the EN, concur with the co-ordinator’s re-draft. Germany: Acceptable. China: Ballast water exchange conditions as well as any other conditions which are not a recognized typical voyage condition are never used in the damage stability calculation. Finland: OK. US: We can accept this addition to the EN (as improved). RINA: Supports the text proposed by the Coordinator. France: Agreement on this addition to the EN with à wording as : “Any conditions, which result in a draught lower than the 10% arrival conditions due to ballast water exchange procedures, are not to be taken as dl.” Norway: Support the suggestion from the coordinator. CLIA: Agree. UK: Agreed, as coordinator’s comments. Round 2 Discussion: All who responded agreed to this improvement to the EN as amended by the co-ordinators. So Reg. 2.11 EN would now read as follows:- Regulation 2.11

Light service draught (dl) – The light service draught (dl) represents the lower draught limit of the minimum required GM (or maximum allowable KG) curve. It corresponds, in general, to the ballast arrival condition with 10% consumables for cargo ships. For passenger ships, it corresponds, in general, to the arrival condition with 10% consumables, a full complement of passengers and crew and their effects, and ballast as necessary for stability and trim. The 10% arrival condition is not necessarily the specific condition that must be used for all ships, but represents, in general, a suitable lower limit for all loading conditions. This is understood to not include docking conditions or other non-voyage conditions. Any conditions which result in a draught lower than the 10% arrival condition due to ballast water exchange procedures are not to be taken as dl.

CONCLUDED - PROPOSAL ACCEPTED BY CG. AWAIT APPROVAL BY SUB-COMMITTEE AT SLF 53.

(See SLF 53/14 para 12.1). Co-ordinator’s Note post SLF 53 – although initially approved in plenary, CLIA’s proposal was not accepted following discussion in the WG and was therefore deleted in SLF 53/WP.6. However, we recall that in the WG, final resolution of the wording of Reg. 2.11 EN was to be decided when we discussed changes to Regulation 5.1. Due to time constraints this did not happen, therefore it is proposed that we re-visit this paragraph in the CG. Co-ordinator’s Note for Round 4 Questionnaire – we will leave this question for the moment and consider it again when we look at the critical KG/GM questions (Q20 etc) in round 5. Co-ordinator’s Note for SLF 54 – see SLF 54/8/1 para. 14.1. This EN to be reviewed in the light of Norway’s proposed revisions (see Annex 2 of SLF 54/8/1).

12 11 Partial subdivision draught (dp) is the light service draught plus 60% of the difference between the light service draught and the deepest subdivision draught.

28 10/01/2012

13 12 Trim is the difference between the draught forward and the draught aft, where the draughts are measured at the forward and aft terminals perpendiculars respectively, as defined in the International Convention on Load Lines in force, [Q3] disregarding any rake of keel.

Regulation 2.13 (ref. SLF 52/17/6 - Norway) Norway proposes to change 2.13 to:- [See also comments under regulation 2.9].

Trim is the difference between the draught forward and the draught aft, where the draughts are measured at the forward and aft terminals of length (L) respectively, disregarding any rake of keel.

R2.13 Definition of Trim Q3. Do you agree with the underlined addition to the definition? Yes

Japan, MI, Norway, Italy, Spain, Denmark, US, Sweden

No

China, Finland, Germany, CLIA, UK

Comments / Alternative Proposals?:- China: Definition of Trim need not be changed as trim measured based on Ls, LBP or L is not significant as the waterline is the same, the Longitudinal trim angle is also the same; the hydrostatic parameters under the waterline, such as LBP and KMT won’t be influenced by the trim definition. If the trim should be revised, the most appropriate is based on LBP. Finland: Refer to Q2. Germany: See comments on Q2 CLIA: No need. Italy: See also Q2. Spain: See comments to Q2. An alternative text could be as follows (anyway we can accept also Norway proposal): “Trim is the difference between the draught forward and the draught aft, where the draughts are measured at the forward and aft perpendiculars respectively, as defined in the International Convention on Load Lines in force , disregarding any rake of keel”. Denmark: Please note that the definitions of aft and forward terminals in Reg. 2.3 and Reg. 2.4 are based on the subdivision length. US: Since “forward terminal” and “aft terminal” are defined terms, in this definition suggest changing to “forward and aft limits” as is used in the definition of forward/aft terminal. Round 1 Discussion: As mentioned in the discussion for Q2, Norway’s proposal could introduce a slight inconsistency by associating “terminals” with “L”, which in 2.3 and 2.4 are defined in relation to “Ls” (as stated by Denmark & US). The US proposal of replacing “terminals” with “limits” would be more consistent but could also be slightly ambiguous as the word “limit” may not be readily associated with “L” by the user (see 2.3 and 2.4). Spain’s proposal overcomes this problem and is very specific. China’s comments are appreciated but if trim is defined as a difference in draughts measured at two reference points then those points must be defined; it is agreed that trim angle is independent of any defined reference points but is, we believe, not commonly used in stability books. There does not appear to be a definition of “trim” in the 2008 IS Code. Q3A. Recognising that Norway has identified a possible source of confusion over the definition of trim and that there seems to be a majority in favour of defining trim over length L (or LBP) to be consistent with the stability book, do you prefer the US proposal to replace “terminals” by “limits” or the more specific proposal by Spain:- “Trim is the difference between the draught forward and the draught aft, where the draughts are

29 10/01/2012

measured at the forward and aft perpendiculars respectively, as defined in the International Convention on Load Lines in force, disregarding any rake of keel”. ? US proposal?

Italy (with comment), France (with comment), Norway (with comment)

Spain’s proposal?

MI, Finland, US, Japan, RINA (with comment), CLIA, UK, Sweden, Denmark

Comments / alternative proposals? MI: Prefer the proposal by Spain. Germany: No – should refer to LBP (and not to L from LoadLine). China: The above proposed text of trim definition is based on the length as defined in Reg.3 of the LL Convention. Normally in the stability booklet the draughts at terminals as defined in Load Line Convention are usually not calculated. However the normally used draft is based on LBP. This LBP is usually found in the Lines Plan and is quite different from the length as defined in Reg.3 of the LL Convention. Italy: US proposal, but using LBP instead of L, as explained in Q2A RINA: Forward and aft terminals are defined in regulation 2 and are associated with the definition Ls. In certain ship arrangements it is possible that the forward/aft terminals limits can be positioned at the extremes of the ship structure see EN regulation 2.1 Figure. In such cases these positions will not be suitable for positioning draught marks. France: Definition of the reference length has a slight influence on actual trim limits. Reference to a well defined length as freeboard length may be preferable to reference to LBP which may be subject to designer choice. Norway: We agree that “terminals” in our proposal might be misleading and the US proposal is supported. Round 2 Discussion: There is a majority of 9 to 4 in favour of Spain’s proposal. We all now seem to agree that trim should be measured over length LBP (or L) and not Ls. But we must await the outcome of our discussions under Q2 to resolve the issue of the exact difference between L and LBP (Germany, Italy, China and France mention the difference here once again). If we could agree that L and LBP are the same then presumably we could use Spain’s proposal. The US proposal has some support but perhaps use of the term “limits” rather than “terminals” may be preventing more members from supporting it as it may still be associated with the use of “limits” in Reg. 2.3 & 2.4 referring to Ls. Q3B (for SLF53 WG). If we agree that L and LBP are equivalent (see Q2) can we then use Spain’s proposal for Reg. 2.13 - “Trim is the difference between the draught forward and the draught aft, where the draughts are measured at the forward and aft perpendiculars respectively, as defined in the International Convention on Load Lines in force, disregarding any rake of keel.” - ? Yes

No

Comments / Alternatives? Spain’s proposal was accepted in WG3 at SLF 53.

Q3. Recommend acceptance at SLF54 14 13 Permeability (μ) of a space is the proportion of the immersed volume of that space which can be occupied by water. [Coordinator’s Note: There is a new IACS Unified Interpretation (UI) for this definition to be presented at MSC 87 in May 2010 - “In determining the permeability of a space, the volume of a space should be taken as the moulded volume, i.e. the immersed volume of a space should be the underwater moulded volume of that space multiplied by the permeability.” (Ref SLF 52/19, Annex 4).

30 10/01/2012

New Note: The UI was accepted at MSC 87 ref MSC87/26/12.12:- ]

New EN for R2.14? Definition of permeability. Q4. If accepted at MSC 87, should this UI be included as a new EN? Yes

China, Finland, Germany, Japan, Norway, Italy, Spain, Denmark, UK, US, Sweden

No

CLIA

Comments / Alternative Proposals?:- MI: If accepted then this definition could be updated rather than adding a new EN. CLIA: Adds nothing and is confusing. Round 1 Discussion: Apart from CLIA and MI, a large majority agreed to include this (now approved) UI in the EN. We could ask CLIA and MI to accept the majority verdict but perhaps the MI suggestion has merit. For example we could simply add “moulded” to the definition in the regulation:- Permeability (μ) of a space is the proportion of the immersed [moulded] volume of that space which can be occupied by water.

Would this make it clear enough to the user that the volume to be used in the damage calculations is (the gross volume less an allowance for internal structure) * (μ) without needing a new EN? Q4A. If we accept the majority view, should we add the IACS UI to the EN without change or should we modify the definition of permeability in Reg 2.14 as proposed by MI (perhaps by adding “moulded” as shown, for example)? Add UI as new EN?

Germany, China, Finland, Japan (with comment), RINA, France (with comment), UK, Sweden, Denmark

Modify Reg 2.14?

MI, US, Italy, Norway, CLIA

Comments / Alternative suggestions for changing the wording of the definition? MI: Modify Reg. 2.14 as proposed. Japan: Japan does not have a strong position. France: Both alternatives seem equivalent. Round 2 Discussion: There is a majority of 9 to 5 in favour of adding the IACS UI to the EN. The co-ordinators have had some discussions with UK industry who say the UI is clearer. Q4B (for SLF53 WG). Can we accept the majority view to include the IACS UI for permeability in a new EN for Reg. 2.14? Yes

No

Comments? This proposal was not accepted by WG3 at SLF 53 so the regulation remains unchanged and no EN is deemed necessary.

NFA at SLF 54. 15 14 Machinery spaces are spaces between the watertight boundaries of a space containing the main and auxiliary propulsion machinery, including boilers, generators and electric motors primarily intended for propulsion. In the case of unusual arrangements, the Administration may define the limits of the machinery spaces.

31 10/01/2012

16 15 Weathertight means that in any sea conditions water will not penetrate into the ship.

17 16 Watertight means having scantlings and arrangements capable of preventing the passage of water in any direction under the head of water likely to occur in intact and damaged conditions. In the damaged condition, the head of water is to be considered in the worst situation at equilibrium, including intermediate stages of flooding.

18 17 Design pressure means the hydrostatic pressure for which each structure or appliance assumed watertight in the intact and damage stability calculations is designed to withstand. 19 18 Bulkhead deck in a passenger ship means the uppermost deck at any point in the subdivision length (Ls) to which the main bulkheads and the ship’s shell are carried watertight and the lowermost deck from which [passenger and or crew – change in red agreed at SLF 53 but see coordinator’s comment under CLIA Q1 below] [passenger and crew][CLIA Q1D(1)] evacuation will not be impeded by water in any stage of flooding for damage cases [defined in regulation 8 and in part B-2 of this chapter] [CLIA Q1D(2)]. [For passenger ships, “evacuation” refers to both passengers and crew in all regulations.] [CLIA Q1D(1)]. The bulkhead deck may be a stepped deck. In a cargo ship the freeboard deck may be taken as the bulkhead deck. [In a cargo ship the freeboard deck may be taken as the bulkhead deck.][Q6D(1)]

R2.19 Definition of Bulkhead deck CLIA Q1

Queries received from CLIA/CCSF between Round 1 and Round 2: Regulation 2.19 How to apply this to Ro-Pax vessels, where the bulkhead deck is the car deck where no passengers are staying during a voyage?

Coordinator’s Comments:

CG Member’s Comments?:- Germany: to be precise, the definition of the bulkhead deck should read:

… lowermost deck from which passenger and/or crew evacuation…

China: No comments. Finland: In Ro-Pax vessels watertight bulkheads are extended up to bulkhead deck, but no evacuation. Critical openings for evacuation routes from below bulkhead deck are located at least 2.4 m above bulkhead deck.

==> bulkhead deck is alternatively and/or lowermost deck.

RINA: There appears to be no justification for assigning the uppermost deck in a passenger ship as the bulkhead deck. It is proposed that regulation 2.19 is amended as follows: 19. Bulkhead deck in a passenger ship means [any] [the uppermost] deck at any point in the subdivision length (Ls) to which the main bulkheads and the ship’s shell are carried watertight and the lowermost deck from which passenger and crew evacuation will not be impeded by water in any stage of flooding for damage cases defined in regulation 8 and in part B-2 of this chapter. The bulkhead deck may be a stepped deck.

32 10/01/2012

In a cargo ship the freeboard deck may be taken as the bulkhead deck. France: In this case only crew members may have to be evacuated, but the same principle is to be applied. For clarification, the wording of reg 2.19 may be modified to “…passenger or crew evacuation…” Norway: The regulation refers to passengers and crew, so evacuation of crew will still be relevant.

Round 2 Discussion: It seems that the best solution to the problem raised by CLIA would be to change the regulation as highlighted below in square brackets:-

19 Bulkhead deck in a passenger ship means the uppermost deck at any point in the subdivision length (Ls) to which the main bulkheads and the ship’s shell are carried watertight and the lowermost deck from which passenger [and/or] crew evacuation will not be impeded by water in any stage of flooding for damage cases defined in regulation 8 and in part B-2 of this chapter. The bulkhead deck may be a stepped deck. In a cargo ship the freeboard deck may be taken as the bulkhead deck.

As co-ordinators we cannot see how RINA’s proposal improves the clarity. The definition must link the top of the watertight bulkheads to the highest deck to which the bulkheads are carried not just any deck – the WT bulkheads also carry to the lower decks but this is not the important point. But we will nonetheless ask the member’s opinion.

CLIA Q1 (for SLF53 WG). Can we accept the change to Reg. 2.19 as highlighted in square brackets in the Round 2 discussion above or do we prefer RINA’s proposal?

Prefer “and/or”?

Prefer RINA’s proposal?

Comments? Co-ordinator’s Note post SLF 53:- In WG3 at SLF 53, the RINA proposal was not accepted but it was agreed to change the text in square brackets to read “or” rather than “and/or”. Since the meeting we wondered whether it would be better to simply delete “passenger or crew” altogether leaving us with “… the lowermost deck from which evacuation will not be impeded …….”. CLIA Q1C (for Round 4 questionnaire). If we are permitted to alter a decision made at the SLF 53 WG, would you prefer Reg. 2.19 to read:- (a) Bulkhead deck in a passenger ship means the uppermost deck at any point in the subdivision length (Ls) to which the main bulkheads and the ship’s shell are carried watertight and the lowermost deck from which passenger or crew evacuation will not be impeded by water in any stage of flooding for damage cases defined in regulation 8 and in part B-2 of this chapter……. or (b) Bulkhead deck in a passenger ship means the uppermost deck at any point in the subdivision length (Ls) to which the main bulkheads and the ship’s shell are carried watertight and the lowermost deck from which passenger or crew evacuation will not be impeded by water in any stage of flooding for damage cases defined in regulation 8 and in part B-2 of this chapter……

33 10/01/2012

Prefer (a)

US, Norway, France, Germany, Spain, EC (but not a strong preference. In any case it should be understood that evacuation concerns both passengers and crew), UK (assure uniform implementation by explicitly stating the obvious).

Prefer (b)

Vanuatu, Sweden, Japan, China, Denmark, Finland, Italy, CLIA, MI (agree the clarity of the text in option (b))

Comments? Vanuatu: (b) is more understandable, less likely to be subject to interpretation. Will (or perhaps there was some prior discussion) there be further discussion on the word “impeded”, is this with respect to depth; or is the presence of any water the criteria? US: Option (a) provides absolute clarity and is unambiguous; option (b) does not and will inevitably be questioned. (i.e. option b would eventually spawn an EN) RINA: No comments at this time. Germany: Option (a) may be more specific and thus may avoid possible future discussions about whether or not crew is also addressed. France: The 2 proposals are almost identical. Round 6 Discussion: Voting is close – 7 favour option (a) although France and the EC express no real preference and 9 favour (b) with 1 neutral. US, UK and Germany firmly believe that (a) provides greater clarity although Vanuatu and MI each prefer (b). On reflection, the co-ordinators now think that (a) may be preferable because there is a danger that crew evacuation in a passenger ship could otherwise be disregarded if it is not specifically mentioned. However, there are other places in the Regulations and EN where the term “evacuation” is used without specifying passenger or crew (for example Reg 7-2.5.2.2 and EN). Perhaps we should make it clear in every regulation / EN or alternatively define “evacuation” in Reg. 2.1918 as always referring to passengers and crew? Vanuatu asks whether “impeded” will be further discussed. We suggest that the EN for Reg. 7-2.5.2.2 makes it clear that partial immersion of the bulkhead deck may be accepted but no water at all is permitted on the evacuation routes (see diagram in EN 7-2.5.2.4). Is this sufficient explanation, Vanuatu? Perhaps some further clarification of “impeded” is needed in this regulation? This gives rise to another query from the co-ordinators. As it stands this definition specifies the bulkhead deck as being the “lowermost deck from which evacuation will not be impeded by water in any stage of flooding for damage cases defined in regulation 8 and part B-2 of this chapter.” The phrase in bold type specifies only the minor damage and bottom damage scenarios and not the majority of the side damage cases in Part B-1. Can anybody remember if this was a deliberate decision –– and if so why? To clarify “evacuation” throughout Ch.II-1 Part B we therefore propose the following compromise by altering Reg. 2.19 as follows:- Bulkhead deck in a passenger ship means the uppermost deck at any point in the subdivision length (Ls) to which the main bulkheads and the ship’s shell are carried watertight and the lowermost deck from which [passenger and crew] evacuation will not be impeded by water in any stage of flooding for damage cases defined in regulation 8 and in part B-2 of this chapter. [For passenger ships, “evacuation” refers to both crew and passengers in all regulations]. The bulkhead deck may be a stepped deck. In a cargo ship the freeboard deck may be taken as the bulkhead deck. CLIA Q1D.

1. Do you agree with the co-ordinators’ proposal to delete “passenger and crew” and add a clarifying sentence defining “evacuation”, similar to that highlighted in red in the discussion paper?

34 10/01/2012

2. Should the “lowermost deck” be determined only by consideration of damage cases defined in Reg. 8 and Part B-2?

Q1 (Y/N)? Yes: Japan, CLIA, Finland, Norway, Germany (with comment), Poland, Italy, UK, France, Denmark No: RINA, US (No; we strongly prefer the “passenger and crew” option as that text is clear and simple. In addition, we do not believe it would be appropriate to insert a secondary definition of “evacuation” within the definition of bulkhead deck (nor do we think a definition of evacuation is necessary)), EC (No, the text is clear as it stands), China (Deleting “passenger and crew” is enough. There is no need to add a clarifying sentence.)

Q2 (Y/N)? Yes: Japan, Finland, Germany, US, Italy, France, Denmark (see comment), China No: CLIA, RINA, Norway, UK (We should consider ending the first sentence at “…and the ship’s shell are carried watertight” and deleting the rest of the sentence as we believe the current definition is confusing).

Comments? / Alternative wording? / Clarification of “impeded”? RINA: Q1. It is proposed that we keep passenger and crew (as this is applicable only to passenger ships) and that we include a new definition for evacuation which defines the evacuation process in two stages i.e. evacuation to muster stations and evacuation from the muster station to the lifesaving appliances. In both cases the definition of bulkhead remains the same. Q1. In the last sentence of 2.19 it is not understood why in a cargo ship the freeboard deck may be taken as the bulkhead deck. This is confusing, as far as we are aware the term bulkhead deck is not used anywhere on cargo ships. Q2. The lowermost deck should be determined by consideration of all damage cases in Part B-1 and B-2 Germany: The definition of the bulkhead deck is difficult to understand (… uppermost deck and … lower most deck …) and may lead to different interpretation, although the practical application does not show these difficulties at the moment. Poland: “And the lowermost deck from which any person will not be impeded by water in any stage of flooding for damage cases.” US: Regarding why the side damage cases from Part B-1 were excluded: We generally recall that it was to keep the definition simpler. If Part B-1 damages were included then a survivability level would have to be specified (i.e. s = [1]) because all damages are not required to be survivable. Regarding “impeded”: We agree that this means no water at all is permitted on the evacuation routes. No strong view on whether clarification is needed. France: Damage cases defined in reg 8 are the only damages for which it is mandatory not to immerse evacuation route. For other damage cases, survival factor will be null if evacuation route is immersed. So it will be necessary that evacuation routes will not be immersed for a sufficient number of damage cases to reach the required index, but there is no specific requirement for damage cases other than defined in reg 8. The word “impeded” may be not sufficiently clear. In reg 7-2 §5.2, it is specified that criterion is immersion of horizontal evacuation route and that this criterion is taken into account only with final waterline. Proposed wording may be : Bulkhead deck in a passenger ship means the uppermost deck at any point in the subdivision length (Ls) to which the main bulkheads and the ship’s shell are carried

35 10/01/2012

watertight and the lowermost deck from which [passenger and crew] horizontal evacuation routes will not be impeded by water in any stage of flooding immersed by final waterline for damage cases defined in regulation 8 in part B-2 of this chapter. [For passenger ships, “evacuation” refers to both crew and passengers in all regulations]. The bulkhead deck may be a stepped deck. In a cargo ship the freeboard deck may be taken as the bulkhead deck. However, explanatory note to regulation 7-2.5.2.2 should apply to this definition to specify what is an horizontal evacuation route and that only evacuation from undamaged spaces is to be considered. Denmark: Regarding Q2 the evacuation routes are already covered by the probabilistic calculations in Part B-1 as si should be taken as 0 if any part of the bulkhead deck in passenger ships considered a horizontal evacuation route or a vertical escape hatch, immerses (Reg. 7-2.5.2.2+5.3.1). For minor damages according to Reg. 8 and Part B-2 we must always be able to evacuate the ship hence the evacuation routes are not allowed to be immersed / impeded by water in those cases.

CLIA Q1 Co-ordinator’s Note:- The variety of views mean that the wording of R2.19 must be resolved at SLF 54. See alternatives in square brackets above.

DISCUSS AT SLF 54

Regulation 2.19 2.18

Bulkhead deck – See Explanatory Notes for regulation 13 for the treatment of a stepped bulkhead deck with regard to watertightness and construction requirements.

20 19 Deadweight is the difference in tonnes between the displacement of a ship in water of a specific gravity of 1.025 at the draught corresponding to the assigned summer freeboard and the lightweight of the ship.

21 20 Lightweight is the displacement of a ship in tonnes without cargo, fuel, lubricating oil, ballast water, fresh water and feedwater in tanks, consumable stores, and passengers and crew and their effects.

22 21 Oil tanker is the oil tanker defined in regulation 1 of Annex I of the Protocol of 1978 relating to the International Convention for the Prevention of Pollution from Ships, 1973.

23 22 Ro-ro passenger ship means a passenger ship with ro-ro spaces or special category spaces as defined in regulation II-2/3.

24 23 Bulk carrier means a bulk carrier as defined in regulation XII/1.1.

25 24 Keel line is a line parallel to the slope of the keel passing amidships through:

.1 the top of the keel at centreline or line of intersection of the inside of shell plating with the keel if a bar keel extends below that line, on a ship with a metal shell; or

.2 in wood and composite ships, the distance is measured from the lower

36 10/01/2012

edge of the keel rabbet. When the form at the lower part of the midship section is of a hollow character, or where thick garboards are fitted, the distance is measured from the point where the line of the flat of the bottom continued inward intersects the centreline amidships.

26 25 Amidships is at the middle of the length (L).

R2.26 (Move definition of “amidships” to replace deleted R2.2 – “mid-length”)

New proposal from co-ordinators for Round 6. Would it be sensible to move the definition of “amidships” from 26 25 to replace the deleted definition 2 for “mid length”? This preserves the existing numbering (apart from 27 26) thus minimizing any cross-referencing problems and ensuring that “amidships” is defined before it is first used in definition 9 8 (for “draught”).

Q66D (for Round 6 Questionnaire). Do you agree with the above proposal?

Yes?

Japan (see comment), CLIA, RINA, Finland, Norway, Germany, Poland, US, Italy, UK, EC, France, Denmark

No? China

Comments? Japan: It should be noted that displacement of initial condition with trim will be changed due to this amendment of the length. Because, the position measuring draught is changed from the middle of Ls to the middle of Lf. Therefore, this revision may affect Attained Index of some ships. Poland: It will ensure that “amidships” is defined before it is first used in def. 9 for draught.

Q66 Members voted 11-1 in favour, China opposes, Japan has a comment.

Can we accept majority at SLF 54? 27 26 2008 IS Code means the International Code on Intact Stability, 2008, consisting of an introduction, part A (the provisions of which shall be treated as mandatory) and part B (the provisions of which shall be treated as recommendatory), as adopted by Resolution MSC.267(85), provided that:

.1 amendments to the introduction and part A of the Code are adopted, brought into force and take effect in accordance with article VIII of the present Convention concerning the amendment procedures applicable to the Annex other than Chapter I: and

.2 amendments to part B of the Code are adopted by the Maritime Safety

Committee in accordance with its Rules of Procedure. [Co-ordinators Note:- The sentences highlighted were not contained in the 2009 Consolidated Edition and come from resolution MSC.269(85)]. [27][28] [Dry cargo ship is a cargo ship of any size but excluding oil tankers and vessels covered by the IBC and IGC Codes.] [Q6D(2)] [28][29] [Small dry cargo ship is a dry cargo ship with 24<= L<= 80 m. and gross tonnage >= 500.] [Q6D(2)]

37 10/01/2012

[Coordinator’s Notes: • The above proposed definitions of cargo ship could alternatively be placed in

amended reg. 4.1. • Note that “cargo ship” is already defined in Part A Reg. 2(g) – “is any ship which

is not a passenger ship”. • We could also place these proposed new definitions in that Part of SOLAS?]

[Q6D(2)]. [All these and any new alternative proposals are to be discussed at SLF 54]

R2.27 Definition of 2008 IS Code Q5. Presumably definition 27 will automatically be included in the next consolidated edition of SOLAS? Yes

China, Finland, Germany, Japan, MI, Norway, CLIA, Italy, Spain, Denmark, UK, US, Sweden

No

Comments?:- Finland: Agree to add proposed text concerning Intact Stability Code 2008, because Part A is now mandatory. Norway: It does not seem appropriate to include the whole application text in this definition. That should be covered in Regulation 5. CLIA: It seems it should be. Denmark: Another proposal is to make it more simple: “27 Intact Stability Code, 2008 (2008 IS Code) means the International Code on Intact Stability, 2008, as amended by the Organization”. Make sure that reference to applicable amendment procedures does not belong in a definition. Round 1 Discussion: This item was included as it was not clear to us whether the IMO Secretariat automatically adds approved MSC Resolutions such as this to the next update of SOLAS. It was designed to act as a reminder that an action is necessary. All are agreed that it is necessary but Norway and Denmark propose that the full text should not be included. Q5A. In accepting that this definition should be added to the next update of SOLAS can we agree to the wording proposed by Denmark:- 27 Intact Stability Code, 2008 (2008 IS Code) means the International Code on Intact Stability, 2008, as amended by the Organization”? Yes, agree with Denmark

MI, Germany, Finland, Italy, Japan, RINA, France, Norway (with comment), CLIA, UK, Sweden, Denmark

No

US (with comment)

Comments / Alternative suggestions for adding the definition Reg. 2.27? China: No comments. US: This maybe a question for the Secretariat but the adopted text format is the same as for the ISPS Code in SOLAS regulation XI-2/1.12. Norway: We believe the standard wording would include a reference to the MSC adoption by resolution MSC.267(85), but the Secretariat will be able to guide the SDS group on this. Round 2 Discussion: Many thanks for your comments US and Norway. As suggested, we will leave this to the Secretariat to include in the next version of SOLAS with the standard wording.

Q5: CONCLUDED – LEAVE TO SECRETARIAT

38 10/01/2012

Regulation 3

Definitions relating to parts C, D and E omitted here (not stability related)

Part B Subdivision and stability

Regulation 4 General

1 The damage stability requirements in part[s] B-1 [through B-4] shall apply to cargo ships of 80 m in length (L) and upwards and to all passenger ships regardless of length but shall exclude those cargo ships which are shown to comply with subdivision and damage stability regulations in other instruments*

developed by the Organization.

1 In Part B-1, .1 regulation 5 shall apply to passenger ships of all sizes and every cargo ship having a length (L) of 24 m and upwards (including tankers covered by MARPOL Annex 1, the IBC and IGC Code). .2 regulation 5-1 shall apply to passenger ships of all sizes and every cargo ship having a length (L) of 24 m and upwards including those vessels which are shown to comply with stability regulations in other instruments* developed by the Organization but shall not apply to tankers covered by MARPOL Annex 1, the IBC and IGC Code. .3 the remaining regulations in Part B-1 shall apply to passenger ships of all sizes and, with the exception of regulations 8 and 8-1, to cargo ships having a length (L) of 80 m and upwards but they shall not apply to any vessels which are shown to comply with subdivision and damage stability regulations in other instruments* developed by the Organization.. [Co-ordinator’s Note for SLF 54:- the above changes highlighted in red were agreed at SLF 53, but have to be altered again to accommodate the footnotes see Q6D(4).] Regulation 4.1 (ref. SLF 52/17/6 - Norway) This administration has seen that the current wording has created misunderstandings particularly in connection with application of the damage stability provisions in regulation 9.8 since they are located in part B-2. The current wording could be understood as meaning that 9.8 need not be applied to ships other than tankers if they are listed in the footnote. The same misunderstanding might also occur if a proposal for a survival criterion in regulation 12 (collision bulkhead) is accepted. It is proposed that the words “through B-4” be deleted to avoid confusion. Part B-3 and B-4 do not include specific damage stability provisions. The exclusion footnote to this paragraph is already correct.

R4.1 Application of Damage Stability Requirements in Parts B1 – B4 Q6. Do you agree that the text in square brackets in Reg. 4.1 should be removed? Yes

China, Finland, Germany, Japan, MI, Norway, CLIA, Italy, UK, US, Sweden

No

Spain (only partly, see comments), Denmark

39 10/01/2012

Comments?:- Spain: In our opinion, according SOLAS current wording, the damage stability provisions contained in 9.8 – Part B2- (bottom damage) should not be applied to cargo ships with L < 80 m. We think that this is a correct idea. For small vessels (trawlers, etcetera), it could be difficult to fit a double bottom extending from the collision bulkhead to the afterpeak bulkhead. In certain areas it is not practicable and compatible with the design and proper working of the ship (for instance, the required height is difficult to achieve in some areas of certain types of small vessels). The current design and configuration of these vessels is not adapted to comply with the alternative damage stability requirements, including bottom damage, contained in regulation 9.8. If we remove the reference to Part B-2, it is possible to understand that regulation 9.8 is applicable to all SOLAS ‘new’ cargo vessels (Chapter II-1 is applicable to cargo vessels of more than 500 gross tonnage – see SOLAS II-1, regulation 1), and not only to cargo vessel with L > 80 m. We think that the reference to B-1 and to B-2 should be maintained in the main text (the problem regarding the application of regulation 9.8 to cargo ships with L> 80 m other than tankers could be clarified in the footnote). It is acceptable to delete parts B-3 and B-4 form the main SOLAS text. In relation to this, we agree with Norway proposal. For vessels with L ≥ 80 m, subject to other subdivision and damage stability regulations contained in other instruments developed by the Organization, we think that it is acceptable and logical to impose the application of regulation 9.8 in case of partial or total absence of the double bottom required by regulation 9, but only if the applicable instrument does not contain its proper bottom damage requirements. In relation to this, we agree with Norway proposal. Denmark: If the square brackets [through B-4] are deleted the bottom requirements in Reg. 9 will be applicable to all cargo ships, i.e. also cargo ships with a length lesser than 80 m. The applicability of the damage stability requirements in Reg. 9.8 has not been investigated for ships having a length less than 80 m. US: With this regulation revision the Explanatory Note for regulation 4.1 could be deleted (it was created to explain this “problem” in the regulation). Japan: Supports the proposal that the words “through B-4” be deleted because the current wording could lead to a misunderstanding that paragraph 9.8 is NOT applied to ships less than 80m. On the other hand, Japan also thinks that the regulations listed in footnote could be applied as alternative regulations in paragraph 9.8. (See also Q44.) Round 1 Discussion: Eleven are in favour of Norway’s proposal but Spain is partly opposed and Denmark is concerned that if it is adopted confusion may arise when applying Regulation 9 (“Double Bottoms in passenger ships and cargo ships other than tankers”) which could be interpreted as applying to cargo ships of all sizes, rather than only to those over 80 metres in L. Japan on the other hand thinks that Reg. 9.8 should be applied to cargo ships less than 80 m (a size which Denmark argues was not investigated when this part of SOLAS 2009 was written). Spain agrees with Denmark on this issue. We could possibly amend the footnote, as suggested by Spain, or even change the title of Regulation 9 to “Double Bottoms in passenger ships [regardless of length] and cargo ships other than tankers [having L >= 80 metres]” to overcome this problem. Japan has also prepared extensive proposals regarding Reg. 9.8 and the associated EN, which we can consider under Q44, below. Japan proposes that Reg. 9.8 could be met by alternatively demonstrating compliance with the regulations listed in the footnote to Reg. 4.1. US suggests that if we adopt Norway’s proposal it should be possible to remove the table in the EN for the footnote to Reg. 4.1 which was inserted to clarify the applicability of specific regulations in parts B1, B2 and B4 to the ship types listed in the footnote.

40 10/01/2012

To summarize, we could 1) adopt Norway’s proposal; 2) clarify that Reg 9.8 only applies to cargo ships >= 80 m by adding [having L >= 80 metres etc] to the title to Reg. 9 (or changing the footnote); 3) Delete the Table in the EN to footnote 4.1 as proposed by the US. However, this proposal, if accepted, would not satisfy Japan’s view that Reg. 9.8 should apply to cargo ships with L < 80 m. Q6A. Can we accept Norway’s proposal to delete “through B-4” as long as we clarify somewhere that Reg. 9.8 does not apply to cargo ships with L < 80 m and so delete the Table in the EN to footnote 4.1, as suggested by the US? Yes

MI (agree this action), Finland, US (with comments), Italy, France (with comments), CLIA, UK, Sweden, Denmark

No

Germany (with comments), RINA (with comments), Norway (with comments)

Comments (particularly on whether or not Reg. 9 should apply to cargo ships with L < 80 m) / Alternatives:- MI: Reg.9 should not apply to cargo ships of L < 80 m. Germany: We are of the position that the requirement for fitting a watertight double bottom is applicable for all cargo vessels, including vessels with a length less than 80m. China: (1) Support to delete “through B-1” [Note: presume this should read B-4, China?] (2) Clarification is needed to be made that Reg.9 (including Reg.9.8) should apply to cargo ships with L < 80 m and the probabilistic damage stab. Requirement of reg.5-1, 6, 7, 7-1, 7-2 and 7-3 should apply to cargo ships with L≥80m. US: Regulation 9 should apply to cargo ships with L < 80 m; this basic application to all SOLAS cargo ships is not changed from previous regulation 12-1. Regarding the specific application of reg 9.8, this is new and the impact on cargo ships with L < 80 m is not clear (and should be further considered). Japan: Before SOLAS 2009, the regulation regarding double bottom for cargo ships applied ALL cargo ships other than tankers, including ships with L <80m (previous SOLAS II-1/12-1. This regulation is in Part B, not Part B-1) If reg.9.8 does not apply to ships with L <80m and reg.9.6 and 9.7 apply to those ships, it would cause confusion whether alternative to double bottom in accordance with reg.9.8 can be accepted or not. If reg.9.1 to 9.5 apply to ships with L < 80m and reg.9.6 to 9.8 do not apply to those ships, Japan agrees with coordinator’s proposal. RINA: We would propose that Regulation 4.1 should be amended as follows:

1. The damage stability requirements in parts B-1 through B-4 shall apply to cargo ships of 80 m in length (L) and upwards and to all passenger ships regardless of length. Those cargo ships which are shown to comply with subdivision and damage stability regulations in other instruments (see footnote) developed by the Organization shall be excluded, but should comply, depending on the ship type, with the regulations indicated in the table in EN Regulation 4.1,

Re regulation 9: The damage stability requirements in regulation 4 only apply to cargo ships of 80 m in length (L) and upwards and to all passenger ships regardless of length. Therefore these requirements are not applicable to cargo ships less than 80 meters unless specified in these regulations i.e. regulation 5. This leads to a further question as to whether or not cargo ships of less than 80 meters, which are required to comply with damage stability requirements, are dealt with in other instruments or in SOLAS.

France: It is assumed that regulation 9.8 will be applied to cargo ship with L>80m if necessary, whichever damage stability regulation is applied (except tankers). It is also assumed that regulation 17.3 will be modified and that reference to reg 8.3 in

41 10/01/2012

corresponding explanatory notes is deleted. Table in EN could be deleted. However, is it clear enough that regulations 5 and 5-1 in part B-1 apply to all ships? Stability information specified in regulation 5-1 is also related to damage stability information (These regulations could be moved in part B-4?) Norway: If the deletion of “through B-4” is accepted then it seems that the table in the EN to footnote 4.1 is no longer needed. However, our position is that Reg. 9.8 shall be applicable even to cargo ships of L<80 m. See SLF 52/17/4. Comments received from CLIA/CCSF between round 1 and 2:

Regulation 4 Footnote in regulation 4 is going to be modified regarding OSV and ships under regulation 27 of the LL Convention. Also footnote referred to SPS ships to be updated. After these modifications there still remain ships under MARPOL 73/78, International Bulk Chemical Code and under Gas Carrier Code, which have to fulfil Reg. 5 and 5-1 in part B-1, but excluded from the application of the damage stability regulation in part B-1. Coordinator’s Comments: The problem highlighted by CLIA/CSSF regarding MARPOL etc should be corrected by the proposed change(s) to the footnote heading? CG Member’s Comments?:- China: No comments. RINA: Supports the coordinator’s comments, see our comments in Q10A. France: Is it clear enough that regulation 5 and 5-1 are not part of damage stability regulations in part B-1? (See comments to Q6A). Norway: Agree with CLIA/CSSF in that guidance on development of limit curves under regulation 5 and 5-1 for these ships must be discussed. It should be noted that intact stability limits are still relevant for loading conditions (e.g. ballast) not covered by MARPOL/IBC/IGC damage stability.

Round 2 Discussion: There is clearly a difference of opinion within the CG members as to whether or not the double bottom regulations in Part B-2 Regulation 9 are applicable to cargo ships of less then L=80 m; the issue has been raised in our report (ref. SLF 53/14, paragraph 13.2) with a request for discussion at SLF 53 and guidance from the S-C. CLIA, supported by Norway, also makes important points regarding cargo ships carrying bulk liquids which are excluded from compliance with the damage stability regulations of Part B-1 but must comply with the intact stability requirements in Part B-1 Reg 5 (and 5-1?). Reg. 5-1 (“Stability information to be supplied to the master”) is a little confusing in terms of its intended application. It cross-refers to MSC/Circ.706 relating to intact stability of tankers during transfer operations (a subject now covered by MARPOL Annex 1, Chapter III). It requests provision of curves or tables of minimum GM against draught (also covered more comprehensively by MARPOL) and then requires that the influence of trim be allowed for but only when the operational trim range exceeds “+/- 0.5% Ls” - a figure which may not be suitable for tankers. France suggests that Reg. 5-1 should be moved to Part B-4 (Stability Management). It is indeed hard to see how it is relevant to tankers. MARPOL covers intact stability for tankers but, as Norway points out, does not require consideration of damage stability when the ship is in ballast. But if MARPOL does not require such consideration as it is only concerned with pollution rather than loss of life, it would seem that there is nothing that can be done to correct this within

42 10/01/2012

SOLAS. We surely cannot require SOLAS probabilistic damage calculations to be carried out only for tanker ballast conditions. It is suggested that the intentions of the regulations are as follows:-

• Part B-1 reg. 5 should be applied to passenger ships of all sizes and every cargo ship of 24 m and above (including tankers).

• Part B-1 regulation 5-1 should be applied to passenger ships of all sizes and every cargo ship of 24 m and above (excluding tankers covered by MARPOL, the IBC and IGC Code but including all vessel types covered by the instruments and regulations in the footnote to reg. 4.1).

• The remaining regulations in Part B-1 should only apply to passenger ships of all sizes and cargo ships of 80 m in length (L) and upwards (but excluding all vessel types covered by the instruments and regulations in the footnote to reg. 4.1).

The issues that we need to put before the S-C are as follows:

1) Currently Part B Reg. 4.1 states “The damage stability requirements in parts B-1 through B-4 shall apply to cargo ships of 80 m in length (L) and upwards and to all passenger ships regardless of length but shall exclude those cargo ships which are shown to comply

with subdivision and damage stability regulations in other instruments* developed by the

Organization”.

2) There is considerable ambiguity in the wording of this regulation which has caused some confusion and resulted in a table being introduced into the EN to define more clearly which regulations in Parts B1-B4 apply to cargo ships and which do not.

3) To try to overcome this, Norway proposed (in SLF 52/17/6) to delete the words “through B-4” but unfortunately some ambiguities remain:-

a) Part B-1 reg.5 is not a “damage stability requirement” but reg. 4.1 as modified by Norway’s proposal could be interpreted as meaning that the intact stability information required by reg. 5 may be ignored for cargo ships with L>=80 m - which is obviously not the intention. To solve this Norway proposed to change the introductory sentence of the footnote to Reg. 4.1 to:

“* Cargo ships shown to comply with the following regulations may be excluded from the application of the damage stability regulations in part B-1:”

This proposal was generally accepted by the CG (see Q7, below). However, the S-C is also invited to look at various further alternatives for improving the clarity of this sentence as discussed under SLF 53/12 paragraph 24 (see also Q10B, below).

b) CLIA, supported by Norway, has pointed out that tankers covered by MARPOL, the IBC and IGC Codes, although excluded from compliance with the damage stability requirements of Part B-1, must comply with Part B-1, regulation 5 and possibly 5-1. Norway is concerned that MARPOL does not require damage stability investigation of ballast conditions. France queries whether it is clear enough that Regs. 5 and 5-1 are not part of the damage stability requirements in Part B-1 and wonders whether Reg. 5-1 should be moved to Part B-4.

c) Discussion of Norway’s proposal in SLF 52/17/6 has raised the issue mentioned in the CG report (SLF 53/14 para. 13.2) as to whether it is the intention of SOLAS 2009 that double bottoms should be fitted in cargo ships other than tankers with length < 80 m. Opinion within the CG is quite sharply divided on this issue which is why we have asked for it to be discussed by the S-C. The discussion should also include Germany’s wider point as to whether or not the other subdivision, watertight and weathertight integrity regulations in Part B-2 (Regs. 10 to 17-1) should all apply where appropriate to dry cargo ships with L < 80 m.

43 10/01/2012

PROPOSAL Below are proposed new draft revisions to the text of Regulation 4.1 and the headings of Part B-2 which try to remove some ambiguities and which are prepared for discussion at SLF 53:- Regulation 4 General 1 [In Part B-1, .1 regulation 5 shall apply to passenger ships of all sizes and every cargo ship having a length (L) of 24 m and upwards (including tankers covered by MARPOL Annex 1, the IBC and IGC Code). .2 regulation 5-1 shall apply to passenger ships of all sizes and every cargo ship having a length (L) of 24 m and upwards including those vessels which are shown to comply with stability regulations in other instruments* developed by the Organization but shall not apply to tankers covered by MARPOL Annex 1, the IBC and IGC Code. .3 the remaining regulations in Part B-1 shall apply to passenger ships of all sizes and, with the exception of regulations 8 and 8-1, to cargo ships having a length (L) of 80 m and upwards but they shall not apply to any vessels which are shown to comply with subdivision and damage stability regulations in other instruments* developed by the Organization.] __________________ * Cargo ships shown to comply with the following regulations may be excluded from the application of the damage stability regulations in part B-1:

Note: It is also proposed to replace the above sentence introducing the footnote to reg. 4.1 with the one below. The explanation as to which parts of part B-1 apply would now be done in the regulation thus over-riding Norway’s proposal in SLF 52/17/6 to improve the existing sentence as shown underlined above. It may also resolve the issues raised by the UK paper MSC 85/23/1 relating to footnotes .6 and .7 (see Q10 below and the CG report to SLF 53 (SLF 53/12 paragraph 24)). Change to:- __________________ * [The following instruments and regulations contain stability requirements for cargo ships:-] .1 Annex 1 to MARPOL etc .2 International Bulk Chemical Code ……etc Note: If the above amendments are agreed to it is also proposed to delete the section of the footnote to Regulation 5.1 referring to MSC/Circ.706 as tankers would be excluded from the regulation and the circular is anyway now incorporated into MARPOL Annex 1, Ch III Reg. 25A:- __________________ + Refer also to the Guidelines for the preparation of intact stability information (MSC/Circ.456); Guidance on the intact stability of existing tankers during transfer operations (MSC/Circ.706); and the Revised Guidance to the master for avoiding dangerous situations in adverse weather and sea conditions (MSC.1/Circ.1228)

44 10/01/2012

PART B-2[*]

SUBDIVISION, WATERTIGHT AND WEATHERTIGHT INTEGRITY

Regulation 9

Double bottoms in passenger ships and cargo ships other than tankers

[Proposed new footnote. A decision is needed on 24 or 80 m in square brackets]:- ____________ [* The regulations in Part B-2 apply to passenger ships regardless of length and to cargo ships of [24][80] m in length (L) and upwards but shall not apply to those cargo ships which are shown to comply with subdivision and damage stability regulations in other instruments developed by the Organization (Ref. footnote to Regulation 4.1).]

Note: The aim of these proposals is to clarify the regulations to be applied to cargo ships thereby enabling the Table in Regulation 4.1 of the EN to be removed. Q6B (for SLF53 S-C and WG). Can we agree to the changes to Reg. 4.1 and the heading of Part B-2 shown under “Proposal” in the Round 2 discussion, above? A decision will also be needed as to whether Part B-2 applies to cargo ships of 24 m L and upward or 80 m L and upward (see square brackets in proposed new footnote to Part B-2). Agree to proposals for Reg 4.1?

Agreed by SLF 53 WG3

Agree to new sentence introducing footnote?


Agree to delete ref to Circ.706 in reg. 5.1 footnote?


Agree to new footnote in Part B-2

Not agreed by SLF 53 WG3

Does B-2 apply to cargo vessels of L>24 or L>80 m?

To be discussed by the new SDS CG for SLF 54 (Ref: SLF 53/WP.6 paragraphs 25 and 26 and TOR 32.5)

Q6C (for round 4 questionnaire). Having made the decisions highlighted above at SLF53 the issue of the size of cargo ship to which Part B-2 applies was referred back to our 2011 CG. Therefore, could you please state whether you think that Part B-2, which includes the DB regulations, should apply to cargo ships of 24 m L and upward or only to 80 m L and upward?

45 10/01/2012

Also, the proposal for a footnote to Part B-2 to clarify the applicability of these regulations was rejected by the WG at SLF 53. However, it would seem that in view of the newly agreed footnote to Reg 4.1 which now only mentions Part B-1, some form of clarification of the applicability of Part B-2 is still needed somewhere – perhaps in the regulation title or by retaining the Table in the EN? Your comments are invited (see also Q10C). B-2 applies to cargo vessels with L>24?

Yes Norway, Japan, France, China, Germany (Generally yes, however the requirements for Reg. 9 may need to be adjusted to those small ships after further investigations), Finland, UK. No Vanuatu Neither US (see comments) RINA (If this was applied to cargo vessels then it would be applicable to ships which are less than 500 gross tons and could raise a conflict between the application of this Part and other Parts of SOLAS, which have an applicability criteria of 500 gross tons, or greater, for cargo ships. There is a requirement in Classification Rules which states that double bottoms need not be fitted in cargo ships less than 500 ton gross tonnage. Noting that a review of cargo ships is currently on the work program in hand at MSC, is it an option at this to forward this issue to DE for inclusion in their work program?).

B-2 only applies to cargo vessels with L>80?

Yes Vanuatu, Italy RINA (While it is the case that Part B-2 could be applied to cargo ships greater that 80 m. However there are requirements in Part B-2, such as Regulation 12 - Peak and machinery space bulkheads, shaft tunnels, which will surely be applicable to SOLAS cargo ships with a length less than 80 m. This may be the case for other paragraphs in Part B-2. It is considered that Part B-2 needs to be reviewed to provide appropriate regulation for cargo ships between 500 GT, and over, and ships with a length greater that 80 m. See comments in paragraph above). Spain (In relation with regulation 9.7 and 9.8 (damage stability requirements - bottom damage) we prefer 80 m. The other regulations should be studied in a case-by case basis. Anyway, it is important to point out that a cargo vessel of 24 m length could have less than 500 GT (SOLAS common limit)). Continued….

46 10/01/2012

Where should we clarify which cargo vessels must comply with B-2?

Vanuatu: With respect to the double bottom issue we think this is less a question of applicability for vessel type(s) but more as a question of the impact on vessels designed to operate from shallower ports. We feel this would tend bloat draught without providing any quantifiable ‘improvement’ characteristics from the application of current rule. Otherwise Administrations will need the flexibility as for Regulation 9.5 for passenger ships; this however seems backwards (and a bit archaic). US: Suggested options: A. Insert a regulation 4.1bis as follows: 4.1bis Except where expressedly provided otherwise, .1 Part B-2 applies to passenger ships and cargo ships. .2 Part B-3 applies to passenger ships. .3 Part B-4 applies to passenger ships and cargo ships. B. The approach used in Parts C and D; a caption under the Part B-2 title: (Except where expressedly provided otherwise part B-2 applies to passenger ships and cargo ships); etc. The applicability should be clear in the regulations; an EN should not be necessary. We prefer option A. Note: this will all now need to be considered/combined in the context of MSC 89/22/8 and its proposed text. Japan: Japan does not have a strong position, but we suggest inserting new paragraph before current reg 9.1, ex; “1 This regulation applies to cargo ships of [24][80] m in length (L) and upwords other than tankers and to all passenger ships regardless of length. 2 A double bottom shall be fitted with ...” RINA: This should be clarified in Regulation 4. Denmark: (with comments). Germany: It’s already laid down in Reg. 4 as updated during SLF 53. We think it’s clear enough. But if the group finds it’s not, we would suggest putting it clearly in SOLAS, not in the EN. Italy: Regulation title. UK: To have a direct reference in the main regulation text would be preferable at this stage.

Further Comments?:- Vanuatu: With respect we submit this not an issue that lends itself to global ‘one size fits all’ style absolutism since under SOLAS the options are limited to the binary set of Passenger vs Cargo vessel. Seeking to apply 9.8 extents of damage based on beam for beamy, shallow draught vessels under 80 meters will likely be remarkably disruptive of the design process. US: We do not believe there should be a cargo ship length threshold for Part B-2. Our understanding of the SLF 53 outcome was that Part B-2 was to be applied to all SOLAS cargo ships irrespective of length (see last sentence of SLF 53/WP.6 paragraph 25). The validity of applying regulation 9.8 to smaller ships was identified as a separate issue and highlighted for consideration as a SDS CG TOR. (see SLF 53/19, paragraphs 14.6 and 14.10.2) Note: we believe only regulations 13-1 and 15-1 have their origins in SOLAS 90 Part B-1 and any legacy connection to L>80. Under SOLAS 90, regulations 9, 10, 11, 12, 15, 16 and 16-1 applied to all cargo ships. Japan: The scope of reg.9.6 to 9.8 should be considered carefully because ships with L <80m need not to calculate si in Part B-1. (See also A.44C.) Denmark: In the old SOLAS the double bottom requirements for cargo ships were included in Reg. 12-1. These requirements were valid to all cargo vessels under SOLAS. Our worries concern the application of Reg. 9.8 for the very small cargo ships only. The clarification should go into SOLAS for clarity and accessibility. France: France considers that B-2 should apply to cargo vessels with L> 24 m whilst keeping in mind that the double bottom requirement with regard to the damage extent and “s” level needs to

47 10/01/2012

be considered / further studied. We refer for example to tugs of 24 m and over and GT > 500. Round 6 Discussion: Many thanks for all your Round 4 comments – this is getting very complicated - let’s hope we can find a way through……! 1) Before going through your Round 4 responses, here is a summary of where the co-ordinators think we stand at the moment, bearing in mind the response from MSC 89 to the German / UK paper MSC 89/22/8:- "22.33 The Committee considered document MSC 89/22/8 (Germany and the UK), proposing to develop amendments to SOLAS regulation II-1/4 in order to clarify the application of SOLAS subdivision standards to cargo ships which are complying with the subdivision standards of other IMO instruments, and agreed to include, in the 2012-2013 biennial agenda of the SLF Sub-Committee and the provisional agenda for SLF 54, a planned output on "Development of amendments to SOLAS regulation II-1/4 concerning subdivision standards for cargo ships", with a target completion date of 2013." 2) As mentioned in our covering e-mail to the Round 5 questionnaire on 6th July 2011, we propose to carry on updating Reg. 4.1 and all the remaining Part B regulations where necessary with the aim of completion at SLF 54 in January 2012 under the terms of the original ToR as specified in SLF 53/19 para. 14.10. There are good reasons for seeking an extension of this completion date to January 2013 (SLF 55), discussed elsewhere, but for the moment we will assume we must meet the original deadline. 3) We must now try to eliminate footnotes wherever possible by incorporating them into the text of the regulations and also reduce EN’s (e.g. the Table in the EN to Reg. 4.1) whilst we have this chance to change the regulations. We note the amendments proposed by Germany and the UK to Regulation 4 in the Annex to MSC 89/22/8 but we will regard these as proposals only as they ignore the changes already agreed at SLF 53 (shown below for easy reference). So we will somehow need to combine the text in the Annex to MSC 89/22/8 with the changes already agreed at SLF 53 (see proposals at end of this discussion). 1 The damage stability requirements in parts B-1 through B-4 shall apply to cargo ships of 80 m in length (L) and upwards and to all passenger ships regardless of length but shall exclude those cargo ships which are shown to comply with subdivision and damage stability regulations in other instruments*


1 In Part B-1, .1 regulation 5 shall apply to passenger ships of all sizes and every cargo ship having a length (L) of 24 m and upwards (including tankers covered by MARPOL Annex 1, the IBC and IGC Code). .2 regulation 5-1 shall apply to passenger ships of all sizes and every cargo ship having a length (L) of 24 m and upwards including those vessels which are shown to comply with stability regulations in other instruments* developed by the Organization but shall not apply to tankers covered by MARPOL Annex 1, the IBC and IGC Code. .3 the remaining regulations in Part B-1 shall apply to passenger ships of all sizes and, with the exception of regulations 8 and 8-1, to cargo ships having a length (L) of 80 m and upwards but they shall not apply to any vessels which are shown to comply with subdivision and damage stability regulations in other instruments* developed by the Organization. Q6

_____________________ * Cargo ships shown to comply with the following regulations may be excluded from the

48 10/01/2012

application of the damage stability regulations in part B-1:

* The following instruments and regulations contain stability requirements for cargo ships:- 4) The other main issues are that, having deleted the original text of Reg. 4.1 and replaced it with text to clarify the applicability of Part B-1, we nowhere, at the moment, specify the applicability of Parts B-2, B-3 and B-4 other than within the regulations themselves or in their titles. 5) For Part B-2, you may recall that there was a proposal made by the co-ordinators to try to define its applicability by means of a new footnote, with square brackets around [24] and [80], but this was rejected at SLF 53 as footnotes are now to be avoided where possible :- [* The regulations in Part B-2 apply to passenger ships regardless of length and to cargo ships of [24][80] m in length (L) and upwards but shall not apply to those cargo ships which are shown to comply with subdivision and damage stability regulations in other instruments developed by the Organization (Ref. footnote to Regulation 4.1).]

5.1) We need to re-examine how and where to define the applicability of part B-2. After further study we have found it is more complicated than the above footnote suggests. Some regulations in B-2 apply to “all” cargo ships, some to cargo ships of L= 80 m and upwards, some to passenger ships (including ro-pax) and some to ro-pax only. Of course, we must find a way of summarizing all this in regulatory text as we do not want another table in the EN. There is a proposal at the end of this document. 5.2) As a preliminary simplifying step we have found that, unlike part B-1, it appears that none of the regulations in part B-2 apply to cargo ships carrying liquids (e.g. tankers, IBC, IGC) so we could define the term “dry cargo ship” for use throughout part B-2. For example the title of Reg. 9 could become “Double bottoms in passenger ships and dry cargo ships” instead of “Double bottoms in passenger ships and cargo ships other than tankers.” 5.3) Often, the applicability is clear from the title or the wording of individual regulations but in Reg. 12, for example, it is not specified in the title. The sources of the regulations in S90 comprise a mixture of those for cargo and passenger ships and this is reflected in the text of the regulations in S2009 where there are many references to “bulkhead deck” but only one to “freeboard deck” (Reg. 12.8). Is there a danger that Reg. 12.1, for example, could be thought to apply exclusively to passenger ships because it only refers to a “bulkhead deck”? Perhaps this problem is covered by the definition of bulkhead deck in Reg. 2.19? Or should it be made clearer in the text of the regulations or the title as, for example, in regulation 15 where there are frequent references to “the bulkhead deck of passenger ships and the freeboard deck of cargo ships”? One way of addressing this issue is indicated in the proposal at the end of this document. 5.4) Another key point to consider for dry cargo ships in part B-2 is to what degree the smaller ones (L < 80 m) should be subject to damage stability analysis. Many of the regulations define subdivision, internal and external water-tightness etc in prescriptive terms and so are easily applied to all sizes of cargo ship without the need for damage calculations. Several, however, require information only obtainable from some degree of damage stability analysis which in turn involves computer modelling etc. Some typical examples are:-

49 10/01/2012

5.4.1) Regs. 9.6, 9.7, 9.8 and 9.9 - if it is decided not to fit a DB in certain areas or if the DB height under a long lower hold is less than prescribed, calculation of si is required for such areas to prove that si = 1. 5.4.2) Reg. 13-1.1 – if relaxation of the degree of water-tightness of openings above the freeboard deck is required it must be demonstrated that any progressive flooding can be easily controlled and that the safety of the ship is not impaired. This could only be determined by damage stability analysis. Regs. 13-1 are almost identical to S90 Reg 25-9 which only applied to cargo ships >= 80 m L. 5.4.3) Reg. 15-1.1 – external openings leading to compartments assumed intact in the damage analysis but which lie below the final damage waterline are required to be watertight. Regs. 15-1 are almost identical to S90 Reg 25-10 which only applied to cargo ships >= 80 m L. 5.4.4) Reg. 16.2 – watertight doors shall be tested by water pressure to a head of water they might sustain in a final or intermediate stage of flooding. In S90, reg. 18 required the head to be taken only to the freeboard deck. For S2009 a damage analysis would therefore be needed to determine the depth of immersion of the door. 5.4.5) Reg. 16-1.2 – any vent trunks passing through the bulkhead deck shall be capable of withstanding the water pressure that may be present within the trunk taking into account maximum allowable heel angle during intermediate stages of flooding, in accordance with reg. 7-2. In S90, this only applied to ro-pax ships. In S2009 (current version), calculations for intermediate stages of flooding are only required for passenger ships so does this regulation only apply to pax (including ro-pax) ships? 5.5) A problem arises when mixing deterministic and probabilistic damage stability calculations - for the latter the damage extents to be assumed are not fixed. In reg. 9.8 (5.4.1, above) deterministic extents of damage are specified and “si = 1” is simply being used as a deterministic “pass/fail” criterion. But for 5.4.2 to 5.4.5, if a full probabilistic damage analysis is carried out, a significant number of cases will fail (s=0) so which damage cases are to be used to determine, for example, the head of water in Reg. 16.2? Is it the damage case producing the lowest A or s value? Alternatively, if a deterministic calculation is to be undertaken, what extents of damage are to be used? One way of addressing these questions is indicated in the proposal at the end of this document. 6) There was a statement in SLF 53/WP.6 para. 25:- “…..This proposed amendment to regulation II-1/4.1 also clarifies that relevant parts of SOLAS chapter II-1, parts B-1 through B-4, also apply to cargo ships of less than 80 m of length, including double bottom arrangements”. In fact, as shown in the new text agreed at SLF 53 (above), the agreed amendment to reg. 4.1 only specified the applicability of B-1. It is important that the applicability of B-2 to B-4 is clarified elsewhere. 7) Also of note are the statements in SLF 53/19 para. 14.6 (SLF Report to MSC):- “The Sub-Committee also supported the applicability of double bottom requirements to all SOLAS ships without any length restrictions and the development of probabilistic bottom damage stability requirements, following a goal-based approach.” And the ToR under 14.10.2:- “consider the validity of applying paragraph 8 pf SOLAS Reg. II-1/9 to smaller ships and, if necessary, suggest appropriate amendments.”

50 10/01/2012

The “development of probabilistic bottom damage stability requirements” refers, we believe, to the work of GOALDS and cannot be fully addressed until their findings are reported to us. 8) In the light of 6) and 7) we will discuss the validity of applying Reg. 9.8 to smaller cargo ships in conjunction with your responses to the Round 4 questionnaire (see item 13.1 below). 9) Part B-3 is clearly applicable only to passenger ships (specified in the title). 10) Some of Part B-4 applies to passenger ships, some to cargo ships and some to ro-ro passenger ships. Just as for part B-2, the applicability of each regulation within part B-4 is usually defined either within the regulation itself or in its title as follows:- 10.1) Regulation 19 – Damage control information – we suggest that the application of regs. 19.1 – 19.5 should be as follows (assuming “dry” cargo ships excludes bulk liquid carriers – see 5.2 above):- 19.1 19.3 and 19.4 – all passenger ships and dry cargo ships of 24 m L and upwards and 500 GT and upwards. 19.2 – all passenger ships only (as specified in text). 19.5 – all passenger ships and dry cargo ships of 80 m L and upwards. It is suggested that the intent of Reg. 19.5 is that damage control information should be supplied to passenger ships of all sizes but only to cargo ships of length 80 m and upwards to which the damage stability requirements of Part B-1 apply. This would exclude all cargo ships complying with the subdivision and damage stability regulations in other instruments (which have their own requirements). 10.2) Regulation 20 – Loading of [Passenger] Ships – it had been unanimously agreed by the CG in 2010 to remove the word “Passenger” from the title (see Q53) but this was not accepted in plenary at SLF 53 (ref. SLF 53/WP.6 para. 21) and the decision was deferred for further consideration by the CG. It will hopefully be resolved in Round 6 (see new discussion for Q53D below). If we finally agree to remove the word “passenger” from the title then we will need to specify which cargo ships the regulation applies to. It is suggested that easiest way to do this is, in Part B-1 reg. 4.1, to specify the general applicability of Parts B-2 and B-4 to passenger ships of all sizes and dry cargo ships (defined as proposed in 5.2 above) “except where expressly provided otherwise” (US proposal). We could then define “small dry cargo ships” as those with L between 24 and 80m but with gross tonnage greater than or equal to 500 tons (based on Part A reg. 3(a)(ii)). This is discussed further under 11) below. If there is no express provision in any title or regulation, the “default applicability” in Part B-2 and B-4 is “passenger ships of all sizes and dry cargo ships” (implying all “SOLAS” sizes but excluding tankers etc). One way of addressing these questions is indicated in the proposal at the end of this document. For information, note that Reg. 20.1 is taken directly from SOLAS90 Part B Reg. 8.7.4; Regs. 20.2 & 20.3 are from SOLAS90 Part B Reg. 9.1 and 9.2. All of these SOLAS90 regulations applied exclusively to passenger ships and there appears to be no equivalent provision in Part B-1 of SOLAS90 (cargo ships). If we do decide to keep “passenger” in the title we could perhaps rely on the IS 2008 Code to cover these provisions for cargo ships.

51 10/01/2012

10.3) Regulation 21 – Periodical operation and inspection of watertight doors, etc., in passenger ships – clearly applies only to passenger ships. 10.4) Regulation 22 – Prevention and control of water ingress, etc – you may recall that a proposal to add [“in passenger and cargo ships”] to the title was not accepted in plenary at SLF 53 (see Q56). The regulations clearly apply to both types and are largely derived from both SOLAS90 Reg. 15 (applicable to passenger ships) and Reg. 25-9 (cargo ships). The new “default applicability” could therefore apply here without the need for amending the title (see proposal at the end of this document). 10.4.1) Freeboard Deck / Bulkhead Deck. Reg. 2.1918 implies that the terms “freeboard deck” and “bulkhead deck” are interchangeable. Our comment on this is that if this regulation applies to both types the words “bulkhead deck” should perhaps be replaced by “bulkhead deck in passenger ships or freeboard deck in cargo ships”. This may result in the wording becoming rather clumsy. Alternatively an EN could be added – “the term ‘bulkhead deck’ in this regulation should be taken to mean ‘freeboard deck’ in cargo ships”. Alternatively, the application of each individual regulation may be understood in context e.g. Reg. 22.1 cross-refers to regulation 13.10 (which only applies to passenger ships). Can we therefore assume Reg. 22.1 only applies to passenger ships? Maybe use of “bulkhead deck” is deliberately used to indicate applicability to passenger ships only but the term “freeboard deck” never appears in this regulation so it is more likely that all the sub-paragraphs apply to both types of vessel? This is all a little confusing – but we have tried the method of repeatedly used “bulkhead deck in passenger ships or freeboard deck in cargo ships” in the proposal at the end of this document. Your comments are invited in Q6D, below. 10.5) Regulations 23 – 25 The application of the remaining regulations in Part B-4 is easily seen in the titles or in the regulations themselves (e.g. Reg. 25.2). The title of reg. 24 may change slightly (see Q56, below) if the USA proposal is accepted:- [Additional requirements measures for the] prevention and control of water ingress, etc., in cargo ships.

11) There is some uncertainty over the lower size limit for cargo ships. Chapter I Part A, Reg. 3 (a) (ii) states that the present regulations unless expressly provided otherwise do not apply to cargo ships of less than 500 gross tonnage. Also Part A Reg. 1(a) states that “Unless expressly provided otherwise, the present regulations apply only to ships engaged on international voyages.” The IS 2008 Code and SOLAS Part B-1 Reg. 5.1 only apply to cargo ships of length 24 m and upwards. It would seem that we should only apply the relevant parts of SOLAS to cargo ships of more than 500 gross tons AND 24 m L and upwards (or as expressly defined in each chapter)? That is, no cargo ship of less than 24 m in length but greater than 500 gross tons would need to comply with SOLAS Part B nor would a cargo ship of less than 500 tons but more than 24 m L. Do you agree? This distinction between dry cargo ships and “small” dry cargo could either be made in the definitions regulation (2) or at the beginning of revised reg. 4.1 (See Q6D, below). 12) We have made a series of proposals at the end of this document which we hope will cover all the issues above and hopefully satisfy most of your responses to round 4, which we now discuss in more detail.

52 10/01/2012

13) Discussion of Round 4 responses to Q6C 13.1) B-2 Applies to cargo vessels with L>24? Seven members were fully in favour. Germany has reservations about Reg. 9 for small ships. Vanuatu was opposed to “one size fits all” , expressing particular concern about applying reg. 9.8 to wide, shallow draught vessels under 80 m L. The US felt that it had already been decided at SLF 53 to apply Part B-2 to all cargo ships irrespective of length. The co-ordinator’s comment 6) above argues that the changes to Reg. 4.1 agreed at SLF 53 only applied to Part B-1 and that the applicability of Parts B2 – B4 still needs to be clarified (i.e the co-ordinators believe that the statement in WP.6 is not strictly correct). We hope the comments under 7), above, clarify the situation with respect to Reg. 9.8 (i.e. we must await the outcome of GOALDS, where new bottom damage statistics have been uncovered and a new probabilistic bottom damage method is being developed). This also applies to Vanuatu’s comment above. We agree with the US note regarding the origin of regs. 13-1 and 15-1 which we therefore think should only be applied to cargo ships of 80 m and upwards - that is, those subject to probabilistic damage analysis in Part B-1. On the whole, we also agree with the US that SOLAS2009 regs. 9, 10, 11, 12, 15, 16 and 16-1 were applied to all cargo ships (i.e. those >= 500 gross tons and with L = 24 m and upwards) in SOLAS90 although comparison is not always one-to-one. Some of these regulations were introduced into SOLAS90 at the same time as the cargo ship probabilistic regulations were introduced in 1992 (for L >= 100m only) but they relate to more general issues of subdivision and watertightness rather than probabilistic damage stability so we would agree with the US on the applicability. Denmark points out that the SOLAS90 DB requirements for cargo ships first appeared in old Reg. 12-1 in 1992, (at the same time as the cargo ship probabilistic regulations) but accept that they applied to all cargo ships. Denmark’s concern, echoing that of France and Germany, arises when reg. 9.8 is applied to smaller cargo ships, for which they feel it may be too onerous. This raises the question, which is the subject of the ToR:- “consider the validity of applying paragraph 8 pf SOLAS Reg. II-1/9 to smaller ships and, if necessary, suggest appropriate amendments.” Given that Reg. 9.8 may eventually be replaced by a new probabilistic regulation, this may be some time off yet, depending on the timetable of the GOALDS project. For now there seem to be at least two possibilities for “relaxing” the regulation:-

a) Reduce s from 1 to some lesser number, such as [0.9] or [0.5] or b) Re-introduce some “flexibility”, as suggested by Vanuatu.

For b) the basic requirements for double bottoms in cargo ships in Regs. 9.1 to 9.4 are taken from SOLAS90 Reg. 12-1. The co-ordinators once thought that the concerns expressed by some delegates over fitting a double bottom in cargo ships under 80 m L could be addressed by using the “escape clause” in Reg. 9.1, which states “as far as this is practicable”. This was quite clearly the case in SOLAS90 (reg. 12-1.1) – but it used to lead to disputes over what standard to apply if a double bottom was not fitted for reasons of “impracticality”. The difficulty of fitting double bottoms in smaller passenger ships was also recognised in SOLAS90 Reg. 12.1.1 where, for example, ships between 50 and 61 metres in length did not need to fit a double in the engine room. We also note that under SOLAS90 the requirements for DB’s in cargo ships only applied to ships constructed on or after 1st February 1992, which is the same date that the probabilistic cargo ships came into force for ships with L >= 100m

53 10/01/2012

However, it is quite clear that in its present form SOLAS 2009 reg. 9.6 permits no flexibility – either a double bottom is fitted or s must equal 1 following bottom damage to areas not fitted with a double bottom. This must have been the intention when the regulations were written. This leaves option a) - a reduction in “s” or not applying regs. 9.6, 9.7 and 9.8 to “small” cargo ships at all. This will be put to you in the questionnaire together with a request for alternative ideas (See Q6D, below). RINA’s clarifying comments on the possible length/tonnage conflict are noted – we hope that 11), above answers this concern. We note with interest their comment that the class rules only require a double bottom to be fitted in cargo ships > 500 ton gross which would support the case of those in favour of fitting double bottoms in smaller cargo ships of < 80 m L. Regarding DE – we would not have time to consult with them if we are to meet our current completion date of SLF54 but we can discuss this option further in the WG at SLF 54 if a time extension to this agenda item is agreed to. 13.2) B-2 only applies to cargo vessels with L>80? Two members fully agree. However, we tend to agree with RINA that we cannot say in general that all the regulations in B-2 apply exclusively to cargo ship of L = 80 metres and upwards as several provisions, such as collision bulkheads (Reg. 12), should be applied to smaller vessels (see item 13.1 above). In general we would argue that the L = 80 and above limit will apply to any regulations involving probabilistic damage stability calculations in Part B-1 either directly or indirectly (including in the latter category Reg. 13-1 and 15-1, as explained in item 13.1 above). Using this principle we would not necessarily agree with Spain that regs. 9.7 and 9.8 should only apply to L = 80 and upwards. Although si, as used in Reg. 9.8, is a probabilistic term it is only being used here as a deterministic criterion for controlling the subdivision of the DB and not as part of a full probabilistic analysis. This also applies, we suggest, to Japan’s argument. We feel that the calculation of si for bottom damages is completely separate from the full side damage stability analysis in Part B-1. However, there is the issue of modelling the ship for damage analysis (see 5.4.1 above). Your opinions are therefore sought in Q6D, (below). 13.3) Where should we clarify which cargo vessels must comply with B-2? The US, RINA and Germany all favour Reg. 4. Denmark says it should be in SOLAS, not the EN (as does Germany). Italy prefers the regulation title; the US would accept this as a second choice with detailed applicability in the regulations (EN should not be necessary). UK prefers direct references in the main regulation text. As discussed above, it may be necessary to use all the above options due to the complexity of the applicability, with some additional clarification of the titles – see new proposal below. 14) New Proposal Below is a proposal which we hope will clarify as many issues as possible without the use of footnotes or EN and also incorporating parts of the Annex to MSC 89/22/8. The highlighting colour code is as follows:- Q6 Original question numbers SOLAS Consolidated Edition 2009; Regulation text still under discussion Resolution MSC.281(85); EN text still under discussion SOLAS Consolidated Edition 2009; Changes to SOLAS agreed up to Round 4 Agreed EN Text Changes Changes to EN text agreed up to Round 4 SOLAS Consolidated Edition 2009; Text changes proposed in Round 6 Resolution MSC.281(85); EN changes proposed in Round 6

54 10/01/2012

The proposal relies on the applicability of Part B-1 being specified in regulation 4.1 with a text similar to that agreed at SLF 53 but eliminating the footnote (to conform with MSC 89/22/8) and the table in the EN. To simplify the text further, we propose to define the term “small dry cargo ship” in reg. 4.1 as being a cargo ship with 24 <= L <= 80 metres AND > 500 gross tons; a “dry cargo ship” is then a cargo ship of any size but expressly excluding tankers covered by MARPOL Annex 1, the IBC and IGC Codes. These definitions can either be placed in reg. 4.1 or under reg. 2. The applicability of Part B-2 is too diverse to cover in the same way as Part B-1 so we propose that in reg. 4.1 we make the statement, as proposed by the US, that it applies to “all passenger ships and dry cargo ships unless expressly stated otherwise”. This will mean clarifying the applicability of each regulation either in the text or the title. A new text has been prepared showing these proposed changes (at the end this document). Part B-3 only applies to passenger ships but part B-4 is similar to B-2 in diversity of application so will also be included in the proposals showing necessary clarifying amendments to the individual texts or titles. Please note that for simplicity the basis document identifying these changes will be the text of the current SOLAS 2009 edition including all the recent changes agreed at SLF 53 etc and those currently unresolved. The proposed changes to Reg. 4.1 (as already amended at SLF 53) to take into account the above suggestions and eliminate the footnote will then read as follows:-

PART B Subdivision and stability

Regulation 4 General

1 The [damage] stability requirements in parts B-1 through B-4 shall apply as follows, [where: “dry cargo ship” is a cargo ship of any size excluding oil tankers and vessels covered by the IBC and IGC Codes. “small dry cargo ship” is a dry cargo ship having 24 <= L <= 80 m. and gross tonnage >= 500.] [Coordinator’s Note: these definitions could alternatively appear in reg. 2]. 1 The damage stability requirements in parts B-1 through B-4 shall apply to cargo ships of 80 m in length (L) and upwards and to all passenger ships regardless of length but shall exclude those cargo ships which are shown to comply with subdivision and damage stability regulations in other instruments*


1 In Part B-1, .1 regulation 5 shall apply to passenger ships of all sizes and every cargo ship having a length (L) of 24 m and upwards (including oil tankers and vessels covered by MARPOL Annex 1, the IBC and IGC Codes). .2 regulation 5-1 shall apply to passenger ships of all sizes and every dry cargo ship having a length (L) of 24 m and upwards including those vessels which are shown to comply with stability regulations in [other] [the following] instruments[*] developed by the Organization[: but shall not apply to tankers covered by MARPOL Annex 1, the IBC and IGC Code.]

55 10/01/2012

• Guidelines for the design and construction of offshore supply vessels, 2006 (MSC.235(82)); (Resolution A.469(XII)); Q8 [Coordinator’s Note – the issue of whether this footnote should be deleted is still under discussion – see SLF54 Agenda Item 7].

• Code of Safety for Special Purpose Ships, 2008 (Resolution MSC.266(84); (Resolution A.534(13)) ; Q9

• Damage stability requirements of regulation 27 of the 1966 Load Lines Convention as applied in compliance with resolutions A.320(IX) and A.514(13), provided that in the case of cargo ships to which regulation 27(9) applies, main transverse watertight bulkheads, to be considered effective, are spaced according to paragraph (12)(f) of resolution A.320(IX), except ships intended for the carriage of deck cargo; and

• Damage stability requirements of regulation 27 of the 1988 Load Lines Protocol, except ships intended for the carriage of deck cargo.

• [MODU Code] Q10

Then EITHER: [ .3 the remaining regulations in Part B-1 shall apply to passenger ships of all sizes and, with the exception of regulations 8 and 8-1, to dry cargo ships [having a length (L) of 80 m and upwards] [ including combination carriers with type B freeboards as defined in SOLAS II-2/3.14 ] [but excluding small dry cargo ships.] [but they] [They] shall not apply to any vessels which are shown to comply with subdivision and damage stability regulations in [other] [the following] instruments[*] developed by the Organization. Q6

• Guidelines for the design and construction of offshore supply vessels, 2006 (MSC.235(82)); (Resolution A.469(XII)); Q8 [Coordinator’s Note – the issue of whether this footnote should be deleted is still under discussion – see SLF54 Agenda Item 7].

• Code of Safety for Special Purpose Ships, 2008 (Resolution MSC.266(84); (Resolution A.534(13)) ; Q9



• [MODU Code] Q10 ] OR (to avoid repeating the list of regulations): See Q6D to choose preference. [ .3 the remaining regulations in Part B-1 shall apply to passenger ships of all sizes and, with the exception of regulations 8 and 8-1, to dry cargo ships [having a length (L) of 80 m and upwards] [ including combination carriers with type B freeboards as defined in SOLAS II-2/3.14 ] [but excluding small dry cargo ships.] [but they] [They] shall not apply to any vessels which are shown to comply with subdivision and damage stability regulations in [other] [the] instruments[*] developed by the Organization [and listed in paragraph 1.2]. Q6

In Parts B-2 and B-4, the regulations shall apply to passenger ships of all sizes and dry cargo ships except where expressly provided otherwise. In Part B-3, the regulations shall apply to passenger ships of all sizes.

56 10/01/2012

___________________ * Cargo ships shown to comply with the following regulations may be excluded from the application of the damage stability regulations in part B-1:

* The following instruments and regulations contain stability requirements for cargo ships:- Q6 & 7

.1 Annex I to MARPOL 73/78, except combination carriers (as defined in SOLAS II-2/3.14) with type B freeboards are not excluded;

.2 International Bulk Chemical Code;

.3 International Gas Carrier Code;

.4 Guidelines for the design and construction of offshore supply vessels, 2006 (MSC.235(82)); (Resolution A.469(XII)); Q8 [Coordinator’s Note – the issue of whether this footnote should be deleted is still under discussion – see SLF54 Agenda Item 7].

.5 Code of Safety for Special Purpose Ships, 2008 (Resolution MSC.266(84); (Resolution A.534(13)) ; Q9

.6 Damage stability requirements of regulation 27 of the 1966 Load Lines Convention as applied in compliance with resolutions A.320(IX) and A.514(13), provided that in the case of cargo ships to which regulation 27(9) applies, main transverse watertight bulkheads, to be considered effective, are spaced according to paragraph (12)(f) of resolution A.320(IX), except ships intended for the carriage of deck cargo; and

.7 Damage stability requirements of regulation 27 of the 1988 Load Lines Protocol, except ships intended for the carriage of deck cargo.

[.8 MODU Code] Q10

A clean text of the above proposed modifications to reg. 4.1 together with all necessary modifications to the titles and/or text of the regulations in Parts B-2 - B-4 are shown at the end of this document for reference and use in the answering the following questions. Q6D (for round 6 questionnaire). In studying the above Round 6 discussion and the proposed changes to reg. 4.1 and the clarification of the application of Parts B-2 to B-4 at the end of this document, could you please answer the following:-

1) In studying 10.4.1, above and the new proposals at the end, do you think we should always use:

a) “bulkhead deck in passenger ships and freeboard deck in cargo ships” b) is there a better way (such as rely on reg. 2.19, for example)? 2) In the proposal in 11) above to define “dry cargo ship” and “small dry

cargo ship” do you think the definitions should be placed: a) in reg. 4.1 (as shown in the proposal at the end of this document) or b) in reg. 2? c) disagree with proposal altogether?

3) For “small” dry cargo ships discussed in the penultimate paragraph of 13.1

and the second paragraph of 13.2 above, do you: a) prefer to reduce the “s=1” requirement in reg. 9.8 or b) allow some flexibility of application or c) not apply reg. 9.6, 9.7 and 9.8 at all or d) have an alternative suggestion? 4) In general do you accept the new proposals at the end of this document for altering reg. 4.1 together with all the individual “applicability” changes shown thus [x] either: a) fully b) in part c) not at all? If your answer is b) please indicate which items you disagree with using [x] as

57 10/01/2012

the reference number and/or suggest improvements in the box below. If your answer is c) please indicate an alternative for clarifying the applicability of the regulations in part B-2 to B-4 (for example Table 4.1 in the EN). 5) Finally, if you agree to the changed text in reg. 4.1 would you prefer the list of regulations deemed equivalent to SOLAS 2009 in 4.1.2 to be: a) fully repeated in 4.1.3 or

b) simply referred to as “listed in paragraph 1.2” (to save undue repetition)? 1) a) or b)? If b) specify alternative

a): Japan, Norway, Italy, RoK, EC (seems appropriate), China.

b): Germany, UK (the matter is best addressed in Reg. 2.19.), France, Denmark (we can use the definition in reg. 2.19)

RINA (In 10.4.1 the implication is that the term bulkhead deck and freeboard deck are interchangeable. The ICLL 1966/1988, regulation 3(9)(a) states that:

“ The freeboard deck is normally the uppermost complete deck exposed to weather and sea, which has permanent means of closing all openings in the weather part thereof, and below which all openings in the sides of the ship are fitted with permanent means of watertight closing. “

This is not compatible with the definition of bulkhead deck in regulation 2.19. Furthermore the definition of freeboard deck is already provided in regulation 2.6 which states :

Freeboard deck is the deck as defined in the International Convention on Load Lines in force.

In regulation 2.19 we would propose to delete the last sentence “In a cargo ship the freeboard deck may be taken as the bulkhead deck. “) US (Option b Given the definition of bulkhead deck in reg 2.19 (and freeboard deck in reg 2.6), standardize all regulation text as follows: • If a regulation or a specific provision within a regulation only applies to a

cargo ship – use the term “freeboard deck”. • If a regulation or a specific provision within a regulation only applies to a

passenger ship or it applies to both passenger and cargo ships – use the term “bulkhead deck”. )

No comment: CLIA (cargo ship issue)

58 10/01/2012

2) a) b) c)? If c) specify alternative

a): Japan, RoK, China b): Norway, UK (a definition of this nature should be placed in Reg. 2), Denmark (to be consistent we should include all definitions in reg. 2.) c): RINA (Re para 11 in the discussion we would comment on the italic text as follows: 1. It would seem that we should only apply the relevant parts of SOLAS to cargo ships of more than 500 gross tons AND 24 m L and upwards (or as expressly defined in each chapter)? Comment: It is our understanding that the 24m L criteria is an ICLL requirement and does not directly influence the SOLAS requirements. 2. That is, no cargo ship of less than 24 m in length but greater than 500 gross tons would need to comply with SOLAS Part B. Comment: It is our understanding that ships with a gross tonnage of 500 or greater would have a length greater that 24 m. Therefore this is not a valid argument. Cargo ships over 500 gross tonnage and 80 metres, or over, in length are to comply with Reg 4 damage stability requirements. Cargo ships 500 gross tonnages and over, with a length less than 80 meters do not require to comply with these damage stability requirements. 3. nor would a cargo ship of less than 500 tons but more than 24 m L. Do you agree? Comment: Agreed. Chapter I Part A, Reg. 3 (a) (ii) states that the present regulations, unless expressly provided otherwise, do not apply to cargo ships of less than 500 gross tonnage.) Germany: (Proposal : Similar to the proposal for 4.1, but excluding 24<=L<= 80m. Add an additional sentence: If not further specified in the regulation (this is to cover Reg. 5 for L> 24,m).) US: (Option c (i.e. do not define “dry cargo ship” and “small dry cargo ship”) We disagree with the statement in 5.2 above that “none of the regulations in part B-2 apply to cargo ships carrying liquids (e.g. tankers, IBC, IGC)”. We believe there are numerous regulations in part B-2 that apply to tankers and there is no need for a “dry cargo ship” definition. We also do not support a definition for “small” cargo ships; we believe any length limits should be included directly in the regulation (e.g. as is currently done in reg 4.1 with the 80m limit)). France (§2 : Is it necessary to introduce a new definition for small cargo ships? It should be sufficient to keep the present wording saying : [ .3 the remaining regulations in Part B-1 shall apply to passenger ships of all sizes and, with the exception of regulations 8 and 8-1, to cargo ships having a length (L) of 80 m and upwards [ including combination carriers with type B freeboards as defined in SOLAS II-2/3.14 ] [but excluding small dry cargo ships.] [but they] [They] shall not apply to any vessels which are shown to comply with subdivision and damage stability regulations in [other] [the] instruments[*] developed by the Organization [and listed in paragraph 1.2] )

59 10/01/2012

3) a) b) c) or d)?

a): Italy, RoK (and b)), France, UK (prefers to have a minimum survivability requirement still be applied for “small” dry cargo ships, for this “s=0.5” which corresponds to about 2.0m survival in waves seems an adequate measure.), Denmark (or b) depending on further studies on very small dry cargo ships (tugs etc.) b): RoK (and a)), Denmark (or a) depending on further studies on very small dry cargo ships (tugs etc.), China. c): Japan (There were no requirements equivalent to Reg.9-6, 7, 8 in SOLAS90 for small cargo ships). US (Option c (i.e. not apply reg. 9.6, 9.7 and 9.8 to cargo ships less than 80m) If regulations 9.6 and 9.7 were revised to indicate “...or a cargo ship of 80m in length and upwards...”, there would still be a DB requirement for cargo ships less than 80m but it would not require the reg 9.8 damage stability assessment if the Administration determined that a full DB was not “practicable and compatible with the design and proper working of the ship”.) Note: We think this item is more appropriately addressed under regulation 9 than under regulation 4.) d): Norway (see comments below) RINA (see comments below) Germany (As smaller vessels tend to sink (particularly for LO-wells), s<1 is mostly not helpful for them. A reduced damage extent is required here, e.g not damaging the spaces adjacent to the parts without regular DB. But most of all, more detailed investigations about the effect of the regulation on smaller vessels are recommended.)

4) a) b) c)? If b) identify items [x] If c) specify alternative

a): RoK , UK (in full), China, Denmark (based on the assumption that the applicability of Reg. 9.8 for small dry cargo ships are further considered under Reg. 9 itself). b): Japan (Japan thinks that it is difficult to apply reg.12.2 to small dry cargo ships. (See also Q.39D-41D)), Norway (see comments below), France (see comments below) b) [10]: RINA (Noted that there is a majority however RINA‘s comment remains as previously stated). c): US (Option c; some items we do not agree with and the rest is too complicated. We will work on an alternative but not sure if it will be ready in time... Other Comments: Germany (To delete the footnote is appreciated by us, but there might be legal problems to do so, as some Codes have another legal status: For example: The SPS-Code is not mandatory.)

5) a) or b)? b): RINA, Norway, RoK, UK, Denmark, China. No comments: Japan N/A: US (do not agree to the changed text in reg 4.1)

60 10/01/2012

Comments / Alternative Proposals?:- RINA on 3): As the regulations currently stand, a double bottom is required for all passenger and cargo ships, other than tankers. In which case cargo ships, 500 gross tonnages and over, require to be provided with a double bottom. This is consistent with current classification practice. It follows that any dispensations or unusual arrangements in the double bottom should comply with the requirements of Regulation 9.8. The text in square brackets .[This does not apply to small dry cargo ships.] [ 3 ] in paragraphs 9.6 & 9.7 can be deleted as the double bottoms requirements are applicable to ships 500 gross tonnages and greater. It is noted that in 9.5 the Administration may permit a double bottom to be dispensed with if satisfied that the fitting of a double bottom would not be compatible with the design and proper working of the ship. We would consider that this is not consistent with the proposed EN which states in Regulation 9.1that the provision of a double bottom is intended to minimize the impact of flooding from a minor grounding. It is considered that where a ship is on short international voyages there is a higher probability of grounding and 9.5 should be reviewed.

It is noted that 9.9 states. “In case of large lower holds in passenger ships, the Administration may require an increased double bottom height of not more than B/10 or 3 m, whichever is less, measured from the keel line. Alternatively, bottom damages may be calculated for these areas, in accordance with paragraph 8, but assuming an increased vertical extent.” It is considered that this philosophy should be extended to cargo ships with large lower holds.

Norway on 3): Keep regulation as it is for all cargo vessels except oil tankers and those complying with IBC or IGC. Norway on 4): Delete “damage stability” in first sentence in Reg. 4.1. The application of part B-2 and B-4 should read: “In Parts B-2 and B-4, the regulations shall apply to passenger ships of all sizes and [dry] cargo ships except where expressly provided otherwise.” France on 4): For regulation 5-1, proposed formulation excludes tankers. The purpose seems to be that for such ships, damage stability is much dependant on loading of cargo tanks, and so minimum GM curves may not be produced. However, such curves may be produced with specific assumptions. An alternative solution may be not to exclude tankers, but to modify regulation 5-1 to give the possibility for some types of ships not to produce minimum GM curves. With proposed wording, application of remaining regulation in part B-1 is limited to dry cargo ship. During discussions to establish SOLAS 2009, this restriction had been deleted to cover tankers which may carry non dangerous cargo. So France would prefer to delete “dry” and reintroduce MARPOL, IBC code and IGC code in the list of instruments. France on 5): If it is said that regulation 5-1 applies to all cargo ships, is it necessary to specify that this include ships covered by listed instruments? It should be sufficient to have the list in paragraph 4.1.3.

Q6 (FOR DISCUSSIONS AT SLF 54) Co-ordinator’s Notes:- This question has become very complicated, involving changes that affect many regulations. We can only suggest that at SLF54 each proposed alteration is dealt with in turn at the particular point of occurrence. Also there are many opinions, meaning that decisions will have to be made by discussion rather than via a CG. To act as a start to these discussions, the co-ordinators have produced a draft version of the applicability of Reg. 4.1, which attempts to put the footnotes into the main text and eliminate the table in the EN to the footnotes whilst trying to incorporate as many of the points raised by members in the CG discussion as possible. Not easy! We apologise if we appear to have ignored some of your excellent comments but this was the only way we could think of trying to make progress.

61 10/01/2012

We have actually produced 2 alternative versions for revising the applicability of parts B-1 through B-4 in reg 4.1 for consideration at SLF 54. The first option excludes proposed new definitions of “dry cargo ship” and “small dry cargo ship”, and relies on the definitions in reg. 2. Also new paragraph 4.1.3 does not repeat the list of regulations in 4.1.2 making the paragraph shorter. Not all members agree with either proposal and the US have produced a paper which gives us another option to look at (ref. SLF 54/8/5) based on its concern that the coordinator’s proposals have removed oil tankers from the equation. Shown below are clean copies of the two options proposed by the coordinators and it is hoped that these can be compared with the new option from the US during the discussions at SLF 54:- [OPTION 1 - the shorter version; those accepting new Reg. 4.1 preferred the shorter version.] [Q6D(5)] [1 The stability requirements in parts B-1 through B-4 shall apply as follows. In Part B-1, .1 regulation 5 shall apply to passenger ships of all sizes and every cargo ship (including oil tankers and vessels covered by the IBC and IGC Codes). .2 regulation 5-1 shall apply to passenger ships of all sizes and every dry cargo ship including those vessels which are shown to comply with stability regulations in the following instruments developed by the Organization:

• Guidelines for the design and construction of offshore supply vessels, 2006 (MSC.235(82)); Q8 [See under Agenda Item 7 at SLF 54]

• Code of Safety for Special Purpose Ships, 2008(Resolution MSC.266(84); Q9



• [MODU Code] Q10 [Majority 8-4 in favour of adding to the list – accept?] .3 the remaining regulations in Part B-1 shall apply to passenger ships of all sizes and, with the exception of regulations 8 and 8-1, to dry cargo ships including combination carriers with type B freeboards as defined in SOLAS II-2/3.14 but excluding small dry cargo ships. They shall not apply to any vessels which are shown to comply with subdivision and damage stability regulations in the instruments developed by the Organization and listed in paragraph 1.2.

In Parts B-2 and B-4, the regulations shall apply to passenger ships of all sizes and dry cargo ships except where expressly provided otherwise. In Part B-3, the regulations shall apply to passenger ships of all sizes. ]

62 10/01/2012

[OPTION 2 - the longer version] [Q6D(5)] [1 The stability requirements in parts B-1 through B-4 shall apply as follows, where: Dry cargo ship is a cargo ship of any size but excluding oil tankers and vessels covered by the IBC and IGC Codes. Small dry cargo ship is a dry cargo ship with 24<= L<= 80 m. and gross tonnage >= 500. In Part B-1, .1 regulation 5 shall apply to passenger ships of all sizes and every cargo ship (including oil tankers and vessels covered by the IBC and IGC Codes). .2 regulation 5-1 shall apply to passenger ships of all sizes and every dry cargo ship including those vessels which are shown to comply with stability regulations in the following instruments developed by the Organization:

• Guidelines for the design and construction of offshore supply vessels, 2006 (MSC.235(82)); Q8 [See under Agenda Item 7 at SLF 54]




• [MODU Code] Q10 [Majority 8-4 in favour of adding to the list – accept?]

.3 the remaining regulations in Part B-1 shall apply to passenger ships of all sizes and, with the exception of regulations 8 and 8-1, to dry cargo ships including combination carriers with type B freeboards as defined in SOLAS II-2/3.14 but excluding small dry cargo ships. They shall not apply to any vessels which are shown to comply with subdivision and damage stability regulations in the following instruments developed by the Organization:

• Guidelines for the design and construction of offshore supply vessels, 2006 (MSC.235(82)); Q8




• [MODU Code] Q10

In Parts B-2 and B-4, the regulations shall apply to passenger ships of all sizes and dry cargo ships except where expressly provided otherwise. In Part B-3, the regulations shall apply to passenger ships of all sizes.]

63 10/01/2012

[For either of the above options the old footnote to reg. 4.1 may be deleted]:-

_________________________

* Cargo ships shown to comply with the following regulations may be excluded from the application of part B-1: .1 Annex I to MARPOL 73/78, except combination carriers (as defined in SOLAS II-2/3.14)

with type B freeboards are not excluded; .2 International Bulk Chemical Code; .3 International Gas Carrier Code; .4 Guidelines for the design and construction of offshore supply vessels (resolution

A.469(XII)); .5 Code of Safety for Special Purpose Ships (resolution A.534(13), as amended); .6 Damage stability requirements of regulation 27 of the 1966 Load Lines Convention as

applied in compliance with resolutions A.320(IX) and A.514(13), provided that in the case of cargo ships to which regulation 27(9) applies, main transverse watertight bulkheads, to be considered effective, are spaced according to paragraph (12)(f) of resolution A.320(IX), except ships intended for the carriage of deck cargo; and


RECOMMEND THE ABOVE BE DISCUSSED AT SLF 54 ALONG WITH 54/8/5.

_____________________ * Cargo ships shown to comply with the following regulations may be excluded from the application of the damage stability regulations in part B-1: [Coordinator’s Note – the reasons for the proposed change (underlined) are given in SLF 52/17/4, Norway, see below. At SLF 53 it was finally agreed to make the following change to the introductory sentence to the footnote (see Q6B):-]

* The following instruments and regulations contain stability requirements for cargo ships:- Proposed change in the footnote to Regulation 4 (ref. SLF 52/17/4 - Norway) The introduction in the footnote seems to be in conflict with the intention that regulations 5 and 5-1 in part B-1 applies to all ships regardless of type. It is proposed that this footnote be amended to read:-


R4.1 heading of footnote (Applicability of the damage stability requirement) Q7. Do you agree with the underlined addition to the footnote heading? Yes

China, Finland, Germany, Japan, MI, Norway, Italy, Spain, Denmark, UK, US, Sweden

No

Comments?:- Spain: See comments to Q6. Round 1 Discussion: All except CLIA are in favour (cargo ship issues are not commented upon by CLIA). Spain’s comments in Q6 were discussed above.

CONCLUDED - PROPOSAL ACCEPTED BUT NOTE POSSIBLE FURTHER AMENDMENTS (SEE Q10) OR NEW ALTERNATIVE (SEE Q6)

64 10/01/2012

Round 2 Discussion: Must await decisions at SLF on Q6B which will also affect Q10.

Any Further Comments?:- SLF 53 WG3 agreed to the proposal in Q6B:- * [The following instruments and regulations contain stability requirements for cargo ships:-]

Q7. At SLF 54 - see Q6D(4) for this issue.

.1 Annex I to MARPOL 73/78, except combination carriers (as defined in SOLAS II-2/3.14)

with type B freeboards are not excluded; .2 International Bulk Chemical Code; .3 International Gas Carrier Code; .4 Guidelines for the design and construction of offshore supply vessels, 2006

(MSC.235(82)); (Resolution A.469(XII)); [Coordinator’s Note - this resolution is still quoted in the S2009 consolidated edition – should the reference be changed to MSC.235(82)? UK paper MSC 85/23/1 proposes that this footnote be deleted altogether (see below)].

PLEASE NOTE THAT THIS ISSUE WILL APPEAR UNDER AGENDA ITEM 12 UK PAPER (MSC 85/23/1) proposes to delete footnote .4 and modify others. This paper was considered at MSC85 in November 2008 under the heading “Subdivision standards for cargo ships” with the following outcome (Ref. MSC 85/26):- 23.32 The Committee considered document MSC 85/23/1 (United Kingdom), proposing to review the application of subdivision standards for cargo ships referred to in the footnote to SOLAS regulation II-1/4, deemed equivalent to part B-1 of SOLAS chapter II-1 to ensure consistency of approach in the application of subdivision standards for cargo ships, and agreed to include, in the work programme of the SLF Sub-Committee and the provisional agenda for SLF 52, a high-priority item on “Subdivision standards for cargo ships”, with a target completion date of 2011. At SLF 52 it was decided as follows (Ref. SLF 52/WP.5 paragraphs 14.1 and 14.2):- Having considered document MSC 85/23/1 (UK), proposing to consider deleting footnote .4 to SOLAS regulation II-1/4 and updating references to the remaining footnotes as necessary, the Sub-Committee noted the view of the delegation of Germany that footnotes .6 and .7 should also be considered in the context of this item and invited Member Governments and international organizations to submit their views to the CG for consideration and advice to the Sub-Committee, as appropriate.

R4.1 Footnote .4 (Change ref. for OSV regs?) Q8. Do you think (a) That the reference to A.469(XII) should be changed to MSC.235(82)? OR (b) That this class of vessel should now comply with SOLAS 2009 and the

footnote removed altogether; see MSC 85/23/1? OR (c) Question (b) needs to be considered separately by the CG? (See also Q10)? Please state preference (a), (b) or (c) / comments:- Option (a): China, Norway, Italy, Denmark Option (b): UK Option (c): Finland, Germany, Norway, Spain, US Comments: China: For (b), It’s not the right time to draw conclusions at this stage as no research report has been submitted to this CG or IMO regarding the influence of upgrading the subdivision standard

65 10/01/2012

from A.469(XII) and MSC.235(82) to SOLAS 2009. For ( c) , if the CG decides that ( c ) is the outcome, then such research should be done Japan: No comments Norway: For (c) This issue merits a separate discussion. The reference should in all cases be MSC.235(82) since the revised chapter applies to new ships. Spain: If maintained in this list, the reference to A.469 (XII) should be changed to MSC.235 (82). Regarding document MSC 85/23/1, in general terms, we agree with the proposal to delete the footnote. But, we do not forget that MSC.235 (82) is considered a “standard of safety equivalent to the relevant requirements of the International Convention for the Safety of Life at Sea, 1974, as amended”. In other words, it is an equivalent standard, not a complementary standard. That is why, we think that for ships of 80 m in length (L) and upwards, the subdivision should comply with the standard requested by MSC.235 (82) or the standard requested by Chapter II-1, Part B-1 standard (or and not and, - the word ‘and’ is suggested in MSC 85/23/1- ). If demonstrated that MSC.235 (82) subdivision standard is not appropriate for an offshore supply vessel with 80 m in length (L) and upwards, the footnote should be removed, and then the applicable damage stability standard will be only the S-2009 standard. Alternatively, the Guidelines for the design and construction of offshore supply vessels (MSC.235 (82)) could be revised again according the latest research and knowledge in relation to damage stability. Denmark: Comments:

(a) but OVS’s with a length greater than 100 m must comply with the probabilistic damage stability requirements of SOLAS Part B-1 (MSC.235(82) only applicable to vessels with a length of less than 100 m)

(b) we should not consider applying SOLAS 2009 unless it can be shown that it is of a higher or equivalent standard to MSC.235(82). There is a question of whether the damage statistics also apply. We also once again have an issue of a deterministic regulation ensuring minor damages are survived and with more stringent compliance criteria than S2009.

US: We support option (c). In regard to the issue of deleting footnote .4, we are sponsoring a comparative study and will provide this information to the SDS CG if completed in time. Note: MSC.235(82) superseded A.469(XII) on 1 December 2006, so the reference should be changed irrespective of any additional consideration of footnote .4. Sweden: No comments. Round 1 Discussion: All agree that as a first step the footnote reference to A.469 should be changed to MSC.235(82) (if the footnote is retained). Regarding the UK’s proposal to delete footnote .4 altogether, there is a strong feeling among those who responded that more research and discussion is needed to determine the degree of equivalence between probabilistic S2009 and deterministic MSC.235 before making a decision. The UK has carried out some in-house work indicating that S2009 may be more onerous but would nonetheless welcome the results from the comparative study underway in the US as rather few ships have to date been cross-checked and resources for undertaking any further necessary work are limited. Denmark’s comments are noted. Regarding point (a), whilst it is true that MSC.235(82) only applies to OSV’s up to 100 m in length there is nothing to say that vessels longer than this must comply with SOLAS – para 1.1.1 states that “the intact and damage stability of a vessel of more than 100 m in length should be to the satisfaction of the Administration”. Denmark’s point (b) that

66 10/01/2012

S2009 may not be a higher standard is also noted which is why more comparative studies are needed to see if there are loopholes in S2009 which could result in a lower safety level. Spain’s comments confirm the general view that more work is needed to determine whether MSC.235 is an appropriate standard to use as an equivalent to S2009. If MSC.235 is adequate Spain does not agree that OSV’s > L=80 m should comply with both S2009 B-1 and A.469 (MSC.235) as proposed by the UK – it should be “either/or”. If necessary, MSC.235 could be revised again to ensure that no safety loopholes exist in comparison with S2009. Proposed Action: Given the current state of knowledge we cannot be certain that deleting footnote .4 (thereby requiring new OSV’s of L > 80m to comply with S2009 Part B-1) will necessarily remove all safety loopholes. It may remove some relating to penetration depth but introduce others which we can only discover by carrying out some comparative research. The US study may not be ready in time for full discussion by this CG, therefore we can only advise the SLF sub-committee at this stage to extend the deadline on this item to allow more time for the necessary research on the comparison between MSC.235 and S2009 Part B-1 to be undertaken, inviting members to contribute as appropriate. Q8A. Do you agree with the Proposed Action, above? Yes

MI, Germany, China, Finland, US, Italy, Japan, RINA (with comment), France (with comment), Norway, UK, Sweden, Denmark

No

Comments / Alternative Proposals?:- China: China has just completed an initial calculation today (2010-09-17) on a simulation design of offshore supply vessel(OSV) with L = 95.03 m. In consideration of multifunction design for large size of OSV will usually certify more than 12 special personnel and the vessel will be governed by 2008 SPS Code, which is out of the scope of this matter, only single function of transporting materials to drilling units is considered. The main difference for the two subdivision designs is that the width of wing compartments are 800mm (see red dash line in figure 1 below) and 1900mm respectively. The purpose of the study is to assess how the offshore supply vessel over 80m can comply with the probabilistic subdivision standard of SOLAS 2009. It is found for both designs, when the deck cargo respectively increase to the maximum of 2750t and 2900t respectively, where the weather criterion of 2008 IS Code reaches marginal 1.0, both MSC.235(82) and SOLAS 2009 are satisfied. Therefore the anticipated adverse influence upon the subdivision design of this vessel induced by SOLAS 2009 has not been observed. For this vessel, the limiting criterion is neither MSC.235(82) nor SOLAS 2009 but IMO weather criterion. It suggests that for OSV of large size SOLAS 2009 is possible to be complied with. In addition, it is noted that the stability criteria of MSC.235(82) is more stringent than SOLAS 2009 for cargo ships more in aspect of positive range of GZ curve, for MSC.235(82), the positive range shall not be less than 20 deg, which in most cases is a limiting criterion for offshore supply vessel. Summary information please see table 1 and table 2 below. Due to time reason, detailed information may be seen at SLF 53.

67 10/01/2012

Figure 1 General arrangement of subdivision Table 1 Principal particulars

Length between perpendiculars LBP 92.9 m Length as defined in LL Convention L 95.03 m

Subdivision length Ls 103.646 m Moulded breadth B 23.4 m Moulded depth D 9.6 m Summer load line draft ds 7.4 m Displacement Disp 12794.0 t Deadweight Dwt 5978.0 t

Table 2 Summary of stability calculation Design No.1

�800mm width of wing Design No.1

�1900mm width of wing

68 10/01/2012

compartment� compartment� Summer load line draft 7.4 m 7.4 m Maximum deck load 2750 t 2900 t IMO weather criterion 1.066 1.078 Positive range of GZ curve of MSC.235(82)

23.20 23.30

Attained index A of SOLAS 2009 (trim of 2%Ls�

A = 0.50939 R = 0.49931

A = 0.51185 R = 0.49931

Bottom damage stability of Regulation SOLAS II-1/9

Satisfied Satisfied

End of China’s Comments.

RINA: While agreeing with the proposed action we would recommend that as MSC.235(82) supersedes Res. A 469(XII) then the footnote should refer to MSC.235(82). France: Damage stability requirement of resolution MSC.235(82) are not equivalent to SOLAS 2009 and are applicable to ships of less than 80m. CLIA: Not directly relevant to CLIA. Round 2 Discussion: It is agreed that if we retain footnote .4 then it needs to be updated to refer to MSC.235(82) rather than resolution A.469(XII). For a full discussion of the proposed removal of the footnote .4, please see the report of the CG to SLF 53 (ref. 53/12). Also refer to SLF 53/12, Q6 and Q10 for discussion of the issues relating to footnotes .6 and .7 and proposed addition of the MODU Code to the “excluded” list. For Q8, we hope that the S-C will agree to our request for an extension to the deadline of Agenda Item 12 to allow time for more research to be carried out. We are very grateful to China for their submission (SLF 53/INF.7) and we hope that the USA will be able to proceed with their work along similar lines. We also think it would be sensible to move this item from AI 12 to AI 14 (SOLAS updates) for conclusion at SLF 54 and we hope the S-C agrees with this proposal (ref SLF 53/12 paragraph 25.2). From China’s study on a ship with L = 92.9 m., it would seem that safety would be improved by combining the deterministic minor damage criteria in MSC.235 with probabilistic SOLAS 2009 for deeper penetration damages. As the UK pointed out in their original paper, an OSV can at present comply with the damage stability requirements of MSC.235 without having any subdivision inboard of 760 mm other than a collision bulkhead, after peak bulkhead and bulkheads enclosing the machinery space. The deterministic minor damage regulations in S2009 currently only apply to passenger ships and have a similar penetration depth to MSC.235 (0.05B but not less than 0.75 m for 36 pax). For the ship in China’s paper 0.05B equates to 1.17 m. As France points out, MSC.235 applies to OSV’s having 24 < L < 100 m whereas the probabilistic S2009 regulations only apply to cargo ships with L >= 80 m. The original UK proposal was to apply A469 only for L < 80 m, a combination of A469 and part B-1 for 80 < L < 100 m and a combination of part B-1 with enhanced A469 for vessels > 100 m. Denmark previously pointed out that the damage statistics used in the S2009 formulations do not cover many vessels < 80 m. long. For these reasons it may not be appropriate to use S2009 in its present form but to consider improving MSC.235 to account for damage penetration >760 mm and to allow for L > 100m. This would satisfy Spain’s objection to combining the two sets of regulations for vessels with L > 80 as proposed in the UK paper. Q8B (for SLF53 S-C and WG). If the S-C agrees to extend the deadline for considering footnote .4 (ref. SLF 53/12 para. 25.2) , do you think that we should then concentrate on improving the safety level of all OSV’s with L>24 m to account for deeper penetration damages by amending MSC.235 only or by combining MSC.235 (amended as appropriate) with S2009 Part B-1, as proposed by the UK in MSC 85/23/1 paragraph 2.6?

69 10/01/2012

Amend MSC.235 only?

France (added in round 4 questionnaire).

Combine Part B-1 with MSC.235 (amended as necessary)?

Comments? This issue was discussed at SLF 53 and it was agreed to wait for the results of further research on the equivalence of MSC.235 and SOLAS 2009 Part B-1 as applied to OSV’s. TOR .1 and .2 for SLF 54 Agenda Item 7 (Cargo Ship Subdivision) now refer. Note for Round 4 questionnaire:- No questions or comments are needed at this stage – we will deal with this item under SLF 54 AI 7 and in the meantime await the results of any research being carried out.

Q8. FOR SLF54:

See SDS CG report SLF 54/7 on the separate agenda item. Also papers SLF 54/7/1 and /INF.2 from US and SLF 53/INF.7 from China. AWAIT OUTCOME OF AI7 BEFORE UPDATING SOLAS R4.1. MEANTIME THE REFERENCE TO THE OSV REGS (A469) CAN BE UPDATED to 2006 (MSC.235(82)).

.5 Code of Safety for Special Purpose Ships, 2008 (Resolution MSC.266(84); (Resolution A.534(13)) ; [Coordinator’s Note - this Resolution is still quoted in the S2009 consolidated edition].

R4.1 ftn .5 (Change reference for SPS?) Q9. Should the reference to A.534 be changed to MSC.266(84)? Yes

China, Finland, Germany, Japan, MI, Norway, Spain, Denmark, UK, US, Sweden

No

Comments?:- Finland: Special purpose Ships have to fulfil Part B-1. Special reductions in respect of N in reg. 6 Norway: Res. MSC.266(84) was approved before the revised chapter entered into force. Consequently the footnote must refer to revised Code. Round 1 Discussion: Finland and Norway’s comments are noted. No opposing views were received.

CONCLUDED - PROPOSAL ACCEPTED BY CG. AWAIT APPROVAL BY SUB-COMMITTEE AT SLF 53

(See SLF 53/14 para 12.2). Accepted at SLF 53

Q9. AT SLF 54, RECOMMEND REFERENCE BE CHANGED AS AGREED AT SLF 53 .6 Damage stability requirements of regulation 27 of the 1966 Load Lines Convention as

applied in compliance with resolutions A.320(IX) and A.514(13), provided that in the case of cargo ships to which regulation 27(9) applies, main transverse watertight bulkheads, to be considered effective, are spaced according to paragraph (12)(f) of resolution A.320(IX), except ships intended for the carriage of deck cargo; and

70 10/01/2012


[Coordinator’s Note - Germany proposed (ref. SLF 52/19 paragraph 14.2) that the inclusion of footnotes .6 and .7 should also be re-considered in the context of the UK paper MSC 85/23/1 (see below) and proposals should be submitted to this CG].

R4.1 ftn .6 and .7; (re-consider?; add MODU Code to list of equivalents to S2009?) Q10. Are there any specific reasons for re-considering footnotes .6 and .7 and/or

any new proposals? Should the CG consider this issue separately alongside the UK proposal to remove footnote .4 (see also Q8)?

Comments / Proposals?:- China: No, footnotes .6 and .7 should be kept. Finland: Removal of footnotes .6 and .7 should be considered by the CG. Japan: Does not support re-opening this issue. MI: Retain footnotes 6 and 7, no valid reason for deletion submitted for consideration. Norway: These footnotes should be considered separately. It should be noted that these regulations will not generate data suitable for a limit curve in accordance with regulation 5-1.2.1. Spain: We can consider also a revision of these footnotes (.6 and .7). Anyway, we need strong technical reasons to justify the removal of footnotes .6 and .7. We suggest circulating between the working group members the available technical studies in relation to this particular matter. In any case, we suggest considering these footnotes separately, the design and configuration of the vessels affected by footnotes .6 and .7 is very different than the affected by footnote .4. This matter should be further studied. Denmark: No. US: Although we are not opposed to re-considering the validity of these footnotes, we think this should be done separately from footnote .4. It would be useful to know the specific concerns associated with footnotes .6 and .7. Sweden: Does not have any specific reasons to re-consider the footnotes. Round 1 Discussion: We believe the suggestion for updating some of the remaining footnotes, specifically .6. and .7, originally came from paragraphs 2.7 to 2.9 in the UK paper MSC 85/23/1 (quoted below for easy reference), supported by Germany at SLF 52. We apologize for not making this clearer in Round 1:- 2.7 A further consideration of significance is that the footnotes to regulation 4 refer to “regulations” meaning IMO instruments, but only .6 and .7 refer to specific regulation numbers. This may be a reflection of the fact that whilst ICLL applies to virtually all SOLAS ships, regulation 27 is merely an option within it. However it may be argued that, for example, (footnote) .5 is only available to ships which comply fully with all Special Purpose Ship provisions. It may also be noted that these equivalences are related to SOLAS part B-1 which includes standards for openings in watertight divisions (regulations 25-9 and 25-10 in the soon to be superseded version). The new part B-1 does not contain such regulations, which have been moved to part B-2 and therefore will no longer be part of the equivalence. 2.8 Noting 2.7 above, it might be considered appropriate to include the MODU Code in the list

71 10/01/2012

of regulations deemed to confer equivalence to part B-1. Scope of the proposal 3 To consider the footnotes to regulation 4 of part B of chapter II-1, as adopted by resolution MSC.216(82). To consider deleting footnote .4, and to update references to the remaining footnotes as necessary. This will potentially widen the application of part B-1, for certain ship types. We have already agreed under Q7 above to clarify the heading of the footnote by adding the words “the damage stability regulations in”. We could further clarify it by adding “instruments and” between “following” and “regulations” to read:- “Cargo ships shown to comply with the following [instruments and] regulations may be excluded from the application of [the damage stability regulations] in part B-1”. Alternatively it may have been the intention only to reference the equivalence to the damage stability regulations within the various instruments, in which case we could change the wording to:- “Cargo ships shown to comply with the [damage stability regulations within] the following [regulations] may be excluded from the application of [the damage stability regulations] in part B-1”. This would still leave open the question of whether or note to include the MODU Code in the list of instruments which are deemed to confer equivalence to part B-1. Q10A. Most members in answering Round 1 expressed little enthusiasm for changing the remaining footnotes as proposed in MSC 85/23/1. Is this still the case in the light of the above discussion or do you think some clarifying changes may be needed as proposed, including the addition of the MODU Code to the list? Yes, changes needed

Finland, US, Japan, RINA, France (with comment), UK, Denmark

No changes

MI, China, Norway, Sweden

Comments / Alternative Proposals / MODU Code?:- MI: Remain of the opinion that the matter of equivalence should be considered as a separate issue. US: We support adding the MODU Code to the list. We also support the following proposed change: “Cargo ships shown to comply with the following [instruments and] regulations may be excluded from the application of [the damage stability regulations] in part B-1”. Japan: Japan does not have a strong position. RINA: As regulation 4 already includes the statement “.....comply with subdivision and damage stability regulations in other instruments”, we would propose that the footnote should be amended as follows:

“Cargo ships shown to comply with the following subdivision and damage stability regulations in other instruments may be excluded from the application of Part B-1”.

France: Ships covered by MODU code cannot be treated by SOLAS 2009, so MODU code should be added to the list. CLIA: Not directly relevant to CLIA. Round 2 Discussion: For a full discussion of the issues relating to footnotes .6 and .7 and the addition of the MODU Code to the list of instruments considered to provide equivalence to S2009

72 10/01/2012

Part B-1 see the CG report to SLF 53 (SLF 53/12 paragraph 24). In order to improve the clarity of the opening part of the footnote to regulation 4.1 in accordance with comments made under paragraph 2.7 of the UK paper MSC 85/23/1 we would like to propose that the S-C consider adopting one of the four alternative texts below, bearing in mind that the CG has already agreed to change the sentence as underlined (see Q7):-


Alternative 1: “Cargo ships shown to comply with the following [instruments and] regulations may be excluded from the application of [the damage stability regulations] in part B-1”. Alternative 2: “Cargo ships shown to comply with the [damage stability regulations within] the following [regulations] may be excluded from the application of [the damage stability regulations] in part B-1”.

Alternative 3: “Cargo ships shown to comply with the following [subdivision and damage stability] regulations [in other instruments] may be excluded from the application of [the damage stability regulations] in Part B-1”.

Alternative 4 (see Q6 for background): “The following instruments and regulations contain stability requirements for cargo ships”:- In addition, there is some support within the CG for adding the MODU Code to the list of instruments deemed to provide equivalence to Part B-1. This could be added as footnote .8. Q10B (for SLF53 S-C and WG). Please state which of the above 4 alternatives you prefer to clarify the opening sentence of the footnote to regulation 4.1. (or propose another). Also please state whether you think that the MODU Code should be added to the list of instruments in the footnote. (Ref. SLF 53/12 para. 24). Prefer Alt 1

Alt 2

Alt 3

Alt 4

Other proposal?

Co-ordinator’s Note after round 4 responses: Denmark included the following alternative in the R4 questionnaire: “Cargo ships shown to comply with the subdivision and damage stability requirements of the following instruments and regulations may be excluded from the application of the damage stability regulations in Part B-1”.

Add MODU Code?

Comments?:- Alternative 4 (“The following instruments and regulations contain stability requirements for cargo ships”) was finally accepted by WG3 at SLF 53 and will be used in conjunction with the agreed revised text for regulation 4.1 (see Q6B). However, Germany is to submit a paper to MSC 89 on the legal status of the footnotes in general as it was felt that such important text should preferably form part of the regulation. So it is possible that regulation 4.1 may need to be looked at again after MSC 89. As we recall, the group was divided on the inclusion of the MODU Code on the list of cargo ships not needing to comply with SOLAS Ch II-1

73 10/01/2012

Part B-1. Also there was not unanimous support for deleting the Table in the EN for Regulation 4.1 (see below) as some felt it was still useful. Therefore the issue of the footnotes, MODU Code and the EN Table will be re-opened for discussion in the CG before SLF 54. Q10C (for Round 4 Questionnaire). If we set aside the question of further changes to the footnote/regulation and inclusion of the table in the EN (see also Q6C), until we hear from MSC 89 in May 2011 (ref paper MSC 89/22/8), could we in the meantime again ask for your opinion on whether the MODU Code should be added to the list of regulations/instruments deemed to be equivalent to SOLAS 2009 Part B-1 in the footnote to Reg. 4.1? We may have to accept a majority vote. Add MODU Code?

Yes: Vanuatu, US, Finland, Italy, UK, France, MI (remain of the opinion that the MODU Code should be added to the list), Spain No: Norway, RINA, Denmark (with comments), Germany

Comments?:- Vanuatu: Please see our previous comment on absolutism; the geometry (and various design constraints) of MODUs, whether semi-submersible or jack-up do not lend themselves to readily accept deep sea vessel definitions with respect to rule application(s). US: For MODUs, we believe the IMO MODU Code provides an “appropriate alternative standard” and should be accepted in this context. We do not think this item should be viewed in terms of strict “equivalency”. RINA: With respect to stability issues the MODU Code is a standalone document, with no reference to the SOLAS Convention. This also the case with the HSC 2000 Code. It is considered that if a reference should be made to the SOLAS stability requirements then this should be made from the MODU Code to the applicable SOLAS regulations. Denmark: The MODU Code damage stability standard is not equivalent to SOLAS Part B-1 as it only includes limited damage penetration. Italy: MSC89 OUTCOME: Application of SOLAS subdivision standards to cargo ships. 22.32 The Committee considered document MSC 89/22/8 (Germany and United Kingdom), proposing to develop amendments to SOLAS regulation II-1/4 in order to clarify the application of SOLAS subdivision standards to cargo ships which are complying with the subdivision standards of other IMO instruments, and agreed to include, in the 2012-2013 biennial agenda of the SLF Sub-Committee and the provisional agenda for SLF 54, a planned output on "Development of amendments to SOLAS regulation II-1/4 concerning subdivision standards for cargo ships", with a target completion year of 2013. Coordinators’ Note: Thanks for latest update from MSC, Italy. Round 6 Discussion: As we are in the process of removing the footnote to Reg. 4.1 and the table in the EN (see Q6 above) we now only need to decide whether the MODU Code should be added to the list of regulations in revised reg. 4.1.2 and 4.1.3. There is a majority of 8 to 4 in favour of adding the MODU Code to the list so our inclination is to accept the majority verdict and propose this change to the SLF sub-committee. We hear the counter arguments from Denmark and RINA but we feel that the MODU Code is a highly specialized set of regulations subject to continuous scrutiny at IMO (we are now in the third re-issue (2009)) and that if there are any deficiencies in the damage stability content (as Denmark states) these would be better addressed within the Code rather than replacing the damage stability section with S2009; a similar argument would apply to RINA’s comments. We remember in the SLF 53 WG that concern was expressed by some members that if we put the MODU Code on the list certain owners might try to classify their vessels as MODU’s in order to avoid complying with SOLAS2009 (for example to avoid fitting a DB). However, we feel that it is the responsibility of each Administration to adjudicate, based on the clear and specific definition in the MODU Code:- 1.3.40. Mobile offshore drilling unit (MODU) or unit is a vessel capable of engaging in drilling operations for the exploration for or exploitation of resources beneath the seabed such as liquid or gaseous hydrocarbons,

74 10/01/2012

sulphur or salt.

CONCLUDED PROPOSAL TO ADD “MODU CODE” TO PROPOSED NEW REGULATIONS 4.1.2

AND 4.1.3 ACCEPTED BY CG ON A MAJORITY VERDICT.

AWAIT APPROVAL BY SUB-COMMITTEE AT SLF 54.

Are there any further comments / objections to this decision? Poland: I support to add MODU CODE to proposed new regulations. US: Fully agree with this conclusion. China: No comments.

Q10.

AT SLF 54 - RECOMMEND THAT MODU CODE BE ADDED TO THE LIST OF REGULATIONS DEEMED EQUIVALENT TO S2009 IN R4.1

[Regulation 4.1 [Coordinator’s Note, for the future of this EN and table see Q6D & Q10] Cargo ships complying with the subdivision and damage stability regulations of other IMO instruments listed in the footnote are not required to comply with part B-1, regulations 6, 7, 7-1, 7-2 and 7-3 but must comply with the regulations indicated in the table below.

Regulation Applies Part B-1

5 X 5-1 X

Part B-2 9 X(1)

10 X 11 X 12 X

13-1 X 15 X

15-1 X 16 X

16-1 X

Part B-4 19 X

22 X 24 X 25 X(2)

(1)

Only applies to cargo ships other than tankers. (2)

Only applies to single hold cargo ships other than bulk carriers. ]

75 10/01/2012

Regulation 4.1 (ref. SLF 52/17/6 - Norway) Include regulation 20 in the table listing applicable regulations found under Regulation 4.1 in the EN. [Co-ordinator’s Note:- changes to Reg. 4.1 are to be the subject of a new Agenda Item (13) at SLF 54, completion 2013, so we may pass on any deliberations via a paper to IMO.] Q11. Do you agree that Reg. 20 (loading of [passenger] ships) should be added

to the above table in the EN, as proposed? Yes

China, Finland, Germany, Japan, MI, Norway, Italy, Spain (see comments), Denmark, UK, US, Sweden

No

Comments?:- Finland: Title to be changed. “Passenger” to be removed. CLIA: ? Not clear what this is doing. Italy: Agreed, but the title should be changed removing the word “passenger” in square bracket. Spain: To be considered in combination with Q53. To include this reference in this table, the term ‘passenger ship’ should be deleted. In any case, in our opinion, from stability purposes, the relevant regulation to be included in the table is only 20.1, not 20.2. Explanatory note: Regulation 20.2 is related to pollution (segregation of oil and water ballast). All ‘SOLAS’ cargo ships (more than 500 GT) are covered by MARPOL, Annex I, regulation 16 (including more clear and complete requirements). Not all passenger ships are covered by MARPOL, Annex I, regulation 16, because this regulation applies only to ships with more than 400 GT, and all passenger vessels engaged on international voyages are covered by SOLAS. Denmark: If the title of Reg. 20 regulation is changed to also include cargo ships, we have no objection if the reg. is added to the table in the EN. US: In principle yes, but see our comment on Q6 about deleting the EN table for regulation 4.1. Round 1 Discussion: Although we have almost unanimous agreement on this, provided the heading of Regulation 20 is changed to “Loading of Ships”, Spain seems to make a good case for only including Reg 20.1. On the other hand, perhaps a simpler solution would come from the US’ proposal to remove this EN table to the footnote altogether (see Q6A, above). IF we have a large “Yes” vote for Q6A then the US proposal could be accepted and we can delete the table altogether. If not then we could simply add Reg. 20.1 to the list as Spain proposes. Q11A. Given the support for changing the title of Reg. 20 and adding it to the Table, is there nonetheless a preference for either (a) deleting the Table altogether as proposed by the US under Q6 above or (b) only adding Reg. 20.1 to the Table as proposed by Spain? Delete Table?

MI, US, Japan, Sweden

Keep Table + 20.1 only?

Germany, Finland, Italy, RINA (with comments), France (with comments), Norway (with comments), CLIA, Denmark

Further Thoughts / Comments?:- MI: Agree deletion.

76 10/01/2012

China: No comments. RINA: We would concur with the proposal to amend the title of regulation 20 to cover both cargo and passenger ships and that the explanatory note for regulation 4.1 is included in the EN. France: Considering the uncertainty on reg 5, 5-1 and 9, it seems more clear to keep the table. Norway: Support Spain. This provision in 20.2 was introduced already in SOLAS-60 and was probably intended as a safety measure in passenger ships to prevent machinery malfunctions rather than as a pollution concern. See also answer to Q6A. Round 2 Discussion: We have proposed a completely new text for reg. 4.1 which should enable the EN table to be deleted meaning that we can no longer add reg 20 (or 20.1) to it. However, if we agree to delete the word “passenger” from the heading of reg. 20 this should not be a problem. So we await the outcome of Q6B after discussion at SLF 53. Comments post SLF 53:- Deletion of “passenger” in the title of Regulation 20 was not agreed to in plenary, with objections from ICS & Greece. So the issue of including this regulation (or only 20.1) in the table is still open for discussion by the CG and depends upon whether it is decided to retain the Table in the EN (see comments above under Q10B). (See SLF 53/WP.6 paragraph 21 for details). Q11C (for Round 4 questionnaire). As it was decided at SLF 53 to retain the word “Passenger” in the title of Reg. 20, this means Reg. 20 (or 20.1) cannot now be added to the Table, which only applies to cargo ships. It is proposed that we take no further action for now until MSC 89 decides on the status of the footnotes in response to the Germany/UK request (ref. MSC 89/22/8) which should then determine whether or not we retain the Table in EN 4.1 etc. Further comments?:- Vanuatu: No US: We have no objection to this. However, we take this opportunity to note our view that an important objective of this agenda item is to clarify regulation applicability. When we are finished, there should be no need for any ENs in this regard. Japan: As stated in the previous session, Japan does not support re-opening this issue. China: No comments. RINA: We would concur with the proposal to amend the title of regulation 20 to cover both cargo and passenger ships. In addition we should retain the table, suitably amended to identify the application to cargo ships and passenger ships. This is particularly relevant with respect to the outcome of the question posed in Q6C. France: Agree to the proposal. Spain: OK, support coordinators’ position. Round 6 Discussion: As we are in the process of removing the footnote to Reg. 4.1 and the table in the EN (see Q6 above), we believe that no further action is needed on Q11. The issue of whether or not to remove “passenger” from the title of reg. 20 is discussed in detail under Q6D, above (item 10.2) and Q53D.

Q11, NFA AT SLF 54

Regulation 4.1, footnote .1 “OBO ships” means combination carriers as defined in SOLAS regulation II-2/3.14 [Coordinator’s Note: This EN should now be deleted from Res MSC.281(85) as the term “OBO” has been removed from footnote .1 in the 2009 Consolidated Edition]. R4.1 footnote .1 Q12. Do you think we need to notify SLF 53 of this change? Yes

China, Germany, Japan, MI, Norway, Italy, Denmark, UK, US, Sweden, France

77 10/01/2012

No

Finland, CLIA

Comments?:- Round 1 Discussion: This item was only introduced as a tidying-up exercise and to act as a flag for future action. There are now 11/2 members in favour of deleting this EN (France also in favour). Q12A. Any further comments at this stage particularly from Finland / CLIA?:- China: No comments. Finland: No further comments. France: This will be included in updated version presented at SLF53. Norway: No comment. CLIA: No further comments- Modification acceptable.


(See SLF 53/14 para 12.3). Deletion agreed at SLF 53

Q12 RECOMMEND EN BE DELETED AS AGREED AT SLF 53

2 The Administration may, for a particular ship or group of ships, accept alternative methodologies if it is satisfied that at least the same degree of safety as represented by these regulations is achieved. Any Administration which allows such alternative methodologies shall communicate to the Organization particulars thereof.

3 Ships shall be as efficiently subdivided as is possible having regard to the nature of the service for which they are intended. The degree of subdivision shall vary with the subdivision length (Ls) of the ship and with the service, in such manner that the highest degree of subdivision corresponds with the ships of greatest subdivision length (Ls), primarily engaged in the carriage of passengers.

Regulation 4.3 (ref. SLF 52/3/3 - Germany) [Coordinator’s Note Round 2:- Apologies – the reference should be to SLF 51/3/3] In this paper, Germany proposed that some of the Explanatory Notes should be made mandatory to improve consistency of application and suggested the following paragraph (3bis) be inserted at this point. “The regulations contained in parts B to B-4 should, in order to ensure their uniform application, be applied in conjunction with the Explanatory Notes adopted by the Organization by resolution [MSC …], as may be amended by the Organization, provided that such amendments are adopted, brought into force and take effect in accordance with the provisions of article VIII of the present Convention concerning the amendment procedures applicable to the annex other than chapter 1. A consequential amendment would then be the deletion of the previously considered reference to the draft Explanatory Notes in a footnote to regulation 6.” [Refer to Reg.6 ] The SLF Sub-committee decided to ask MSC 85 to emphasize the importance of the EN but stopped short of suggesting that they be made mandatory. At SLF 51 the German

78 10/01/2012

delegation reserved its position on the issue with the following statement:- “The delegation of Germany stated that they regarded a uniform application of the Explanatory Notes as a crucial prerequisite to implement the safety standard, as defined in the revised SOLAS chapter II-1, uniformly. A respective document, SLF 51/3/3 had been presented to the SLF sub-Committee. This document had been discussed in the group only briefly. The delegation noted that the group had not been willing to follow the German proposal to, firstly, regard the Explanatory Notes as mandatory and, secondly, to identify high-priority specific items to ensure a uniform application of the regulations. Germany reserved its position on the decision of the group and still regarded it as essential for the uniform application of the Explanatory Notes that they should be regarded as an integral part of the new SOLAS chapter II-1. For the delegation of Germany, the issues contained in regulation 4, paragraph 1; regulation 5-1, paragraphs 2, 3 and 4; regulation 7, paragraphs 1 and 2; regulation 7-2, paragraphs 2, 4.1.1, 5.2.1, 5.2.2 and 5.3.1; regulation 7-3, paragraph 2; regulation 9, paragraphs 1,2,6,7,8 and 9; and regulations 15-1, paragraph 1 are particularly sensitive.” [Ref SLF 51/17 para 3.21].

EN (general) Q13. Do you think discussions on the issue of mandatory EN should be re-opened? Yes

Germany, Norway, CLIA, Spain, Denmark, UK

No

China, Finland, Japan, MI, Italy, Sweden

Comments?:- Finland: Majority at SLF51 was against. If EN become mandatory, the document will have to be revised. Germany: If the EN become mandatory they will have to be revised. May be split in 2 parts (part A mandatory, part B explanations). Norway: While the intent is supported it should be taken into consideration that MSC 85 approved them on the assumption that they were written as voluntary. A new review for the purpose of making them mandatory will probably be a long-term task. Spain: We agree totally with Germany point of view. We also consider that the Explanatory Notes should be regarded as an integral part of the new SOLAS chapter II-1. If the majority of the group decides that only part of the Explanatory Notes is mandatory, we can support (in general terms) German proposal in relation with the more sensitive regulations and paragraphs. We also suggest that the application of the interpretation contained in regulation 6.2.4 (“reduced degree of hazard”) should be mandatory. According the Explanatory Notes, to accept this relaxation, the distance from the nearest land is limited to 20 miles, but, in the past (in relation to the application of A.265 resolution), in some cases, these relaxations were accepted for all ‘short international voyages’. This relaxation affects strongly the required level of safety (R factor), which is, in our opinion the key factor related to S-2009 regulations. Denmark: Either a mandatory EN or an update of SOLAS incorporating the definitions from the EN is needed. US: In our view, it would be more appropriate to consider this issue intersessionally following SLF 53 when the Chapter II-1 revisions are further developed. Sweden: We do not believe that at this time there will be a more constructive discussion regarding this matter. However a uniform application of the regulations is preferred. Round 1 Discussion: The CG is very evenly divided on this issue (6/6) with several suggestions and ideas. This outcome, and our current work on upgrading some of the regulations, suggests that we are not yet in a position to say that we have definitive versions of either the

79 10/01/2012

regulations or the EN bearing in mind the preamble to MSC.281(85) (Ref. MSC 85/26/Add.1 Annex 22):- “Being desirous that definitive Explanatory Notes should be adopted when more experience in the application of the aforementioned subdivision and damage stability regulations and the Interim Explanatory Notes had been gained”. Proposed Action: It is proposed that the responses received to the Round 1 questionnaire be reported to the Sub-Committee with a recommendation that the issue be kept on the agenda for further discussion by the CG after SLF 53, more or less as proposed by the US. Spain obviously has a strong position on the N factor in Regulation 6.2.4 which she may wish to take further with more urgency? Q13A. Do you agree with the action proposed in the discussion above?

Yes

MI, Germany, Finland, US, Italy, Japan, RINA (with comment), France (with comment), Norway, CLIA, UK, Sweden, Denmark

No

Comments / Alternative Proposals?:- MI: Concur. China: No comments. RINA: In practice designers, flag administrations and their RO’s will apply the Explanatory Notes(EN) on a mandatory basis anyhow, so there should be no major impact if the EN were made mandatory sooner rather than later. France: Yes on the principle, but we consider that revision of SOLAS 2009 cannot be done independently from explanatory notes.

CONCLUDED - PROPOSAL TO KEEP ISSUE OPEN ACCEPTED BY CG. AWAIT APPROVAL BY SUB-COMMITTEE AT SLF 53.

(See SLF 53/14 para 13.3). Comments post SLF 53:- This item was not specifically raised during SLF 53 to our recollection but will be kept open for SLF 54 Q13C for Round 4 questionnaire. We will keep the issue of mandatory EN open for further discussion at SLF 54. Does anybody have any new thoughts on this subject in the meantime? Comments?:- Vanuatu: No US: No comments Japan: It will take a long time to review the whole EN paragraph by paragraph to become EN mandatory, so Japan hesitates to support. China: No comments RINA: In practice designers, flag administrations and their RO’s will apply the Explanatory Notes (EN) on a mandatory basis anyhow, so there should be no major impact if the EN were made mandatory sooner rather than later. Denmark: No further thoughts. Germany: In this context it should be discussed.

i) whether EN contain requirements beyond the scope of SOLAS and ii) how legal aspects are to be considered (implementation schedule, legal status, refer to

SPS-Code which is also not mandatory) In addition if the EN will be made mandatory, the EN need to be restructured, similar as the IS code in a mandatory part, a part for guidance and supplementary information. This requires a lot of time and work and is outside of the ToR. Finland: No. EC: Preferably EN should be followed, so everybody applies the same rules. However, at the same time it should be considered if a certain degree of flexibility is necessary.

80 10/01/2012

Spain: We maintain our previous position: part of the Explanatory Notes should be made mandatory. Round 6 Discussion: From your comments we have some points to make:-

1. Reviewing the EN to decide which should be mandatory is a medium to long-term task and it would not be advisable to start it until the regulations themselves have stabilised. For example there is still considerable work to be done on the ro-ro regulations (Agenda Item 6), and on cargo ship subdivision (AI 7) both of which are due to complete at SLF 55 in January 2013.

2. The SOLAS updates Agenda Item (8) is due to complete at SLF 54, in January

2012 so it is most unlikely that anything useful can be completed in the remaining time but there are good reasons for asking for an extension for another year to harmonize with the completion date of the other agenda items.

3. Germany states that in their opinion, the amount of work involved in dividing the

S2009 EN into mandatory and non-mandatory sections would put the issue outside the scope of our own ToR.

4. Our proposal would therefore be that we advise the S-C of your thoughts in

our final report with a recommendation that members wishing to pursue the issue of mandatory EN should prepare a case for MSC to adopt it as a new agenda item for consideration in due course by SLF.

5. In the meantime we will concentrate on finalizing the updates and EN in time for

SLF 54 (or 55). Q13D (for Round 6 Questionnaire). Do you agree with the proposal outlined in bold in the discussion above (point 4)?

Y? Japan, CLIA, RINA, Norway, Germany, Poland, US, Italy, RoK, UK, France, Denmark, China, EC (Yes, but after this task we're on now has been finalized. It may also be good first to gain further experience).

N? Finland

Comments?

Q13 There was a 14-1 majority in favour of proposal 4 (above, in bold) so this was put into the report to the S/C (ref. SLF 54/8/1 paragraph 15.10) for action to be taken as appropriate. 4 Where it is proposed to fit decks, inner skins or longitudinal bulkheads of sufficient tightness to seriously restrict the flow of water, the Administration shall be satisfied that proper consideration is given to beneficial or adverse effects of such structures in the calculations.

Regulation 4.4

See Explanatory Notes for regulation 7-2.2, for information and guidance related to these provisions.

81 10/01/2012

Part B-1 Stability

Regulation 5 Intact stability information*

1 Every passenger ship regardless of size and every cargo ship having a length (L) of 24 m and upwards, shall be inclined upon its completion[. and the elements of its stability determined]. [The light ship displacement and the longitudinal, transverse and vertical position of its centre of gravity shall be determined.][Q15] In addition to any other applicable requirements of the present regulations, ships having a length of 24 m and upwards constructed on or after 1 July 2010 shall as a minimum comply with the requirements of part A of the 2008 IS Code. [Co-ordinators Notes:-

1. The sentence beginning “In addition …” is not contained in the 2009 Consolidated Edition and comes from resolution MSC.269(85) which also deletes the word “information” from the heading.

2. The asterisk (* above) and associated footnote (below) were included in the 2009 Consolidated Edition. CG members may wish to consider whether this footnote and the asterisk should now be removed as the reference to the 2008 IS Code is included in Reg 5.1 itself. See also 5-1.2].

Q14. Will the changes highlighted in yellow to the heading, Reg. 5.1 and footnote be automatically included in the next Consolidated Edition of SOLAS? See also Q19. Yes


No

Comments?:- CLIA: No consequence. US: Regarding whether the footnote and asterisk should now be removed; we think they probably should be kept because the regulation is specific to Part A of the 2008 IS Code and the recommendations in Part B should also be used. Round 1 Discussion: This item was simply intended to flag up that action is required to ensure that resolution MSC.269(85) will be incorporated into the next version of SOLAS. The US suggests that the footnote and asterisk should be retained, for the reasons they state (although perhaps the wording of the footnote would have to be changed now that 1st July 2010 is past; also, if we kept the footnote, would we still need the reference to A.749 as well as 2008 IS Code?). Q14A. Do you agree with the US that we should keep the footnote and asterisk and if so, should the footnote refer to both A749 and 2008 IS Code or only to the latter? Yes, keep footnote+asterisk

Germany, Finland, US, RINA, France (with comment), CLIA, UK, Sweden, Denmark

No, remove footnote+asterisk

MI, Italy, Japan (with comment), Norway

82 10/01/2012

If “Yes”, do we refer to both A749 and 2008 IS Code or only 2008 IS Code?

Germany, Finland, France, CLIA only IS2008, US: We think both A749 and 2008 IS Code will need to be included in the footnote because A749 will be applicable to any ships built from 1 Jan 2009 until 1 July 2010. RINA: Supports the US proposal to include both A.749 and the 2008 IS Code Part B. Sweden: A749 and 2008 IS Code.

Comments / Further Thoughts?:- China: No comments. Japan: Japan thinks that changes highlighted in yellow provide sufficient information. France: 2008 IS Code is equivalent to A749. Additional elements incorporated in 2008 IS Code may be applied to ships constructed before 1st July 2010. Norway: Remove. Since new regulation 2.27 and 5.1 are now in force the footnote and the asterisk would seem redundant. Round 2 Discussion: There is a 9 to 4 majority in favour of keeping the footnote and the asterisk and of those in favour 3 felt that the footnote should still refer to both A749 and the 2008 IS Code as in the 2009 Consolidated Edition. Norway and Japan consider that the footnote and asterisk could be removed; Norway considers that as there is a now a definition for the 2008 IS Code in reg. 2.27 the asterisk and footnote are redundant. The 2 options are shown below to help make the choice:- (Alternative 1) Remove asterisk and footnote: Intact stability 1 Every passenger ship regardless of size and every cargo ship having a length (L) of 24 m and upwards, shall be inclined upon its completion and the elements of its stability determined. In addition to any other applicable requirements of the present regulations, ships having a length of 24 m and upwards constructed on or after 1 July 2010 shall as a minimum comply with the requirements of part A of the 2008 IS Code. (Alternative 2) Retain asterisk and footnote: Intact stability* 1 Every passenger ship regardless of size and every cargo ship having a length (L) of 24 m and upwards, shall be inclined upon its completion and the elements of its stability determined. In addition to any other applicable requirements of the present regulations, ships having a length of 24 m and upwards constructed on or after 1 July 2010 shall as a minimum comply with the requirements of part A of the 2008 IS Code. _______________________ ∗ Refer to the Code on Intact Stability for All Types of Ships covered by IMO Instruments,

adopted by the Organization by resolution A.749(18), as amended. From 1 July 2010, the International Code on Intact Stability, 2008, adopted by resolution MSC.267(85), is expected to enter into force.

Q14B (for SLF53 S-C and WG). Do members prefer alternative 1 or alternative 2?

Alternative 1?

Alternative 2?

83 10/01/2012

Comments / Further Thoughts / If we keep the footnote should we change “From 1 July 2010, the International Code on Intact Stability, 2008, adopted by resolution

MSC.267(85), is expected to enter into force.” to “On 1 July 2010, the International Code on Intact Stability, 2008, adopted by resolution MSC.267(85), entered into force.” ? Also would we need to mention that MSC.1/Circ.1292 permitted early application of the 2008 IS Code? Comments post SLF 53:- As these amendments had already been agreed by MSC we have no choice but to adopt them. However it was agreed to change the footnote as highlighted in red below to reflect that 1 July 2010 is now in the past. It was decided not to mention MSC.1/Circ.1292 in the footnote.

Q14. ASK SECRETARIAT TO AMEND FOOTNOTE FOR NEXT ISSUE OF SOLAS

_______________________ ∗ Refer to the Code on Intact Stability for All Types of Ships covered by IMO Instruments,

adopted by the Organization by resolution A.749(18), as amended. On From 1 July 2010, the International Code on Intact Stability, 2008, adopted by resolution MSC.267(85), entered is expected to enter into force.

Regulation 5.1 (ref. SLF 52/17/6 - Norway) Many modern ships are built with an unsymmetrical distribution of mass and/or buoyancy in the transverse direction. This could make it difficult for the ship’s master to plan the loading in such a manner that the ship will not have excessive list before proceeding to sea. Bearing In mind the requirements of regulation 5-1, this Administration is of the opinion that the transverse centre of gravity (TCG) should be included in the elements of stability provided to the ship’s master, even if it estimated that this value will be close to zero. Including the amendment previously adopted by resolution MSC.269(85) it is proposed that the paragraph be amended to read: 1 Every passenger ship regardless of size and every cargo ship having a length (L) of 24 m and upwards, shall be inclined upon its completion. The light ship displacement and the longitudinal, transverse and vertical position of its centre of gravity shall be determined. In addition to any other applicable requirements of the present regulations, ships having a length of 24 m and upwards constructed on or after 1 July 2010 shall as a minimum comply with the requirements of part A of the 2008 IS Code. It should be considered whether the Explanatory Notes should include a comment to the effect that a formal inventory of the transverse centre of gravity will only be required when it is to be expected that the TCG will differ significantly from zero due to the ship’s design. Q15. Do you agree to the amendments in square brackets in Reg. 5.1 (and

underlined above)? If so should we add a new EN regarding TCG, as proposed by Norway?

Yes

Finland, Germany, Japan, Norway, CLIA, Italy, Spain, Denmark, UK, US, Sweden

No

China

84 10/01/2012

Comments / Proposals for new EN?:- China: TCG of lightweight is not significant in the stability calculation. Spain: In case of a significant unsymmetrical distribution of mass and/or buoyancy in the transverse direction, probably the guidance for the conduct of an inclining test contained in Part B of the 2008 IS Code, and in the internal procedures of the Classification Societies, should be adapted, e.g.:

- In the recommended IS Code procedure mean draught (average of port and starboard readings) should be calculated. This mean draught is used in the calculations, assuming the ship upright.

- The plotted line obtained from the weight movements (port & starboard) is assumed to be theoretically straight.

- Etcetera. In other words, using the recommended and standardized procedure, the transverse position of the lightship could not be obtained in a correct way for a significant unsymmetrical distribution of mass and/or buoyancy in the transverse direction. Denmark: No addition to the EN needed. Lightship TCG should be determined for all vessels. US: Although we don’t necessarily disagree with the impetus of the suggested Explanatory Note (i.e. a formal inventory of the transverse centre of gravity will only be required when it is to be expected that the TCG will differ significantly from zero), such an EN would seem to be contrary to the proposed regulation text. Round 1 Discussion: There is substantial agreement on this issue (11/1), with the exception of China. We would agree with China that in most cases lightweight TCG is not significant but there have been circumstances in which ignoring a non-zero TCG has led to the loss of a ship, which is the basis of Norway’s concern. There is already significant provision made for the determination of TCG in the 2008 IS Code, extracts of which are shown below for easy reference:- 2.24 A lightweight survey involves taking an audit of all items which should be added, deducted or relocated on the ship at the time of the inclining test so that the observed condition of the ship can be adjusted to the lightship condition. The mass, longitudinal, transverse and vertical location of each item should be accurately determined and recorded. Using this information, the static waterline of the ship at the time of the inclining test as determined from measuring the freeboard or verified draught marks of the ship, the ship‘s hydrostatic data, and the sea water density, the lightship displacement and longitudinal centre of gravity (LCG) can be obtained. The transverse centre of gravity (TCG) may also be determined for mobile offshore drilling units (MODUs) and other ships which are asymmetrical about the centreline or whose internal arrangement or outfitting is such that an inherent list may develop from off-centre mass. …………….. 4.1.4 Functional requirements 4.1.4.1 The stability instrument should present relevant parameters of each loading condition in order to assist the master in his judgment on whether the ship is loaded within the approved limits. The following parameters should be presented for a given loading condition:

.1 detailed deadweight data items including centre of gravity and free surfaces, if applicable;

.2 trim; list;

.3 draught at the draught marks and perpendiculars;

.4 summary of loading condition displacement; VCG; LCG, TCG; VCB, LCB, TCB,

LCF, GM and GML;

.5 table showing the righting lever versus heeling angle including trim and draught;

.6 down-flooding angle and corresponding down-flooding opening; and

85 10/01/2012

.7 compliance with stability criteria: Listings of all calculated stability criteria, the

limit values, the obtained values and the conclusions (criteria fulfilled or not fulfilled).

Spain may have a valid point in suggesting that the 2008 IS Code Inclining Experiment procedure should be amended to indicate how the lightship TCG is to be calculated for ships with asymmetry etc. Such changes as may be necessary to the 2008 IS Code will presumably have to be made by the IS WG/CG? Also provision would be needed in the trim and stability book (and computer software) for showing TCG and Transverse Moment. The US point is also valid – the proposed regulation amendment states that TCG shall always be determined whereas the proposed EN implies that this is not always necessary. One could also imagine questions as to the threshold value at which the TCG “differs significantly from zero”. Proposed Action: To try to overcome these problems given the broad agreement on emphasizing the importance of including TCG in the intact stability information for certain ship types and acknowledging that the 2008 IS Code already makes some provision for this, could we propose inserting the following sentence into Reg. 5.1 with no change to the EN?:- 1 Every passenger ship regardless of size and every cargo ship having a length (L) of 24 m and upwards, shall be inclined upon its completion and the elements of its stability determined. [These shall include the light ship displacement, LCG, VCG and, at the discretion of the Administration, TCG for ships which are asymmetrical about the centreline or whose internal arrangement or outfitting is such that an inherent list may develop from off-centre mass]. In addition to any other applicable requirements of the present regulations, ships having a length of 24 m and upwards constructed on or after 1 July 2010 shall as a minimum comply with the requirements of part A of the 2008 IS Code. Q15A. Do you agree with the additional sentence in square brackets in the proposed action in the discussion, above, being inserted into Reg. 5.1? Yes

MI, Germany (with comment), Finland, Italy, Japan, RINA (with comment), Norway (but with comment), CLIA (but with comment), UK, Sweden, Denmark

No

France (with comment)

Comments / Alternatives?:- Germany: We would prefer when such wording is incorporated to the IS2008 Code. China: No comments. US: Given the generally limited need to formally determine the TCG (and the difficulty of establishing a threshold; i.e. the proposed “at the discretion of the Administration”), an alternative could be to only address this issue in the EN. Possible EN text could be: “The elements of stability include light ship displacement and the longitudinal and vertical position of the centre of gravity. In addition, the transverse centre of gravity should be determined for ships which are asymmetrical about the centreline or whose internal arrangement or outfitting is such that an inherent list may develop from off-centre mass.” RINA: Supports the proposed action with the text “at the discretion of the administration” deleted. Where there is an unsymmetrical distribution of mass around the longitudinal centreline then this will be identified at the inclining test. The correction of the TCG to equal zero may be achieved by permanent or variable ballast. France: The only way to verify that TCG is not significantly different from zero is to measure it, so we prefer the previous wording (The light ship displacement and the longitudinal,

86 10/01/2012

transverse and vertical position of its centre of gravity shall be determined). Anyway, even if light ship is symmetrical, loading condition during the weighing test may not be symmetrical. This should result from a standard weighing and inclining test procedure, and it would be preferable to amend the IS Code accordingly. Norway: Prefer the original proposal in SLF 52/17/6. However, if there is a strong position for the new proposal in square brackets, this could be supported. CLIA: But the previously proposed text, simply requiring TCG to be determined, was sufficient. Round 2 Discussion: Although 11 to 1 members supported the amendment proposed by the co-ordinators the comments indicate that other alternatives may be preferred. These alternatives are therefore presented below for consideration at SLF 53:- Alternative 1 (Norway’s original proposal): 1 Every passenger ship regardless of size and every cargo ship having a length (L) of 24 m and upwards, shall be inclined upon its completion [and the elements of its stability determined]. The light ship displacement and the longitudinal, transverse and vertical position of its centre of gravity shall be determined. Norway also suggested that “the EN should include a comment to the effect that a formal inventory of the transverse centre of gravity will only be required when it is to be expected that the TCG will differ significantly from zero due to the ship’s design”. Alternative 2 (Co-ordinator’s proposal in Round 1 discussion (mostly taken from definition 2.24 in the IS 2008 Code): 1 Every passenger ship regardless of size and every cargo ship having a length (L) of 24 m and upwards, shall be inclined upon its completion and the elements of its stability determined. [These shall include the light ship displacement, LCG, VCG and, at the discretion of the Administration, TCG for ships which are asymmetrical about the centreline or whose internal arrangement or outfitting is such that an inherent list may develop from off-centre mass]. RINA suggests removing “at the discretion of the Administration”. Alternative 3 (USA’s proposal): Keep the regulation unchanged but add the following EN:- “The elements of stability include light ship displacement and the longitudinal and vertical position of the centre of gravity. In addition, the transverse centre of gravity should be determined for ships which are asymmetrical about the centreline or whose internal arrangement or outfitting is such that an inherent list may develop from off-centre mass.” Alternative 4 (Germany): Leave determination of lightship TCG to the 2008 IS Code. France suggests the 2008 IS Code inclining test procedure may need to be amended for TCG. Q15B (for SLF53 S-C and WG). Which alternative is preferred?

Alternative 1?

Alternative 2?

Alternative 3?

Alternative 4?

Comments / Further Alternatives?:- Comments post SLF 53:- In the end Norway’s original proposal (Alternative 1) was accepted without any additional EN.

Q15. AGREED AT SLF 53: RECOMMEND ACCEPTANCE AT SLF 54

87 10/01/2012

2 The Administration may allow the inclining test of an individual cargo ship to be dispensed with provided basic stability data are available from the inclining test of a sister ship and it is shown to the satisfaction of the Administration that reliable stability information for the exempted ship can be obtained from such basic data, as required by regulation 5-1. A weight survey shall be carried out upon completion and the ship shall be inclined whenever in comparison with the data derived from the sister ship, a deviation from the lightship displacement exceeding 1% for ships of 160 m or more in length and 2% for ships of 50 m or less in length and as determined by linear interpolation for intermediate lengths or a deviation from the lightship longitudinal centre of gravity exceeding 0.5% of Ls L is found. Regulation 5.2 (ref. SLF 52/17/6 - Norway) Replace Ls with load line length (L) for consistency (see Regulation 2.9 and 2.13 for details). R5 (Inconsistency between L and Ls; possible removal of footnote) Q16. Do you agree that L should replace Ls? Yes

Japan, MI, Norway, Spain (see comments), Denmark, UK, US, Sweden

No

China, Finland, Italy

Comments?:- Germany: A uniform, comprehensive approach shall be taken. Spain: We consider very urgent to find a solution to this matter. As an additional information, in relation to this tolerance (0,5%L):

- SOLAS II-1 regulation 5.2 makes reference to Ls. - Previous Chapter II-1 (regulation 22) makes reference to L. - MSC/Circ.1158 makes reference to LBP. - IACS UI SC155 (last revision Feb 2008) makes reference to MSC/Circ.1158 tolerances. - 2008 IS Code difference between ships subject to SOLAS, and ships not subject to

SOLAS (“For the purpose of paragraphs 8.1.2 and 8.1.5 the length (L) means the subdivision length (LS) as defined in regulation II-1/2.1 of the 1974 SOLAS Convention, as amended. For ships to which the Convention applies, and for other ships the length (L) means the length of ship as defined in 2.12 of the Purpose and Definitions of this Code”).

This SOLAS regulation applies to new and existing vessels, for an existing vessel the Ls length should be calculated (Ls was only defined for cargo vessel subject to ‘old’ regulation 25-2). For a vessel (new or existing) not subject to any damage stability requirements, but subject to this regulation, it makes no sense to calculate Ls length. To avoid confusion between Administrations, designers, shipyard, and classification societies, we totally support the proposal of using the length L, unifying the different existing references in different IMO instruments. Round 1 Discussion: There is good support for the proposal to replace Ls with L (8/3) with Spain giving excellent examples of the general lack of consistency but 3 members oppose it and 2 have not indicated a preference. However, the coordinators now believe that we should be very wary of replacing Ls with L because Reg. 5.2 is quite similar in wording to the 2008 IS Code Ch 8.1.2 for which, as pointed out by Spain, there is a footnote (35) stating:-

88 10/01/2012

“For the purpose of paragraphs 8.1.2 and 8.1.5 the length (L) means the subdivision length (Ls) as defined in regulation II-1/2.1 of the 1974 SOLAS Convention, as amended. For ships to which the Convention applies, and for other ships, the length (L) means the length of ship as defined in 2.12 of the Purpose and Definitions of this Code.” [The “Convention” referred to in the second sentence is presumably the 1966 ILLC?]. It could cause confusion if we now changed Ls to L in SOLAS. If we are quite certain that it does need to be changed then it should be done in consultation with the IS WG/CG who will need to change footnote 35. Q16A. Would you now agree that we should maintain consistency with the 2008 IS Code and retain the use of Ls in Reg. 5.2? Yes

Germany, China, Finland, Italy, Japan, France (with comments), CLIA, Sweden, Denmark

No

MI, US (with comment), RINA (with comments), Norway (with comment), UK (with comment)

Comments / Objections?:- MI: No, concur with Spain that a unifying exercise is required to use L throughout the relevant instruments. US: Although no strong view, our general preference would be to switch to L (and adjust the IS Code footnote accordingly). RINA: The determination of LCG, VCG, TCG are obtained from the result of the inclining experiment as required by regulation 10.1 of the 1966 ILLC. The process by which a decision not to hold an inclining experiment is included in both the ILLC and SOLAS convention. With hindsight the duplication of the information to be supplied to the master, required by the ILLC and the intact stability information required by SOLAS is unfortunate. There is no definition of Ls in the ILLC. It is therefore difficult to understand to see how Ls, a damage stability nomenclature, can be used in what is an intact stability situation. It would appear that this position has arisen due to the inclusion of Ls in the 2008 IS Code. However if this was an oversight it should not be perpetuated in the 2009 SOLAS amendments. France: It seems that the intent of IS Code was to be in line with SOLAS 2009, but the wording of the foot note is unclear. The sentence “For ship to which the convention applies and for other ships…” seems to cover all ship types, so the only reasonable interpretation would be that Ls would be used only for ships to which SOLAS 2009 damage stability requirements apply. In this case, Ls should be retained, but additional sentence should be added: “If ship is excluded from the application of the damage stability regulations in part B-1, Ls will be replaced by L”. Norway: However, referring to Q2A; if it is decided to use a unified definition of LBP instead of L, we will opt for consistency with this value, not a footnote in the IS Code. UK: We are not convinced that there is any benefit in retaining the use of Ls in Regulation 5.2. Round 2 Discussion: Although 9 members were in favour of keeping Ls following the co-ordinator’s previous comments on the footnote to the 2008 IS Code, it seems that there is still quite strong support (5) for using L instead of Ls in regulation 5.2 for consistency. If we ignore the 2008 IS Code footnote (35) for the moment, reg. 5.2 allows dispensation from the need to carry out an inclining test on an individual cargo ship. Regulation 5.1 already defines the length of cargo ships in terms of length (L) of 24 m and upwards. As stated in Q62, below, it has been noted that when ship length is being used as a “threshold”, as in this regulation, then it is more consistent with the rest of SOLAS to use L, which is a figure known earlier in the design phase, than Ls. We still need to consider possible differences between L and LBP (see Q2 and Q3), (now hopefully resolved?) Circ 1158 uses LBP for determining the % threshold (see below).

89 10/01/2012

Could we therefore agree that the other length thresholds in reg. 5.2 (50 m and 160 m) should refer to L and that it would therefore be consistent to use L for the % deviation of lightship LCG, as originally proposed by Norway. If so, we should perhaps consider changing the text to make this absolutely clear:- ………………. A weight survey shall be carried out upon completion and the ship shall be inclined whenever in comparison with the data derived from the sister ship, a deviation from the lightship displacement exceeding 1% for ships of 160 m or more in length (L) and 2% for ships of 50 m or less in length (L) and as determined by linear interpolation for intermediate lengths or a deviation from the lightship longitudinal centre of gravity exceeding 0.5% of [Ls] [L] is found. If we can agree to these changes then we should advise the S-C that footnote 35 to the 2008 IS Code will need to be altered:- 35 [For the purpose of paragraphs 8.1.2 and 8.1.5 the length (L) means the subdivision length (LS) as

defined in regulation II-1/2.1 of the 1974 SOLAS Convention, as amended]. For ships to which the Convention applies, and for other ships the length (L) means the length of ship as defined in 2.12 of the Purpose and Definitions of this Code.

Q16B (for SLF53 S-C and WG). Can we agree to the changes made to reg. 5.2 as shown in the round 2 discussion, above, and to notify the S-C that a change is needed to footnote 35 in the 2008 IS Code, as shown above, for consistency? Yes

No

Further comments?:- At SLF 53, the WG agreed to replace Ls with L in Reg. 4.2 and to advise the S-C that the following change will therefore be needed in footnote 35 of the 2008 IS Code:- 35 [For the purpose of paragraphs 8.1.2 and 8.1.5 the length (L) means the subdivision length (LS) as

defined in regulation II-1/2.1 of the 1974 SOLAS Convention, as amended]. For ships to which the Convention applies, and for other ships the length (L) means the length of ship as defined in 2.12 of the Purpose and Definitions of this Code.

Clarification of the “length” terms in the 160 m and 50 m thresholds as also being L, was not considered necessary. Q16C (for Round 4 questionnaire). This is more of a housekeeping issue but does anybody know who is responsible for advising the IS group of our decision which will mean a change to footnote 35 of the 2008 IS Code? Will the secretariat do this automatically or is it up to the coordinators? Comments?:- US: We suggest this item be included in the SDS CG report as a specific action requested of the S/C; i.e. request the S/C instruct the IS WG to consider this item at SLF 54. Note: In the published IS Code this is no longer footnote 35; it is a footnote to Part B regulation 8.1.2. In addition, it seems the entire footnote should be deleted (not just the first sentence). China: No comments RINA: SLF 53 /WP. 6 ”The group ........and consequently agreed that footnote 35 to the 2008 IS Code should be altered in order to reflect this change.” It would have been expected that this would have been included in the Actions on the Sub Committee but this was not the case. Conclude that this action will need to be reintroduced by the CG at SLF 54?

90 10/01/2012

Denmark: No. UK: Suggest that the coordinators report to the secretariat the need of the said revision. Round 6 Discussion: Thank you all for your comments and to the US for noticing that there is a difference in the treatment of the footnotes between MSC.267(85) (where all the footnotes are sequentially numbered) and the published 2008 IS Code where asterisks are used throughout. We are not sure why this change was made but to ensure there is no confusion we will specify both footnote 35 in Res. MSC.267(85) and the asterisked footnote in 2008 IS Code, Part B, reg. 8.1.2 in our report to the S/C when we ask them to notify the IS WG. The US suggests that the entire footnote in the IS Code should be deleted. It is therefore proposed that we should also ask the S/C in our report that the IS WG be instructed to consider the validity of this entire footnote in the light of the changes we have agreed to the use of L and Ls in SOLAS2009. Q16D (for Round 6 Questionnaire). Do you agree with the action outlined in bold type in the discussion above)? Yes? Japan, CLIA, RINA, Finland, Norway, Germany, US, Italy, UK, France,

Denmark, China, EC (Yes, the rest of the text of the footnote seems superfluous.) No?

Are there any further comments? RINA: Agree with the US suggestion. Germany: A general overview would be good, where the use of L and Ls has been changed.

Q16 This issue was included in the report to the S/C (Ref. 54/8/1 paragraph 15.3) with an invitation to take action as appropriate.

3 The Administration may also allow the inclining test of an individual ship or class of ships especially designed for the carriage of liquids or ore in bulk to be dispensed with when reference to existing data for similar ships clearly indicates that due to the ship’s proportions and arrangements more than sufficient metacentric height will be available in all probable loading conditions. 4 Where any alterations are made to a ship so as to materially affect the stability information supplied to the master, amended stability information shall be provided. If necessary the ship shall be re-inclined. The ship shall be re-inclined if anticipated deviations exceed one of the values specified in paragraph 5. 5 At periodical intervals not exceeding five years, a lightweight survey shall be carried out on all passenger ships to verify any changes in lightship displacement and longitudinal centre of gravity. The ship shall be re-inclined whenever, in comparison with the approved stability information, a deviation from the lightship displacement exceeding 2% or a deviation of the longitudinal centre of gravity exceeding 1% of [Ls] L [Q17] is found or anticipated. Regulation 5.5 (ref. SLF 52/17/6 - Norway) Replace Ls with load line length (L) for consistency (see Regulation 2.9 and 2.13 for details). Q17. Do you agree that L should replace Ls as in Regulation 5.2? Yes

Japan, MI, Norway, Spain, Denmark, UK, US, Sweden

No

China, Finland, Italy

91 10/01/2012

Comments?:- Germany: A uniform, comprehensive approach shall be taken. Spain: See Q.16 Denmark: Believes this question refers to Reg. 5.5. Prefer LBP mainly because unified interpretation below uses LBP; this is commonly available data in ship’s documents. Round 1 Discussion: Again there is good support for the proposal to replace Ls with L, with Spain referring to their response to Q16 but 3 members oppose it and 2 have not indicated a preference. However, the coordinators’ argument for consistency with the 2008 IS Code (see Q15) is also valid for Reg. 5.5, which is identical to Ch 8.1.5 of the IS Code having the same footnote (35). Therefore we must ask the same question as for Q16. Q17A. Would you now agree that we should maintain consistency with the 2008 IS Code and retain the use of Ls in Reg. 5.5? Yes

Germany, China, Finland, Italy, Japan, France (with comment), CLIA, Sweden, Denmark

No

MI, US (with comment), RINA, Norway (with comment), UK

Comments / Objections?:- MI: No, concur with Spain that a unifying exercise is required to use L throughout the relevant instruments. US: Although no strong view, our general preference would be to switch to L (and adjust the IS Code footnote accordingly). RINA: See response to Q16A. France: Same definition as for reg 5.2 should be applied. Norway: The text in the IS Code is only a footnote in the non-mandatory part that can easily be changed as an editorial matter. UK: We are not convinced that there is any benefit in retaining the use of Ls in Regulation 5.2. Round 2 Discussion: This will now depend on the outcome of Q16B, above. To maintain consistency we should accept Norway’s original proposal to replace Ls with L in reg. 5.5. Q17B (for SLF53 S-C and WG). If we answer “Yes” to Q16B, then do you agree that we should also change Ls to L in reg. 5.5 as originally proposed by Norway? Yes

No

Further comments?:- The SLF 53 WG agreed to change Ls to L.


6 Every ship shall have scales of draughts marked clearly at the bow and stern. In the case where the draught marks are not located where they are easily readable, or operational constraints for a particular trade make it difficult to read the draught marks, then the ship shall also be fitted with a reliable draught indicating system by which the bow and stern draughts can be determined.

Regulation 5 − Intact stability information

Reference is made to MSC/Circ.1158 (Unified interpretation of SOLAS chapter II-1) regarding lightweight check. [Included below for easy reference:-]

92 10/01/2012

MSC/Circ.1158

24 May 2005 UNIFIED INTERPRETATIONS TO SOLAS CHAPTER II-1 PART B-1 REGULATION 5

(PREVIOUSLY SOLAS CHAPTER II-1 REGULATION 22) REGARDING STABILITY INFORMATION FOR PASSENGER AND CARGO SHIPS

LIGHTWEIGHT CHECK

1 The Maritime Safety Committee, at its eightieth session (11 to 20 May 2005), with a view to providing assistance to the Administrations in the implementation of the requirements of the 1974 SOLAS Convention and in order to ensure the uniform application thereof, approved the unified interpretations of the Convention, as set out in the annex. 2 Member Governments are urged to:

.1 take note of the annexed unified interpretations and use them when applying the relevant requirements of the 1974 SOLAS Convention; and

.2 bring the annex unified interpretations to the attention of all interested parties.

93 10/01/2012

MSC/Circ.1158

ANNEX

1. A sister ship is a ship built by the same yard from the same plans.

2. A lightweight check is considered the acceptable means of being satisfied that the data from a lead sister ship’s inclining test can be used for a subsequent ship. The Administration may request regular repeats of inclining tests and/or require each individual passenger ship to be inclined, as detailed below.

3. For any newly built sister ship with known differences from the lead sister ship, a detailed weights and centres calculation to adjust the lead ship’s lightship properties should be carried out. The validity of the calculated lightship properties should be assessed by carrying out a lightweight check unless the implications regarding the stability of the ship indicate that an inclining test should be performed. The acceptable deviation of lightship displacement should be:

For L≤50m 2% of the lightship displacement of the lead ship.

For L≥160m 1% of the lightship displacement of the lead ship.

For intermediate length by linear interpolation.

In addition, the deviation of lightship longitudinal centre of gravity should not exceed 0.5% of the LBP of the lead ship. Where the deviation exceeds either of these limits, an inclining test should be carried out. Where the deviation is within these limits the actual lightship weight and longitudinal centre of gravity derived from the lightship check should be used in conjunction with the higher of either the lead ship’s vertical centre of gravity or the calculated value.

4. For a ship in service which undergoes alterations with calculable differences in lightship properties which materially affect the stability information supplied to the master, a detailed weights and centres calculation to adjust the lightship properties should be carried out. To avoid an inclining test, the deviation of lightship displacement should not exceed 2% of the original approved lightweight or 2 tonnes, whichever is greater, or that approved following the most recent major alteration or conversion. In addition, the deviation of lightship longitudinal centre of gravity from the original or that approved following the most recent major alteration or conversion should not exceed 1% of the LBP of the ship. Where the deviation exceeds either of these limits, an inclining test should be carried out. Where a ship is within these limits the calculated values of lightweight, lightship LCG and lightship VCG should be used in all subsequent stability information supplied to the master.

5. For all passenger ships, a lightship survey should be carried out at periodical intervals not exceeding five years to verify any changes in lightship displacement and longitudinal centre of gravity. The ship should be re-inclined whenever, in comparison with the originally approved stability information or that approved following the most recent major alteration or conversion, the deviation of the lightweight and/or lightship longitudinal centre of gravity exceeds the limits in paragraph 4 above. Where a ship is within these limits, the values of lightweight and lightship LCG derived from the lightship survey should be used in conjunction with the VCG derived from the most recent inclining experiment in all subsequent stability information supplied to the master.

94 10/01/2012

Regulation 5-1 Stability information to be supplied to the master * [Coordinator’s Note: Norway is proposing several changes and a re-organization of Regulations 5-1 and 7 and the EN. A clean version of these proposals without notes and comment is contained in Appendix 1 at the end of this document for easy reference. Appendix 2 shows a clean version of the current text of SOLAS 2009 Regs 5-1 and 7 with EN, also for reference].

1 The master shall be supplied with such information satisfactory to the Administration as is necessary to enable him by rapid and simple processes to obtain accurate guidance as to the stability of the ship under varying conditions of service. A copy of the stability information shall be furnished to the Administration.

2 The information should include:

.1 curves or tables of minimum operational metacentric height (GM) [and maximum permissible trim] versus draught which assures compliance with the relevant intact [stability requirements of part A of the 2008 IS Code] and [relevant] damage stability requirements, alternatively corresponding curves or tables of the maximum allowable vertical centre of gravity (KG) versus draught, or with the equivalents of either of these curves;

Regulation 5-1.2.1 (ref. SLF 52/17/4 Annex A para. 1.1 - Norway) Add words shown underlined above to emphasize that there will be trim limitations. R5-1.2.1 (Need to emphasize trim limits) Q18. Do you agree that the underlined text in square brackets should be added? Yes

China, Finland, Germany, Japan, MI, Norway, CLIA, Italy, Denmark, UK, US, Sweden

No

Spain

Comments?:- Finland: Further support to add into end of 5-1.3; Applied trim values shall coincide in all stability information intended for use on board. New paragraph proposed to insert 5-1.4; The stability limits intended for use on board shall be presented as consolidated data taken from the applicable intact and damage stability of these regulations. Information not required for determination of stability and trim limits should be separated from this information. Existing paragraph 5-1.4 and 5-1.5 to be renumbered 5-1.5 and 5-1.6 In reg 4 footnote after proposed modifications there still remain ships under other stability instruments to fulfil damage stability regulation. Therefore proposed new paragraph 5-1.4 will be preferred. Japan: The trim range limited in accordance with 2008 IS code should also be included. Spain: The proposal of the curve representing maximum permissible trim versus draught is not very clear, in our opinion. See Q21 for further details. Denmark: It has to be made clear what is intended by curves or tables of maximum permissible trim, and the ones presented later in the document are potentially confusing for ship’s staff.

95 10/01/2012

Round 1 Discussion: Although there is very strong (12/1) support for Norway’s proposal there are still some practical difficulties in providing the draught/trim/limiting GM/KG curves in a form easily usable on board especially if we want to consolidate all the intact and damage criteria appropriate to particular ships across the operating range of draughts and trims into one simple graph or table. We are very grateful to Norway for all the work they have done on many questions relating to the provision of curves of minimum GM or maximum KG for use on board (refer to Appendix 1 at the end for their full proposals). Also thanks to Finland for their proposals for ensuring that trim is dealt with consistently in all the relevant intact and damage regulations. This is a rather complicated issue and it must be doubtful as to whether a satisfactory overall solution can be obtained within the CG before SLF 53. To contribute to the discussions here are some further points for consideration:- 1) Regarding Japan’s point, the requirements of the 2008 IS Code regarding trims / GM are:- 2.1.7 If curves or tables of minimum operational metacentric height (GM) or maximum centre of gravity (VCG) are used to ensure compliance with the relevant intact stability criteria those limiting curves shall extend over the full range of operational trims, unless the Administration agrees that trim effects are not significant. When curves or tables of minimum operational metacentric height (GM) or maximum centre of gravity (VCG) versus draught covering the operational trims are not available, the master must verify that the operating condition does not deviate from a studied loading condition, or verify by calculation that the stability criteria are satisfied for this loading condition taking into account trim effects. 2) There does appear to be a conflict between the 2008 IS Code requirement for the limiting curves to cover the range of operational trims in contrast with the S2009 amendments in Reg 5-1.3 which only require the influence of trim to be taken into account when the operational trim range exceeds +/- 0.5% of Ls [L]. 3) Reg 5-1.4 only describes how to calculate the minimum GM (maximum KG) curves for the subdivision index and suggests that the limiting values are simply to be those used in the calculation of si at each of the 3 designated draughts. It is now quite usual for software to adjust the GM/KG at each designated draught to give an overall critical GM/KG curve such that A=R. 4) There could be a significant difference between minimum GM and maximum KG curves when trim variation is taken into consideration since KM varies with trim whereas KG does not. If a ship has an operational trim of < 0.5% Ls then for damage stability the level trim minimum GM only needs to be calculated. This means that the ship could operate at, say, 0.4% Ls bow trim and still be applying the level trim limiting GM value for the A>=R criterion for a particular draught. 5) A numerical example may illustrate the problem more clearly. Suppose the minimum required GM for A>=R at level trim is 1.2 metres at a particular draught and the level trim KM at the same draught is 11.36 m giving a maximum allowable KG of (11.36 – 1.2 = 10.16 m) and suppose the actual KGf is 10.14 metres giving a margin of compliance of 0.02 metres. At a bow trim of 0.4%L, the minimum required GM remains at 1.2 metres according to the current regulations, whereas the actual KM at the same draught may now be only 11.31 metres. According to this, the maximum allowable KG will be (11.31 – 1.2 = 10.11 m) giving a non-compliance margin of 0.03 metres. So use of level trim minimum GM up to a trim of 0.5%L indicates compliance whereas in fact the condition would be non-compliant if maximum allowable KG’s were to be used. This illustrates the uncertainty which surrounds use of using fixed level trim limiting GM’s in a situation of varying operational trim. This error could be removed or reduced if limiting GM/KG points were calculated for level trim, maximum operational bow trim and maximum operational stern trim at each of the 3 draughts ds, dp and dl. It is suggested that a minimum of 3 trims should always be calculated but this could be increased to give a suitable spread of calculated points for interpolation at each of the 3 draughts if the maximum operational bow or stern trim were excessive (say > +/- 0.5% L).

96 10/01/2012

Proposed Action: Acknowledging the strong support for Norway’s proposal, but also Finland’s alternative and the points raised by Japan, Spain and Denmark it is proposed that we examine the overall situation with regard to the provision and presentation of limiting KG/GM curves for a range of draughts and trims in the context of the points raised in the above discussion and in the questions raised on this issue below (Q20 – 25) then try to draw some conclusions at the end, starting with Norway’s proposals in Appendix 1. So please also refer to Appendix 1 for further discussion on this and related issues. Q18A. Any comments at this stage?:-

Comments received: France: Two different subjects are mixed : - First question concerning the indication of trim limit is still valid. We would support the proposal from Finland to include it in paragraph 3: “Maximum permissible trim versus draught which assures compliance with the relevant intact and damage stability requirements shall be included in stability information”. We don’t support the necessity to add a new paragraph 5-1.4, considering that it is already included in paragraph 5-1.2.1. - Question on the influence of trim on the results is an additional question. The example presented by coordinators highlights the fact that generally, if constant GM or KG is kept for a trim range, presentation in max KG is more favourable for trim by bow and presentation in GM is more favourable for trim by stern. Much higher difference may be observed (up to 0.20m). So limit of 0.5% of Ls may be questioned. Norway: Norway’s proposals are related to the decision made by SLF at an early stage of the revision work that only one trim shall be used for dl. The problems we see now as consequences of that principle were obviously not foreseen at that time. Judging by the comments collected by this questionnaire we believe it should be acceptable to act on this experience and discuss whether it would in fact be better to reverse that decision and re-write the regulations accordingly. As this would take some time we believe our proposals will still be useful as a stop-gap measure until updated provisions are available. CLIA: No comments. Additional comments received from CLIA/CCSF between Round 1 and Round 2: Regulation 5-1 The use of separate GM limiting curves for different trims, resulting in an envelope curve needs to be reconsidered in view of the Norwegian proposals in SLF52/17/4. The use of an envelope curve seems to be not adequate, but simultaneously the misuse of the regulation, in particular for cargo ships, has to be prevented by the explanatory notes.

Coordinator’s Comments: Again, please refer to Appendix 1 for further discussion of this issue.

CG Member’s Comments?:- France: See Q21.

CLIA: See comments to Appendix 1, Question 1.

Round 2 Discussion: Many thanks to France, Norway and CLIA for their additional comments. We will continue the discussion under new Appendix 3 which includes further proposals for presenting limiting GM/KG curves/tables to allow for the operating trim and all the criteria as an alternative to Norway’s proposal in Appendix 1. See also Q20, 21, 23, 25 and 26. Post SLF 53 Discussion:- In the WG it was agreed to accept Norway’s original proposal to add “and maximum permissible trim” as shown in red above.


97 10/01/2012

.2 instructions concerning the operation of cross-flooding arrangements; and

.3 all other data and aids which might be necessary to maintain the required intact stability [according to the requirements of part A of the 2008 IS Code] and stability after damage.

________________________ ∗ Refer also to the Guidelines for the preparation of intact stability information (MSC/Circ.456);

[Guidance on the intact stability of existing tankers during transfer operations (MSC/Circ.706) SLF 53 WG3 agreed this deletion (see Q6)]; and the Revised guidance to the master for avoiding dangerous situations in following and quartering seas (MSC.1/Circ.1228).

Q19. Will the changes highlighted in yellow to Reg. 5-1.2.1 and 5-1.2.3 be automatically included in the next Consolidated Edition? See also Reg. 5.1 (Q14). Yes

Finland, Germany, Japan, MI, Norway, CLIA, Italy, Spain, UK, Sweden

No

China, Denmark, US

Comments?:- US: They will not automatically be added because they were not part of the MSC 85 adopted amendments. However, we support the changes as proposed / highlighted in yellow. Round 1 Discussion: Thank you for this clarification, US. We cannot identify the source of these amendments. Q19A Given the US’ clarification, would you now agree that the texts highlighted in yellow in Regs 5-1.2.1 and 5-1.2.3 should be included? Yes

MI, Germany, Finland, US, Italy, Japan, RINA, Norway, CLIA, UK, Sweden, Denmark

No

France (with comment)

Comments?:- France: Part A of 2008 IS code is defined as the minimum requirement in regulation 5.1. Additional criteria may be applied, so it seems not to be a good option to repeat regulation 5.1. Round 2 Discussion: The inclusion of the text change has almost total support (12-1) but France correctly states that there is already a footnote referring to the 2008 IS Code under regulation 5.1 so perhaps this is unnecessary repetition. Propose this question be put at SLF 53. Q19B (for SLF53 WG). Is there support for France’s view that the text changes highlighted in yellow in reg. 5-1.2.1 and 5-1.2.3 are unnecessary? Yes

No

Comments?:- At the SLF 53 WG the proposed text insertions referring to the intact stability requirements of the 2008 Code were deemed unnecessary in the light of France’s comment on the footnote to Reg. 5.1 and are therefore deleted.

Q19 NFA at SLF 54

Regulation 5-1.2

Any limiting GM (or KG) requirements arising from provisions in regulation 6.1 (regarding partial attained subdivision indices), regulation 8 or regulation 9, which are in addition to

98 10/01/2012

those described in regulation 5-1.4, should also be taken into account when developing this information. 3 The stability information shall show the influence of various trims in cases where the operational trim range exceeds +/- 0.5% of [Ls] [L]. [Applied trim values shall coincide in all stability information intended for use on board.] [Coordinator’s Note – reason for underlined change given in SLF 52/17/4, Norway, see below. Further note post SLF 53 – it was finally agreed to change Reg. 5-1.3 to read as shown in red:-]

3 The intact and damage stability information required by regulation 5-1.2 shall encompass the operating range of draught and trim. Applied trim values shall coincide in all stability information intended for use on board. Regulation 5-1.3 (ref. SLF 51/3/2 – US and Sweden) This provision that the influence of various trims on the stability information need only be taken into account if the operational trim range exceeds +/- 0.5% of Ls should be revisited (also in regulation 7.2). Associated comment from the United Kingdom: In our experience, particularly with ro-ro passenger ships, the influence of trim can become important at much lower % Ls values. Regulation 5-1.3 (ref. SLF 52/17/4 Annex A para. 1.2 - Norway) Add words shown underlined above to ensure consistent use of trim. Regulation 5-1.3 (ref. SLF 52/17/6 - Norway) Replace Ls with load line length (L) for consistency (see Regulation 2.9 and 2.13 for details). Q20. (a) Do you agree that L should replace Ls in 5-1.3 as in Regulation 5.2 and 5.5? (b) Do you agree that the underlined sentence in square brackets should be

added? (c) Does the operational trim range of +/- 0.5% need to be re-considered? (a) Please answer Yes or No:- Yes: MI, Norway, Spain, Denmark, UK, US, Sweden, Japan No: China, Finland (see Q17), Germany, CLIA, Italy (b) Please answer Yes or No:- Yes: MI, Norway, CLIA, Spain, Denmark, UK, Sweden No: China, Finland, Germany, Japan, Italy Abstain: US (may need further information) (c) Comments / suggestions?:- To be re-considered: Finland, Denmark, UK Not to be re-considered: China, Japan, MI, Norway, Italy, Sweden Finland: Ro-pax type vessels are very sensitive to change of trim. Germany: A uniform, comprehensive approach shall be taken. Norway: No; not until a more detailed justification has been presented. In particular it must be investigated whether a change could affect the calibration of the R-formulas in regulation 6. Spain: We need further/additional details. To calculate only one limiting GM curve (or the minimum possible number of GM limiting curves) is more intuitive, simply and preferable. Anyway, if clearly demonstrated that for a specific type of vessel +/- 0.5% is too much, we can change the limit for this type of vessel. Denmark: Yes, it is in any case worth checking the influence of trims on the attained index, particularly if GM has been lowered to obtain A=R.

99 10/01/2012

UK: We suggest that until such time that Passenger Ships (particularly ROPAX vessels) survival assessment is revised satisfactorily and indicates otherwise, the range should be +/- 0.2%. US: We think additional justification is needed to re-consider the 0.5% trim threshold. Sweden: Not at this time, but if it can be clearly shown that there is a potential risk for these vessels the trim range for specific types of vessel can be re-considered. (a) Round 1 Discussion: A majority of 8/5 think that L should replace Ls in Regs 5-1.3. However, in the light of the discussions to Q16 and 17, where there now appears to be a strong case for using Ls, should we not be consistent and continue to use Ls throughout Regulation 5? Q20(a)A. Would you agree that it would be preferable to use Ls throughout Reg. 5 for reasons both of internal consistency and consistency with the 2008 IS Code footnote 35? Yes

Germany, Finland, Italy, Japan, CLIA, Sweden, Denmark

No MI, US (with comment), RINA, Norway (with comment), UK (with comment) Comments?:- US: Although no strong view, our general preference would be to switch to L (and adjust the IS Code footnote accordingly). RINA: See response to Q16A. France: This could be accepted, but this paragraph seems to apply to all ship types, so as for reg.5, it should be added that for ships not complying with damage stability requirements of Part B-1, Ls will be replaced by L. Usual practice for ship complying with damage stability regulations in other IMO instrument is to define required GM for trim variation of less than 0.5% of Ls. So it may be considered that trim range up to 0.5% of Ls is only applicable to ships complying with damage stability requirements of Part B-1. In this case, “in case where the operational trim range exceeds +/-0.5% of Ls” should be deleted from paragraph 3 which applies to all ships. Norway: The text in the IS Code is only a footnote that can easily be changed as an editorial matter. UK: We think that the use of Ls, which is essentially only for internal subdivision layout “mapping”, does not bring any real benefit to the master in assessing the loading characteristics other then adding further complications; in the case of Regulation 5 and 5-1 it can easily be avoided. (a) Round 2 Discussion: If we agree to the proposal in Q16 and Q17 then for consistency we should change Ls to L (as in reg. 5.2 and 5.5) and ask the S-C to note that the 2008 IS Code footnote 35 will need to be amended. Q20(a)B (for SLF53 WG). For consistency with reg. 5.2 and 5.3, would you agree that we should also use L in place of Ls in reg. 5-1.3? Yes

No

Comments?:- (b) Round 1 Discussion: A majority of 8/5 are in favour of adding text to Reg. 5-1.3 to clarify that trims for all the relevant stability regulations must be accounted for. The discussion under Q18 indicates that there may be some difficulties in trying to reconcile the +/- 0.5% operating trim range referred to in this regulation with that from, for example, the intact stability 2008 IS Code requirements, where either the operational trim range of whatever magnitude must be covered at all draughts or special loading calculations must be carried out if the loading condition lies outside the pre-determined range (impractical for damage stability, but see Reg. 5-

100 10/01/2012

1.5). Another point which should be clarified is whether the +/- 0.5%L trim range only refers to the calculation of the “A>=R criterion” or does it also include Reg. 6.1 (0.9R or 0.5R at each partial index) and also the limiting GM/KG curves derived from the minor damage regulations (Reg. 8) and the double bottom regulations (Reg. 9)? If we change “B1 through B4” to read “B1” (see Q6), then Reg. 9 will lie outside the range of damage stability regulations as defined in Reg. 4.1 In many ways it would make consistency with all the other intact and damage regulations easier if we could remove the reference to +/- 0.5% L altogether and re-word Reg. 5-1.3 to read simply:- “3 The stability information shall show the influence of [various] trim[s] [on limiting KG/GM] [in cases where] [across] the operational trim range [exceeds +/- 0.5% of Ls ]”. Q20(b)A. Could you accept this modification to Reg 5-1.3 as a technically valid alternative to Norway’s original proposal for dealing with trim in all the relevant stability regulations? Yes

MI, Italy, Japan, France (with comments), CLIA, UK, Sweden

No

Germany, Finland, Norway, Denmark

Comments?:- France: This change is a major change because in this case, reference to 0.5%Ls would only apply to Part B-1 of SOLAS (specified in reg 7.2). This is however more in line with usual presentation of results and it can be considered that this presentation of constant required GM for a trim range can only be applied in the context of probabilistic damage stability. This would cancel comments on Q20(a)A. It would be necessary to explain how to combine requirements of SOLAS Part B-1 for which required GM is applicable to a trim range with intact stability criteria calculated for different trims. (b) Round 2 Discussion: Many thanks to France for their additional comments. It is agreed that this is a major change which also will involve other regulations in Part B-1 (including changes to reg. 7.2, as mentioned by France). We will continue the discussion under new Appendix 3 which includes further proposals for presenting limiting GM/KG curves/tables to allow for the operating trim and all the criteria as an alternative to Norway’s proposal in Appendix 1. It is based on the discussion at the end of Appendix 1 (ref. Appendix 1Q1) which had some support. See also Q18, 21, 23, 25 and 26. (c) Round 1 Discussion: Only 3 members felt that the +/- 0.5% trim range should be re-considered with a further 4 saying that more justification should be provided first. Some reasons for re-consideration have been outlined in the discussions under Q18 and 20(b) above but Norway’s point about the possible need to re-calibrate “R” is potentially serious, perhaps requiring expert advice from the HARDER team. If there is a positive response to Q20(b)A, however, we could remove the +/- 0.5% restriction altogether which would simplify harmonisation with the other intact and damage stability regulations. Proposed Action: As for Q18, it is proposed that we examine the overall situation with regard to the provision and presentation of limiting KG/GM curves for a range of draughts and trims in the context of the points raised in the above discussion and in the questions raised on this issue below (Q21 – 25) and then try to draw some conclusions at the end, starting with Norway’s proposals in Appendix 1. So please also refer to Appendix 1 for further discussion on this and related issues.

101 10/01/2012

Q20(c)A. Any comments at this stage?:- Comments received: US: Comment regarding possible need to re-calibrate “R”: in our view this is not a significant concern because the original process to establish the “R” formulas was not that precise in reality (selection/number of sample ships; assumptions made for sample ship calculations; R regression; etc.). France: Trim range of 0.5% Ls may be estimated as too large considering the possible discrepancy between required GM and maximum KG when ship trim differ from reference trim. In practice, index which would be attained with the maximum allowable trim, including the range of +/- 0.5% Ls is not known. A more strict approach would be to verify that with the maximum allowable trim applicable to GM/KG curve, attained index A would not be less than [0.98]*R, A being weighted on the 3 drafts. To illustrate the influence of trim on calculated attained index, you will find enclosed, an example of variation of attained index with the trim variation, assuming constant GM and constant KG. (for a large cruise ship with Ls = 320m; trim positive by bow) :-

Attained index

0.810.820.830.840.850.860.870.880.890.90

-1.5 -1 -0.5 0 0.5 1 1.5trim

Constant GMConstant KG

If a limit of [0.98] R was given for attained index, maximum trim by stern would be of about -1m if maximum KG curve is adopted and -0.4m if minimum GM is adopted.

END of COMMENTS by FRANCE (c) Round 2 Discussion: Many thanks to the US and France for their comments regarding the somewhat approximate basis for the derivation of “R” and the considerable influence of trim on “A” respectively. We also share France’s concern with the difference between using GM (trim dependent) and KG (independent of trim). These comments would tend to confirm that “R” is an average, global measure of safety. To be more precise perhaps the formulae for “R” should have shown some variation with trim too. As it is we are currently comparing an attained index “A” which can vary with trim against an averaged “R” derived by regression from data which was not correlated to show the variation of damage stability with trim. For this reason we have proposed in Appendix 3 a series of changes to the regulations and EN which may go some way towards reducing these problems and help towards better integration of the intact and damage stability limiting GM/KG curves/tables. Please refer to Appendix 1Q1 and Appendix 3 for further discussion.

102 10/01/2012

Post SLF 53 – it was finally agreed to change Reg. 5-1.3 to read as shown below :-

3 The intact and damage stability information required by regulation 5-1.2 shall encompass the operating range of draught and trim. Applied trim values shall coincide in all stability information intended for use on board. This change also resolves Q20(a) and 20(b).

AT THIS POINT THE WG DECIDED TO LEAVE FURTHER QUESTIONS RELATING TO THE PROVISION OF STABILITY INFORMATION TO THE MASTER FOR CONSIDERATION BY THE CG IN 2011. SO QUESTIONS 21 THROUGH 26 ARE AT PRESENT COVERED BY THE PROPOSED ALTERNATIVES IN APPENDIX 1 AND 3 and THESE TOPICS WILL BE RE-OPENED BY THE CG IN ROUND 5. PLEASE SEE APPENDICES 1 to 5 AT THE END OF THIS DOCUMENT.

FOR SLF 54 IT IS SUGGESTED THAT ATTENTION IS FOCUSSED ON APPENDIX 5 WHICH CONTAINS NORWAY’S REVISED PROPOSALS AS THESE WERE GENERALLY PREFERRED BY THE 2011 CG. RE-START WG/SLF 53 DECISIONS AND WORK OF 2011 CG AT R7.3 (CLIA Q2).

[4 For ships which have to fulfil the stability requirements of [part B-1] [these regulations], [Coordinator’s Note: this change is proposed in SLF 51/3/2 and supported by Norway in SLF 52/17/6, see below] information referred to in paragraph 2 is determined from considerations related to the subdivision index, in the following manner: Minimum required GM (or maximum permissible vertical position of centre of gravity KG) for the three draughts ds, dp and dl are equal to the GM (or KG values) of corresponding loading cases used for the calculation of survival factor si. For intermediate draughts, values to be used shall be obtained by linear interpolation applied to the GM value only between the deepest subdivision draught and the partial subdivision draught and between the partial load line and the light service draught respectively. Intact stability criteria will also be taken into account by retaining for each draft the maximum among minimum required GM values or the minimum of maximum permissible KG values for both criteria. [If the subdivision index is calculated for different trims, several required GM curves will be established in the same way]. [If the subdivision index is calculated for different trims, a single envelope curve for required GM should be developed. If required KG is produced, then several required KG curves will be established]. [Coordinator’s Note: the change to the last sentence is proposed in SLF 51/3/2 for the reasons below).] ]

------------ Regulation 5-1.4 (ref. SLF 51/3/2 – US and Sweden) In order to allow/be consistent with [an earlier] proposal from Norway (under regulation 7.2 below) regarding calculation of A for different trims, it is proposed to re-word the last sentence of this paragraph as follows:

“If the subdivision index is calculated for different trims, a single envelope curve for required GM should be developed. If required KG is produced, then several required KG curves will be established.”

------------

103 10/01/2012

Because the limiting GM (or KG) guidance provided to the master in accordance with regulation 5-1 could be impacted by the requirements in regulations 8 and 9 (and the partial attained subdivision indices in regulation 6.1), the following text was added to the Explanatory Notes under regulation 5-1.2:

“Any limiting GM (or KG) requirements arising from provisions in regulation 6.1 (regarding partial attained subdivision indices), regulation 8 or regulation 9, which are in addition to those described in paragraph 4, shall also be taken into account when developing this information.”

[Coordinator’s Note: This change to the EN has already been made.] In this regard, the text “stability requirements of part B-1” in regulation 5-1.4 could be replaced by “stability requirements of these regulations” (because regulation 9 is located in part B-2, not part B-1). ------------ Norway now proposes (in SLF 51/17/4) to replace the whole of Regulation 5-1.4 with [4 The stability limits intended for use on board shall be presented as consolidated data taken from the applicable intact and damage stability calculations of these regulations. Information not required for determination of stability and trim limits should be separated from this information. ] and introduce a new Regulation 5-1.5 (see below for reasons):- [5 If the damage stability is calculated in accordance with part B-1 of these regulations a stability limit curve is to be determined using linear interpolation between the minimum required GM assumed for each of the three draughts ds, dp and dl. When additional subdivision indices are calculated for different trims, a single envelope curve based on the minimum values from these calculations shall be presented. If it is intended to develop curves of maximum permissible KG it shall be ensured that the resulting maximum KG curves correspond with a linear variation of GM. ] ------------ Regulation 5-1.4 (ref. SLF 52/17/6 Annex - Norway) Document SLF 51/3/2 contains a proposal that the text “stability requirements of part B-1” in the first sentence of regulation 5-1.4 could be replaced by “stability requirements of these regulations” (because regulation 9 is located in part B-2, not part B-1). This Administration supports this proposal. ------------ Regulation 5-1.4 (ref. SLF 52/17/4 Annex A para. 1.3- Norway) Paragraph 5-1.4 does not cover damage stability limits resulting from deterministic regulations in cases where the footnote to regulation 4 has been applied. The information regarding stability limits in this paragraph can be simplified if the provisions regarding probabilistic calculations are kept in regulation 7 as far as possible and provisions regarding limit curves are kept in this regulation. The paragraph should be replaced in order to become independent of applied criteria:- Proposed replacement for Regulation 5-1.4:- The stability limits intended for use on board shall be presented as consolidated data taken from the applicable intact and damage stability calculations of these regulations. Information not required for determination of stability and trim limits should be separated from this information.

104 10/01/2012

The principles concerning presentation of intact stability and GM/KG values in existing paragraph 4 are then moved into a new paragraph: Proposed new Regulation 5-1.5 (ref. SLF 52/17/4 Annex A para. 1.4 - Norway) If the damage stability is calculated in accordance with part B-1 of these regulations a stability limit curve is to be determined using linear interpolation between the minimum required GM assumed for each of the three draughts ds, dp and dl. When additional subdivision indices are calculated for different trims, a single envelope curve based on the minimum values from these calculations shall be presented. If it is intended to develop curves of maximum permissible KG it shall be ensured that the resulting maximum KG curves correspond with a linear variation of GM. [Co-ordinators Note: If the above new regulation is accepted then existing paragraph 5-1.5 will have to be re-numbered 5-1.6]. 5 When curves or tables of minimum operational metacentric height (GM) versus draught are not appropriate, the master should ensure that the operating condition does not deviate from a studied loading condition, or verify by calculation that the stability criteria are satisfied for this loading condition.

Regulation 5-1.3 and 5-1.4 (see also regulation 7.2)

1. Linear interpolation of the limiting values between the draughts ds, dp and dl is only applicable to minimum GM values. If it is intended to develop curves of maximum permissible KG, a sufficient number of KMT values for intermediate draughts must be calculated to ensure that the resulting maximum KG curves correspond with a linear variation of GM. When light service draught is not with the same trim as other draughts, KMT for draughts between partial and light service draught must be calculated for trims interpolated between trim at partial draught and trim at light service draught

2. In cases where the operational trim range is intended to exceed ±0.5% of Ls, the original GM limit line should be designed in the usual manner with the deepest subdivision draught and partial subdivision draught calculated at level trim and actual service trim used for the light service draught. Then additional sets of GM limit lines should be constructed on the basis of the operational range of trims which is covered by loading conditions of partial subdivision draught and deepest subdivision draught ensuring that intervals of 1% Ls are not exceeded. For the light service draught dl only one trim is to be considered. The sets of GM limit lines are combined to give one envelope limiting GM curve. The effective trim range of the curve should be clearly stated.

Regulation 5-1.3 and 5-1.4 (see also regulation 7.2) (ref. SLF 52/17/4 Annex C para. 1 - Norway) The notes regarding design of limit curves should be moved to this regulation to improve user-friendliness. 1.1 Amend title to accommodate the new paragraph. Delete reference to now empty 7.2. Proposed title to read:-

105 10/01/2012

“Regulations 5-1.3, 5-1.4 and 5-1.5” 1.2 The following is transferred from 7.2, note 3 and amended slightly where shown underlined:- 3 If multiple GM limiting curves are obtained from damage stability calculations of differing trims in accordance with regulation 7, an envelope curve covering all calculated trim values should be developed. Calculations covering different trim values should be carried out in steps not exceeding 1% of Ls. The whole range including intermediate trims should be covered by the damage stability calculations. Refer to the example showing an envelope curve obtained from calculations of 0 trim and 1% of Ls.

1.3 Move the sketch from 7.2, note 3 accordingly:-

1.4 Add new note 4:- 4 As an alternative to an envelope curve, the calculations for additional trims may be carried out with one common GM for all of the trims assumed at the deepest subdivision draught ds and the partial subdivision draught dp respectively. The lowest values of each partial index As and Ap across trims will then be used in the summation of the attained subdivision index A according to regulation 7.1. At the light service draught the partial index Al is assumed constant. This will result in one GM limit curve based on the GM used at each draught. A trim limit diagram showing the assumed trim range is then developed as shown in the figure. Insert new figure:

106 10/01/2012

1.5 Add new note EN5:- 5 It is not required that the trim values at ds and dp coincide as long as the limitations with respect to variation between trims are observed at each draught. The applicable trim limits may then be marked at 0.5% Ls [L] in excess of the largest calculated trims as shown in the figure. There will be no trim limits in the draught range between dl and dp unless the limiting GM is governed by other applicable intact or damage stability criteria. Comments received from CLIA/CCSF between round 1 and 2:

Regulation 5-1.3 and 5-1.4 EN 2 It should be admitted that trim variations may be observed down to light service draft. In addition the GM limiting value for temporary conditions as described under regulation 2 has to be defined. Following alternative wording is proposed : “In cases where the operational trim range is intended to exceed ±0.5% of Ls, the original GM limit line should be designed in the usual manner with the deepest subdivision draught and partial subdivision draught calculated at level trim and actual service trim used for the light service draught. Then additional sets of GM limit lines should be constructed on the basis of the operational range of trims which is covered by loading conditions ensuring that: - Intervals of 1% Ls are not exceeded between initial conditions at each draft. - The trim of each loading condition does not exceed 0.5% Ls difference in comparison with of one of the GM limiting curve at corresponding draft. - Verifications of regulation 8 and 9, if applicable, have to be done for all initial conditions with different trims. The sets of GM limit lines are combined to give one envelope limiting GM curve. The effective trim range as a function of draft for application of the curve should be clearly stated. For any loading conditions, which result to a lower draught than dl due to ballast

107 10/01/2012

water exchange procedures, the same minimum GM value as for dl is to be taken”. Coordinator’s Comments: See also discussions in Appendix 1 for this issue. CG Member’s Comments?:- France: The only new item is the last one concerning possibility to sail with a draft lower than dl. Proposition to consider the same GM value as for dl can be accepted. Round 2 Discussion: Thank you France. For completeness it would be very helpful if CLIA/CSSF could draft a set of revised regulations and EN covering reg. 5-1 and 7.2 to compare with those proposed in Appendix 1 and Appendix 3 to enable us to check their proposals more easily (see also CLIA’s comments under Q18A). Further comments?:- Q21. Looking at Regulation 5-1.4 and the EN, it would appear that the amendments proposed in SLF 51/3/2 have been superseded by Norway’s proposals in SLF 52/17/4 and 52/17/6. The EN amendment in 51/3/2 would then be superseded by Norway’s revised EN, which also includes alterations to Reg. 7. A clean copy of all the proposed SOLAS text revisions and the changes to the EN are shown in Appendix 1 at the end of this questionnaire. Taking into account all the comments and notes above would you agree to the amendments to Regulation 5-1 with EN as proposed by Norway and as shown in Appendix 1? Yes

China (but amended diagram needed), Finland (with comment), Germany (with comment), Japan, MI, Norway, Italy (with comment), US (with comment), Sweden

No

CLIA, Spain, Denmark, UK

Comments / Alternative Proposals?:- China: Reference is made to the trim limiting curve on page 3 of the annex of document SLF 52/17/4�Norway�. Following figure is a hard-copy:

108 10/01/2012

This is a good proposal except that the two slope lines should be vertical and the trapezoid

curve should be rectangular as the proposed figure by Norway uses two different sets of trim range in the calculation of partial index A for draught dp and ds respectively.

Paragraph 2 of notes to Regulation 5-1.3 and 5-1.4 of MSC.281(85) says “then additional sets of GM limit lines should be constructed on the basis of the operational range of trims which is covered by loading condition of partial subdivision draught and deepest subdivision draught ensuring that intervals of 1% Ls are not exceeded”. I interpret this sentence in this way: draught dp and ds represent cargo loading conditions. “Operational range of trims” is the trim range starting from the least trim to the maximum trim on the sorted results of the trims of all cargo loading conditions. For example, if the real trims(i.e., without deduction of ±0.5%Ls for all cargo loading conditions are sorted and listed as below:

-1.7%Ls, -0.4% Ls, 0.8% Ls, 1.6% Ls, 2.4% Ls

Then the real trim range is -1.7% Ls ~2.4% Ls. Trim range of -1.2% Ls ~1.9% Ls. range should

be applied in the calculation of partial index A for both dp and ds. This means the trim range of dp is the same as the trim range of ds. Although for the cargo loading conditions in the loading manual, the range of trims of the loading conditions of which the draft is ds may differ from the trims range of the loading conditions of which the drafts are less than ds, but in real operation the loading conditions may differ from the loading manual and the real trims of ds may exceed the used trim range and run into the trim range of dp. And the same case may occur for the used trim range of dp. Therefore using two separate trim ranges for draught dp and ds respectively is only of theoretical meaning and may not be consistent with the real operation. However, using the same trim range for both draught dp and ds as illustrated above is practical and concords with the explanatory notes. END of CHINA’s PROPOSALS Finland: Reg 5-1.4 (proposed 5-1.5, see Q18). Propose to add ; “If the subdivision index is calculated for different trims, an envelope curve with the highest GM values of the several required GM curves will be established in the same way. Agree with Norwegian proposed text into EN with the exception that calculations for trim variation also include variable trim for dl.

109 10/01/2012

Germany: has the following comments (the wording of the proposed text by NOR would need to be revised at several parts (including the diagram)!)

a) We regard it as NOT meaningful that the light service draft dl is “fixed” in draft/trim (as a consequence Al is constant). Such restriction is in conflict with the general methodology of the probabilistic concept

we regard dl as a “design parameter” which can be freely chosen by the designer. This includes that calculations for trim variation also include variable trims for dl. Any load cases need later to be verified to be within the limitations of trim/GM as a result of the damage stability calculation. This allows full flexibility for the designer and also inherits the required safety level

b) With respect to Reg. 5.1.5 and the diagram we have the following comments:

It is proposed that in the draft range between dl and dp NO trim limitation is valid. We are concerned for drafts close below dp as here per proposed definition no limit exists.We regard it as important that the trim limitation of +/- 0.5%L is valid for the entire draft range. This is to be seen in conjunction with our proposal that trim variations for dl are allowed.

MI: Proposals acceptable as a complete package including use of ‘L’. Norway: It is realised that the second figure may be difficult to explain, however the principle for dealing with draughts below dp can not be dealt with without considering the effect on A and the calibration of the R-formulas. CLIA: This issue and the EN is handled in the CSSF work. Italy: Yes in principle but the lack of trim limits in the draught range between dl and dp is not acceptable. Spain: We do not agree with the proposal contained in points .4 and .5 (“As an alternative to an envelope curve, the calculations for additional trims may be carried out with one common GM for all of the trims assumed...”). The proposed limiting trim curve is not very clear for us. Anyway, if the group decides to accept the proposal, we have two comments:

1) What are the trim limits between dl and dp? 2) We suggest to change the axis (e.g. draught X axis and trim Y axis):

110 10/01/2012

END of SPAIN’s COMMENTS Denmark: In terms of presentation, I would be concerned that the trim limit diagram will be potentially confusing to ship’s staff, we prefer UK’s proposal for a trim limit diagram. Also Reg 5-1.5 should be the maximum of minimum GM limit curves. EN 3, Ls should be changed to L for consistency? We agree with the principle to clarify the regulations, but think that the presentation of max trim needs to be improved. UK: We are of the opinion that the details of each trim value used in the calculations should be presented as separate curves, alongside with the envelope curve (see Q25). US: Yes in principle; however some details need to be further considered and refined. e.g. The relationship between proposed new regulation 5-1.4 and the existing provision in regulation 5-1.2 is unclear to us; should these paragraphs be consolidated or should paragraph 4 precede paragraph 2? Also as indicated in the Coordinator’s Note, the new figure for EN paragraph 4 needs additional details / clarifications. Round 1 Discussion: In view of the complexity of the proposals and the number of comments received, this table has been duplicated in Appendix 1 which contains all the changes proposed by Norway. So please turn to Appendix 1 for continuation of the discussion and the Round 2 questions. This also applies to Q23 and Q25. Comments / Alternative Proposals?:- France: To satisfy the requirement that “for all intended service conditions the difference in trim in comparison with the reference trim used for calculation will be less than 0.5% of Ls”, it may be necessary to made calculations at light service draft for different trims (see regulation 7.2 in

111 10/01/2012

explanatory notes). So we propose just to delete last sentence of paragraph (“ the partial index Al is considered constant for the purpose of these calculations”). Maximum KG and minimum GM are not equivalent. For some type of ship, trim variation may induce large variation in GM with a constant KG. For these ships, variation of attained index will be less if KG is kept constant with trim variation than if GM is kept constant (see comment to Q20). So it may be considered that use of maximum permissible KG curves would be more correct in these cases. If subdivision index is calculated for different trim, it would be better to establish the envelope curve on maximum permissible KG rather than minimum GM (See influence of trim on attained index presented with previous question). If one envelope KG curve is defined, required GM values will be different depending on the trim. (The reverse situation would happen if envelope curve is made on required GM.) In proposed diagram of trim versus draft, trim limit curves should cover the whole draft range and not be limited between dp and ds.

Round 2 Discussion: Many thanks to France for these new comments. As co-ordinators we have tried to overcome the problems raised by all members by proposing modifications to reg. 5-1 and 7 and the EN (see new Appendix 3 where we will continue these discussions). See also Q18, 20, 23, 25 and 26. Any further comments at this point?:-

Calculated pointsTrim limits

0.5%Ls 1%Ls

0.5%Ls 0.5%Ls

0.5%Ls

1%Ls

Trim limit

ds

dp

dl

0.5%Ls

0.5%Ls

112 10/01/2012

Regulation 6 Required subdivision index R *

1 The subdivision of a ship is considered sufficient if the attained subdivision index A, determined in accordance with regulation 7, is not less than the required subdivision index R calculated in accordance with this regulation and if, in addition, the partial indices As, Ap and Al are not less than 0.9R for passenger ships and 0.5R for cargo ships. Regulation 6.1

To demonstrate compliance with these provisions, see the Guidelines for the preparation of subdivision and damage stability calculations, set out in the appendix, regarding the presentation of damage stability calculation results.

2 For all ships to which the damage stability requirements of this chapter apply, the degree of subdivision to be provided shall be determined by the required subdivision index R, as follows:

.1 In the case of cargo ships greater than 100 m in length (Ls):

.2 In the case of cargo ships not less than 80 m in length (Ls) and not

greater than 100 m in length (Ls):

where Ro is the value R as calculated in accordance with the formula in subparagraph .1.

.3 In the case of passenger ships:

where:

N = N1 + 2N2 N1 = number of persons for whom lifeboats are provided N2 = number of persons (including officers and crew) the ship is

permitted to carry in excess of N1. ____________________________ * The Maritime Safety Committee, in adopting the regulations contained in parts B to B-4,

invited Administrations to note that the regulations should be applied in conjunction with the explanatory notes developed by the Organization in order to ensure their uniform application.

See notes under Regulation 4.3 regarding proposal by Germany to remove this footnote. [Coordinator’s Note:- Please also refer to Q.13.]

113 10/01/2012

.4 Where the conditions of service are such that compliance with paragraph 2.3 of this regulation on the basis of N = N1+ 2N2 is impracticable and where the Administration considers that a suitably reduced degree of hazard exists, a lesser value of N may be taken but in no case less than N = N1 + N2

Regulation 6.2.4

Regarding the term “reduced degree of hazard”, the following interpretation should be applied: A lesser value of N, but in no case less than N = N1 + N2, may be allowed at the discretion of the Administration for passenger ships, which, in the course of their voyages, do not proceed more than 20 miles from the nearest land.

Regulation 7 Attained subdivision index A [Coordinator’s Note: For a summary of the changes proposed to Regulations 5-1 and 7 and the EN by Norway see Appendix 1, 2 and 3 at the end of this document].

1 The attained subdivision index A is obtained by the summation of the partial indices As, Ap and Al, (weighted as shown) calculated for the draughts ds, dp and dl defined in regulation 2 in accordance with the following formula:

Regulation 7.1 (ref. SLF 52/17/4 Annex A para. 2.1- Norway) Modify paragraph 7.1 to allow for multiple calculations. Remove brackets in text: 1 An attained subdivision index A is obtained by the summation of the partial indices As, Ap and Al, weighted as shown, calculated for the draughts ds, dp and dl defined in regulation 2 in accordance with the following formula:

Q22. Do you agree with the underlined proposed changes to Reg. 7.1? Yes

China, Finland, Germany, Japan, Norway, CLIA, Italy, Spain, Denmark, Sweden

No UK, US Comments?:- MI: “Yes” to removal of brackets around ‘weighted as shown’ “No” to use of ‘An’ UK: We propose that the partial indices should be considered as “equally” weighted in considering all passenger vessels. US: We prefer the original text. Round 1 Discussion: The majority are in favour of Norway’s proposal, which is designed to alert the user to the fact that more than one index A may need to be calculated depending on trim, as described in Reg. 7.2. The US prefers the original text and the MI only accepts part of the proposal. The UK’s point is acknowledged but seems to relate to a much bigger issue which would probably need to be introduced and discussed separately. Q22A Are the MI, UK and US able to accept the majority view which is to adopt Norway’s proposal as it stands? Yes

MI accepts, US, France, UK (cargo ships only)

No

114 10/01/2012

Further Comments / Objections?:- France: can also support the proposal. UK: We think that the original text can be retained until we properly discuss in detail the use of “equally” weighted partial indices for passenger ships. Comments received from CLIA/CCSF between round 1 and 2:

Regulation 7.1 1. The attained subdivision index A is obtained by the summation of the partial indices As, Ap and Al, weighted as shown, calculated for the draughts ds, dp and dl defined in regulation 2 in accordance with the following formula: Coordinator’s Comments: CLIA/CSSF have the same opinion as MI. Can they also accept the majority view as asked in Q22A? CG Member’s Comments?:- CLIA: Yes, CLIA: Agree. Round 2 Discussion: Nearly all members now accept Norway’s proposals, which will make the first sentence of reg. 7.1 read:- An attained subdivision index A is obtained by the summation of the partial indices As, Ap and Al, weighted as shown, calculated for the draughts ds, dp and dl defined in regulation 2 in accordance with the following formula:

The UK still opposes these modifications for passenger ships so we will take it to SLF 53 for further discussion. Q22B (for SLF53 WG). Can we accept Norway’s proposed modifications to the opening sentence of reg. 7.1? Yes

No

Further Comments?:-

A = 0.4As + 0.4Ap + 0.2Al

Each partial index is a summation of contributions from all damage cases taken in consideration, using the following formula:

A = Σpi si

where:

i represents each compartment or group of compartments under consideration,

pi accounts for the probability that only the compartment or group of

compartments under consideration may be flooded, disregarding any horizontal subdivision, as defined in regulation 7-1,

si accounts for the probability of survival after flooding the compartment or group of compartments under consideration, and includes the effect of any horizontal subdivision, as defined in regulation 7-2.

115 10/01/2012

Regulation 7.1

1. The probability of surviving after collision damage to the ship hull is expressed by the index A. Producing an index A requires calculation of various damage scenarios defined by the extent of damage and the initial loading conditions of the ship before damage.

Three loading conditions should be considered and the result weighted as follows:

A = 0.4As + 0.4Ap + 0.2Al

where the indices s, p and l represent the three loading conditions and the factor to be multiplied to the index indicates how the index A from each loading condition is weighted. 2. The method of calculating the A for a loading condition is expressed by the formula:

i=t Ac = ∑ pi [vi si]

i=1

2.1 The index c represents one of the three loading conditions; index i represents each investigated damage or group of damages and t is the number of damages to be investigated to calculate Ac for the particular loading condition.

2.2 to obtain a maximum index a for a given subdivision, t has to be equal to T, the total number of damages.

3. In practice, the damage combinations to be considered are limited either by significantly reduced contributions to A (i.e. flooding of substantially larger volumes) or by exceeding the maximum possible damage length.

4. The index A is divided into partial factors as follows: pi The p factor is solely dependent on the geometry of the watertight

arrangement of the ship vi The v factor is dependent on the geometry of the watertight arrangement

(decks) of the ship and the draught of the initial loading condition. It represents the probability that the spaces above the horizontal subdivision will not be flooded.

si The s factor is dependent on the calculated survivability of the ship after the

considered damage for a specific initial condition 5. Three initial loading conditions should be used for calculating the index A. The loading conditions are defined by their mean draught d, trim and GM (or KG). The mean draught and trim are illustrated in the figure below.

116 10/01/2012

Regulation 7.1 (ref. SLF 52/17/4 Annex C para. 2.1- Norway) 2.1 Amend note EN5 to cover each calculation of A for multiple trims. It is considered that note EN6 could remain unchanged: “5 Three initial loading conditions should be used for calculating each index A. The loading conditions are defined by their mean draught d, trim and GM (or KG). The mean draught and trim are illustrated in the figure below. The light service condition will be common for all calculations of index A.”

Q23. Do you agree with the underlined proposed changes to Reg 7.1 EN 5? Yes

China, Finland, Japan, Norway, Spain, Denmark, Sweden

No

Germany, MI, Italy, UK, US, France [added in Round 2 with comment)

Comments?:- China: Propose to replace “mean draught d” with “correspondent draught d” as color text below:

“5 Three initial loading conditions should be used for calculating each index A. The loading conditions are defined by their meancorrespondent draught d, trim and GM (or KG). The mean draught and trim are illustrated in the figure below. The light service condition will be common for all calculations of index A.”

Germany: Refer to our answer to Q21. CLIA: See CSSF EN for this issue. Italy: Not acceptable because there may be loading conditions corresponding to light service draught with different trims. US: We prefer the original text; this EN is describing the general case. Round 1 Discussion: In view of the complexity of the proposals and the number of comments received, this table has been duplicated in Appendix 1 which contains all the changes proposed by Norway. So please turn to Appendix 1 for continuation of the discussion and the Round 2 questions. This also applies to Q21 and Q25. France: comment added in round 2 response No agreement to add “The light service condition will be common for all calculations of index A.” It may be necessary to calculate attained index with different trim at light service draft to cover the whole draft/trim range of all loading conditions. Round 2 Discussion: With France’s new comments, opinion is quite evenly divided on Norway’s proposal for dealing with the light service condition in the EN (7 in favour, 6 against, with China proposing an alternative). We can continue this discussion under new Appendix 3 which includes further proposals for presenting limiting GM/KG curves/tables to allow for the

117 10/01/2012

operating trim and all the criteria as an alternative to Norway’s proposal in Appendix 1. See also Q18, 20, 21, 25 and 26. Any further comments?:-

6. The GM (or KG) values for the three loading conditions could, as a first attempt, be taken from the intact stability GM (or KG) limit curve. If the required index R is not obtained, the GM (or KG) values may be increased (or reduced), implying that the intact loading conditions from the intact stability book must now meet the GM (or KG) limit curve from the damage stability calculations derived by linear interpolation between the three GMs. Regulation 7.1 (ref. SLF 52/17/4 Annex C para. 2.2- Norway) It is believed that it would be beneficial to provide some guidance as to what extent deviations from the draught and trim in the light service condition may be accepted without performing new calculations. This could be relevant where data for a sister ship in a series is to be used or if the results of an inclining test or lightweight survey differ from the assumed loading case used for partial index Al. The following interpretation is proposed for inclusion as a new note 7: 7 A previously approved partial index Al may be considered to remain valid for a sister ship and in other cases where differences in light ship particulars result in minor deviations from the assumed draught and trim in the light service condition. It is recommended that the limits for validity of stability documentation in case of lightship deviations set out in regulation 5.2 be applied also for this purpose.” Q24. Do you agree with this proposed addition to Reg. 7.1 EN? Yes

China, Finland (with comments), Japan, MI, Norway, Spain (but see comments), Denmark, Sweden, US (but may be confusing as proposed)

No

Germany (with comments), Italy (with comments), UK

Comments?:- Finland: Into proposed addition also include a reference to changes between PRELIMINARY and FINAL damage stability calculations - not only to sister ships. “.. remain valid for a sister ship and in other cases...”. “Other cases” is too vague to suggest that it could also mean changes between Preliminary and Final calculations. [Co-ordinator’s Note: wording changed slightly from original submission for clarity – hope it is OK as revised, Finland! Wording for explanatory note amendment by Finland would be needed here, if proposal accepted]. Germany: NO support for this paragraph as the deviation is related to “lightship data” only. In our view the deviation must be linked to “lightservice draft/Ballast Arrival” as this can also be subject to changes from PRELIMINARY to FINAL Stability Booklet or within a series of vessels. As a consequence we propose the following definition of acceptable tolerance/deviation for “lightservice draft/Ballast Arrival”

- Draft [+1%] of displacement (based on data from “light service draft), i.e. for draughts bigger than initial dl a small tolerance of +1% of light service displacement is acceptable (definition of negative tolerance not needed as a smaller draft would be beneficial for the Al Index)

- Definition of acceptable trim deviation not needed as in the GERMAN proposal (refer to Q21) dl is considered as a design parameter and trim variations for dl are acceptable (i.e.

118 10/01/2012

designer has to carry out damage stability calculation that covers the full operational trim over the entire draft range)

Norway: Norwegian paper. We realise that it would perhaps be better to replace the reference to regulation 5.2 with the actual limits. CLIA: CSSF EN work. Italy: Alternative text – “A previously approved partial index Al may be considered to remain valid for a sister ship and in other cases where differences in light ship particulars result in minor deviations from the assumed draught and trim in the light service condition. It is recommended that the limits for validity of stability documentation in case of draught and trim deviations be the following: +/- 1% of displacement at light service draught (dl); +/- 0.5 % of Ls” Spain: Only as a remark. Regulation 5.2 only applies to cargo vessels (“The Administration may allow the inclining test of an individual cargo ship to be dispensed with provided basic stability data are available from the inclining test of a sister ship...”). In line with this assumption, we propose to accept this proposal only for cargo ships. US: We think this proposal may be confusing. However we agree it may be useful to have some discussion as to what extent deviations from the draught and trim in the light service condition may be accepted (given a [single] light service draft condition). Round 1 Discussion: There is considerable general support for the need to make some provision for small changes in dl and corresponding service trim arising, for example, from differences in preliminary and final lightship particulars, a series of new “sister” cargo vessels with minor variations, the growth in lightship of passenger ships as measured by the 5-yearly lightship check or minor modifications to cargo/passenger ships (MSC/Circ.1158 covers these situations, see under Q17, above). The US believes the proposal as it stands may be confusing but is open for dialogue. Spain points out that 5.2 applies only to cargo ships and would only accept an extra EN applied to these ships. Norway now thinks it would be better to include the deviation limits in the EN rather than cross-refer to Reg. 5.2. Germany and Italy have come up with text proposals, including specific limits for dl but Germany does not consider a trim limit necessary; Finland is concerned that “in other cases”, as proposed by Norway is too vague if the intention is also to allow for differences between preliminary and final lightship data in a new or converted ship. Proposed Action: To try to accommodate as many suggestions as possible here is a draft amended version of Norway’s original proposal for further consideration making use of the existing limits and situations from MSC/Circ.1158: 7 A previously approved or preliminary partial index Al may be considered to remain valid where small differences in light ship particulars result in minor deviations from the assumed draught (dl) and actual trim in the light service condition. It is recommended that the limits for determining whether partial index Al remains valid be based on the permitted deviations in displacement and LCG set out in MSC/Circ.1158 for deciding whether or not an inclining test is needed. Q24A Given the wide support for Norway’s proposal but acknowledging that there are several suggestions for alternative texts, would you be able to support the compromise text shown under “Proposed Action” for Reg. 7.1 new EN7? Yes

MI, Finland, Italy, Japan, France (with comment), Norway, CLIA (with comment), UK, Sweden, Denmark

119 10/01/2012

No

Germany (with comment), US (with comment).

Comments / Should this only apply to cargo ships?:- MI: Can support compromise text. Germany: No, reference shall be made to light service draft (but not to lightweight) (refer to previous position from GER). France: Situation may be slightly different if comparison is made between a sister ship or between final and provisional calculations. For a sister cargo ship, if difference in lightship is within the given tolerance, the two ships will be considered as identical and stability documents will be identical. In this case, proposed amendment would not be necessary. Final stability document or result of a passenger sister ship will be based on the results of the weighing and inclining test and there is no chance that result will be identical to previous one. Proposed amendment should cover these cases, so it should be also applicable to passenger ships. Practical problem may arise if final lightship (or sister ship in case of a passenger ship) is lighter than previous one. Light service draft may be outside of the draft range. Even for a few centimetres, it would be necessary to extrapolate the required GM curve (Constant GM between calculated dl and actual dl?). CLIA: This should not only apply to cargo ships. US: We do not think reference to MSC/Circ.1158 is appropriate. Possibly use the deviations in reg 5.2 for cargo ships and reg 5.5 for passenger ships. We do not think guidance of this nature regarding reg 7.1 should be restricted only to cargo ships based on reg 5.2. Round 2 Discussion: Although most agree that a new EN is needed there is still not unanimous approval for the wording of Norway’s proposal (or the modified version). The US suggests using reg. 5.2 for the % deviations (as originally proposed by Norway) rather than MSC/Circ.1158 but Norway (and Italy and Germany) think it preferable to use actual deviation limits. The reason for Norway’s original proposal was to try to avoid the extra work needed in re-calculating A if dl changes slightly (also affecting dp). For passenger ships, the definition of dl in reg. 2.11 and the accompanying EN does permit some flexibility so that dl could be a declared value agreed with the Administration for use throughout the lifetime of the ship unless major modifications are carried out. Under IMO Res. A265 the MCA had a recent case where a passenger ship fitted some extra accommodation but it was decided that the lightest service draught (do) could remain the same as the increased lightweight could be compensated by reduced ballast and/or consumables in the 10% arrival condition. Even for cargo ships, some flexibility is possible by varying arrival consumables. What is different about S2009 is that under Reg. 7.2 the light service draught is to be used with the actual service trim resulting in much less flexibility and some difficulties in creating limiting KG/GM curves. The methods proposed in Appendix 3 could overcome these problems by removing the fixed service trim (as originally proposed by Germany). With some flexibility already permitted for dl in EN 2.11, it may not then be necessary to say very much in the new EN7. For example:- 7 For both passenger and cargo ships, the light service draught (dl) as defined in Regulation 2.11 and the accompanying Explanatory Notes may be assumed to remain valid unless the ship undergoes lengthening or other modification to the external hull resulting in changes in the stability characteristics. 7 A previously approved or preliminary partial index Al may be considered to remain valid where small differences in light ship particulars result in minor deviations from the assumed draught (dl) and actual trim in the light service condition. It is recommended that the limits for determining whether partial index Al remains valid be based on the permitted deviations in displacement and LCG set out in MSC/Circ.1158 for deciding whether or not an inclining test is needed.

120 10/01/2012

Q24B (for SLF 53 WG). If we can overcome the problem of the fixed service trim in reg. 7.2 (as proposed in Appendix 3 for example), can we agree to adding a simplified new EN 7, as proposed under round 2 discussion, above? Yes

No

Further Comments/ proposals?:- [2 In the calculation of A, the level trim shall be used for the deepest subdivision draught and the partial subdivision draught. The actual service trim shall be used for the light service draught. If in any service condition, the trim variation in comparison with the calculated trim is greater than 0.5% of [Ls] [L], one or more additional calculations of A are to be submitted for the same draughts but different trims so that, for all service conditions, the difference in trim in comparison with the reference trim used for one calculation will be less than 0.5% of [Ls] [L]. ] ------------------------------ Regulation 7.2 (ref. SLF 51/3/2 Annex – US and Sweden) The treatment of trim in the damage stability calculations is an item that has been identified for further consideration (this item is also related to the stability information required under regulation 5-1). At SLF 49, Norway made an oral proposal leading to extensive discussions regarding GM limiting curves for different trims (see figure/proposal below). There was extensive support for the proposal but it was dropped for not being exactly in line/allowed by the wording of the last sentence in regulation 5-1.4 (see proposed revision to regulation 5-1.4 above to allow this). This issue and proposal should be revisited.

Trims used in calculations

Related comments from the United Kingdom: We have seen examples in stability information booklets based on the current regulations where only level trim minimum GM curves are shown. The booklet then shows a loading condition where the vessel has some stern trim and seems to comply with the minimum GM curve and yet if the trim is taken off by shifting a load horizontally, the condition would not comply. The reason is that KM generally increases as the ship trims by the stern and so therefore does GM, while KG remains fixed. Some yards/owners take advantage of this effect and it can

121 10/01/2012

lead to discrepancies with the onboard stability computer. We can envisage a similar loophole being exploited in the SOLAS 2009 regulations where regulation 5-1.3 requires trimmed information only if the operational trim range exceeds +/- 0.5% of Ls. For these reasons we would like to suggest that only maximum allowable KG curves/tables be used. We propose a further simplification for presenting the limiting KG curves to make them easier to read (see figure below). It can be seen that calculations for 9 points are required encompassing the entire range of draught and trim. The curves are derived by linear interpolation between trims for each of the 3 draughts and compliance can easily be checked by spotting on the trim and KG from the loading condition and interpolating the critical KG curve at the actual draught. Any restrictions in trim at a particular draught can also be shown easily by simple use of shading to indicate prohibited ranges of operation. Critical KG‘s can also arise from regulation 8 (minor damage), regulation 9 (bottom damage) and may arise from the new stability criteria to be introduced into regulation 8-1 (return to port). Intact stability could also influence the critical KG curves. All of these extra curves could be incorporated into this simple diagram with the worst critical KG at each draught/trim combination being plotted but still with only 3 limiting curves for the master to use.

In our experience, particularly with ro-ro passenger ships, the influence of trim can become important at much lower %Ls values. Our proposed method of plotting limiting KG against trim for the three calculated draughts at three trims would therefore always be applied to every ship, regardless of the size of the operational trim range (on the basis that all ships have some trim at some time). ------------------------------ Regulation 7.2 (ref. SLF 52/17/6 - Norway) Replace Ls with load line length (L) for consistency (see Regulation 2.9 and 2.13 for details). ------------------------------ [Coordinator’s Note: Norway now proposes to replace the whole of Regulation 7.2, see below. Please refer to Q25, which covers all the following proposed changes.]

122 10/01/2012

Regulation 7.2 (ref. SLF 52/17/4 Annex A para. 2.2 - Norway) In 7.2 replace the current text to cover principles discussed above [under Regulations 5-1.3 and 5-1.4]. The word “actual” could be replaced with “anticipated” to provide some flexibility if the trim in the final stability calculations deviates from preliminary results due to variations in the lightship particulars: 2 As a minimum, the calculation of A shall be carried out at level trim for the deepest subdivision draught ds and the partial subdivision draught dp. The [actual] [anticipated] service trim shall be used for the light service draught dl. If in any anticipated service condition within the draught range from ds to dp the trim variation in comparison with the calculated trims is greater than 0.5% of Ls, one or more additional calculations of A are to be performed for the same draughts, but including sufficient trims to ensure that for all intended service conditions the difference in trim in comparison with the reference trim used for one calculation will be less than 0.5% of Ls. The partial index Al is considered constant for the purpose of these calculations. ------------------------------ Regulation 7.2

1. The calculations for differing trim should be carried out with the same initial trim for the partial and deepest subdivision draughts. For the light service draught, the actual service trim should be used (refer to the Explanatory Notes for Regulation 2.11).

Regulation 7.2 (ref. SLF 52/17/4 Annex C para. 3- Norway) 3.1 Note 1 does not correspond with the principles in 5-1.4 regarding trims. Note 1 and 2 will in any case become redundant and could be deleted if the regulations are amended as proposed in Annex A of SLF 52/17/4. 2. Each combination of the index within the formula given in regulation 7.1 should not be less than the requirement given in regulation 6.2. Each partial index A should comply with the requirements of regulation 6.1.

3. Example:

Based on the GM limiting curves obtained from damage stability calculations of each trim, an envelope curve covering all calculated trim values should be developed.

Calculations covering different trim values should be carried out in steps not exceeding 1% of Ls. The whole range including intermediate trims should be covered by the damage stability calculations. Refer to the example showing an envelope curve obtained from calculations of 0 trim and 1% of Ls.

123 10/01/2012

Regulation 5-1.3 and 5-1.4 (see also regulation 7.2) (ref. SLF 52/17/4 Annex C para. 1 - Norway) 1.2 The following is transferred from 7.2, note 3 [to 5-1] and amended where underlined:-

3 If multiple GM limiting curves are obtained from damage stability calculations of differing trims in accordance with regulation 7, an envelope curve covering all calculated trim values should be developed. Calculations covering different trim values should be carried out in steps not exceeding 1% of Ls. The whole range including intermediate trims should be covered by the damage stability calculations. Refer to the example showing an envelope curve obtained from calculations of 0 trim and 1% of Ls. 1.3 Move the sketch from 7.2, note 3 accordingly. Regulation 7.2 (ref. SLF 52/17/4 Annex C para. 3- Norway) 3.2 It is proposed to move the contents of note 3 regarding design of limit curves to 5-1.4 or delete it as redundant. Q25. Norway proposes to replace the existing text of Reg 7.2 and re-organize and

re-number the remaining regulations and EN in association with Reg 5-1.4 (see Appendix 1 for complete version). It is assumed that these amendments are intended to replace Norway’s earlier proposals in SLF 51/3/2. An alternative proposal from the UK in 51/3/2 suggests that maximum allowable KG’s rather than minimum GM’s should be used and that the limiting curves should be presented as a variation against trim for the 3 specified draughts (assuming linear interpolation between draughts). Combined critical KG curves would then cover all the relevant stability criteria, both intact and damage. No specific changes to the text of the Regulations or EN were proposed.

As this is a fairly complex issue we would simply like to ask if there is support at this stage for Norway’s package of proposals for Reg 7 as shown in Appendix 1; are there any objections, questions or alternative proposals?

124 10/01/2012

Yes (Accept Norwegian proposals in App 1)

China, Finland, Germany, MI (but see comments), Norway, Italy, US

No

Japan, Spain (see comments), Denmark, UK, Sweden

Comments, reasons, alternative proposals?:- Finland: Support Norway. No support for UK proposal. Prefer GM-limiting rather than KG-limiting curves. Germany: Support Norway’s proposal (strong objections against UK proposal!) Japan: It is not clear how to deal the case that the trim in the loading case between Dp and Dl exceeds the range of calculated trim. MI: Could support Norway’s proposals because they are in a package but the UK suggestion of using max allowable KGs and resulting combined critical KG curves has considerable merit and should be further discussed before a final decision is made. CLIA: CSSF EN work. Italy: See also comments on item 21. Spain: We accept the proposals except the trim versus draught graph. As we have explained, it is not very clear in our opinion. We have made one proposal:

- To change the axis (e.g. draught X axis and trim Y axis):

125 10/01/2012

Spain (continued): Regarding UK proposal, we think it is more clear than the other proposed trim limit curve (we can accept it), but we think that for the master is more intuitive to have GM or KG curves versus draught (and different curves depending on trim), e.g.:

Max Allowable KG vs Draught

4

4.5

5

5.5

6

6.5

7

7.5

8

8.5

4 4.5 5 5.5 6 6.5 7

Draught (m.)

Criti

cal K

G (m

.)

Trim Aft Trim 0 Trim Fwd

End of Spain’s Proposals Denmark: We wonder if it is worth considering whether the trim limits should be restricted to no greater than the calculated conditions, as it is for deterministic damage stability. Consider that if the partial indices are at 0.5R or 0.9R for a particular trim, allowing 0.5%L more trim will most certainly reduce the attained partial indices. US: We support in principle; details subject to further consideration. Round 1 Discussion: In view of the complexity of the proposals and the number of comments received, this table has been duplicated in Appendix 1 which contains all the changes proposed by Norway. So please turn to Appendix 1 for continuation of the discussion and the Round 2 questions. This also applies to Q21 and Q23. Round 2 Discussion: Please see new discussions which are now appended to Appendix 3.

New Paragraph 7.3 (ref. SLF 52/17/4 Annex A para. 2.3 - Norway) Add a new paragraph 7.3 for emphasis:

3 Each additional value of A calculated in accordance with paragraph 2 shall comply with regulation 6 and 7.1 Q26. Do you agree that this new paragraph should be added? Yes

China, Finland, Germany, Japan, Norway, CLIA, Italy, Spain, Denmark, UK, US, Sweden

No

MI

Comments?:- US: Note: this provision could be added directly to regulation 7.2. Round 1 Discussion: There is almost unanimous support for this proposal (12/1) but US suggests that it could be added to Reg. 7.2. This would avoid having to re-number the remaining paragraphs and any possible cross-referencing problems but it might lose some impact; also it would need re-wording slightly:- 3 Each additional value of A calculated in accordance with [paragraph 2] [these provisions] shall comply with regulation 6 and 7.1

126 10/01/2012

Q26A Given the wide support for Norway’s proposal but acknowledging the US suggestion that the sentence could instead be added to Reg. 7.2 could you please state your preference? New 7.3

France (with comment), CLIA

Add to 7.2

MI, Germany, Finland, Italy, Japan, Norway (with comment), UK, US (with comment), Sweden, Denmark

Comments?:- MI: Accept as addition to 7.2. France: This additional sentence seems to be obvious considering regulation 6. Norway: We can both support the US suggestion or a new 7.3 as originally proposed. US: Note: the original Norway proposal was “... comply with regulation 6.1 and 7.1.” Round 2 Discussion: Apologies. Norway’s proposal was indeed referring to reg. 6.1 Thank you US. So if we add this sentence to reg. 7.2, as the majority agree, then it should read: [2 In the calculation of A, the level trim shall be used for the deepest subdivision draught and the partial subdivision draught. The actual service trim shall be used for the light service draught. If in any service condition, the trim variation in comparison with the calculated trim is greater than 0.5% of [Ls] [L], one or more additional calculations of A are to be submitted for the same draughts but different trims so that, for all service conditions, the difference in trim in comparison with the reference trim used for one calculation will be less than 0.5% of [Ls] [L]. Each additional value of A calculated in accordance with [paragraph 2] [these provisions] shall comply with regulation 6.1 and 7.1 ]. Proposed Action: As we do not have a unanimous view on whether to append the sentence to reg. 7.2 or add a new reg. 7.3 and in view of the concerns elsewhere regarding interpolation between dl and dp, it is proposed that this discussion be continued in the wider context of an alternative proposal (see Appendix 3) which would change this paragraph considerably. Further Comments?:- [Co-ordinators Note: If new paragraph 7.3 is preferred then the subsequent paragraphs and EN shown in blue below will have to be re-numbered.] 3 When determining the positive righting lever (GZ) of the residual stability curve in the final stage of flooding, [Q27B] the displacement used should be that of the intact condition. That is, the constant displacement method of calculation should be used.

[Post SLF 53 note:- It was decided in the WG to add “in the final stage of flooding”, as highlighted in red, above (see also Reg. 7.6, Q27) but not to include a further clarifying sentence at the end saying “During intermediate stages of flooding the added weight method should be used”. However, it was agreed to include a new EN at this point. For origin of this text see discussions under Reg. 7.6, Q27, below]:-

Regulation 7.3

“The purpose of calculation of sequential flooding is to ensure that any intermediate flooding stage or phase will not lead to a lower si value. During intermediate phases of flooding, the added weight method is used and only one free surface needs to be assumed for water in spaces flooded during the current stage. In the final phase (full

127 10/01/2012

phase) of each stage the lost buoyancy [constant displacement] method is used, so one free surface is assumed for all flooded spaces.” [Further Note from the coordinators post SLF 53:- Maybe we need to consider changing the first sentence of the new EN slightly to introduce the idea that residual GZ is to be calculated for both IS and final stage flooding where appropriate eg:- “In some damage scenarios it is possible that the residual GZ curve will reach its minimum value during intermediate stages or phases of flooding rather than at the final stage. In these cases, during intermediate etc etc…………. Your comments on this proposed change are invited under Q27B, below. After further discussions in the 2011 CG the following text changes were voted upon:-

Regulation 7.3 During For intermediate phases of flooding (see Reg. 7-2.2 with Explanatory Notes and Reg. 7-2.5.4), [Q27D(1)- 11-0 unanimous vote in favour of change]the added weight method is used and only one free surface needs to be assumed for water in spaces flooded during the current stage. In the final phase (full phase) of each stage the [lost buoyancy] [constant displacement] method is used, so one free surface is assumed for all flooded spaces. [In both cases, GZ is referred to the intact displacement]. [Q27D(2)] [Should we allow for multiple free surfaces - opinion divided 5 “Yes” 6 “No.”] [Q27D(3)]

4 The summation indicated by the above formula shall be taken over the ship’s subdivision length (Ls) for all cases of flooding in which a single compartment or two or more adjacent compartments are involved. In the case of unsymmetrical arrangements, the calculated A value should be the mean value obtained from calculations involving both sides. Alternatively, it should be taken as that corresponding to the side which evidently gives the least favourable result.

5 Wherever wing compartments are fitted, contribution to the summation indicated by the formula shall be taken for all cases of flooding in which wing compartments are involved. Additionally, cases of simultaneous flooding of a wing compartment or group of compartments and the adjacent inboard compartment or group of compartments, but excluding damage of transverse extent greater than one half of the ship breadth B, may be added. For the purpose of this regulation, transverse extent is measured inboard from ship’s side, at right angle to the centreline at the level of the deepest subdivision draught.

Regulation 7.5

1. With the same intent as wing tanks, the summation of the attained index A should reflect effects caused by all watertight bulkheads and flooding boundaries within the damaged zone. It is not correct to assume damage only [to the centreline] to one half of the ship breadth B and ignore changes in subdivision that would reflect lesser contributions.

128 10/01/2012

R7.5 EN (Difference between B/2 and centreline)

Comments received from CLIA/CCSF between round 1 and 2:

The EN refer to the centreline of the ship rather than to B/2 for the transverse extent of the damage: With the same intent as wing tanks, the summation of the attained index A should reflect effects caused by all watertight bulkheads and flooding boundaries within the damaged zone. It is not correct to assume damage only to the centreline to one half of the ship breadth B and ignore changes in subdivision that would reflect lesser contributions. Coordinator’s Comments: It would seem that the proposal by CLIA/CSSF better reflects the wording in the Regulation – but what is the difference between the centreline and B/2? CG Member’s Comments?:- MI: Can agree CLIA proposal which provides more consistent wording. Germany: At the ends of the vessel B/2 line crosses the CL, so that a different penetration depth is achieved. France: Agreement on the proposal. B/2 is different from centreline where deepest waterline is not at B/2 from centreline. Norway: Agree with CLIA, but the following might be clearer: “It is not correct to assume only a damage penetration equal to one half of the ship breadth B and ignore lesser penetrations that would reflect lesser contributions.” CLIA: B/2 may create damages beyond the CL, where the waterline has not the full breadth anymore (e.g. Forward end). UK: No need to change “centreline” reference. US: We can accept this proposed change. Round 2 Discussion: There is some support for CLIA’s proposal (apart from UK); Norway has an alternative. We propose that this should go to the WG at SLF 53 to obtain further opinion and views on Norway’s proposal. CLIA Q2 (for SLF53 WG). Do we prefer CLIA’s proposal or Norway’s amendment or no changes? CLIA?

Norway ?

No change?

Comments?:- The WG at SLF 53 accepted CLIA’s proposal.

CLIA Q2 RECOMMEND ACCEPTANCE OF TEXT CHANGE AT SLF 54

2. In the forward and aft ends of the ship where the sectional breadth is less than the ship’s breadth B, transverse damage penetration can extend beyond the centreline bulkhead. This application of the transverse extent of damage is consistent with the methodology to account for the localized statistics which are normalized on the greatest moulded breadth B rather than the local breadth. Where longitudinal corrugated bulkheads are fitted in wing compartments or on the centreline, they may be treated as equivalent plane bulkheads provided the corrugation depth is of the same order as the stiffening structure. The same principle may also be applied to transverse corrugated bulkheads.

129 10/01/2012

6 In the flooding calculations carried out according to the regulations, only one breach of the hull and only one free surface need to be assumed [in the final stage of flooding]. [Coordinator’s Note: see SLF 52/17/5, below, Q27. Change in red accepted by WG at SLF 53]. The assumed vertical extent of damage is to extend from the baseline upwards to any watertight horizontal subdivision above the waterline or higher. However, if a lesser extent of damage will give a more severe result, such extent is to be assumed.

[Should anything be added here on multiple free surfaces?] [Q27D(3) see Reg 7.3 EN] Regulation 7.6 (ref. SLF 51/3/2 Annex – US and Sweden) The assumption/simplification that “only one free surface need be assumed” in the flooding calculations should be reconsidered. ------------------ However, associated with including this item for future reconsideration were several additional concerns as follows:

------------------ Regulation 7.6 (ref. SLF 52/17/5 Annex - Norway) Document SLF 51/3/2 contains a proposal that the assumption/simplification “only one free surface need be assumed” in the flooding calculations should be reconsidered.

This Administration agrees with this view. In particular, the current text conflicts with calculations of intermediate stages of flooding. As a minimum, the regulation text should be amended to read: 6 In the flooding calculations carried out according to the regulations, only one breach of the hull and only one free surface need to be assumed in the final stage of flooding. The assumed vertical extent of damage is to extend from the baseline upwards to any watertight horizontal subdivision above the waterline or higher. However, if a lesser extent of damage will give a more severe result, such extent is to be assumed.

R7.3 & 7.6 and new EN for R7.3 Q27. Taking into account points a and b in SLF 51/3/2 (above), do you agree

with Norway’s proposal to amend Reg 7.6 as shown in the underlined text or is more consideration of this issue needed before such a change can be made?

Yes (accept Norway’s addition to the existing text):

China, Finland, Norway, Spain, UK

a. If the use of multiple free surfaces were to be adapted in the future, then the basis for how the R-index was developed would also have to be reconsidered. What would the GM requirement level for SOLAS 90 ships be if instead of one free surface, multiple free surfaces were applied?

b. It has been assumed in the SOLAS 2009 regulations some generally approved

simplifications. This seems to be in line with the whole harmonization work; i.e. what has been done over the last 15 years. To account for multiple free surfaces is quite a complicated matter. For example in the cabin area the space has been considered as one room. Because the space is extending from side to side the effect of multiple free surfaces is very large in the calculations. But in reality there are cabin blocks, which certainly will change the calculated value.

130 10/01/2012

No

(do not accept Norway’s addition to the existing text): Germany, Italy, Denmark

Comments / More consideration needed / Alternatives / Proposals?:- Finland: Final stage is acceptable to have only one free surface. Method how to notice free surfaces during intermediate stages and phases to be also clearly defined. This may require further studies. If damage is considered to have a very large number of intermediate stages the stability curve of the last intermediate stage must be practically the same as the stability curve of the final stage (calculated with the lost buoyancy method) since in reality the flooding is a continuous process. Also the spirit of the rule concerning the damage extents should not be violated. Germany: Final stage OK, but the method how free surfaces are to be applied for intermediate stages has to be defined clearly. Japan: Our proposal: “multiple free surfaces may be assumed in the intermediate stage of flooding.” should be inserted in either regulation text or EN. MI: Matter requires further consideration. CLIA: More consideration. Spain: The use of multiple free surfaces is more correct from a physical point of view, but we agree with your opinion, to account for multiple free surfaces is quite a complicated matter, and we think that it is for future reconsideration. Any modification in relation to this matter should me made jointly with software suppliers and with the ship designers. Denmark: Some research showing the implications and feasibility of this amendment should be undertaken before making a decision. US: We believe more consideration of this complex issue is needed. Sweden: More consideration needed. Round 1 Discussion: There is considerable hesitation and concern expressed by members over the important issue of multiple free surfaces (MFS). However, it seems hard to argue against Norway’s statement in SLF 52/17/5 that:- “In particular, the current text conflicts with calculations of intermediate stages of flooding”. At the Malmo inter-sessional meeting in December 2003, there was discussion around the issue of including a probabilistic “s” factor to account for transient asymmetrical flooding, which can lead to the vessel capsizing before the equalisation process has time to commence. Rapid loss arising from the formation of MFS on vessels with multiple decks below and just above the waterline has also been observed in model tests. These phenomena were finally omitted from the harmonisation regulations as the brief was to ensure that S2009 gave rise to an equivalent level of safety to the then current regulations (S90), which did not allow for them so they were flagged up for possible later inclusion under the heading of “future developments”. This raises the question of whether we are still bound by the “equivalence to S90” requirement or can we now, if there is shown to be a compelling need, increase the safety level provided by S2009 in certain areas (such as allowing for MFS)? Is it possible to do this without re-calculating “A” for many S90 ships allowing for MFS, for example, then revising the “R” index accordingly – a long and expensive process? Or can we retain the same “R” index but simply ask for MFS to be accounted for during intermediate stages of flooding, as proposed by Norway?

131 10/01/2012

There is also an issue of complexity, touched on by several members – it would be quite difficult to ensure a rational approach to the calculation of multiple free surfaces during intermediate stages of flooding in complex “rooms” without employing time-based flooding simulations, which are not widely available. On the other hand, as Norway suggests, intermediate stage flooding calculations are somehow being undertaken at the present time for new S2009 designs (although there are rumours that they are being overlooked in some cases as being “too complex”, which may be due to lack of clarity/guidance in the Regs and EN). In this respect, Finland’s comment hinting that intermediate stages are being calculated using an added weight, rather than a lost buoyancy method is intriguing. Is this the commonly accepted practice? Older software packages used to determine the final equilibrium situation having first allowed users to nominate the number of stages with the % filling depth for each stage in the affected rooms. The software would then divide the total weight of floodwater at final equilibrium in each room by the number of stages and work out the damage stability accordingly at each stage (all based on lost buoyancy). The aim was to find if there was a risk of capsize at any time during the intermediate flooding sequence, but the choice of filling depths in each progressively-flooded room was largely a matter of “judgment” (i.e. guesswork!) and it was possible to miss the worst combination altogether. Perhaps it is more valid to calculate residual stability using lost buoyancy only for those compartments breached and directly open to the sea and added weight for those which are progressively flooded? Your thoughts on using added weight during IS flooding would be welcome. It therefore seems clear that if we do agree to Norway’s proposal (5 members in favour), some further explanation of the treatment of multiple free surfaces during intermediate stage flooding may be needed in the text and/or the EN, as suggested by Japan. Also, as suggested by Finland, the wording of the regulation may need to be changed slightly to accommodate Norway’s proposal so as to avoid a misunderstanding that only one breach of the hull is to be considered in the final stage of flooding [implying that many breaches are to be considered during other stages]. Proposed clarification:- 6 In the flooding calculations carried out according to the regulations, only one breach of the hull [is to be considered] and only one free surface need[s] to be assumed in the final stage of flooding. Proposed Alternative Actions:- Either (1) We report to the SLF sub-committee that we have considered Norway’s proposed amendment to Reg 7.6 in SLF 52/17/5 regarding MFS but have concluded that this issue, although urgently in need of attention, first needs more research into finding out how best to make allowance for it within the Regulations and EN. Or (2) We acknowledge the risk of ignoring the possibility of MFS any further and accept Norway’s proposal [amended as shown?] then attempt to include some new regulatory text (and/or EN) on the treatment of MFS during intermediate stage flooding, based on current best practice. Q27A. Please indicate which alternative you prefer:-

Yes to Alt (1)

MI, Japan, CLIA (with comment), UK, Sweden

Yes to Alt

(2)

Germany, Finland, Italy (with comments), France (with comments), Norway (with comment), US (with comments), Denmark

132 10/01/2012

Please also note that Germany and Finland raise the issue of using the added weight method during intermediate stages of flooding in their response to Q35. [Coordinator’s Note: Inserted here for easy reference .. Finland: Method how to notice free surfaces during intermediate stages and phases to be also clearly defined. This may require further studies. If damage is considered to have a very large number of intermediate stages the stability curve of the last intermediate stage must be practically the same as the stability curve of the final stage (calculated with the lost buoyancy method) since in reality the flooding is a continuous process. Also the spirit of the rule concerning the damage extents should not be violated. Germany: Intermediate phases have to be calculated by “added weight” method.] Comments / Other Alternatives / If Alt (2) is chosen do you support the proposed clarification?:-

Italy: We support the proposed clarification, but only in conjunction with the clarification submitted by CLIA/CSSF on the intermediate filling phases with the “added weight” method [Coordinator’s Note: see under CLIA, below.] RINA: If multiple free surfaces can occur from a single breach, in either the intermediate or final stages of flooding, then the loss of GM from each free surface will have a cumulative effect and must be considered. This is particularly important when a ship is being operated based on data from the limiting GM/KG and the operational limit is close to the GM/KG envelope. It is noted that intact stability takes into account multiple free surfaces. France: The question is related to intermediate phases which are treated with added weight method. From our understanding, the meaning is that only one free surface is considered for all spaces flooded in the same stage. At the end of each stage, filling level in flooded compartments reach the outside water level, so one free surface is observed. More precise wording would be : “During intermediate phases of flooding, added weight method is used and only one free surface need to be assumed for water in spaces flooded during the current stage. In final phase (full phase) of each stage lost buoyancy method is used, so one free surface is assumed for all flooded spaces.” Norway: Supports proposed clarifications. Please also see answer to Q35A. [Coordinator’s Note: Inserted here for easy reference – “Using constant displacement in this context where no initial masses are considered lost (as opposed to cargo in MARPOL etc) will normally be slightly conservative with respect to the effect on the righting lever. We are not sure if the wording in regulation 7.3 was included for this reason. Please note that our proposal and MSC/Circ.406/rev.1 relates to the “final survival conditions”. We agree that the question on whether to disregard the transient added mass in partially flooded spaces not communicating directly with the sea as well as handling of free surface effects in these spaces should be discussed further.”] CLIA: See CLIA/ CSSF comments to reg. 7-2.2 EN3 which supports added weight method for intermediate phases, resulting in more than one free surface. [Coordinator’s Note: inserted here for easy reference:- 3. For each damage scenario, the damage extent and location determine the initial stage of flooding. Calculations should be performed in stages, each stage comprising of at least two intermediate filling phases in addition to the full phase per flooded space. Unrestricted spaces in way of damage should be considered as flooded immediately. Every subsequent stage involves all connected spaces being flooded simultaneously until an impermeable boundary or final equilibrium is reached. If due to the configuration of the subdivision in the ship it is expected that other intermediate stages of flooding are more onerous, then those should be investigated Additional explanation: The purpose of calculation of sequential flooding is to ensure that any intermediate

133 10/01/2012

flooding stage or phase will not lead to a lower si value. The calculation of the intermediate filling phases should be carried out using the “added weight” method, resulting in more than one free surface.

] US: Generally yes; however, we believe Japan’s proposal to explicitly indicate ‘multiple free surfaces may be assumed in the intermediate stage of flooding’ has merit. Note Regarding the discussion (and general issue) of maintaining an equivalent level of safety to the S90 regulations: It is our view that SLF is no longer bound by the original harmonization “equivalence to S90” requirement (and we should stop interjecting the “re-calculation of S90 sample ships to revise the R index” issue into our current work). May be this issue should be specially addressed and concluded? Round 2 Discussion: There are several issues arising from the question of allowing for MFS. 1) As it was not covered by the previous SOLAS regulations, implementing new MFS regulations within S2009 would mean that the “equivalent level of safety” principle no longer applies. The US raises this point and we therefore propose to seek confirmation from the S-C that we are no longer bound by the “equivalence to SOLAS90” constraint (ref. SLF 53/14 paragraph 13.1). 2) There was a small majority (7-5) in favour of early implementation of Norway’s proposed amendment as opposed to conducting further research first. 3) If we accept the majority view we could change reg. 7.6 as proposed by Norway and as amended slightly to:- “6 In the flooding calculations carried out according to the regulations, only one breach of the hull [is to be considered] and only one free surface need[s] to be assumed in the final stage of flooding.” 4) There is a proposal by Japan, supported by the US, to add further clarification:- “6 In the flooding calculations carried out according to the regulations, only one breach of the hull [is to be considered] and only one free surface need[s] to be assumed in the final stage of flooding. [Multiple free surfaces may be assumed in the intermediate stage of flooding.]”

Spaces flooded during intermediate flooding phase Spaces flooded during intermediate flooding phase

134 10/01/2012

5) It seems that there is general agreement that the added weight method should be used during intermediate stages. This may mean we will also need to consider altering reg. 7.3 (see also Norway’s proposals under Q35):- “3 When determining the positive righting lever (GZ) of the residual stability curve [in the final stage of flooding], the displacement used should be that of the intact condition. That is, the constant displacement method of calculation should be used [During intermediate stages of flooding the added weight method should be used ].”

6) The question then arises as to the need for a new EN for reg. 7.6 (and/or 7.3). As a starting point, we suggest that France’s submission could be used for this purpose, maybe beginning with CLIA’s to the EN for reg 7-2.2 (EN3):- “The purpose of calculation of sequential flooding is to ensure that any intermediate flooding stage or phase will not lead to a lower si value. During intermediate phases of flooding, the added weight method is used and only one free surface needs to be assumed for water in spaces flooded during the current stage. In the final phase (full phase) of each stage the lost buoyancy[constant displacement] method is used, so one free surface is assumed for all flooded spaces.” Proposed Actions:- 1) Raise the general issue of equivalence between S2009 and previous SOLAS regulations in plenary for a decision from the S-C. 2) In the WG discuss the question of either (a) doing further research or (b) trying to change regulations [7.3 and] 7.6 and the EN now. 3) If (b), discuss the above changes to reg. 7.3, 7.6 and the EN and report back to plenary. Q27B (for SLF 53 S-C). 1) If we believe we have uncovered safety deficiencies in SOLAS 2009 are we now free to propose improvements without being constrained by the requirement to maintain an equivalent level of safety to the previous SOLAS regulations? (for SLF 53 WG) 2a) Do we wish to delay amending reg. [7.3 and] 7.6 and accompanying EN to allow for the effect of multiple free surfaces until further research is carried out? OR, 2b) Do we wish to change reg. [7.3 and] 7.6 as soon as possible? 3) If 2b) Can we accept any of the proposed changes to reg. 7.3 and 7.6 and EN, made under the round 2 discussion above? Q1 (Y/N)? Post SLF 53 note:- “The Sub-Committee agreed that it was no longer

bound to maintain an equivalent level of safety to the previous SOLAS chapter II-1 subdivision and damage regulations and that this new output is aimed at refining and improving the current SOLAS chapter II-1, based on experience gained in the application of its provisions. If the current work uncovers safety deficiencies in the chapter then they should be corrected”. (Ref. SLF 53/WP.1 paragraph 14.5).

Q2 Prefer 2(a) or 2(b)?

The WG at SLF 53 decided to accept Norway’s original proposal without any changes, as shown highlighted in red, above.

135 10/01/2012

Q3 If 2(b), state

preferred wording (or alternative)?

Similar changes were agreed by the WG at SLF 53 to Reg. 7.3 in association with a new EN based on Round 2 discussion point 6), above. As the WG did not agree to include the proposed sentence relating to IS flooding, the coordinators now believe that the opening sentence of the proposed new EN for Reg 7.3 should be changed slightly to read:- “In some damage scenarios it is possible that the residual GZ curve will reach its minimum value during intermediate stages or phases of flooding rather than at the final stage. In these cases, during intermediate etc etc…………. The currently agreed text for the EN for Reg. 7.3 reads:- “[The purpose of calculation of sequential flooding is to ensure that any intermediate flooding stage or phase will not lead to a lower si value]. During intermediate phases of flooding, the added weight method is used and only one free surface needs to be assumed for water in spaces flooded during the current stage. In the final phase (full phase) of each stage the lost buoyancy [constant displacement] method is used, so one free surface is assumed for all flooded spaces.”

Q27C (for Round 4 questionnaire). Would you agree to replacing the opening sentence in the EN for Reg. 7.3 (shown in square brackets with strikethrough, above) with the text in green as proposed under Q3 above?:- Yes Vanuatu, US, Sweden, Norway, Japan, China, RINA, Denmark, Italy, UK,

Spain, EC (however, ongoing research (GOALDS and EMSA 2) might have a bearing on this. Results of these studies should be taken into account), CLIA (this seems to explain it better. No objection), MI (agree the revised opening sentence provides greater clarity).

No Germany, Finland, France

Further Comments?:- Germany: The wording shown above in red/grey should be kept, also keep the first sentence in the square brackets. Finland: The text shown above in red/grey should be kept, and also first sentence “The purpose of calculation …” to be kept. See also our comments for Q27. France: Survival factors are calculated with different formula for intermediate or final stages of flooding, so it should not be made reference to GZ curve to compare these stages. The purpose of regulation 7.3 is to determine the way of calculation of the GZ curve, for intermediate or final stages of flooding, so it should be sufficient to write : During intermediate phases of flooding, the added weight method is used and only one free surface needs to be assumed for water in spaces flooded during the current stage. In the final phase (full phase) of each stage the lost buoyancy [constant displacement] method is used, so one free surface is assumed for all flooded spaces. In both cases, GZ is referred to the intact displacement.” Round 6 Discussion: There is a clear majority (14 – 3) in support of the proposed changes (summarized below, for easy reference):- 2 When determining the positive righting lever (GZ) of the residual stability curve

in the final stage of flooding, the displacement used should be that of the intact condition. That is, the constant displacement method of calculation should be used.

136 10/01/2012

Regulation 7.3

“[The purpose of calculation of sequential flooding is to ensure that any intermediate flooding stage or phase will not lead to a lower si value]. In some damage scenarios it is possible that the residual GZ curve will reach its minimum value during intermediate stages or phases of flooding rather than at the final stage. In these cases, Dduring intermediate phases of flooding, the added weight method is used and only one free surface needs to be assumed for water in spaces flooded during the current stage. In the final phase (full phase) of each stage the lost buoyancy [constant displacement] method is used, so one free surface is assumed for all flooded spaces.” In response to comments from Finland, France and Germany, the red text in italics highlighted in grey was agreed by the WG at SLF 53. The strikethrough and the text highlighted in green was proposed by the co-ordinators in round 4 as the sentence “The purpose of calculation of sequential flooding etc” suddenly appears in an EN supposed to be clarifying a regulation which now refers (in its altered form) only to the final stage of flooding. The sentence would have been more appropriate if the regulation itself had mentioned IS flooding, as was originally proposed, but this was not agreed to by the WG. Also, those reading revised reg. 7.3 will immediately wonder what the SOLAS requirements are for the other stages of flooding, which is why the new EN appears here with the introductory sentence in green. Another reason for deleting the sentence beginning “The purpose of calculation … etc” was that it does not seem to add any further explanation to existing Reg. 7-2.2 concerning calculation of the least of the s-factors from all flooding stages. The existing EN (3) for reg. 7-2.2 already contains specific guidance on the computation of IS flooding - the only thing not specified is the use of the added weight method. When we proposed the additional sentence in green (above) we had not made the connection with EN (3) for reg. 7-2.2. So, to avoid duplication, we now think it may be better to link the new EN for reg. 7.3 to reg. 7-2.2 and 7-2.5.4 as shown below (more or less as France suggests except for the changes highlighted in green):- Regulation 7.3

During For intermediate phases of flooding (see Reg. 7-2.2 with Explanatory Notes and Reg. 7-2.5.4), the added weight method is used and only one free surface needs to be assumed for water in spaces flooded during the current stage. In the final phase (full phase) of each stage the lost buoyancy [constant displacement] method is used, so one free surface is assumed for all flooded spaces. [In both cases, GZ is referred to the intact displacement]. As we now understand it, the standard practice is to use the added weight method for intermediate stages of flooding and the lost buoyancy method in the final stage of flooding. We wanted the regulations and EN to reflect this practice, so we hope you can now agree to the above changes. We are sorry for changing things around again. We are not 100% sure that the last sentence in square brackets above, proposed by France, is correct as we had thought it may be more logical to base the GZ for intermediate flooding on the (intact displacement + added weight). Perhaps this is too difficult for software to handle (?) but it would give a more conservative result. We invite your opinion in Q27D(2), below. Another issue, which is more relevant to reg. 7.6, and is not directly related to IS

137 10/01/2012

flooding is that certain model tests have shown that a multi-deck vessel with several horizontal watertight boundaries below and/or just above the waterline could, when suffering a single breach of the hull, very quickly accumulate large free surface moments on several decks simultaneously with potentially very dangerous consequences. The fact that we are now no longer bound to maintain an equivalent level of safety to S90 leaves us free to consider whether this possibility should be allowed for in reg. 7.6 by, for example, removing the phrase “and only one free surface” and perhaps adding a new EN. The calculation of this phenomenon may be difficult, however, involving a water-on-deck approach. So, again, your opinions are invited in Q27D(3), below. Please note earlier discussions in large working document. Q27D (for Round 6 Questionnaire).

1) Do you agree to the new proposal for the EN to reg. 7.3 referring to reg. 7-2.2 etc, as shown in the discussion above?

2) Do you agree that we should add the last sentence in square brackets, as proposed by France?

3) In reg. 7.6, do you think any action is needed to account for the possibility of multiple free surfaces, as outlined in the last paragraph of the discussion?

Q1 (Y/N)? Yes: Japan, RINA, Finland, Norway, Germany, US, Italy, UK, France, Denmark, China No Comments: CLIA

Q2 (Y/N)? Yes: Japan, Poland, France, Denmark, UK (can we modify the suggested text to “in both cases, GZ curve is calculated with the vessel’s intact displacement”?). No: RINA (We concur with the coordinators comments), Finland, Norway, Germany (No, the square brackets are not needed and may only add more confusion.), US (No – do not add), Italy, China No Comments: CLIA

Q3 (Y/N)? Yes: RINA, Norway, Poland, UK (In principle “yes” to indicate that multiple free surfaces may be assumed in the intermediate stages of flooding), EC (Yes, it seems appropriate to take account of multiple free surfaces, thereby fully taking into account ' water on deck'.) . No: Japan, Italy, Finland, China, Denmark (not at this stage), US (It is our understanding that the current agreed to text for reg 7.6 now indicates “...only one free surface need to be assumed in the final stage.” Under the circumstances it seems this maybe sufficient for the regulation text (i.e. now allows consideration of multiple free surfaces in the intermediate stages but without an explicit requirement to consider them). Then guidance on when multiple free surfaces should be considered could be added to the EN. (so our response is no)). No Comments: CLIA

Further Comments?:- Norway on 2): The coordinators’ comment with regard to problems for software to calculate could be relevant. However, it should be possible. RINA on 3): We would agree with the correspondence coordinators comments with regards to paragraph 7.6. It would appear that there are several options that could be considered for the assessment of water which could be entrapped in spaces above the final damaged water and accumulate large free surface moments with the consequential impact on the damage stability of the ship.

1. Apply the requirements for water on Ro-Ro decks in accordance with SOLAS/CONF.3 - Resolutions of the Conference of Contracting Governments to the International

138 10/01/2012

Convention for the Safety of Life at Sea, 1974 - (November 1995) - Resolution 14 - Regional agreements on specific stability requirements for ro-ro passenger ships - (Adopted on 29 November 1995). 2. Wait for the results of the research projects. 3. Demonstrate compliance with an administrations requirement.

Finland on 3): By applying multiple free surfaces there will be inconsistencies between different individual designs. How to define spaces in watertight compartment? During transient flooding (during first seconds) multiple free surfaces have effect. But how realistic are model test results? Has the movements of striking vessels studied during the first seconds? Germany on 3): The consistent application of multiple free surfaces may be very difficult and depends very much on individual designs. Multiple free surfaces as seen during model tests usually appear only during the first seconds of flooding, which are in any way very unclear (e.g. which influence has the striking vessel) Poland on 3): Action is needed to account for the possibility of multiple free surfaces. France on 3): According to proposed wording, two free surfaces may be taken into account during intermediate phases of flooding. If more than two free surfaces have to be considered, this would induce the consideration of too many possible flooding sequences, so it would not be possible to remain within the present simplified approach. This should be dealt with flooding simulation approach, taking into account actual process of flooding water. Phenomenon of accumulation of water on deck (water level in flooded compartment above sea level) should be taken into account in the formulation of survival factor. China on 3): The influence caused by multiple free surfaces may need to be further considered, but it may be also very difficult for software to handle.

Q27 For R7.3 and new EN the text change in red was agreed at SLF 53 and there was a unanimous vote of 11-0 in favour of the green text below (Q27D(1)). There was a wide range of views on Q27D(2) and (3), however, so these issues must be discussed at SLF 54 (see also R7.6). 3 When determining the positive righting lever (GZ) of the residual stability curve in the final stage of flooding, [Q27B] the displacement used should be that of the intact condition. That is, the constant -displacement method of calculation should be used. Regulation 7.3 During For intermediate phases of flooding (see Reg. 7-2.2 with Explanatory Notes and Reg. 7-2.5.4), [Q27D(1)- 11-0 unanimous vote in favour of change]the added weight method is used and only one free surface needs to be assumed for water in spaces flooded during the current stage. In the final phase (full phase) of each stage the [lost buoyancy] [constant displacement] method is used, so one free surface is assumed for all flooded spaces. [In both cases, GZ is referred to the intact displacement]. [Q27D(2)] [Should we allow for multiple free surfaces - opinion divided 5 “Yes” 6 “No.”] [Q27D(3)]

DISCUSS AT SLF 54

7 If pipes, ducts or tunnels are situated within the assumed extent of damage, arrangements are to be made to ensure that progressive flooding cannot thereby extend to compartments other than those assumed flooded. However, the Administration may

139 10/01/2012

permit minor progressive flooding if it is demonstrated that its effects can be easily controlled and the safety of the ship is not impaired.

Regulation 7.7

1. Pipes and valves directly adjacent to a bulkhead or to a deck can be considered to be part of the bulkhead or deck, provided the separation distance is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc. Valves which are situated as close practicable to the bulkhead or deck, but exceeding due to their size the order of the stiffening structure should still be assumed to be part of the bulkhead or deck.

Coordinator’s Note post SLF 53:- The above addition to the text was agreed after some discussion at the SLF 53 WG (see CLIA Q3, below) Regulation 7.7 EN 1 (Stiffeners may be small relative to pipes or valves)


CLIA Q3 Modification with regard to location of separation valves at watertight bulkheads and decks. Application in practice has shown that the size of the stiffeners might sometimes be too small for large pipe diameters. “Pipes and valves directly adjacent to a bulkhead or to a deck can be considered to be part of the bulkhead or deck, provided the separation distance on either side of the bulkhead or deck is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc. Valves which are situated within the distance defined above and as close practicable to the bulkhead, but exceeding due to their size the order of the stiffening structure should still be assumed to be part of the bulkhead.” . Coordinator’s Comments: If this is acceptable we would suggest using “in size the depth” instead of “due to their size the order” in the last sentence:- Valves which are situated within the distance defined above and as close as practicable to the bulkhead, but exceeding in size the depth of the stiffening structure should still be assumed to be part of the bulkhead.” CG Member’s Comments?:- MI: Could agree to the co-ordinators revised text. Germany: Acceptable. Finland: Support. Italy: The proposal is supported. Norway: It is perhaps a better option to handle such large diameter pipes and long spool pieces/valves as recesses, i.e. the zone limits are to be moved away from the bulkhead. CLIA: Agree. US: We can accept this proposed change. Text suggestions: (1) delete the words within the distance defined above and because they are not (or we wouldn’t need this caveat). (2) add “or deck” after bulkhead to cover both.

140 10/01/2012

Round 2 Discussion: We must point out that similar EN’s appear in two other places (reg. 7-1.1.1 EN 7 and reg. 7-1.1.2 EN 12). Also note that reg.7-1.1.1 EN 8 would support Norway’s position. For consistency we would either need to consider possible changes to all three EN’s or simply to leave all three as they are. CLIA Q3 (for SLF53 WG). Given that we have other EN’s covering the issues raised by CLIA do you think we should look at revising all three EN’s or should we leave them all alone? Revise all 3

EN’s?

Leave all 3 EN’s

alone?

Further Comments?:- Post SLF 53 comments:- The WG at SLF 53 amended each of the EN’s as appropriate (see changes highlighted in grey).

CLIA Q3 [Coordinator’s Note:. There is a new proposal to harmonize the text with reg. 7-1.1.1 EN7 and reg. 7-1.1.2 EN 12, as highlighted in green, below. For full discussion see reg 7-1.1.2 EN12, under CLIA Q6D. Support is good but US and RINA have some reservations on the proposed amendments in green below for this EN ]:- 1. Pipes and valves directly adjacent to a bulkhead or to a deck can be considered to be part of the bulkhead or deck, provided the separation distance on either side of the bulkhead or deck is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc. Valves which are situated as close as practicable to the bulkhead or deck, but exceeding due to their in size the order depth of the stiffening structure should still be assumed to be part of the bulkhead or deck. ]

DISCUSS FURTHER AT SLF 54 2. The provision for allowing “minor progressive flooding” should be limited to pipes penetrating a watertight subdivision with a [total] cross-sectional area of not more than [710 mm

2] [an equivalent pipe diameter of Ls/5000] between any two watertight

compartments. [The total cross-sectional area of all [this] [these] small pipes should [have a cross-sectional area of not more than] [not exceed] [an equivalent pipe diameter of Ls/1000]]. [Coordinator’s Note post SLF 53:- For details of agreed changes and need for further consideration by CG in 2011 see comments at end of CLIA Q4, below.] R7.7 EN2 (Pipe area limit for limiting progressive flooding should be based on L?)


CLIA Q4 On cruise vessels, but also on other type of ships, there are a number of systems with small pipe diameters which may not have a significant influence on progressive flooding. The group is of the opinion that the ship size should be a criterion to determine the maximum allowable diameter or cross section area of pipes, for which progressive flooding can be ignored. The final wording has to be further discussed at the SDS WG.

141 10/01/2012

“The provision for allowing “minor progressive flooding” should be limited to pipes penetrating a watertight subdivision with a [total] cross-sectional area of not more than [710 mm2][an equivalent pipe diameter of Ls/5000] between any two watertight compartments. [The total cross-sectional area of all this small pipes should have a cross-sectional area of not more than [an equivalent pipe diameter of Ls/1000]]”. . Coordinator’s Comments: If the above is accepted, the wording of the last sentence could be tidied up slightly:- [The total cross-sectional area of all [this] small pipes should [have a cross-sectional area of not more than] [not exceed] [an equivalent pipe diameter of Ls/1000]]”. CG Member’s Comments?:- MI: Could agree to the co-ordinators revised text. Germany: Acceptable. Finland: Support. Italy: The co-ordinator’s proposal is supported. Norway: Do not support the suggestion at this stage. CLIA: Agree. US: Although we are willing to revisit this issue, the CLIA proposal requires justification and further discussion prior to accepting any changes. Historical note: The current 710 mm2 originated from the following IACS submission to the SDS CG between SLF 49 and 50: “By minor progressive flooding is assumed a [single] pipe penetrating a watertight subdivision and having an internal diameter of less than [0,03] m”. Round 2 Discussion: There is good support for CLIA’s proposal but US and Norway have some reservations. It is therefore proposed that we put the issue to the SLF 53 WG so that other members views can be expressed bearing in mind the historical background provided by the US. CLIA Q4 (for SLF53 WG). Do you support CLIA’s proposal (as amended if necessary)?

Yes

No

Further Comments? Coordinator’s Note post SLF 53:- Some changes to the text of the EN were agreed to emphasize the WG’s feeling that it was the aggregate cross-sectional area of all the small pipes (shown highlighted in grey, above). However we as coordinators remain of the opinion that “not exceed” reads better than “have a cross-sectional area of not more that” (avoids repetition). We also made a note during the WG meeting that this entire issue should be reconsidered by the CG because of reservations by Norway and the US. CLIA Q4 (for Round 4 questionnaire). 1) Do you think that CLIA’s original proposal to change Reg. 7.7 EN2, as amended by the WG at SLF 53 (see below), is acceptable:- 2. The provision for allowing “minor progressive flooding” should be limited to pipes penetrating a watertight subdivision with a [total] cross-sectional area of not more than [710 mm


compartments. [The total cross-sectional area of all [this] [these] small pipes should [have a cross-sectional area of not more than] [not exceed] [an equivalent pipe diameter of Ls/1000]].

142 10/01/2012

2) If “yes” do you agree that the following wording for the second sentence, as proposed by the coordinators, is preferable?:- The total cross-sectional area of all small pipes should not exceed an equivalent pipe diameter of Ls/1000]

Q1 Yes China, Finland, Italy, CLIA, MI, EC (however, it should be realised that this makes the requirement (far) more stringent for smaller ships (< 150 m), while there is a relaxation for large ships which might be acceptable. Although there is no further justification why this would be necessary), Spain (It seems to be more correct to connect “minor progressive flooding” with the ‘size’ (length, tonnage) of the vessel, instead of assuming a fixed value. BUT, FOR PRACTICAL REASONS, a fixed value could be a good alternative for small vessels (i.e.: passenger vessels with Ls of less than 50 m, for these small vessels a cross-sectional limit area of 50/5000 and 50/1000 could be maintained allowing “minor progressive flooding”).

No Vanuatu, US, Sweden, Norway, Japan, RINA, Denmark, Germany (Ls/1000 seems very much (e.g. equivalent pipe diameter for 300m vessel: 300m/1000=0.3m). No specific limit should be mentioned in this regulation. See proposal below as a possible compromise).

Q2 Yes Japan, China, Finland, Italy, CLIA, Spain, MI (agree that this text is preferable)

No Vanuatu (can’t agree at this stage), Denmark US (deleting the second “cross-sectional area” could cause some confusion). EC (Should this be Ls/5000? Ls/1000 gives a diameter of 25 cm, which seems not to be 'minor'.)

Further Comments? (especially from US and Norway who have reservations on this entire issue):- Vanuatu: We too have reservations; in part because we seem to be ignoring units and making no distinction between the uses of the piping in this discussion. Use of words like “total” and “equivalent” without referents is not conducive to clarity either. US: We agree that the current EN (that limits the total cross-sectional area of all pipes between any two watertight compartments to 710mm2 – an equivalent pipe diameter of 30mm) is quite strict, and therefore we are not opposed to some scale factor to account for ship size. We can generally accept the single pipe scale factor of Ls/5000, but we think the total cross-sectional area scale factor of Ls/1000 is excessive (it allows 25 max sized single pipes between any 2 compartments). We think Ls/2000 may be more appropriate, which would allow approximately 6 max sized single pipes between any 2 compartments. Sweden: Agrees with the US reservation. Norway: We are not against to limit the amount of progressive flooding in relation to the size of the vessel. However, we see that the former cross-sectional area of 710mm2 corresponds in the new guidelines for a vessel with Ls around 30 meters. The new guidelines is therefore a relaxation and needs to be considered more thoroughly with regard to bilge pumping capacity in relation to the “minor progressive flooding”. Furthermore, some wording should be included in the EN related to making sure that the safety of the ship is not impaired (bilge system not operation after damage, size of flooded compartment, A/R ratio etc.).

Japan: In the case of small ships, Ls/5000 is too small, ex. Pipe diameter not more than 16 ϕ is

required for the ships with Ls =80m, however generally used CO2 pipe diameter is more than 20

143 10/01/2012

ϕ

Japan thinks only the criterion of total cross–sectional area of all small pipes is needed. With regard to Q2, the criteria of total cross–sectional area of all small pipes, Japan supports coordinator’s proposal. [Co-ordinator’s Note: Sorry about the line spacing here!] China: We think the reason why Ls/1000 and Ls/5000 was determined, need to be clarified. RINA: The flow of water through the pipes, which are considered to lead to minor progressive flooding, should take into account issues such as: the total flow and whether this will be continuous; vertical distance from the damage waterline to the pipe outlet; how will the water in that space be controlled; whether the minor progressive flooding will have an impact on essential services in that space ,etc Denmark: Using Ls seems to unfairly penalise the piping and arrangement of smaller vessels, particularly since the pipe sizes of the systems in question are by and large fixed. It is also by no means established that Ls and pipe diameter are the only variables that correlate with the severity and survivability of progressive flooding. Germany: Proposal for compromise: [As guidance] the provision for allowing “minor progressive flooding” should be limited to pipes penetrating a watertight subdivision with cross-sectional area of not more than an equivalent pipe diameter of Ls/5000 between any two watertight compartments. [The total area of such pipes should be a small as practicable, taking into account the position of the pipes, the size and location of the room.] France: It appears that there is a mistake in transcription of CLIA proposal. Equivalent diameter of Ls/1000 should be replaced by Ls/5000. Round 6 Discussion: For clarification, the question was asked whether the following text for reg. 7.7 EN2 as originally proposed by CLIA and modified by the SLF 53 WG was acceptable:- 2. The provision for allowing “minor progressive flooding” should be limited to pipes penetrating a watertight subdivision with a cross-sectional area of not more than an equivalent pipe diameter of Ls/5000 between any two watertight compartments. The total cross-sectional area of all these small pipes should [have a cross-sectional area of not more than] [not exceed] [an equivalent pipe diameter of Ls/1000]. The co-ordinators had proposed that the text could be simplified further by using “not exceed” to avoid repeating the term “cross-sectional area” twice in the same sentence. The final square brackets were left in case of dispute over the size of the Ls/1000 term. These issues were returned to the CG for further discussion. In response to France’s comment we have checked the original CLIA proposal and confirm that it has been correctly transcribed. Regarding the units, use of “equivalent” and “total”, (Vanuatu’s points) we guess the EN means, for a ship of 50 metres in length Ls, for example, that no individual pipe should exceed 50/5000 metres (= 10mm) in diameter which is equivalent to 78.5 mm2 in cross-sectional area. The total diameter of all such individual pipes should not exceed 50/1000 metres (= 50mm) which is equivalent to a total cross-sectional area of 1963 mm2. This is clearly much greater than the figure of 710 mm2 which the original EN would have permitted (based on a single pipe of 30 mm diameter) and, as many have pointed out, represents a big relaxation for larger vessels (see graph below). For Ls =300 m, for example, the maximum total pipe diameter representing the upper limit for minor progressive flooding would be 300 mm (10 “standard” 30 mm pipes) or 70696 mm2 cross-sectional area.

144 10/01/2012

R7.7 EN2; Max Pipe Areas to avoid Minor Progressive flooding

0.0

1000.0

2000.0

3000.0

4000.0

5000.0

0 100 200 300 400

Ship Length Ls m

Pipe

Are

a m

m2

Individual Pipe Area mm2(CLIA)

Total Pipe Area mm2 (CLIA)

Total Pipe Area mm2 (Original)

Total Pipe Area mm2 (USproposal)

We have also shown the US proposal (Ls/2000) on the above graph for comparison. As Spain, EC, Japan and Denmark point out any simple ratio based only on Ls can produce difficulties, particularly for smaller vessels. For example, for Ls = 50 m the US proposal would lead to a maximum individual pipe diameter of only 10 mm, and a total pipe diameter of 25 mm. As Denmark says, there is no certainty that Ls and pipe diameter are the only variables to be considered (RINA provides details of other variables) and Norway points out that the bilge pumping capacity is of importance. Japan and Denmark mention standardized pipe diameters which are independent of ship length for engineering reasons (for example, the minimum diameter of a CO2 pipe is 20 mm, according to Japan). Proposal 1. To overcome some of these problems Germany proposes to keep Ls/5000 as the limit for individual pipes but not to set a limit for the total area of all pipes – saying that such area should be kept as small as practicable taking into account the position of the pipes, size of room etc. Proposal 2. As an alternative the co-ordinators propose keeping the current limit for total pipe area of 710 mm2 (one standard pipe of 30 mm diameter) for ships up to 150 m Ls. For ships of 150 m Ls and upwards we could adopt part of the US proposal by setting an upper limit of 6 standard pipes (180 mm diameter in total) for a vessel of length, say, Ls = 350 m and upwards and interpolating for intermediate Ls between 150 and 350 m, as shown below:-

145 10/01/2012

Total Pipe Area mm2 (co-ordinator's proposal)

0

5000

10000

15000

20000

25000

30000

0 50 100 150 200 250 300 350 400

Ship Length Ls (m.)

Pipe

Are

a (m

m2)

If a maximum figure for any individual pipe is still deemed necessary we suggest that this could be Ls/5000 m for ships of 150 m Ls and upwards (equating to approximately 1 standard pipe diameter at Ls = 150 m and 2 standard pipe diameters for Ls = 350 m). The wording of EN 2 would then become:- 2. For ships up to Ls = 150 m the provision for allowing “minor progressive flooding” should be limited to pipes penetrating a watertight subdivision with a total

cross-sectional area of not more than 710 mm2 between any two watertight

compartments. For ships of Ls = 350 m and upwards the provision for allowing “minor progressive flooding” should be limited to pipes penetrating a watertight subdivision with a total cross-sectional area of not more than 25500 mm

2 between any two watertight

compartments For ships between Ls = 150 and 350 m, the total cross-sectional area should be obtained by linear interpolation between the above figures. For ships of Ls = 150 m and upwards no individual pipe should exceed a diameter of Ls/5000 m.

146 10/01/2012

CLIA Q4D (for Round 6 questionnaire). Recognising that the use of ratios such as Ls/1000 and Ls/5000 can result in some anomalies, especially for smaller ships, would you agree to change EN 2 either along the lines proposed by Germany (Ls/5000 for individual pipes but no specific figure for the total area) or would you prefer to have all the figures specified as proposed above by the co-ordinators? Or is there a better way?

Prefer Germany’s proposal?

RINA (No), Germany (Yes), Poland (Yes)

Prefer co-ordinator’s proposal?

Japan, CLIA, UK, Denmark, Finland (with comment), Norway (with comment), China, Italy RINA (No), Germany (could be acceptable), US (Generally prefer the co-ordinator’s proposed approach; subject to further discussion and potential adjustment of the details), EC (Yes, seems reasonable. We believe that it is sufficient when the total cross sectional area is defined, so the last sentence of the proposal would not be necessary.)

Alternative proposal?

RINA: It is considered that the proposed EN amendments to limit the size of pipes are not necessary. See comments below. Germany: Delete numerical specification from the EN. France: (see below)

Further Comments? RINA: It is noted that the text regulation 7.7 as been amended by deleting the text which states that: “The Administration may permit minor progressive flooding, if it is demonstrated that its effects can be easily controlled and the safety of the ship is not impaired.” No minor progressive flooding should be allowed unless it is controlled and it is documented in the damage stability control books/plan. If this text is added to the proposal then it follows that each minor progress flooding case should be assessed in the damage stability calculations and an assessment made on a case by case basis in accordance with the requirements stated above. Consequently it is not necessary to provide any controls on the size of the pipes. Finland: Co-ordinator’s proposal sets also limit for a total area of all pipes. Norway: We support in principal. However, the actual limit for vessels of Ls > 350 m should be evaluated, 25500 mm2 corresponds to 36 standard pipes. Germany: Any specification of “minor” by numbers is unfortunate. As e.g. Denmark and RINA point out, there are numerous factors affecting the amount of water and the relevance of the space flooded. A proposal would to delete the EN to just have the regulation 7.7 remain: “However, the Administration may permit minor progressive flooding if it is demonstrated that its effects can be easily controlled …” This will allow for reasonable consideration of all possible arrangements according to each specific vessel. France: Calculations have been made to evaluate the maximum section of pipes through which progressive flooding may be neglected. Calculations have been made on three test ships, assuming following assumptions: - Such pipes induce progressive flooding for half of damage cases. - Amount of flooding water is calculated after 1 hour - Loss in attained index is limited to 0.002 ( which corresponds to the variation of attained index for a variation of about 2cm in GM of initial conditions for the test ships) Maximum volume of water resulting from progressive flooding through pipe has been calculated

147 10/01/2012

so that loss attained is limited to 0.002, assuming that progressive flooding occurs for half of damage cases. Progressive flooding is supposed to occur through for and aft watertight bulkhead of the compartment. Only critical damage cases for which survival factor is less than 1 are supposed to be affected. Three typical residual GZ curves are assumed. Section of pipes through each bulkhead which give such progressive flooding within 1 hour is then calculated. Results are the following :

Lpp Ls Displacement Pipe area m m t mm²Ship 1 289 323 76000 3260Ship 2 205 221 23000 1710Ship 3 44 46 800 540

Calculated area should be considered as the total pipe area per bulkhead. From these results, proposed redaction of explanatory notes could be : For ships up to Ls = 150 m the provision for allowing “minor progressive flooding” should be limited to pipes penetrating a watertight subdivision with a total cross-sectional area of not more than 710 mm² between any two watertight compartments. For ships of Ls = 150 m and upwards total cross-sectional area of pipe should not exceed the equivalent of a diameter of Ls/5000 m. Comparison with proposed formula :

Proposed formula

Ls/5000 with a

minimum of 30mm Ls Pipe area Diameter Pipe area m mm² mm mm²Ship 1 323 3260 65 3278Ship 2 221 1710 44 1534Ship 3 46 540 30 710

For small ships, it could be admitted to consider a shorter time.

CLIA Q4

[Coordinator’s Note: There are two proposals for replacing reg. 7.7 EN2 – the majority favour option 2 but there are reservations – RINA, Germany, Norway and France. OPTION 1: 2. The provision for allowing “minor progressive flooding” should be limited to pipes penetrating a watertight subdivision with a total cross-sectional area of not more than [an equivalent pipe diameter of Ls/5000] between any two watertight compartments. [The total area of such pipes should be as small as practicable, taking into account the position of the pipes and the size and location of the room.]

148 10/01/2012

OPTION 2: [2. For ships up to Ls = 150 m the provision for allowing “minor progressive flooding” should be limited to pipes penetrating a watertight subdivision with a total cross-sectional area of not more than 710 mm

2 between any two watertight

compartments. For ships of Ls = 350 m and upwards the provision for allowing “minor progressive flooding” should be limited to pipes penetrating a watertight subdivision with a total

cross-sectional area of not more than 25500 mm2 between any two watertight

compartments For ships between Ls = 150 and 350 m, the total cross-sectional area should be obtained by linear interpolation between the above figures. For ships of Ls = 150 m and upwards no individual pipe should exceed a diameter of Ls/5000 m]. ]

DISCUSS AT SLF 54

149 10/01/2012

Regulation 7-1 Calculation of the factor pi

General 1. The definitions below are intended to be used for the application of part B-1 only. 2. In regulation 7-1, the words “compartment” and “group of compartments” should

be understood to mean “zone” and “adjacent zones”.

3. Zone – a longitudinal interval of the ship within the subdivision length. 4. Room – a part of the ship, limited by bulkheads and decks, having a specific

permeability.

5. Space – a combination of rooms. 6. Compartment – an onboard space within watertight boundaries. 7. Damage – the three dimensional extent of the breach in the ship. 8. For the calculation of p, v, r and b only the damage should be considered, for the

calculation of the s-value the flooded space should be considered. The figures below illustrate the difference.

Damage shown as the bold square:

Flooded space shown below:

150 10/01/2012

Regulation 7-1 para 1 (ref. SLF 51/3/2 Annex – US and Sweden) In the definition of “b”, the term “deepest subdivision loadline” should be replaced by “deepest subdivision draught”.

Regulation 7-1 para 1 (ref. SLF 52/17/5 Annex - Norway) Document SLF 51/3/2 contains a proposal that in the definition of “b”, the term “deepest subdivision load line” should be replaced by “deepest subdivision draught”. This seems to be an oversight made when the text was drafted and Norway proposes that the revision be implemented.

R7-1.1 (Replace “load line” with “draught” (twice))

. Q28. Do you agree to the change proposed in SLF 51/3/2 and supported by Norway in SLF 52/17/5?

Yes


No

Comments?:- Spain: Probably it is better to use the term deepest subdivision draught instead of deepest subdivision load line. Additional question: is it needed any clarification or explanatory note in regulation 18 (Assigning, marking and recording of subdivision load lines for passenger ships)?

151 10/01/2012

Additional information: The term “deepest subdivision load line” is defined in regulation 2, it is the water-line which corresponds the greatest draught permitted by the subdivision requirements which are applicable. Deepest subdivision draught (ds) is the waterline which corresponds to the summer load line draught of the ship. ¿Differences? For example, the fresh water draught is higher than the summer load line draught, is it equivalent to the deepest subdivision load line or not? Round 1 Discussion: There is unanimous support for this - so it is proposed to adopt it. Spain has some questions - for example on EN for Reg. 18. We cannot see a definition for “deepest subdivision load line” in Reg. 2 as mentioned by Spain – could this comment be clarified, please? The load line is the physical mark denoting a particular assigned/calculated draught. In the context of the definition of “b” the draught in question is clearly ds. FW draughts etc are not really relevant here as they are all basically equivalent to ds but with allowances for different water densities, sea areas etc.

CONCLUDED - PROPOSAL ACCEPTED (SUBJECT TO CONFIRMATION BY SPAIN)

Comments on Spain’s questions / any objections to accepting this proposal? CLIA: No objections. Round 2 Discussion: We are ready to accept Norway’s proposal subject to final clarification of comments and acceptance by Spain. Discuss in SLF 53 WG. Q28B (for SLF 53 WG). Can we all now agree to Norway’s proposal to replace “deepest subdivision load line” with “deepest subdivision draught” in the definition of “b”? Yes

No

Further comments (for example on Spain’s query regarding possible EN for reg. 18)?:- Post SLF 53 comments:- It was agreed to replace “deepest subdivision load line” with “deepest subdivision draught”. Needs correcting as shown in SLF 53-WP.6:-

Q28C (for Round 4 questionnaire). Although it was agreed at the SLF 53 WG to replace “deepest subdivision load line” with “deepest subdivision draught” in the definition of “b” in Reg. 7-1.1, Spain still had one or two earlier related queries:- “Additional question: is it needed any clarification or explanatory note in regulation 18 (Assigning, marking and recording of subdivision load lines for passenger ships)? Additional information: The term “deepest subdivision load line” is defined in regulation 2, it is the water-line which corresponds the greatest draught permitted by the subdivision requirements which are applicable. Deepest subdivision draught (ds) is the waterline which corresponds to the summer load line draught of the ship. ¿Differences? For example, the fresh water draught is higher than the summer load line draught, is it equivalent to the deepest subdivision load line or not?” Does Spain, or anybody else, wish to explore these questions further?

152 10/01/2012

Yes

UK – we support to propose change as the term “load line” is more in line with certification of the vessel to indicate operational limits which will result from the Index-A calculations of which this regulation constitutes a subset. France

No Vanuatu, US, Norway, China, RINA, Denmark , Germany, Finland, Italy, MI

Further comments?:- France: Deepest subdivision draught is assumed in sea water condition. It may be necessary to specify that all calculations must be done with a sea water density of 1.025. Spain: The term “deepest subdivision load line” was included in Reg. 2 of previous SOLAS versions, it was our mistake!!! (sorry for the mistake...). Round 6 Discussion: Thank you Spain for clearing up the small misunderstanding. Regarding France’s comment on SW / FW, the use of SW seems to be assumed, for example, in reg. 18.5 and 18.7. For UK, the change from “subdivision loadline” to “subdivision draught” was unanimously agreed previously (except for Spain) so we propose to take no further action on this item.

Q28. CONCLUDED NO FURTHER ACTION AT THIS TIME.

RECOMMEND “DEEPEST SUBDIVISION LOAD LINE” TO BE REPLACED WITH “DEEPEST SUBDIVISION DRAUGHT.”

Any final comments / objections? US: Fully agree with this conclusion. China: No

153 10/01/2012

154 10/01/2012

Regulation 7-1.1.1 [Coordinators Note: the following paragraphs 1-12, including the diagrams, are all EN] 1. The coefficients b11, b12, b21 and b22 are coefficients in the bi-linear probability density function on normalized damage length (J). The coefficient b12 is dependent on whether Ls is greater or less than L

* (i.e. 260 m); the other coefficients are valid

irrespective of Ls

Longitudinal subdivision

2. In order to prepare for the calculation of index A, the ship’s subdivision length Ls is divided into a fixed discrete number of damage zones. These damage zones will determine the damage stability investigation in the way of specific damages to be calculated.

3. There are no rules for the subdividing, except that the length Ls defines the extremes for the actual hull. Zone boundaries need not coincide with physical watertight boundaries. However, it is important to consider a strategy carefully to obtain a good result (that is a large attained index A). All zones and combination of adjacent zones may contribute to the index A. In general it is expected that the more zone boundaries the ship is divided into the higher will be the attained index, but this benefit must be balanced against extra computing time. The figure below shows different longitudinal zone divisions of the length Ls

4. The first example is a very rough division into three zones of approximately the same size with limits where longitudinal subdivision is established. The probability that the ship will survive a damage in one of the three zones is expected to be low (i.e. the s-factor is low or zero) and, therefore, the total attained index A will be correspondingly low.

5. In the second example the zones have been placed in accordance with the watertight arrangement, including minor subdivision (as in double bottom, etc.). In this case there is a much better chance of obtaining higher s-factors.

6. Where transverse corrugated bulkheads are fitted, they may be treated as

155 10/01/2012

equivalent plane bulkheads, provided the corrugation depth is of the same order as the stiffening structure. [7. Pipes and valves directly adjacent to a transverse bulkhead can be considered to be part of the bulkhead, provided the separation distance is of the same order as the bulkhead stiffening structure. The same applies for small recesses, drain wells, etc.] [Coordinator’s Note:. There is a new proposal to harmonize the text with reg. 7.7 EN1 and reg. 7-1.1.2 EN 12, as highlighted in green, below. For full discussion see reg 7-1.1.2 EN12, below under CLIA Q6D. Support is good but Norway has some reservations on the proposed amendments in green below for this EN ]:- 7. Pipes and valves directly adjacent to a transverse bulkhead or to a deck can be considered to be part of the bulkhead or deck, provided the separation distance on either side of the bulkhead or deck is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc.]

8. For cases where the pipes and valves are outside the transverse bulkhead stiffening structure, when they present a risk of progressive flooding to other watertight compartments that will have influence on the overall attained index A, they should be handled either by introducing a new damage zone and accounting for the progressive flooding to associated compartments or by introducing a gap.

9. The triangle in the figure below illustrates the possible single and multiple zone damages in a ship with a watertight arrangement suitable for a seven-zone division. The triangles at the bottom line indicate single zone damages and the parallelograms indicate adjacent zones damages.

Z 1 Z2 Z3 Z4 Z5 Z6 Z7

156 10/01/2012

Figure illustrates the possible single and multiple zone damages in a ship.

10. As an example, the triangle illustrates a damage opening the rooms in zone 2 to the sea and the parallelogram illustrates a damage where rooms in the zones 4, 5 and 6 are flooded simultaneously.

11. The shaded area illustrates the effect of the maximum absolute damage length. The p-factor for a combination of three or more adjacent zones equals zero if the length of the combined adjacent damage zones minus the length of the foremost and the aft most damage zones in the combined damage zone is greater than the maximum damage length. Having this in mind when subdividing Ls could limit the number of zones defined to maximize the attained index A.

12. As the p-factor is related to the watertight arrangement by the longitudinal limits of damage zones and the transverse distance from the ship side to any longitudinal barrier in the zone, the following indices are introduced:

157 10/01/2012

158 10/01/2012

END OF EN for Regulation 7-1.1.1

159 10/01/2012

Regulation 7-1.1.2 (ref. SLF 51/3/2 Annex – US and Sweden) Reduction factor “r” for damages of transverse extent limited to “b” is dependent on the length of the damage. This takes into account the fact that a breach of limited longitudinal extent cannot have a deep penetration. On the contrary, very long damages are raking type damages, so the probability to have a deep penetration may be reduced for very long damages. If minor damage above an intermediate deck is considered, depth of the breach below the waterline may be limited, so it can be obtained either from a raking damage or from a breach generated by a ramming ship with shallow draft. In both cases, the

160 10/01/2012

probability to have a deep penetration is low. This is not taken into account in the regulation. In all cases, the “r” factor should take account of the structural resistance of the ship to an external impact. --------------- Regulation 7-1 para 1.2 (ref. SLF 52/17/5 Annex - Norway) Document SLF 51/3/2 contains a proposal that the “r” factor should take account of the structural resistance of the ship to an external impact. Although this Administration would agree that this principle could be made an option in the future, it is believed that extensive work is required to develop a unified method suitable for inclusion in the regulation. R7-1.1.2 (Should raking damage and structural resistance be taken into account?) Q29. In SLF 51/3/2 it is suggested:- (a) that the regulations as they stand do not take into account the possibility that

long raking damages will tend to have a shallower depth of penetration and (b) that the “r” factor should take into account structural resistance to side

impact. In 52/17/5, Norway agrees with point (b) in principle but points out that it would

require a great deal of work to bring into force. (a) Does “r” need modifying for raking damages? Yes or No:- Yes: Germany (with comments), MI, US, Sweden No: China, Finland, Japan, Norway (not now), CLIA, Italy, Spain, Denmark, UK (b) Does “r” need modifying for structural resistance? Yes or No:- Yes: Germany (with comments), Sweden No: China, Finland, Japan, Norway, CLIA, Italy, Spain, Denmark, UK, US, MI (may be too difficult, see comments) (a) Comments / suggestions / proposals / more consideration needed?:- China: The probabilistic damage stability regulations of Part B-1 mainly deal with collision casualties; raking damages need not be considered. Therefore “r” need not be modified for raking damages. Finland: Before doing any changes to “r” more investigation is needed. It is preferable first to see effect of SOLAS2009 on design, before modifying “r”-factor. Germany: More investigations and data to support the approach needed. Norway: More extensive work is required; cf. SLF 52/17/5. “r” was never intended for raking damages as that was not within the TOR. Modification will be required if it is decided to include raking damages in the chapter. Spain:- S-2009 is a result of a lot of years of research. We know that the method involves many simplifications, but to change these assumptions of the method will involve a lot of new studies (new comparisons with the existing fleet, new statistic data, etcetera). From a practical point of view we prefer to maintain the basics assumptions and simplifications of S-2009. Denmark: We would prefer to see some research into the statistics, mechanics and implications before considering a change. Particularly since with probability, the frequency of raking damages compared to other damages is important US: The issue of raking damage should be further considered. France: [comment added in Round 2] Comment in SLF 51/3/2 was related to minor damages above intermediate decks which may not result from collision with a large ship. In this case, breach penetration probability should be linked to the position of the intermediate deck below the waterline.

161 10/01/2012

Round 1 Discussion: (a) Does “r” need modifying for raking damage? Four members agree that “r” should be modified for raking damage and nine disagree. However, of the 9 opposed to the idea 3 think that the issue needs some further research as do 2 of the 4 in favour. So the vote actually splits into 2 totally in favour, 5 require more research before deciding and 6 are totally opposed. So 11 out of 13 are not in favour of either immediate action or any action being taken at all. This suggests that the issue should be flagged up to SLF with a recommendation for it to be put on the “back burner” for now until more pressing issues are resolved. (b) Comments / suggestions / proposals / more consideration needed?:- China: This is too complicated, absolutely “No”. Finland: Before doing any changes to “r” more investigation is needed. It is preferable first to see effect of SOLAS2009 on design, before modifying “r”-factor. Germany: More investigations and data to support the approach is needed. Japan: As Norway points out, this study requires a great deal of work. MI: The structural resistance to side impact will vary along the length of a ship depending on whether it occurs mid way between transverse bulkheads or near a bulkhead and is totally dependent on the size, trajectory and speed of the impacting ship. Suggest that this proposal may be too difficult to develop any further. Norway: There seems to be no imminent need to modify “r” for structural resistance, but we support that an option be developed at a later stage. Spain: Same comments as previous paragraph. Additionally, to evaluate the structural resistance of a certain area of a vessel (taking into account all the ship’s service life) is very complicated. Denmark: Structural resistance is indeed important and we would welcome research into how it could be accounted for. It seems though that having different r factors for different types of vessels is a move away from harmonisation (which may indeed be needed), is likely to increase complexity and may have undesired consequences and implications; we are thinking about vessels with changes in structure along the length of the vessel, vessels fitted with sponsons and of cruise vessels where a revision of the r factor may boost the A index. Round 1 Discussion: (b) Does “r” need modifying for structural resistance? Here the response is more clear-cut with 11 opposed and only 2 in favour, 1 of whom asks for more investigations and data. So in this case it also proposed that we flag up the issue with SLF for possible future consideration but with a somewhat lower priority than raking damage. Q29A Do you agree with the proposed actions for items (a) and (b)?

(a) Report issue to SLF but recommend action be delayed Yes or No:- Yes: MI, Germany, Finland, Italy, Japan, France (with comment), Norway, CLIA (with comment), UK, US, Sweden, Denmark No: China (b) Report issue to SLF but recommend action be delayed Yes or No:- Yes: MI, Germany, Finland, Italy, Japan, Norway, CLIA (with comment), UK, US (with comment), Sweden, Denmark No: China (a) Comments / suggestions / further proposals? France: The issue of raking damage, or more generally probability of damage penetration according to damage length is an important issue that should be treated. But we can agree on the conclusion that this is a complicated item so it can be postponed waiting for further investigation, but such investigations should be encouraged by IMO. CLIA: But this issue requires a longer term approach as we are not in a position to move forward on it now due to a lack of statistical evidence. (b) Comments / suggestions / further proposals? France: This is also an important issue. Rules should encourage the design of ships having

162 10/01/2012

better resistance to impact of ramming ship, so we are not sure that this should have a lower priority than raking damage. CLIA: This is also a longer term objective. US: Regarding “action delayed”; for this item we believe the report should reflect the general view that although maybe technically correct, including structural resistance would be extremely complex and is therefore considered unfeasible at this time. Round 2 Discussion: It will be noted that the issues of raking damage and structural resistance to damage have been raised in the CG report (ref. SLF 53/14 paragraph 13.4) by asking the S-C whether we should continue to discuss them further in the CG prior to SLF 54 or whether they should be temporarily set aside pending further research.

AWAIT DECISION BY SUB-COMMITTEE AT SLF 53. (See SLF 53/14 para 13.4).

Post SLF 53 Comment:- This issue was not discussed in plenary so we will assume no further action is needed for this CG session and bring it back for the S-C’s attention at SLF 54 unless any CG member has objections? Q29C (for Round 4 questionnaire). Are you happy that we should we leave these issues until at least SLF 54? Yes

Vanuatu, US, Sweden, Norway, Japan, China, RINA, Denmark, Finland, Germany, Italy, EC, CLIA, MI, France, ICS, Spain

No

Comments?:- Vanuatu: We submit that this matter is better dealt with by delegations writing papers proposing specific remedies on this matter; rather than comments in CG. Denmark: Pending further research. France: This subject would need further investigation and it is difficult to reach a conclusion before SLF 54. Round 6 Discussion: There is unanimous approval for this action. Perhaps these issues should be given a separate agenda item?

Q29. CONCLUDED WE WILL MENTION THE ISSUES OF RAKING DAMAGE AND STRUCTURAL

RESISTANCE TO SIDE DAMAGE IN THE CG REPORT TO SLF 54. RECOMMEND NFA UNLESS DIRECTED BY S/C (SLF 54/8/1 para. 15.4).

Regulation 7-1.1.2 [Coordinator’s Note: the following paragraphs 1-12, including the diagrams, are all EN] Transverse subdivision in a damage zone

1. Damage to the hull in a specific damage zone may just penetrate the ship’s watertight hull or penetrate further towards the centreline. To describe the probability of penetrating only a wing compartment, a probability factor r is used, based mainly on the penetration depth b. The value of r is equal to 1, if the penetration depth is B/2 where B is the maximum breadth of the ship at the deepest subdivision draught ds, and r = 0 if b = 0.

2. The penetration depth b is measured at level deepest subdivision draught ds as a transverse distance from the ship side right-angled to the centreline to a longitudinal barrier.

163 10/01/2012

3. Where the actual watertight bulkhead is not a plane parallel to the shell, b should be determined by means of an assumed line, dividing the zone to the shell in a relationship b1/b2 with

4. Examples of such assumed division lines are illustrated in the figure below. Each sketch represents a single damage zone at a water line plane level ds and the longitudinal bulkhead represents the outermost bulkhead position below ds + 12.5 m.

Regulation 7-1.1.2 (ref. SLF 52/17/3 – Finland) There has been a general agreement, as stated in documents SLF 50/19 (paragraph 3.15) and SLF 51/3 (paragraph 5.8), on the need for further clarification of the transverse penetration depth. This is necessary because of complex waterline shapes. A proposal is made to add information to paragraph 1.2 in Reg II-1/7-1 in the Explanatory Notes as set out in the Annex. These two new paragraphs are preferably inserted between paragraphs 4 and 5 in the existing EN in Reg 7-1.1.2 “Transverse subdivision in a damage zone”. [See below]

164 10/01/2012

ANNEX TRANSVERSE SUBDIVISION INTERCEPTING THE HULL

4.1 If a transverse subdivision intercepts the deepest subdivision draught waterline within the extent of the zone, b is equal to zero (0) in that zone for the transverse subdivision in question, see figures 1 and 2.

In the above illustrated cases, b differing from zero (0) can be obtained by moving the aft limit of the zone according to figure 3 or by including an additional zone according to figure 4.

R7-1.1.2 New EN diagrams between EN 4 and EN 5 . Q30. Do you agree with the diagram additions to the EN for Reg. 7-1.1.2 between

current EN 4 and 5 as first proposed by Finland in SLF 52/17/3? Yes

China, Finland, Germany, Norway, Italy, Spain (but see comments), Denmark, UK, US, Sweden, MI (but see comments)

No

Comments / Alternatives?:- Finland: Part of the waterline including multiple coordinates proposed in SLF 52/17/3 to be included also in EN. [Co-ordinator’s Note:- Many apologies, Finland – the missing part is now included below. We hope that those who said “yes” are also happy with the new part!]. MI: Think these cases are valid for inclusion but more detail of the orientation and value of ‘b’ needs to be added for consistency with the existing diagrams.

165 10/01/2012

Norway: Supports the intention of a unified interpretation. CLIA: see CSSF paper. Spain: Possibly, figure 3 is not necessary. We think that it could be acceptable to accept, taking into account figure 1, that b differing from zero. Regarding figures 3 and 4, the situation is more clear: the interpretation seems to be necessary. UK: It is the preferred option of the UK delegation that the use of “fictitious” zones must be allowed but kept to a minimum to avoid increasing the amount of calculations required. Round 1 Discussion: There is unanimous overall support for these proposed enhancements to the EN but there are one or two comments to be addressed before we can fully adopt them. MI would like more detail of the orientation, and the addition of “b”. Spain’s comments are a little unclear – they seem firstly to say that Fig. 3 is not necessary then in the next sentence that it is necessary. Can you please clarify this for us, Spain? The UK’s comment is appreciated - there is already something in the EN on the subject of “fictitious” zone boundaries being balanced against computing time but it is hard to see how this can be specified as it will vary from ship to ship and user to user (Ref. Reg 7-1.1.1 EN 3). Proposed Action: As some of the diagrams were omitted from the Round 1 questionnaire we will give more time for further consideration and invite Finland to see if it is possible to improve them still further along the lines suggested by MI. Also await clarification of Spain’s comments. Q30A: Please also examine the “missing” diagrams below; do you still agree with inclusion of all the diagrams in the EN and with MI’s request for more information to be shown? Yes

MI, Germany, Finland, Italy, Japan, France (but see comments), Norway, CLIA, UK, US, Sweden, Denmark

No

China

Comments / Regarding the EN figures in general – should we consider adding sequential figure numbers with titles throughout the EN for ease of reference? France: The proposed examples are not satisfactory from a theoretical point of view as actual probability not to damage longitudinal bulkhead in given example is not null, but they are in line with current explanatory notes. This is generally a pessimistic assumption, but may be not the case if symmetrical flooding is obtained with non limited damage extent. In addition, case where deepest waterline doesn’t intercept the aft terminal is not treated. France had made a proposal on this point which had not been retained in the final explanatory notes by lack of consensus, but they may be presented again. CLIA: Yes (add sequential numbering for figures in EN). US: Yes (add sequential numbering for figures in EN). Round 2 Discussion:- There is a good majority in favour of inserting these diagrams into the EN but France has some reservations; MI would like more explanation of the orientation and an indication of where “b” is. China is now opposed. There is support from CLIA and the US for adding sequential figure numbers throughout the EN for ease of reference. As there remain some issues unresolved with this item we proposed that it is discussed at the SLF WG. France may also wish to re-present the diagrams which were previously left out of the EN for further consideration. Q30B (for SLF 53 WG). In the lights of comments by France and the MI and China’s position, can we accept the diagrams as presented by Finland or do they need further clarification? Please also see further proposal by CLIA (below). Yes

No Comments / would further clarification help, China?:- Post SLF 53 comment:- It was agreed in the WG that Finland would clarify the figures to satisfy the Marshall Islands query and that France would re-present her diagrams which were previously left out of the EN.

166 10/01/2012

MISSING PART NOW ADDED:- Part of the waterline including multiple coordinates 4.2 If the deepest external subdivision draught waterline on the studied side of a single hull ship includes a part where multiple transversal (y) coordinates occur for a longitudinal (x) location, a straightened reference waterline can be used for the calculation of b. If this approach is chosen, the original waterline is replaced by an envelope curve including straight parts perpendicular to the centreline where multiple transversal coordinates occur, see figures 1 to 4. The maximum transverse damage extent B/2 is then also calculated from the reference waterline.

Q30C (continued) (for Round 4 questionnaire). Can Finland and France please help us with revised and new diagrams as promised at SLF 53?

167 10/01/2012

Further thoughts or comments?:- Denmark: No further thoughts. France: France will prepare an alternative proposal and will discuss it with Finland. Finland: Has supplied the following revised text and diagrams for the EN (see next two pages). Round 6 Discussion: Thank you, Finland. We hope this clarifies things for the MI and China? France may still have some issues, however. Here is a reminder of France’s comments on Finland’s previous diagrams, taken from the large working document:- “The proposed examples are not satisfactory from a theoretical point of view as actual probability not to damage longitudinal bulkhead in given example is not null, but they are in line with current explanatory notes. This is generally a pessimistic assumption, but may be not the case if symmetrical flooding is obtained with non limited damage extent. In addition, case where deepest waterline doesn’t intercept the aft terminal is not treated. France had made a proposal on this point which had not been retained in the final explanatory notes by lack of consensus, but they may be presented again”. Are France and Finland in agreement? Q30D(for Round 6 questionnaire). Can we now accept these new diagrams and text for the EN? Yes?

Japan, CLIA, Finland, Germany, Denmark, China, US (Subject to possible further refinements), Italy, UK (yes to 4.2 paragraph explaining “ Part of the waterline including multiple coordinates” ),

No? UK (no to 4.1 – see comments), France (see comments)

Further Comments? UK: It has already been discussed and the current treatment of the actual watertight bulkheads which is not a plane parallel to the shell. If one would like to be more accurate fictitious zones may be introduced. If the principle of limited b1(=2xb2) is observed then for the cases where measured b1=0 will be modified to 2xb2. France: §4.1 : Figure 1 : Waterline seems to intercept the longitudinal subdivision at a certain distance from the transverse subdivision, so b1 should not be 0 Figure 3 : If aft limit of the zone is the aft terminal, moving the aft limit will modify the subdivision length, which seems not acceptable, so in this case the only solution is to create an additional zone. §4.2 : In all figures, two transverse lines seems to limit the considered zone. In figure 1 and 3, the aft transverse line is very close to the aft end of the waterline, but, however, intercepts it - which suggests that the zone is not the aft zone. We propose to delete the aft line or to move it forward to have a more clear intersection with the waterline

Q30 A MAJORITY OF 9-2 ARE IN FAVOUR OF THE NEW TEXT AND DIAGRAMS BELOW. HOWEVER FRANCE AND THE UK HAVE SOME SPECIFIC PROBLEMS AND THE US BELIEVES THAT FURTHER REFINEMENTS MAY BE NEEDED.

DISCUSS AT SLF 54

168 10/01/2012

TRANSVERSE SUBDIVISION INTERCEPTING THE HULL

4.1 If a transverse subdivision intercepts the deepest subdivision draught waterline within the extent of the zone, b is equal to zero (0) in that zone for the transverse subdivision in question, see figures 1 and 2.

Figure 1 Figure 2 In the above illustrated cases b differing from zero (0) can be obtained by moving the aft limit of the zone according to figure 3 or by including an additional zone according to figure 4.

Figure 3 Figure 4

169 10/01/2012

Part of the waterline including multiple coordinates 4.2 If the deepest external subdivision draught waterline on the studied side of a single hull ship includes a part where multiple transversal (y) coordinates occur for a longitudinal (x) location, a straightened reference waterline can be used for the calculation of b. If this approach is chosen, the original waterline is replaced by an envelope curve including straight parts perpendicular to the centreline where multiple transversal coordinates occur, see figures 1 to 4. The maximum transverse damage extent B/2 is then also calculated from the reference waterline.

Figure 1 Figure 2

Figure 3 Figure 4

170 10/01/2012

R7-1.1.2 EN

Extra comments received from CLIA/CCSF between round 1 and 2:

A number of proposals have been made (also in relevant SLF52/17 papers) to deal with a clear interpretation for hull forms resulting in unusual waterlines. This proposal is supported by the group (comment from CLIA): .Additional Explanation: Where at the extreme ends of the ship the subdivision exceeds the waterline at the deepest subdivision draught, the damage penetration b or B/2 is to be taken from centre line. The following figure illustrates the shape of the B/2 line:

Coordinator’s Comments: CG Member’s Comments?:- Germany: Acceptable. China: I cannot understand the above text. How to measure penetration “b” in this case? More detailed figure and/or explanation may be needed. Finland: Support. Italy: Agree with CLIA/CSSF explanation. France: See comments for Q30A. US: Not sure we understand the orientation of the B/2 line. (B/2 is a fixed value) EN2 for reg 7.5: In the forward and aft ends of the ship where the sectional breadth is less than the ship’s breadth B, transverse damage penetration can extend beyond the centreline bulkhead. This application of the transverse extent of damage is consistent with the methodology to account for the localized statistics which are normalized on the greatest moulded breadth B rather than the local breadth. CLIA Q5. Round 2 Discussion:- There are mixed views on this proposal so it is suggested that it is discussed further at the SLF 53 WG in conjunction with Q30B, above. Post SLF 53 comments:- It was agreed in the WG to ask CLIA to improve their proposed diagram in the light of the above comments, particularly from China and the US, in time for SLF 54.

B/2 line

deepest subdivision waterline

171 10/01/2012

CLIA Q5C (for Round 4 questionnaire) Can CLIA please help us with revising this diagram as promised at SLF 53? Space for Revised Diagram / Further thoughts or comments?:- CLIA: May be best to come from Germany/France. Germany: (Has provided a new diagram – see below. Many thanks.) France: The sketch is acceptable to France. Co-ordinator’s Note: This refers to the above sketch, we suppose. Round 6 Discussion: We recall that China, US and France had issues with the old diagram. The following comments by the US are taken from the working document: “Not sure we understand the orientation of the B/2 line. (B/2 is a fixed value) EN2 for reg 7.5: In the forward and aft ends of the ship where the sectional breadth is less than the ship’s breadth B, transverse damage penetration can extend beyond the centreline bulkhead. This application of the transverse extent of damage is consistent with the methodology to account for the localized statistics which are normalized on the greatest moulded breadth B rather than the local breadth". CLIA Q5D (for Round 6 questionnaire). Can we now accept the revised diagram and proposed text for the EN (below)? Yes?

Japan, CLIA, Finland, Norway, Germany, Denmark, China, US (but see comments below), Italy, France, UK (yes, in principle, but see comments below)

No?

Further Comments – especially US? Co-ordinator’s Note: The diagram is a little blurred. If accepted, could Germany please supplya clearer version? (See below – new diagram received in Round 6 responses). THANK YOUGERMANY. 12. Where at the extreme ends of the ship the subdivision exceeds the waterline at thedeepest subdivision draught, the damage penetration b or B/2 is to be taken from centreline. The following figure illustrates the shape of the B/2 line:

172 10/01/2012

US: Will this diagram be included as an EN under Reg 7-1.1.2 or would it be better to incorporateit into the EN2 for reg 7.5? If incorporated into the EN2 for reg 7.5 (which we think fits better),the diagram text may need some minor edits to align with the existing text of EN2 for reg 7.5. UK: In order to enhance the diagram, we would like to suggest that the label “Penetration b” bereplaced with “B/2”, and keep the rest the same. Perhaps another diagram can be used to show“penetration b” to a specific longitudinal bulkhead.

CLIA Q5 THERE IS A VOTE OF 11-0 IN FAVOUR OF THIS TEXT AND DIAGRAM BUT THE USAND THE UK EACH HAVE SOME SUGGESTED IMPROVEMENTS.

DISCUSS AT SLF 54

173 10/01/2012

174 10/01/2012

10. A damage giving a transverse extent b and a vertical extent H2 leads to the flooding of both wing compartment and hold; for b and H1 only the wing compartment is flooded. The figure below illustrates a partial subdivision draught dp damage.

175 10/01/2012

11. The same is valid if b-values are calculated for arrangements with sloped walls. 12. Pipes and valves directly adjacent to a longitudinal bulkhead can be considered to be part of the bulkhead, provided the separation distance is of the same order as the bulkhead stiffening structure. The same applies for small recesses, drain wells, etc. Valves which are situated as close practicable to the bulkhead [or deck], but exceeding in size the depth of the stiffening structure should still be assumed to be part of the bulkhead [or deck].

END OF EN for Regulation 7-1.1.2

[Coordinator’s Note: The changes to reg. 7-1.1.2 EN12 in grey below were agreed at SLF 53. There is a new proposal to harmonize the text with reg. 7.7 EN1 and reg. 7-1.1.1 EN 7, as highlighted in green, below. Note that the word “longitudinal” was in the original EN but had been removed. It is now proposed to restore it. [CLIA Q6D. Majority in favour but RINA Norway US and France have reservations; ]:- [12][13]. Pipes and valves directly adjacent to a longitudinal bulkhead or to a deck can be considered to be part of the bulkhead or deck, provided the separation distance on either side of the bulkhead or deck is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc. Valves which are situated as close as practicable to the bulkhead or deck, but exceeding due to their in size the order depth of the stiffening structure should still be assumed to be part of the bulkhead or deck.] R7-1.1.2 EN12 (Stiffeners may be small relative to pipes or valves)


CLIA Q6 (see also R7.7 EN1 and R7-1.1.1 EN7) Modification with regard to location of separation valves at watertight bulkheads and decks. Application in practice has shown that the size of the stiffeners might sometimes be too small for large pipe diameters. This is the same change as proposed for Reg. 7.7 EN2 above. The additional guidance for machinery is done to reflect physics as closely as possible. “Pipes and valves directly adjacent to a bulkhead or to a deck can be considered to be

176 10/01/2012

part of the bulkhead or deck, provided the separation distance on either side of the bulkhead or deck is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc. Valves which are situated within the distance defined above and as close practicable to the bulkhead, but exceeding due to their size the order of the stiffening structure should still be assumed to be part of the bulkhead.” . Coordinator’s Comments: If this is acceptable we would suggest using “in size the depth” instead of “due to their size the order” in the last sentence:- Valves which are situated within the distance defined above and as close as practicable to the bulkhead, but exceeding in size the depth of the stiffening structure should still be assumed to be part of the bulkhead.” CG Member’s Comments?:- MI: Could agree to the co-ordinators revised text. Germany: Acceptable. Finland: Support. Italy: Agree with CLIA/CSSF. Japan: Supports coordinator’s suggestion. France: Depth of stiffening structure is not a practical limitation, so this proposal may be accepted. Maximum absolute value could be added (800mm or a percentage of B). Norway: It is perhaps a better option to handle such large diameter pipes and long spool pieces/valves as recesses, i.e. the zone limits are to be moved away from the bulkhead. CLIA: Agree. US: We can accept this proposed change. Text suggestion: delete the words within the distance defined above and because they are not (or we wouldn’t need this caveat). Note: (1) This text was copied from reg 7.7 EN1, which applies to both bulkheads and decks. This EN only applies to longitudinal bulkheads. (2) If this text is agreed to, it also shows up in reg 7-1.1.1 EN7 (for transverse bulkheads) and it would seem logical to make the same change there. Round 2 Discussion: We must point out that similar EN’s appear in two other places (reg. 7.7 EN 1 and reg. 7-1.1.2 EN 12). Also note that reg.7-1.1.1 EN 8 would support Norway’s position. For consistency we would either need to consider possible changes to all three EN’s or simply to leave all three as they are. CLIA Q6 (for SLF53 WG). Given that we have other EN’s covering the issues raised by CLIA do you think we should look at revising all three EN’s or should we leave them all alone? (See also CLIA Q3, above). Revise all 3 EN’s?

Leave all 3 EN’s alone?

Comments?:- Post SLF 53:- It was agreed in the WG to amend the text as highlighted in grey, above but it may not be necessary to added the words “or deck” as the EN relates specifically to longitudinal bulkheads. CLIA Q6C (for Round 4 questionnaire). Should we remove the words “or deck” as shown in square brackets? Yes

US, Sweden, Norway, Japan, China, Denmark, Spain, MI (agree removal of “or deck”) RINA (If the text is to be amended to include “deck” then the original text should also be amended).

177 10/01/2012

No

Vanuatu (retain for clarity), Germany, Finland, Italy, France.

Further thoughts or comments?:- Vanuatu: We submit that it is conceivably possible that a pipe run through a bulkhead ells (L’s) into a deck, if this clarity is not provided, which way would the penny drop? China: “as close practicable” may be too vague. [Coordinator’s Note: We have also noticed that, if retained, this should read “as close AS practicable”.] RINA: The additional text in grey ” Pipes and valves directly adjacent to a longitudinal bulkhead can be considered to be part of the bulkhead, provided the separation distance is of the same order as the bulkhead stiffening structure…….” The proposed text “as far as practicable” does not impose any restriction which is intended by the original text. France: This paragraph refers to longitudinal bulkheads, but the same comment may apply to regulation 7.7 EN1 which refer to valves directly adjacent to bulkhead or deck. Round 6 Discussion: The co-ordinators seem to have become a little confused here - the text shown for EN 12 is not that which was finally agreed to by the SLF 53 WG – we are sorry for this mistake. We need to look again more closely at all three places where EN’s beginning with “pipes and valves” occur - to try to ensure consistency. For ease of reference we will start in each case with the original regulation and EN then show how things were changed in the CG and by the SLF 53 WG:- 1) Reg. 7.7 7 If pipes, ducts or tunnels are situated within the assumed extent of damage, arrangements are to be made to ensure that progressive flooding cannot thereby extend to compartments other than those assumed flooded. However, the Administration may permit minor progressive flooding if it is demonstrated that its effects can be easily controlled and the safety of the ship is not impaired.

Regulation 7.7

1. Pipes and valves directly adjacent to a bulkhead or to a deck can be considered to be part of the bulkhead or deck, provided the separation distance is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc. CLIA, between round 1 and 2 in last year’s CG, proposed to modify the original EN as highlighted below since “application in practice has shown that the size of the stiffeners might sometimes be too small for large pipe diameters”. 1. Pipes and valves directly adjacent to a bulkhead or to a deck can be considered to be part of the bulkhead or deck, provided the separation distance on either side of the bulkhead or deck is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc. Valves which are situated within the distance defined above and as close as practicable to the bulkhead, but exceeding due to their size the order of the stiffening structure should still be assumed to be part of the bulkhead. CLIA Q3 After discussions in last year’s CG and in the WG at SLF 53 it was agreed to change the original EN as highlighted in grey (ref. SLF.53/WP.6 Annex 5, p. 39):- 1. Pipes and valves directly adjacent to a bulkhead or to a deck can be considered to be part of the bulkhead or deck, provided the separation distance on either side of the bulkhead or deck is of the same order as the bulkhead or deck stiffening structure. The

178 10/01/2012

same applies for small recesses, drain wells, etc. Valves which are situated as close as practicable to the bulkhead or deck, but exceeding due to their size the order of the stiffening structure should still be assumed to be part of the bulkhead or deck. However, Norway expressed some reservations (WP.6, same reference):- “Norway considers that it would be better to introduce new zone limits for large diameter pipes and valves/spool pieces”. The coordinators previously pointed out that similar EN’s appear in two other places (reg. 7-1.1.1 EN 7 and reg. 7-1.1.2 EN 12). Also note that reg. 7-1.1.1 EN 8 would support Norway’s position (at least when determining damage zone boundaries). For consistency we would either need to consider possible changes to all three EN’s or simply to leave all three as they are. 2) Reg. 7-1.1.1 The regulation is too lengthy to include here but relates to the calculation of factor p(x1, x2). There are 12 EN’s describing how the length Ls is subdivided into damage zones. EN7 and EN8, under the general heading of “longitudinal subdivision”, state the following:- 7. Pipes and valves directly adjacent to a transverse bulkhead can be considered to be part of the bulkhead, provided the separation distance is of the same order as the bulkhead stiffening structure. The same applies for small recesses, drain wells, etc.

8. For cases where the pipes and valves are outside the transverse bulkhead stiffening structure, when they present a risk of progressive flooding to other watertight compartments that will have influence on the overall attained index A, they should be handled either by introducing a new damage zone and accounting for the progressive flooding to associated compartments or by introducing a gap.

There have been no questions or discussions on EN’s 7 or 8 by the CG. 3) Reg. 7-1.1.2 This regulation (also lengthy) covers the calculation of factor r(x1, x2, b) relating to the side penetration depth. There are 12 EN’s under the general heading “Transverse subdivision in a damage zone”. The original EN 12 reads as follows:- 12. Pipes and valves directly adjacent to a longitudinal bulkhead can be considered to be part of the bulkhead, provided the separation distance is of the same order as the bulkhead stiffening structure. The same applies for small recesses, drain wells, etc. The text is very similar to Reg. 7.7 EN 1 except that “longitudinal bulkhead” replaces “bulkhead or to a deck” and the words “bulkhead or deck” are replaced each time with “bulkhead” (clearly referring to the longitudinal bulkhead). Reg. 7-1.1.1 EN 7 is exactly the same as the above except that “transverse” replaces “longitudinal”. CLIA, between round 1 and 2 in last year’s CG, proposed to make the following changes as highlighted making the EN exactly the same as their proposal for Reg. 7.7 EN 1:- 12. Pipes and valves directly adjacent to a bulkhead or to a deck can be considered to be part of the bulkhead or deck, provided the separation distance on either side of the

179 10/01/2012

bulkhead or deck is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc. Valves which are situated within the distance defined above and as close as practicable to the bulkhead, but exceeding due to their size the order of the stiffening structure should still be assumed to be part of the bulkhead. After discussion in last year’s CG and in the WG at SLF 53 it was agreed to change the original EN as highlighted in grey (ref. SLF.53/WP.6 Annex 5, p. 57):- 12. Pipes and valves directly adjacent to a longitudinal bulkhead or to a deck can be considered to be part of the bulkhead or deck, provided the separation distance on either side of the bulkhead or deck is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc. Valves which are situated as close as practicable to the bulkhead or deck, but exceeding due to their in size the order depth of the stiffening structure should still be assumed to be part of the bulkhead or deck. It should be noted that, in the new sentence which begins “Valves which …. etc” the SLF 53 WG made some changes to this EN which were not made in EN 1 for Reg. 7.7. For example “due to their” was replaced with “in” and “order” with “depth”. As co-ordinators, we prefer this version so propose that EN 1 for Reg. 7.7 be changed accordingly. SUMMARY – LATEST AGREED TEXTS To try to improve consistency in the EN for the three regulations we have placed the latest agreed versions together below to make it easier to see the differences. The currently agreed changes are highlighted in grey:- Reg 7.7 1. Pipes and valves directly adjacent to a bulkhead or to a deck can be considered to be part of the bulkhead or deck, provided the separation distance on either side of the bulkhead or deck is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc. Valves which are situated as close as practicable to the bulkhead or deck, but exceeding due to their size the order of the stiffening structure should still be assumed to be part of the bulkhead or deck. Reg. 7-1.1.1 7. Pipes and valves directly adjacent to a transverse bulkhead can be considered to be part of the bulkhead, provided the separation distance is of the same order as the bulkhead stiffening structure. The same applies for small recesses, drain wells, etc.

8. For cases where the pipes and valves are outside the transverse bulkhead stiffening structure, when they present a risk of progressive flooding to other watertight compartments that will have influence on the overall attained index A, they should be handled either by introducing a new damage zone and accounting for the progressive flooding to associated compartments or by introducing a gap. Reg. 7-1.1.2 12. Pipes and valves directly adjacent to a longitudinal bulkhead or to a deck can be

180 10/01/2012

considered to be part of the bulkhead or deck, provided the separation distance on either side of the bulkhead or deck is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc. Valves which are situated as close as practicable to the bulkhead or deck, but exceeding due to their in size the order depth of the stiffening structure should still be assumed to be part of the bulkhead or deck. PROPOSED CHANGES FROM CURRENTLY AGREED TEXT TO IMPROVE CONSISTENCY – HIGHLIGHTED IN GREEN BELOW Reg 7.7 1. Pipes and valves directly adjacent to a bulkhead or to a deck can be considered to be part of the bulkhead or deck, provided the separation distance on either side of the bulkhead or deck is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc. Valves which are situated as close as practicable to the bulkhead or deck, but exceeding due to their in size the order depth of the stiffening structure should still be assumed to be part of the bulkhead or deck. Reg. 7-1.1.1 7. Pipes and valves directly adjacent to a transverse bulkhead or to a deck can be considered to be part of the bulkhead or deck, provided the separation distance on either side of the bulkhead or deck is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc.

8. For cases where the pipes and valves are outside the transverse bulkhead stiffening structure, when they present a risk of progressive flooding to other watertight compartments that will have influence on the overall attained index A, they should be handled either by introducing a new damage zone and accounting for the progressive flooding to associated compartments or by introducing a gap. Reg. 7-1.1.2 12. Pipes and valves directly adjacent to a longitudinal bulkhead or to a deck can be considered to be part of the bulkhead or deck, provided the separation distance on either side of the bulkhead or deck is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc. Valves which are situated as close as practicable to the bulkhead or deck, but exceeding due to their in size the order depth of the stiffening structure should still be assumed to be part of the bulkhead or deck. CLIA Q6D (for Round 6 questionnaire). To improve consistency, could you accept the proposed texts for the three EN’s as highlighted above in green? Yes?

Japan, CLIA, RINA (see comments below), Finland, Denmark, Norway (with comment), Germany, US (Partially, see comments), Italy, UK, EC, China, France (with comment)

No?

181 10/01/2012

Further thoughts or comments?:- RINA: See RINA comments to CLIA-Q4D repeated below for ease of reference : It is noted that the text regulation 7.7 as been amended by deleting the text which states that: “The Administration may permit minor progressive flooding, if it is demonstrated that its effects can be easily controlled and the safety of the ship is not impaired.” No minor progressive flooding should be allowed unless it is controlled and it is documented in the damage stability control books/plan. If this text is added to the proposal then it follows that each minor progress flooding case should be assessed in the damage stability calculations and an assessment made on a case by case basis in accordance with the requirements stated above. Consequently it is not necessary to provide any controls on the size of the pipes. Norway: We agree to the editorial changes for consistency. However, we are still of the opinion that it is better to introduce new zone limits for large diameter pipes and valves/spool pieces. US: Our preference is that only the EN for reg 7.7 include “deck” (i.e. that reg 7-1.1.1 only be for “transverse bulkhead” and reg 7-1.1.2 only be for “longitudinal bulkhead”). This is because reg 7-1 does not address horizontal subdivision issues, which are only handled by the v-factor in reg 7-2.6. Therefore it seems sufficient to cover decks under the general provision in reg 7.7. Also this does not address the consistency issue regarding reg 7-1.1.1 EN 7 and EN8 where you don’t get the new “valves which are situated as close as practicable...” option. For these valves they must “be handled either by introducing a new damage zone and accounting for the progressive flooding to associated compartments or by introducing a gap”. So this actually conflicts with the general provision in reg 7.7 that seems to apply broadly. This is generally related to the issue Norway expressed concern about. Although we have no strong view on which way to go, we think this needs further discussion in the WG. France: Paragraph 7-1.1.2, refers to transverse subdivision, so only longitudinal bulkhead are concerned. The tolerance is only useful for valves situated outside of the bulkhead referring to centreline, but as stiffening structure may be on either side, proposed wording is correct.

CLIA Q6 [Coordinator’s Note: The changes to reg. 7-1.1.2 EN12 in grey below were agreed at SLF 53. There is a new proposal to harmonize the text with reg. 7.7 EN1 and reg. 7-1.1.1 EN 7, as highlighted in green, below. Note that the word “longitudinal” was in the original EN but had been removed. It is now proposed to restore it]. [ All in favour but RINA Norway US and France have reservations; ]:- [12][13]. Pipes and valves directly adjacent to a longitudinal bulkhead or to a deck can be considered to be part of the bulkhead or deck, provided the separation distance on either side of the bulkhead or deck is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc. Valves which are situated as close as practicable to the bulkhead or deck, but exceeding due to their in size the order depth of the stiffening structure should still be assumed to be part of the bulkhead or deck.]

DISCUSS FURTHER AT SLF 54

182 10/01/2012

183 10/01/2012

Regulation 7-2 Calculation of the factor si General

1. Initial condition – an intact loading condition to be considered in the damage analysis described by the mean draught, vertical centre of gravity and the trim. Or alternative parameters from which the same may be determined (eg. displacement, GM and trim). There are three initial conditions corresponding to the three draughts ds, dp and dl.

2. Immersion limits – immersion limits are an array of points that are not to be immersed at various stages of flooding as indicated in regulations 7-2.5.2 and 7-2.5.3.

3. Openings – all openings need to be defined: both weathertight and unprotected. Openings are the most critical factor to preventing an inaccurate index A. If the final waterline immerses the lower edge of any opening through which progressive flooding takes place, the factor “s” may be recalculated taking such flooding into account. However, in this case the s value should also be calculated without taking into account progressive flooding and corresponding opening. The smallest s value should be retained for the contribution to the attained index.

1 The factor si shall be determined for each case of assumed flooding, involving a compartment or group of compartments, in accordance with the following notations and the provisions in this regulation.

θe is the equilibrium heel angle in any stage of flooding, in degrees; θv is the angle, in any stage of flooding, where the righting lever becomes negative, or the angle at which an opening incapable of being closed weathertight becomes submerged; GZmax is the maximum positive righting lever, in metres, up to the angle θv; Range is the range of positive righting levers, in degrees, measured from the angle θe. The positive range is to be taken up to the angle θv; Flooding stage is any discrete step during the flooding process, including the stage before equalization (if any) until final equilibrium has been reached.

184 10/01/2012

Regulation 7-2.1

1. In cases where the GZ curve may include more than one “range” of positive righting levers for a specific stage of flooding, only one continuous positive “range” of the GZ curve may be used within the allowable range/heel limits for calculation purposes. Different stages of flooding may not be combined in a single GZ curve.

2. In figure 1, the s-factor may be calculated from the heel angle, range and corresponding GZmax of the first or second “range” of positive righting levers. In figure 2, only one s-factor can be calculated.

1.1 The factor si, for any damage case at any initial loading condition, di, shall be obtained from the formula:

si = minimum { sintermediate,i or sfinal,i x smom,i }

where:

sintermediate,i is the probability to survive all intermediate flooding stages until the final equilibrium stage, and is calculated in accordance with paragraph 2;

sfinal,i is the probability to survive in the final equilibrium stage of flooding. It is calculated in accordance with paragraph 3; smom,i is the probability to survive heeling moments, and is calculated in accordance with paragraph 4.

2 The factor sintermediate,i is applicable only to passenger ships (for cargo ships sintermediate,i should be taken as unity) and shall be taken as the least of the s-factors obtained from all flooding stages including the stage before equalization, if any, and is to

185 10/01/2012

be calculated as follows:

where GZmax is not to be taken as more than 0.05 m and Range as not more than 7°. sintermediate,i = 0, if the intermediate heel angle exceeds 15º. Where cross-flooding fittings are required, the time for equalization shall not exceed 10 min.

Regulation 7-2.2 (ref. SLF 51/3/2 Annex – US and Sweden) “sintermediate” should vary progressively as a function of heel. Therefore the proposal would be to have a K factor as for “s final”:

where:

Kint = For final equilibrium θmax is of 15 degrees compared to 12 deg in present SOLAS. For intermediate stages, maximum angle of 15 deg would give a θmax of 18.75 deg. Proposed values may be:

θmin-int = 10 degrees θmax-int = 18 degrees

R7-2.2 (changes to sintermediate, i ) . Q31. Do you agree with the above modifications to Reg 7-2.2? Yes

MI, Norway, Denmark, Sweden

No

Finland, Germany, Japan, UK, US, Italy

Comments / Alternatives / More consideration needed?:- China: The influence of new factor “Kint” should be investigated. Finland: This modification would need more investigations. NO preferred. Japan: Further consideration should be needed. Norway: Supports to include a formula, however the actual values needs further consideration. CLIA: Don’t know the impact. Italy: Not agreed, this methodology was never assumed when analysing the initial sample ships. Spain: We need more information about this proposal. Anyway, we think that the following sentence should be added to this proposal: “where: Kint = 1 if θe ≤ θmin Kint = 0 if θe ≥ θmax”

186 10/01/2012

As far as we understand, compared with present S-2009, the situation is as follows: Present S-2009 US and Sweden proposal

θe-int ≤ 10 º (same sint values) kint = 1 (same sint values) 10 < θe-int ≤ 15 º (higher sint values) (lower sint values) 15 < θe-int < 18 º sint ≥ 0 sint = 0 θe-int ≥ 18 º sint = 0 sint = 0

Representing the situation in a graphical way:

0,00

0,20

0,40

0,60

0,80

1,00

1,20

1,40

1,60

1,80

2,00

0 2 4 6 8 10 12 14 16 18 20

sint (currentS-2009) / sint (newproposal)

Equilibrium angle (º)

We have two main concerns about the proposal:

- To permit a maximum equilibrium angle for intermediate stages of 18º is possibly too much for a passenger vessel (panic, difficulties in evacuation, etcetera). This equilibrium angle could be maintained during 10 minutes.

- We do not know the practical effect of reducing the values of sint between 10º and 15º. We suggest analyzing the effect in a passenger vessel database, before the final decision.

END of SPAIN’s COMMENTS US: More consideration of this issue is appropriate. However, generally we don’t think this type of “scale” factor is necessary for an intermediate stage “s”. Round 1 Discussion: Opinion is fairly evenly divided on this issue – 4 in favour and 6 against. However, of those in favour only Norway has comments positively supporting a new formula (not necessarily this one) but, in common with 5 other members, thinks that more consideration of this proposal is needed before adoption. Italy is against it altogether, arguing that adopting this methodology would invalidate the sample ship calculations [which led to the determination of “R”, implying that previous work would need to be repeated using the new Kint factor]. Spain contributes a graph showing the effect on sint of introducing the heel scaling factor Kint and is concerned about the use of 18 degrees as a maximum heel angle criterion over a possible interval of 10 minutes on a passenger ship. Spain wants further consideration as does the US but the latter doubts if a scale factor such as Kint is necessary for sint; CLIA would like to know the likely impact. . Although the proposal is taken from a joint US/Sweden paper SLF 51/3/2 it may not necessarily

187 10/01/2012

have come from these countries. It seems that more justification of the need to modify sint, (from the proposal’s originator, if possible) may help to convince us that the extra work involved is strictly necessary. Q31A In light of the views expressed, particularly the request for further consideration, do you agree that we should ask for more background from the originator of the proposal on the need for introducing factor Kint, especially as it may involve considerable extra research work, as highlighted by Italy? Yes

MI, Germany (with comment), Finland, Italy (with comment), Japan, Norway, CLIA, US, Sweden, Denmark

No

UK (with comment)

Comments / Alternative suggestions? Germany: We would assume a considerable impact of such change, therefore a detailed analysis is needed before any decision is taken. Italy: More background is always welcome, however we do not support new methodologies on this specific issue. France: When establishing SOLAS2009, maximum heel values have been determined in comparison with SOLAS90. K factor in sfinal formula gives a value of 1 if heel is less than or equal to 7° which was the minimum value of maximum heel for SOLAS90. However, contribution to attained index is still taken into account up to a heel angle of 15° which exceed the maximum heel of 12° admitted for SOLAS90. If similar approach is adopted for sint, maximum heel of 15° should be applied to obtained an s=1, but contribution may still be considered for larger heel angles. As explained, the proposed value is obtained so to have an extrapolation from 15° comparable to this from 12 to 15° adopted for heel in final stage. Range from 10° to 18° is proposed to have values comparable to the range 7° to 15° for final equilibrium, but other values may be adopted. ( Range from 12° to 18° would keep a mean value of 15°. Present formulation for sint is not in line with probabilistic concept ( s=1 if heel = 15.000° and s=0 if heel = 15.001°). UK: No, not because argument is not substantial enough, mainly we think that rather than plugging in an another artificial factor which may affect the overall calibration of the attained index i.e. required index, this must be considered in a wider context of factor-s formulation. Therefore it should not be adopted here. US: Clarification note: The joint Sweden/US paper SLF 51/3/2 was a SDS CG report; it was not a Sweden/US position paper. Specifically, SLF 51/3/2 submitted the composite “holding file” of assorted items to potentially address at some point in the future. From my archival records this particular proposal regarding Kint was made by France. Round 2 Discussion:- Thank you France for explaining the reasoning behind this proposed change. What do the CG members think? Q31B (for SLF 53 WG) In light of the explanation for the changes to the formula for sintermediate, i now provided by France can you agree to their proposal? Yes

No

Comments / Alternative suggestions? Post SLF 53 Comment:- There was little support for this proposal by France in the WG and it was therefore not adopted. Q31C (for Round 4 questionnaire) Any final comments?:-

Comments?:- China: No comments. RINA: No comment at this time.

188 10/01/2012

Denmark: No further comments. Germany: No further comments. Italy: Still NOT ACCEPTED. EC: Ongoing research might have a bearing on this. Results of this research should be taken into account. France: France is still convinced that this would improve the method without increasing significantly the complexity of calculations. It is experienced that with present formulation, significant steps in attained index may be observed for a very low variation in GM. This can raise doubts in calculation procedure when analysing the results. To be more in line with the actual limit of 15 deg, we would amend our proposal by fixing : θmin-int = 12 deg θmax-int = 18 deg Spain: To permit a maximum equilibrium angle for intermediate stages of 18º is possibly too much for a passenger vessel (panic, difficulties in evacuation, etcetera). This equilibrium angle could be maintained during 10 minutes (it is not only for a seconds). We think that 15º is an acceptable value for a maximum intermediate equilibrium angle. Round 6 Discussion: As France has made a further proposal we feel obliged to re-open this matter for further comments and, if necessary, to discuss it again at SLF 54, remembering that we are now no longer bound by the restriction to maintain the same safety level as previous SOLAS. If the completion date for this agenda item is extended for another year, it may, as EC suggests, be better to wait for the outcome of ongoing research projects, particularly GOALDS, where the “s” factor is being re-examined and we understand that a problem similar to the one noted by France (rapid change in A arising from small change in GM) has emerged. There is also a point made by Spain (see Q32D, below) that if we decide to apply intermediate stage flooding to cargo ships, as proposed by Norway and supported by several other members, then we would need to re-examine the formula for sintermediate anyway, which is specific to passenger ships (e.g. sint=0 for heel > 15 deg whereas the maximum heel for cargo ships is 30 degrees). For easy reference, France’s original proposal is shown below:- Regulation 7-2.2 “sintermediate” should vary progressively as a function of heel. Therefore the proposal would be to have a K factor as for “s final”:

where:

Kint = For final equilibrium θmax is of 15 degrees compared to 12 deg in present SOLAS. For intermediate stages, maximum angle of 15 deg would give a θmax of 18.75 deg. Proposed values may be:

θmin-int = 10 degrees θmax-int = 18 degrees

Note that France is now proposing to change θmin-int from 10 to 12 degrees. Q31D (for Round 6 questionnaire). Do you agree that we should delay completing this item until further research into possible changes to the “s”- factor is available?

189 10/01/2012

Yes?

Japan, CLIA, RINA, Finland, Norway, Germany, Poland, Italy, UK, China, Denmark, France (see comment below), EC (Yes, the on-going research may have a bearing on this.)

No?

US (We think we should try to close some items)

Have you any further thoughts or comments?:- France: Note that within GOALDS project a new formulation for survival factor is proposed, but it applies only to final stage of flooding and there is no real new criterion proposed for intermediate stages of flooding.

Q31. R7-2.2

THIRTEEN MEMBERS PREFERRED TO AWAIT NEW RESEARCH INTO “s-factor”. US OPPOSES, BELIEVING WE SHOULD CLOSE THIS ITEM.

DISCUSS AT SLF 54 ----------------------------------- Regulation 7-2.2 (ref. SLF 52/17/6 - Norway) Document SLF 51/3/2 mentions that “several delegations believed that intermediate stages of flooding should be considered for some cargo ships and that this issue should be revisited in any future revision of the regulations.” This Administration agrees with this view, but this issue needs further consideration before such criteria can be developed. As an interim measure it is proposed that the first sentence be amended to cover passenger ships only: “2 For passenger ships the factor sintermediate,i is [applicable only to passenger ships (for cargo ships sintermediate,i should be taken as unity) and shall be] taken as the least of the s-factors obtained from all flooding stages including the stage before equalization, if any, and is to be calculated as follows:” ……. The following text reflecting what is already included with respect to cargo ships in the EN is then added at the very end of the paragraph: “For cargo ships the factor sintermediate,i is taken as unity, except in those cases where it is found [anticipated] that the ship would capsize and sink during the intermediate stages, in which case sintermediate,i is taken as 0.” [Coordinator’s Note: The complete text of Reg 7-2.2, proposed as an interim measure by Norway in SLF 52/17/6, would then become]:- “2 For passenger ships the factor sintermediate,i is taken as the least of the s-factors obtained from all flooding stages including the stage before equalization, if any, and is to be calculated as follows:

For cargo ships the factor sintermediate,i is taken as unity, except in those cases where it is found [anticipated] that the ship would capsize and sink during the intermediate stages, in which case sintermediate,I is taken as 0.”

190 10/01/2012

R7-2.2 (apply intermediate stage flooding to cargo ships) . Q32. Do you agree with the above interim re-drafting of Reg 7-2.2 as proposed

by Norway? (But see also Q34 regarding the EN, below, before answering). Yes

Finland, Germany, Norway, Italy, Spain, Denmark, UK, US, Sweden

No

China, Japan, MI

Comments / Alternatives?:- China: China reserves the position that for cargo ships the stability in intermediate stages of flooding need not be considered. CLIA: Norway version. Don’t know effects. Spain: The term “would capsize and sink during the intermediate stages” should be clarified. Denmark: Including the Kint factor in the formula (Q31). We support the view that intermediate stages of flooding should be considered for cargo vessels particularly for cross-flooding. However we would like to know the reasoning behind the original exclusion of intermediate stages for cargo vessels. US: Although we are generally supportive of this approach, this issue requires further consideration. Round 1 Discussion: Nine out of 13 support this proposal; with 3 opposed and CLIA doubtful of the effects (however, as it would only affect cargo ships, it may not concern them). Of those against, only China has a comment; of those in favour Spain requires some clarification, Denmark would like to know why cargo ships were originally omitted and the US would prefer some further consideration. Norway realises that the issue needs further consideration and their proposed change to the regulation is therefore only an interim measure. Another point is that Norway is proposing to introduce new regulatory text which is rather more explicit than that already agreed to in the current EN, and will give it mandatory status. EN 9 currently reads:- Cargo ships

9. If the Administration considers that the stability in intermediate stages of flooding in a cargo ship may be insufficient, it may require further investigation thereof.

Although a significant majority support Norway’s proposal, we should also bear in mind the responses to Q34 where a majority of 8 to 5 preferred to keep EN 9 as it is rather than change it into a regulation. We should also note that there is a considerable difference between “found” and “[anticipated]” in Norway’s proposal; the former implies a full calculation with extra work for the designer whereas the latter implies a judgement based on previous experience and possible discussions with the Administration. Italy’s comments in answer to Q30 should surely also be taken into account as well, since applying intermediate stage flooding, as proposed by Norway, to the original sample of cargo ships could imply that “R” would need to be revised. A further point is that the “complete” text of Reg 7-2.2 given in the co-ordinator’s note in Round 1 omits the limits for GZmax and range as well as the sentence relating to cross-flooding. The full regulation as proposed by Norway should therefore read something like:-

191 10/01/2012

“2 For passenger ships the factor sintermediate,i is taken as the least of the s-factors obtained from all flooding stages including the stage before equalization, if any, and is to be calculated as follows:

where GZmax is not to be taken as more than 0.05 m and Range as not more than 7°. sintermediate,i = 0, if the intermediate heel angle exceeds 15º.

For cargo ships the factor sintermediate,i is taken as unity, except in those cases where it is found [anticipated] that the ship would capsize and sink during the intermediate stages, in which case sintermediate,I is taken as 0. [For passenger and cargo ships], where cross-flooding fittings are required, the time for equalization shall not exceed 10 min.”

Presumably, if Norway’s proposal were to be adopted, EN 9 could be deleted? Finally, if we use “found” rather than “anticipated” in adopting Norway’s interim proposal, the implication is that a full stage-flooding calculation would also be needed for cargo ships. If we then equate “capsize and sink” with either GZmax or range = 0 or intermediate heel exceeding 15 degrees, then we may as well simply require passenger and cargo ships to be fully checked for sintermediate, i, changing the opening wording of the existing regulation to:- 2 The factor sintermediate,i is applicable only to passenger [and cargo] ships (for cargo ships sintermediate,i should be taken as unity) and shall be taken as the least of the s-factors obtained from all flooding stages including etc ……… and deleting EN9. Summary. Given that 3 members are either opposed to any changes to Reg 7-2.2 and EN 9 for cargo ships or would like any reference to intermediate stage flooding for cargo ships removed altogether, it seems there are now 4 options open to us: Option 1: Apply intermediate stage flooding only to passenger ships. Remove (for cargo ships ……. as unity) in Reg 7-2.2 and delete EN9. Option 2: Leave Reg 7-2.2 and EN 9 as it stands – the Administration decides if further investigation is needed. Option 3: Accept Norway’s proposal with the wording of the Regulation 7-2.2 as outlined above using the “anticipated” option in square brackets (slight word changes such as improving “capsize and sink” may also be needed) and delete EN9. Option 4: Apply intermediate stage flooding to both cargo and passenger ships. Modify the opening sentence of Reg 7-2.2 as shown above and delete EN9. . Q32A. Bearing in mind also your previous response to Q34, please indicate

which of the above 4 options you prefer – or give alternatives. Option 1

China

192 10/01/2012

Option 2

MI, France (with comments), Sweden

Option 3

Germany, Italy, Japan (with comment), Norway (with comment), UK, Denmark

Option 4

US

Comments / Alternatives?:- Japan: Japan prefers “anticipated”. France: This question has been discussed several times and a compromise has been found as written in explanatory notes. Formulation « in those cases where it is found [anticipated]” suppose that calculations have been done. (Is it possible to anticipate such problems without doing calculations?). If such calculations are done, it would be logical to take them into account even if they don’t influence the attained index. Norway: To Denmark’s query on exclusion of intermediate stages for cargo ships: The HARDER project proposed including intermediate stages for cargo ships but this was turned down by a small majority of members of the SDS correspondence group to SLF 47 with the argument that it was not required under the old chapter (i.e. not within the terms of reference). See SLF 47/3/2 paragraph 13. CLIA: Not directly relevant - cargo ship issue. Round 2 Discussion:- Many thanks to Norway for providing the historical background to Denmark’s query in round 1. Opinion favours option 3 but it is by no means unanimous so the matter will have to go to the SLF 53 WG for further discussion to see if agreement can be reached. Option 2 (3 supporters) favours keeping the regulation and EN as they are. Option 3 (6 supporters) favours changing the text as follows and deleting EN 9. 2 For passenger ships the factor sintermediate,i is taken as the least of the s-factors obtained from all flooding stages including the stage before equalization, if any, and is to be calculated as follows:

where GZmax is not to be taken as more than 0.05 m and Range as not more than 7°. sintermediate,i = 0, if the intermediate heel angle exceeds 15º. For cargo ships the factor sintermediate,i is taken as unity, except in those cases where it is [found] [anticipated] that the ship would capsize and sink during the intermediate stages, in which case sintermediate,I is taken as 0. [For passenger and cargo ships], where cross-flooding fittings are required, the time for equalization shall not exceed 10 min.” France questions whether it is possible to anticipate whether a ship will capsize and sink during intermediate stage flooding without undertaking full stage-flooding calculations. Q32B (for SLF 53 WG). Can you accept the majority view in favour of Norway’s interim proposal shown in the round 2 discussion above? If so, would you prefer use of the word “found” or “anticipated” as shown in square brackets? Do you accept Norway’s proposal?

Denmark, Finland, Italy : yes (comments added in Round 4 response)

193 10/01/2012

If yes, do you prefer “found” or “anticipated”?

Denmark, Italy : prefer “anticipated” Finland : “found”. Refer also comment from France in Q32A (comments added in Round 4 response)

Further Comments / Alternatives?:- Post SLF 53 Comment:- This item was discussed in some depth and, as reported in the report of the WG to plenary, option 2 from the Round 1 discussion notes was preferred (i.e. leave the regulation and EN unchanged, thereby allowing the Administration to decide if further investigation is needed for cargo ships). However, the WG chairman said that because of the variety of views expressed this issue could be re-opened in the 2011 CG. Q32C (for Round 4 questionnaire):- This question relates to Norway’s interim proposal to calculate intermediate stages of flooding for cargo ships. For the full background and earlier discussions see the working document. As stated, the WG at SLF 53 preferred to make no changes but the chairman left the issue open for discussion in the 2011 CG. Do you therefore support Norway on this issue or do you prefer to leave the regulation as it stands? Q34 covers the EN. Support Norway?

Yes: US, Norway, Finland No: Vanuatu Other: Spain (In general terms yes, but we think that the sentence “would capsize and sink” should be clarified (based on s value calculations?, using passenger vessel criteria?). Obviously, it is not possible in cargo vessels to assume the same formula to evaluate the stability during intermediate stages of flooding, because, for example, in a cargo vessel a maximum final equilibrium angle of 30º is permitted (in the formula, only 15º is permitted for intermediate stages of flooding). As a conclusion:

1) The best solution is to generate a new specific formula or criteria for cargo vessels intermediate stages of flooding.

2) If this solution is not possible, maybe a compromise solution is to add a sentence similar to the included in MARPOL Annex I: “The Administration shall be satisfied that the stability is sufficient during intermediate stages of flooding”.)

No change? Japan, China, Denmark, Germany, Italy, MI (leave as is) Further Comments?:- Vanuatu: We align ourselves with Spain’s comment as reported from WG. Capsizing and sinking are two separate conditions; the second doesn’t necessarily follow the first, and not immediately. Norway: With “anticipated” instead of “found”. Japan: As expressed in the WG, Japan supports option 2. RINA: With regards to Norway’s proposal which modifies the text with options for [found] [anticipated] it is difficult to understand how ship designers are going to know when a ship will capsize and sink without carrying out calculations. This is also the line previously taken by France. It is recognized that there are many cargo ships greater than 80 m in length, where designs vary from the traditional general cargo ship i.e. dedicated car carriers; research ships; supply ships, etc . Therefore it is considered that intermediate stage flooding should apply to both cargo and passenger ships and modify Para 7.2.2 as previously proposed: “The factor sintermediate,i is applicable only to passenger and cargo ships (for cargo ships sintermediate,i should be taken as unity) and shall be taken as the least of the s-factors obtained from all flooding stages including etc”

194 10/01/2012

Denmark: Leave it up to the Administration to decide. UK: Considering the ease of running such calculations now, both passenger and cargo vessels must be treated the same way. Therefore the opening sentence may be modified to reflect this. France: France prefers to leave the text as it is, until we are convinced that intermediate stages of flooding are absolutely necessary also for cargo ships. Round 6 Discussion: Two members fully support Norway’s proposal requiring intermediate stage flooding to be calculated for vulnerable cargo ships whereas 6 favour no change to the current regulation and EN (which leaves the decision as to whether or not further investigation of stage flooding is needed to the Administration). Vanuatu supports Norway but shares Spain’s concern that if the proposal is adopted we will need to make a distinction between the terms “capsize” and “sink”. RINA supports Norway in principle saying that there may be a large variety of ship types with L > 80 m under the “cargo ship” category, some of which may be vulnerable to stability loss during stage flooding. However, RINA cannot see how it is possible to tell in advance without doing calculations whether a particular design will be vulnerable (therefore favouring “found” rather than “anticipated”, in contrast to Norway, who prefers “anticipated”). The UK considers that passenger and cargo vessels should be treated in the same way thereby supporting Norway in principle. Spain supports Norway in general (apart from the expression “capsize and sink”) but points out that the formula for sint may need to be revised (see under Q31D, above). If this is not possible, Spain proposes that we should add a sentence from MARPOL (see text under “Spain” above). However, the text seems very similar to what we already have in current EN (9) (If the Administration considers that the stability in intermediate stages of flooding in a cargo ship may be insufficient, it may require further investigation thereof). France prefers to leave the text and EN alone until we are convinced that stage flooding for cargo ships is absolutely necessary.

SUMMARY:- Fully support Norway: Finland, US, Norway, UK Would support amended proposal: Vanuatu, Spain, RINA Leave things as they are: Japan, China, Denmark, Germany, Italy, MI, France So we have 7 who favour some sort of change and 7 who don’t! PROPOSAL: As the result leaves us divided we will need to take the matter back to SLF 54. In the meantime it would seem from comments by Spain and others that Norway’s proposal to amend reg. 7-2.2 as shown below and remove EN 9 would need further consideration:- _________ 2 For passenger ships the factor sintermediate,i is taken as the least of the s-factors obtained from all flooding stages including the stage before equalization, if any, and is to be calculated as follows:

where GZmax is not to be taken as more than 0.05 m and Range as not more than 7°. sintermediate,i = 0, if the intermediate heel angle exceeds 15º. For cargo ships the factor sintermediate,i is taken as unity, except in those cases where it is [found] [anticipated] that the ship would [capsize and sink] during the

195 10/01/2012

intermediate stages, in which case sintermediate,I is taken as 0. [For passenger and cargo ships], where cross-flooding fittings are required, the time for equalization shall not exceed 10 min.” _________ For example, some suggest we may need to include a separate formula for cargo ships perhaps with different values for 0.05 and 7 and/or a new “K” factor as proposed by France in Q31D, above. We also need to resolve the square bracket issues. Would Norway accept, for example, the point made by several delegates that it is not realistic to predict how the vessel will respond to stage-flooding without performing full calculations? Or, was it Norway’s intention that a new formula or extensive calculations would not be necessary because sint for cargo ships would either be 0 (if θmax is 30 degrees or more, for example) or 1 (in all other cases)? The co-ordinators therefore propose that it would be best at this stage to ask Norway and her supporters to further clarify the original proposal and submit a revised text for re-consideration by the CG and the SLF 54 WG. Q32D (for Round 6 questionnaire). To try to resolve these issues at SLF 54 do you accept the co-ordinator’s proposal in the last sentence of the discussion paper that it would be best at this stage to ask Norway and her supporters to further clarify the original proposal and submit a revised text for re-consideration by the CG and the SLF 54 WG? Yes?

RINA, Finland, Norway (with comment), Poland, US, Italy, UK, France, Denmark

No? Germany, China

If No, would you still prefer to leave the Reg./EN as they are?

Germany (See comment), China (Agreed – leave as they are)

Any further thoughts / alternatives?:- CLIA: (N/A – cargo ship issue) Norway: Since we are no longer limited by keeping the same safety level as the previous SOLAS, Norway is of the opinion that there should be no difference between cargo and passenger ships with regard to intermediate stage of flooding. However, s=0 when heel exceeds 15 degrees to cargo vessels may be evaluated. Germany: Leave reg and EN as they are, i.e. no intermediate stages to be checked for cargo vessels Poland: I agree with Norway proposed that intermediate stage of flooding should also be considered for some cargo ships. US: As a general supporter of the Norway proposal, we were thinking more the sint = 0 or 1 case (as capsize was the fail criteria; not 30 deg). However, we recognize that this type of approach in a SOLAS regulation is not good (as pointed out by several). Therefore, if there is not clear support for a full intermediate stage requirement for cargo ships at SLF 54 then we think it is probably best to just stay with the current approach and EN.

Q32: FURTHER DISCUSSION IS NEEDED AT SLF 54 [Co-ordinator’s Note: Norway has proposed that reg. 7-2.2 should take more account of IS flooding on cargo ships. We have a revised text for this change but Norway has

196 10/01/2012

been asked to clarify the proposal as support is not unanimous. The current revised text is:-

2 For passenger ships the factor sintermediate,i is taken as the least of the s-factors obtained from all flooding stages including the stage before equalization, if any, and is to be calculated as follows:

where GZmax is not to be taken as more than 0.05 m and Range as not more than 7°. sintermediate,i = 0, if the intermediate heel angle exceeds 15º. For cargo ships the factor sintermediate,i is taken as unity, except in those cases where it is [found] [anticipated] that the ship would [capsize and sink] during the intermediate stages, in which case sintermediate,I is taken as 0. [For passenger and cargo ships], where cross-flooding fittings are required, the time for equalization shall not exceed 10 min.] [In the 2011 CG, 9-2 were in favour of Norway producing new text; Germany and China oppose; Norway and US have comments.]

[How we answer this question could also affect the EN (originally reg. 7-2.2 EN 9) for cargo ship IS flooding.] [Q34]

Discuss at SLF 54 Regulation 7-2.2 Intermediate stages of flooding

1. The case of instantaneous flooding in unrestricted spaces in way of the damage zone does not require intermediate stage flooding calculations. Where intermediate stages of flooding calculations are necessary in connection with progressive flooding, or flooding through non-watertight boundaries [CLIA Q7 – accepted at SLF53]they should reflect the sequence of filling as well as filling level phases. Calculations for intermediate stages of flooding should be performed whenever equalization is not instantaneous, i.e. equalization is of a duration greater than 60 s. Such calculations consider the progress through one or more floodable (non-watertight) spaces. Bulkheads surrounding refrigerated spaces, incinerator rooms and longitudinal bulkheads fitted with non-watertight doors are typical examples of structures that may significantly slow down the equalization of main compartments.

Regulation 7-2.2 EN 1 (Add reference to flooding through non-WT boundaries)


CLIA Q7 A number of clarifications with regard to progressive, sequential and cross flooding have been made for the application of the rules.

197 10/01/2012

1. The case of instantaneous flooding in unrestricted spaces in way of the damage zone does not require intermediate stage flooding calculations. Where intermediate stages of flooding calculations are necessary in connection with progressive flooding [or non-watertight boundaries], they should reflect the sequence of filling as well as filling level phases. Calculations for intermediate stages of flooding should be performed whenever equalization is not instantaneous, i.e. equalization is of a duration greater than 60 s. Such calculations consider the progress through one or more floodable (non-watertight) spaces. Bulkheads surrounding refrigerated spaces, incinerator rooms and longitudinal bulkheads fitted with non-watertight doors are typical examples of structures that may significantly slow down the equalization of main compartments. Coordinator’s Comments: CG Member’s Comments?:- Germany: Yes. Finland: Support. Italy: Agreed. France: In order to clarify the sentence, we propose : Where intermediate stages of flooding calculations are necessary in connection with progressive flooding [or flooding through non-watertight boundaries], they should reflect…. US: We can accept this proposed change. Round 2 Discussion:- All those who replied were in support of CLIA’s amendment but France proposed a further clarification (underlined above) which seems to improve the text. CLIA Q7 (for SLF53 WG). Can we accept CLIA’s proposal, as amended by France, to change reg. 7-2.2 EN 1? Yes

No

Further Comments / Alternatives?:- Post SLF 53 Comment:- The amendment to the EN by CLIA as modified by France was agreed in the WG (see above).

CLIA Q7 AGREED AT SLF 53

Flooding boundaries

2. If a compartment contains decks, inner bulkheads, structural elements and doors of sufficient tightness and strength to seriously restrict the flow of water, for intermediate stage flooding calculation purposes it should be divided into corresponding non-watertight spaces. It is assumed that the non-watertight divisions considered in the calculations are limited to “A” class fire-rated bulkheads and do not apply to “B” class fire-rated bulkheads normally used in accommodation areas (e.g., cabins and corridors). This guidance also relates to regulation 4.4. For spaces in the double bottom in general only main longitudinal structures with a limited number of openings have to be considered as flooding boundaries. [CLIA Q8 – accepted at SLF53]

Regulation 7-2.2 EN 2 (Clarification of DB flooding boundaries)


CLIA Q8 Regulation 7-2.2 EN 2 2. If a compartment contains decks, inner bulkheads, structural elements and doors

198 10/01/2012

of sufficient tightness and strength to seriously restrict the flow of water, for intermediate stage flooding calculation purposes it should be divided into corresponding non-watertight spaces. It is assumed that the non-watertight divisions considered in the calculations are limited to “A” class fire-rated bulkheads and do not apply to “B” class fire-rated bulkheads normally used in accommodation areas (e.g., cabins and corridors). This guidance also relates to regulation 4.4.

Additional explanation: For spaces in the double bottom in general only main longitudinal structures with a limited degree of openings have to be considered as flooding boundaries.

Coordinator’s Comments: Would suggest using “number” rather than “degree”? CG Member’s Comments?:- MI: Concur with proposal. Germany: Degree is more precise, as the ratio of opening compared to the total area is important and not the number of openings. Finland: Support “degree”. Japan: Supports comments of CLIA/CCSF and the coordinator. France: This additional explanation is useful. Correction suggested by coordinator is acceptable. The problem may be that there may be several longitudinal webs. In case of symmetrical compartment, most penalising assumption will be to split the compartment in way of the axial web. CLIA: “Degree of opening” reflects the situation better. It is not the number of openings that is relevant, but the relationship between opening area and total area. UK: Agreed. US: We are not in favour of this proposed change. Round 2 Discussion:- Of those who commented, there is good support for CLIA’s proposal but the US is not in favour. A slight majority of those in favour prefer the original CLIA text rather than replacing “degree” with “number”. As support for the proposal is not unanimous we will take the issue to SLF 53 to allow the other members to express their opinion. CLIA Q8 (for SLF53 WG). Can we accept CLIA’s proposal to change reg. 7-2.2 EN 2? Accept CLIA’s proposal?

If yes, do you prefer “degree” or “number”?

Further Comments / Alternatives?:- Post SLF 53 Comment:- The amendment to the EN by CLIA was agreed in the WG (see above), with members preferring to use “limited number of openings” rather than “limited degree of openings”.

CLIA Q8

AGREED AT SLF 53

199 10/01/2012

Sequential flooding computation

3. For each damage scenario, the damage extent and location determine the initial stage of flooding. Calculations should be performed in stages, each stage comprising of at least two intermediate filling phases in addition to the full phase per flooded space. Unrestricted spaces in way of damage should be considered as flooded immediately. Every subsequent stage involves all connected spaces being flooded simultaneously until an impermeable boundary or final equilibrium is reached. If due to the configuration of the subdivision in the ship it is expected that other intermediate stages of flooding are more onerous, then those should be investigated.

R7-2.2 EN3 (Use of added weight method in IS flooding)


CLIA Q9 Regulation 7-2.2 EN 3 3. For each damage scenario, the damage extent and location determine the initial stage of flooding. Calculations should be performed in stages, each stage comprising of at least two intermediate filling phases in addition to the full phase per flooded space. Unrestricted spaces in way of damage should be considered as flooded immediately. Every subsequent stage involves all connected spaces being flooded simultaneously until an impermeable boundary or final equilibrium is reached. If due to the configuration of the subdivision in the ship it is expected that other intermediate stages of flooding are more onerous, then those should be investigated Additional explanation: The purpose of calculation of sequential flooding is to ensure that any intermediate flooding stage or phase will not lead to a lower si value. The calculation of the intermediate filling phases should be carried out using the “added weight” method, resulting in more than one free surface.

Coordinator’s Comments: See discussion for Q27A regarding use of added weight method. CG Member’s Comments?:- Germany: Yes.

Spaces flooded during intermediate flooding phase Spaces flooded during intermediate flooding phase

200 10/01/2012

China: Support. Finland: Support. Italy: Agreed. France: France had proposed more precise proposals which had not been retained concerning intermediate stages. See comments in Q27A for intermediate phases. US: Although this needs further discussion, we generally support this additional explanatory text. Round 2 Discussion:- There is good support for these enhancements to the EN which overlap to some extent with a new proposal for an EN to reg 7.3 and/or 7.6 (see Q27B), which attempts to include France’s suggestion on intermediate phases. We would welcome more suggestions from France on intermediate stages to clarify this EN further. It is suggested that we take this to the WG for further discussion and to obtain the views of other members. CLIA Q9 (for SLF53 WG). Can we accept CLIA’s proposed additions to reg. 7-2.2 EN 3? Accept CLIA’s proposal?

Further Comments / More improvements?:- Post SLF 53 Comment:- The amendments to the EN by CLIA, including the proposed diagrams, were not agreed to by the WG. No changes needed.

CLIA Q9 NFA AT SLF 54

Cross-flooding/equalization

4. In general, cross-flooding is meant as a flooding of an undamaged space on the other side of the ship to reduce the heel in the final equilibrium condition.

In general, cross-flooding is used to reduce heel in the final equilibrium situation in order to improve survivability following [asymmetrical] damage. It is achieved by allowing flood water to cross into an undamaged watertight space on the other side of the ship through a special device such as a pipe or duct. Typical examples of such cross-flooding devices are shown below where the after wing tanks are connected via a cross-flooding pipe and the forward double bottom wing void spaces are connected via a cross-flooding duct.

In general, cross-flooding is used to reduce heel in the final equilibrium [situation] [stage of flooding] in order to improve survivability following [asymmetrical] damage. It is achieved by allowing flood water to cross into an undamaged watertight space on the other side of the ship through a special device such as a pipe or duct. Typical examples of such cross-flooding devices are shown below where the after wing tanks are connected via a cross-flooding pipe and the forward double bottom wing void spaces are connected via a cross-flooding duct. [CLIA Q10D(1)][Do we accept the new changes in green? The changes in grey and the diagram below were accepted at SLF 53. Will the diagram be clear when printed in black and white?] [Voting 11-2 in favour of changes in green; Italy China oppose; France has comments; discuss at SLF 54. See below for full discussion leading up to round 6. ]

201 10/01/2012

R 7-2.2 EN 4 (cross-flooding) CLIA Q10 (for SLF53 WG). Can we accept the proposed amendments and additions to reg. 7-2.2 EN 4 as shown in the round 2 discussion in the working document? Post SLF 53 Comment:- The amendments to EN 4 proposed in the Round 2 discussion, originating from CLIA and France, were finally agreed to by the WG, as was inclusion of a new diagram (see above). The 2011 SDS CG may wish to consider whether we need to include the word “asymmetrical” where shown in square brackets, in the above new text. CLIA Q10C (for Round 4 questionnaire). Should we add “asymmetrical” to the revised text of EN 4 as shown in square brackets in the grey highlight above? Yes

Vanuatu, US, Japan, China, Denmark, Germany, Finland

No

Sweden, RINA, Italy, EC (the text is clear as it stands), UK (not sure if this actually brings any benefit over the current text), CLIA (no real need), MI (No, adding 'asymmetrical' is superfluous since the whole concept of probabilistic damage stability is asymmetrical).

Further Comments?:- US: In the first sentence, the term “final equilibrium situation” is unconventional. Suggest “final equilibrium stage of flooding” (this seems generally consistent with terminology in reg 7-2.1.1 and 7-2.2). Sweden: Already implied. Norway: No comments. Italy: “Asymmetrical” is not correct when calculations are made according to resolution MSC.245(83) in case of down-flooding. France: If cross flooding is restricted to heel correction, it should apply only in case of asymmetrical flooding, but it is not necessary to specify it. From our opinion more general wording should have been adopted. In practice, this interpretation is not in line with the new interpretation allowing alternative method by time domain flooding simulation which is presented in a more general wording. Round 6 discussion: There are 7 in favour and 8 (with France) against the co-ordinator’s proposal to include “asymmetrical” where shown. We can easily accept the slight majority decision and keep the wording more general as Italy and France prefer. However, the US has a new issue and prefers the use of “stage of flooding” in the

202 10/01/2012

opening sentence instead of “situation” for reasons of consistency with other regulations. We therefore propose that EN 4 should now read as follows, as highlighted in green:- In general, cross-flooding is used to reduce heel in the final equilibrium [situation] [stage of flooding] in order to improve survivability following [asymmetrical] damage. It is achieved by allowing flood water to cross into an undamaged watertight space on the other side of the ship through a special device such as a pipe or duct. Typical examples of such cross-flooding devices are shown below where the after wing tanks are connected via a cross-flooding pipe and the forward double bottom wing void spaces are connected via a cross-flooding duct. CLIA Q10D(1) (for Round 6 questionnaire). Can you accept the changes highlighted in green above? Yes?

Japan, CLIA, RINA, Finland, Norway, Germany, US, UK, EC, Denmark France (but see comment)

No? Italy, China

Further Comments?:- France: France is always of the opinion that a more general wording should be adopted so that for any progressive flooding which may improve the ship situation (higher s factor), justification of cross-flooding time must be done. Otherwise, situation before cross-flooding should be considered as a “final stage” for s factor calculation.

CLIA Q10D(1) DISCUSS AT SLF 54

R 7-2.2 EN 4 (cross-flooding)

CLIA Q10


Regulation 7-2.2 EN 4 4. In general, cross-flooding is meant as a flooding of an undamaged [watertight] space on the other side of the ship [through a special device like a pipe or duct] to reduce the heel in the final equilibrium condition.

Additional explanation: Typical examples for cross-flooding devices are pipes to connect wing tanks or small cofferdams to connect both sides of a void space in the double bottom

203 10/01/2012

Alternatively to the procedure as described above a time-domain flooding simulation may be carried out to assess the smallest values of sintermediate or sfinal. Coordinator’s Comments: If accepted we would recommend changing the last sentence slightly: [Alternatively] [As an alternative] to the procedure [as] described above, a time-domain flooding simulation may be carried out to assess the smallest values of sintermediate or sfinal. CG Member’s Comments?:- Germany: Yes. China: Up to now not enough evidence of successful computer software of time-domain flooding which can do this simulation. How can the administration assess and recognize such software and its calculation results? Finland: Support. Italy: Agreed. France: “In general cross flooding device is meant to flood an undamaged space in order to improve survivability of the ship for the damage case.” Existing text would remain after : “The cross flooding time should be calculated ….. In any cases where complete fluid equalization exceeds 10 min, the value of sfinal used in the formula in paragraph 1.1 should be the minimum of sfinal at 10 min or at final equalization.” Additional paragraphs : “If no justification of cross flooding time is given, survival factor is calculated as sfinal for situation before equalization.” “Alternatively to the procedure as described above, a time-domain flooding simulation may be carried out to assess the smallest values of sintermediate (for situations within 600s) or sfinal (for situation after 600s).” CLIA: Agree. UK: Agree with the Coordinator’s Comments. US: We generally support the proposed changes and additional explanatory text.

204 10/01/2012

Round 2 Discussion:- There is good support for these proposals (6 in favour). France suggests an alternative to EN 4 and 2 extra paragraphs after EN 8. China raises the important issue of how administrations are supposed to validate and approve time-domain simulations. Some process of bench-marking the computer software used by industry would seem to be necessary before we can include this as an alternative. In looking again in more detail at the current EN 4, with the alternatives proposed by CLIA and France, we wondered whether it could be changed as follows to combine the best of both alternatives:- 4. In general, cross-flooding is used to reduce heel in the final equilibrium situation in order to improve survivability following [asymmetrical] damage. It is achieved by allowing flood water to cross into an undamaged watertight space on the other side of the ship through a special device such as a pipe or duct. Typical examples of such cross-flooding devices are shown below where the after wing tanks are connected via a cross-flooding pipe and the forward double bottom wing void spaces are connected via a cross-flooding duct. …. Insert diagram New EN 9. If no justification for cross-flooding time is provided, the survival factor is to be calculated as sfinal for the situation before equalization.” New EN 10. As an alternative to the procedure described above a time-domain flooding simulation may be carried out to assess the smallest values of sintermediate (for situations within 600s) or sfinal (for situation after 600s).” Renumber EN 9 to EN 11 This still leaves the question raised by China as to whether we should allow the use of time domain simulations if some administrations are at present unable to verify them. CLIA Q10 (for SLF53 WG). Can we accept the proposed amendments and additions to reg. 7-2.2 EN 4- 8 as shown in the round 2 discussion above? If so, should we include new EN 10 suggesting the alternative of using time-domain simulation? Accept CLIA/France proposals as amended?

If yes, should we include new EN 10?

Further Comments / Alternatives?:- Post SLF 53 Comment:- The amendments to EN 4 proposed in the Round 2 discussion, originating from CLIA and France, were finally agreed to by the WG, as was inclusion of a new diagram (see above). The 2011 SDS CG may wish to consider whether we need to include the word “asymmetrical” where shown in square brackets, in the above new text. The proposed new EN 9 (see Round 2 discussions) was not accepted by the WG but proposed new EN 10 was accepted (see Round 2 discussions and new text inserted where appropriate below). We have now noticed that we have a sub-heading “Cargo ships” just before EN 9 so perhaps we need to re-number new EN 10 as EN 9 and re-number existing EN 9 as EN 10 (see below for clarification)?

205 10/01/2012

CLIA Q10C (for Round 4 questionnaire). Do you agree with inserting new EN 9 as shown above and the re-numbering of old EN 9 as EN 10? Yes

US (see comment), Norway, Japan, RINA, Denmark (with comment), France, Germany, Finland, Italy, UK, CLIA, MI, Spain

No

Vanuatu, China

Further Comments?:- US: Based on our comments/proposals in Q33C above (also repeated below), we believe some modification of new EN 9 is needed (i.e. deletion of the sintermediate (for situations within 600s) or text). We do agree with the reordering of these 2 ENs. Repeated from Q33C: EN 6 for reg 7-2.2 does not seem consistent with regulation 7-2.1.1 (i.e. according to reg 7-2.1.1 it is not the smallest value of sintermediate or sfinal, as is indicated in EN 6). In addition, an EN in this context seems unnecessary (i.e. the “normal” case that is compliant with the 10 minute time limit in reg 7-2.2) and should be deleted. Then we propose combining EN 7 and 8 as follows: In any cases where complete fluid equalization exceeds 10 min, the value of sfinal used in the formula in regulation 7-2.1.1 should be the minimum of sfinal at 10 min or at final equalization. The sfinal at10 min is calculated for the floating position achieved after 10 min of equalization. This floating position is computed by calculating the amount of flood water according to resolution MSC.245(83) using interpolation, where the equalization time is set to 10 min, i.e. the interpolation of the flood water volume is made between the case before equalization (T = 0) and the total calculated equalization time. Note: it is questionable whether the approach in EN 7 and 8 are actually permitted by reg 7-2.2 RINA: Intermediate stage flooding should be considered for cargo ships see RINA response to Q32C Denmark: Though positive for the approach the validation and benchmarking of the available time domain simulations packages is a concern. Finland: Refer also to MSC 245(83) par 4, which allows time-domain simulations as an alternative method. Also instantaneous flooding (below 60 seconds) could be allowed to verify alternatively with time domain method. Round 6 Discussion: We have a large majority (13-2) in favour of inserting the new EN 9 and re-numbering old EN 9 as EN 10 under the “cargo ships” sub-heading as highlighted in grey above. We have included the US proposals as a new question (Q67D, above) and, if accepted, this would change new EN 9 and affect the numbering. RINA’s comments are dealt with under new Q32D, above. We thank Finland for bringing our attention to paragraph 4 in MSC.245(83), indicating that IMO has already accepted, in principle, the use of CFD, time domain simulations or model testing as an alternative. We share Denmark and China’s concerns about benchmarking and how Administrations are expected to approve these alternative submissions but it seems that we must accept that they are now permissible under MSC.245(83). Before concluding this question we must await the outcome of our discussions on Q67D which gives us a chance to ask you whether you think we should also include CFD and model-testing in new EN10, for consistency. CLIA Q10D(2) (for Round 6 questionnaire). As we await the outcome of Q67D, can we in the meantime ask whether you think we should include CFD and model testing as extra alternatives in new EN 10 for consistency with MSC.245(83) para. 4?

206 10/01/2012

Yes Japan, CLIA, RINA (see comments), Finland, Germany, US, Italy, Denmark, UK, France (see comment)

No China (see comment)

Further Comments?:- RINA: It is concluded that at this time the procedures for CFD or model testing are not currently available; therefore they will not be available when this round of EN amendments is completed. If this is the case then it is concluded that these procedures will be submitted as new MSC work items. France: From our memories, this paragraph has been adopted at SLF 53? China: Model testing may be an option.

CLIA Q10D(2) TEN MEMBERS SUPPORT INCLUSION OF CFD OR MODEL TESTING. CHINA OPPOSES. RECOMMEND ACCEPTANCE OF THE FOLLOWING AMENDMENT AT SLF 54 ON A MAJORITY VOTE: 9. As an alternative to the procedure described above a time-domain flooding simulation [,computational fluid dynamics (CFD) or model testing][CLIA Q10D(2); 10-1 in favour; recommend change]may be carried out to assess the smallest values of [sintermediate (for situations within 600s) or][US propose deletion, see Q33C] sfinal (for situation after 600s).

US TO CONFIRM REQUEST FOR ABOVE-MENTIONED DELETION AT SLF 54 5. The cross-flooding time should be calculated in accordance with the Recommendation on a standard method for evaluating cross-flooding arrangements (resolution MSC.245(83)). If complete fluid equalization occurs in 60 s or less, it should be treated as instantaneous and no further calculations need to be carried out. Additionally, in cases where sfinal = 1 is achieved in 60 s or less, but equalization is not complete, instantaneous flooding may also be assumed if sfinal will not become reduced. In any cases where complete fluid equalization exceeds 60 s, the value of sintermediate after 60 s is the first intermediate stage to be considered. Only passive open cross-flooding arrangements without valves should be considered effective for instantaneous flooding cases.

Regulation 7-2.2 EN paragraph 5 (ref. SLF 52/17/1 – Germany) 1 This document wishes to recall the need for uniform application of the probabilistic provisions and refers, in particular, to the cross-flooding calculation as required by SOLAS regulation II-1/7-2 (resolution MSC.216 (82)).

2 A specification of the calculation procedure is given in the EN on SOLAS regulation II-1/7-2.2, paragraph 5 of which reads: “In any cases where complete fluid equalization exceeds 60 s, the value of sintermediate after 60 s is the first intermediate stage to be considered….” Background 3 More and more damage cases will not lead to symmetric flooding scenarios. In those, cross-flooding may be the reliable measure to achieve residual stability margins, which, if proven to result in favourable s-values, can be taken into account in the summation of the attained subdivision index. 4 SOLAS provisions as supported by the EN do not provide for the degree of clarity needed for the calculation of cross-flooding arrangements, as might be deemed necessary.

207 10/01/2012

5 Germany understands that it was not intended when the related regulations were developed to consider the floating position after 60 seconds of equalization as the first intermediate stage, as resolution MSC.245(83) (Recommendation on a standard method for evaluating cross-flooding arrangements) is based on the assumption that the damaged compartments are flooded completely before equalization starts. 6 It is Germany’s view that the consideration of the first intermediate stage after 60 seconds as per regulations II-1/7-2 is not the most conservative approach with respect to ship safety. Proposal 7 Germany proposes that at the first intermediate stage it should be assumed that the damaged compartment(s) have been flooded and no equalization through cross-flooding has yet occurred. Regulation 7-2.2 EN 5 and MSC.245(83) (first intermediate stage not the worst?) . Q33. Do you agree that, at the first intermediate stage, no equalization via cross-

flooding has yet occurred? If so, should 7-2.2 EN5 be modified? Yes

China, Germany, MI, Norway, Spain, Denmark, US

No Finland, Japan, CLIA, Italy, UK

Comments / Alternatives / Proposals for Modification?:- China: The original text of EN in MSC.281(85) for the first stage of flooding for cross-flooding arrangement is too complicated and Germany’s proposal simplifies the calculation. China supports Germany. Japan: This sentence should be kept consistent with the case of after 10 minutes of equalization (Regulation 7-2.2 EN paragraph 7.7). Norway: The interpretation in 7-2.2 EN5 is in conflict with the definition of “flooding stage” in 7-2.1 and needs to be modified. Italy: Did not support document 52/17/1 by Germany. It is recalled that the text of this Explanatory Notes was the result of a joint proposal from ITALY and FINLAND, agreed in the previous ISCG Questionnaire (EN Circular 3) by a large majority (9 in favour, and only 1 contrary). It is also underlined that the current interpretation avoids unrealistic discontinuities in the calculation process. Denmark: Regarding point 4, we agree that the SOLAS and EN needs to provide more clarity and also whether cargo vessels and passenger vessels should be subject to the same standard with respect to cross and intermediate stage flooding.

UK: We consider that until the issue of transient flooding is also addressed no further modification is needed. As it was shown in the past and considered in the early development of the harmonized regulations, the transient stages of flooding can have a substantial impact on vessel stability, primarily due to “multiple free surfaces”.

US: Regulation 7-2.2 EN5 should be modified.

France: (comments added after Round 2) Proposed formulation is more simple, but the problem is the definition of “damaged compartments” which is based on the room definition adopted for calculations. Definition of compartment may be based on flooding calculation. For large compartment extending over ship axis with connection of restricted area between two parts, it may be necessary to justify that complete flooding will occur in less than 60s. If flooding occurs in more than 60s, compartment must be split in two rooms. With proposed wording, there will be a gap in the calculation assumption if flooding time extends from 60 to 61s which is not satisfactory. The intent of present wording is to have a progressive approach, but this approach is effectively more complex.

208 10/01/2012

Round 1 Discussion: Opinion is fairly evenly divided on this issue with 7 in favour and 5 against Germany’s proposal to designate the first intermediate stage of flooding as the moment when the damage compartment has been flooded but equalization has not yet commenced. As coordinators, we have some difficulties with Germany’s proposal – for example point 6 suggests that in Reg 7-2 the first intermediate stage of flooding occurs after 60 seconds but we cannot see this written anywhere. To us, the combination of Reg 7-2, EN5 and MSC.245(83) in their present form make some sense:- 1) According to the definitions in Resolution MSC.245(83) paragraph 1:-

: Angle before commencement of cross-flooding. This assumes that the cross-flooding device is fully flooded but that no water has entered into the equalizing compartment on the opposite side of the damage (see appendix 1).

that is - when a room is damaged, floodwater is assumed to instantly fill it and the cross-flooding pipe or duct up to the entry point into the receiving space. This could be called the first stage of flooding in accordance with the definition of “flooding stage” in Reg 7-2. It is not associated with any time scale; in MSC.245(83) this stage is assumed to occur instantly and is given the designation T=0 in EN7. It is not the first intermediate stage of flooding - this may occur later. 2) Cross-flooding time is then calculated as the time it takes to fill the receiving space from that “first stage” (T=0) until equilibrium is achieved. If this takes longer than 60 s, then the status of the ship after 60 seconds is calculated and this is designated as the first intermediate stage. If it takes less than 60 seconds, flooding is assumed to be instantaneous with “sintermediate, i” determined as described in EN5. 3) EN 6 and 7 then describe what happens during the next 10 minutes where final equalization, if not already reached instantaneously or within 60 s, is either achieved or not. . Q33A. Do you agree with points 1-3 in the discussion above that Reg 7-2.2, EN5

and MSC.245(83) already give a sufficiently clear picture of how to treat cross-flooding or do you think that further clarification is needed?

No changes needed

MI (concur), Finland, Italy, Japan, CLIA, UK, Sweden

Changes needed

Germany, China, France (with comments), Norway (with comment), US (with comment), Denmark

Comments / Alternatives / Proposals for Modification to Reg. 7-2.2 or EN?:- Germany: Germany is still of the opinion that discrepancies between SOLAS, EN and MSC.Res.245 exist. We try to explain the background in form of a sample.

SOLAS allows “active cross-flooding devices” i.e. manual action by a crew member is needed to open a valve or similar. For such case it is logical that a damage stage exists which only includes the initial damaged rooms and no cross flooding at all can be considered. Having this in mind the same principle should be applied for “passive cross-flooding devices” which act automatically for the following reason

• The size of a damage acc. to SOLAS2009 (based on compartment limits) is in most cases considerably bigger than the effective diameter of the cross-flooding device. Therefore the amount of water volume that has already passed the flooding duct should be considered negligible (safe side approach)

• Acc. to MSC.Res.245 the basis for the calculation of cross flooding time is a damage cases which does not account any cross flooding

For these reason we propose to apply the principle as laid down in SLF52/17/1 and incorporate

209 10/01/2012

this to the EN.

China: The pictures in figure 1 of appendix 1 of MSC.245(83) are too small to clearly see the text on it, China has very big difficulty in developing the program code. This figure should be redrawn to be as clear as possible.

France: Considering discussions on the subject, it appears that regulations or explanatory notes are not enough clear. Problem is the definition of the first intermediate stage and our understanding is the following : In explanatory notes it is said that “unrestricted spaces in way of damage should be considered as flooded immediately” which will correspond to the first intermediate stage. However the fact that a space is “unrestricted” should be justified by verifying that it is completely flooded within 60s. Otherwise for calculations, it should be split in several rooms flooded at different stages. Alternative proposal in explanatory notes is to consider that the first intermediate stage corresponds to the situation after 60s. This supposes that a flooding simulation is achieved and incorporated in probabilistic calculation. If definition of rooms used when applying the first method corresponds to a situation where they are flooded within a time close to 60s, the two approaches should give comparable results for the first intermediate stage, but this cannot be the case for all damage cases and all initial conditions.

Norway: We think the German proposal is consistent with the wording (“any” and “before”) of regulation 7-2.1.

US: We do not understand your discussion regarding the distinction between the first stage of flooding in accordance with the definition of “flooding stage” in Reg 7-2.2 and the first intermediate stage of flooding (that may occur later). In cross-flooding cases (as clarified by the proposed text provided by CLIA in the prior question), we agree with Germany’s proposal that the first intermediate stage of flooding should be (the potentially worst case) where the damaged compartment has been flooded but prior to any equalization via cross-flooding. Round 2 Discussion:- Opinion is very evenly divided on the issues raised by Germany (7 supporting “no change” and 6 still considering changes to be needed). For China’s point regarding the diagrams in fig. 1 of MSC.246(83), we have produced improved versions (see under MSC.245, below). It is clear that the issues will need to be discussed at the SLF 53 WG with the help of the new diagrams. We can understand the point being made by Germany and the US that we should be attempting to find the worst case before cross-flooding starts and this will be when the room is initially damaged and there is as yet no water in the cross-flooding duct or pipe. This, however, is not how

the calculation of cross-flooding time is defined according to MSC.245(83) where is the angle of heel which occurs when the damaged room and the cross-flooding pipe or duct are filled. If this is not the case then MSC.245 would need to be amended. Also, Germany’s argument is that if the damage size is large the volume of flood water will be very large in comparison with the cross-flooding pipe or duct so water will not spread “instantaneously”. However, if the pipe or duct volume is as small as Germany suggests, then

whether it contains flood water or not will make very little difference to the calculation of . However, if the pipe or duct restricts flow significantly then perhaps it would be better to assume that only the damaged room(s) floods “instantaneously” and that time T=0 is set to when flow through the cross-flooding device commences. This would mean changes to MSC.245(83). Q33B (for SLF 53 WG). To start the discussions off, would you agree that the

definition of in MSC.245(83) should be altered so that the angle is calculated before water enters the cross-flooding pipe or duct and that this should be designated as the “first intermediate stage” of flooding for the purpose of calculating the equalization time?

210 10/01/2012

Yes, change is needed

No, changes are not needed

Comments / Alternatives / Proposals for Modification?:- Post SLF 53 Comment:- Germany’s proposal was not accepted by the WG. However, as it could have involved change(s) to MSC.245(83) it may not have lain within our ToR which only covers S2009 updates. We do have another issue with MSC.245(83) – improving the diagrams – and to get those changed it now appears that we will need to go through IMO procedures for amending an MSC Resolution. So perhaps that would be an opportunity for Germany to re-open the debate on the cross-flooding issue they raised here and the two items could be dealt with at the same time in another forum. Further Comments by SDS CG 2011?:- Q33C (for Round 4 questionnaire); for full background see the working document:- As we must follow IMO procedures and make changes to MSC.245(83) separately, 1) Do you agree that we should ask the Secretariat to initiate the process of including our improvements to the cross-flooding diagrams? 2) At present cross-flooding through the duct or pipe can be considered to be instantaneous. If Germany wishes, would you want to support them in re-presenting their proposals to IMO to clarify the definition of “first intermediate stage” of flooding in MSC.245 (83)?

Q1 Yes Vanuatu, US, France, Norway, China, RINA, Denmark, Germany, Finland, Italy, UK, Spain

No Japan

Q2 Yes US (see comment), Norway, China, Denmark, Germany, UK, Spain

No Vanuatu, Japan, Italy, France

Further Comments (especially from Germany on Q2):- US Q2: The aim of this question is not so clear to us. If the question is whether the definition of

and the associated figure in Appendix 1 of MSC.245(83) should be revised to reflect no water in the cross-flooding device (for the “before cross-flooding case”), we can agree to this. However, we view the purpose of MSC.245(83) as only providing a methodology to calculate cross-flooding times, not to provide guidance for what is the first intermediate stage of flooding. Defining/clarifying the first intermediate stage of flooding should be done in the EN. Historic note regarding MSC.245(83): The original input regarding the cross-flooding device being filled with water before commencement of cross-flooding is as follows (submitted in the SDS CG for SLF 49): “Before cross flooding: For “before cross flooding there is an anticipated closing device in front of the cross flooding pipe on the reverse ship side of the damage (see Appendix II), so that no water can flow into the equalizing compartment”. So it seems this was more of a general assumption, which was incorporated into the guidance, than anything else. ----------------------------------------------------------------------------------------

211 10/01/2012

Separate / new issue regarding cross-flooding and regulation 7-2.2 EN 6: EN 6 for reg 7-2.2 does not seem consistent with regulation 7-2.1.1 (i.e. according to reg 7-2.1.1 it is not the smallest value of sintermediate or sfinal, as is indicated in EN 6). In addition, an EN in this context seems unnecessary (i.e. the “normal” case that is compliant with the 10 minute time limit in reg 7-2.2) and should be deleted. Then we propose combining EN 7 and 8 as follows: In any cases where complete fluid equalization exceeds 10 min, the value of sfinal used in the formula in regulation 7-2.1.1 should be the minimum of sfinal at 10 min or at final equalization. The sfinal at 10 min is calculated for the floating position achieved after 10 min of equalization. This floating position is computed by calculating the amount of flood water according to resolution MSC.245(83) using interpolation, where the equalization time is set to 10 min, i.e. the interpolation of the flood water volume is made between the case before equalization (T = 0) and the total calculated equalization time. Note: it is questionable whether the approach in EN 7 and 8 are actually permitted by reg 7-2.2. Denmark: Experience using MSC.245(83) has shown that it is difficult to comply. Even if a passenger ship has u-shaped tanks cross flooding according to MSC.245(83) can take more than 60 sec. The range of responses suggests that perhaps the regulations are not as clear as they might be; leading to varying application, and therefore we would support clarification. Germany: Looking at the working document, question Q33 relates to the interpretation of the 1st intermediate stage and has been answered already by most of the delegations. A majority is of the opinion that the definition of the 1st intermediate stage has to be updated; i.e. EN 7-2.2. Germany realizes that the application of the first intermediate still allows significant different interpretations, without knowing which one is more conservative. Therefore this subject needs to be further explored within the WG. France: The basic problem is always the definition of individual rooms. If cross flooding duct is of large dimension, it has to be defined as a room. If it is demonstrated that this room is flooded within less than 60s, it can be considered as instantaneously flooded. In the example of MSC.245(83), cross flooding device is identified as a pipe with a closing device. In this case, volume of pipe may be considered as negligible, but in practice, filling of this pipe will start only when valve will be opened. It can be consider that this is an example, so there is no need to update it. Additional comment could be added in explanatory notes. Round 6 Discussion: For Q1 there is a large majority (12-1) in favour of advising the Secretariat that we consider the diagrams in Appendix 1 of MSC.245(83) need to be improved - so we will take the necessary action. We hope the honourable delegation from Japan can accept this large majority verdict? For Q2 the voting was 7-4 in favour of Germany’s original proposal relating to reg. 7-2.2 EN5 being re-considered by IMO (it being recognised that our SDS CG does not currently have the required ToR for changing MSC.245(83) even if we think this necessary). However, as shown by your responses to Q1, we must change MSC.245(83) anyway to improve the diagrams, one of which (Fig. 1(c)) relates directly to the point that concerns Germany. So the idea was that we should ask the SLF sub-committee to allow us to make further changes to MSC.245(83) to ensure that it harmonises with our agreed interpretations of cross-flooding times, first stage of flooding etc which we also may wish to change in SOLAS 2009 Reg. 7-2.2 and/or the EN’s. This may involve re-considering Germany’s original proposal (below) in another forum as it was not accepted in the SLF 53 WG:- Regulation 7-2.2 EN paragraph 5 (ref. SLF 52/17/1 – Germany)

1 This document wishes to recall the need for uniform application of the probabilistic provisions and refers, in particular, to the cross-flooding calculation as required by SOLAS regulation II-1/7-2 (resolution MSC.216 (82)).

2 A specification of the calculation procedure is given in the EN on SOLAS regulation II-1/7-2.2,

212 10/01/2012

paragraph 5 of which reads: “In any cases where complete fluid equalization exceeds 60 s, the value of sintermediate after 60 s is the first intermediate stage to be considered….” Background 3 More and more damage cases will not lead to symmetric flooding scenarios. In those, cross-flooding may be the reliable measure to achieve residual stability margins, which, if proven to result in favourable s-values, can be taken into account in the summation of the attained subdivision index. 4 SOLAS provisions as supported by the EN do not provide for the degree of clarity needed for the calculation of cross-flooding arrangements, as might be deemed necessary. 5 Germany understands that it was not intended when the related regulations were developed to consider the floating position after 60 seconds of equalization as the first intermediate stage, as resolution MSC.245(83) (Recommendation on a standard method for evaluating cross-flooding arrangements) is based on the assumption that the damaged compartments are flooded completely before equalization starts. 6 It is Germany’s view that the consideration of the first intermediate stage after 60 seconds as per regulations II-1/7-2 is not the most conservative approach with respect to ship safety. Proposal 7 Germany proposes that at the first intermediate stage it should be assumed that the damaged compartment(s) have been flooded and no equalization through cross-flooding has yet occurred. Taking each of your comments in turn: US. We hope we have explained the purpose of Q2 in our opening remarks, above. We apologise for not making the intent more clear. We simply wanted to try to establish whether or not Germany wished to pursue their proposal further, if necessary as a new agenda item or in another forum, and whether other SDS CG members would support this. We entirely agree with the US that the EN (or the regs) should define the first intermediate stage of flooding – it was our mistake to suggest in the question that this should be done in MSC.245(83). In fact, we believe that it is already defined in EN 5 which states that sintermediate should be the value calculated after 60 seconds of cross-flooding but only in cases where the time for complete fluid equalization exceeds 60 seconds or sfinal does not achieve a value of 1 within 60 seconds. At this point, we agree with the US, that EN 5 sentence 1 hands responsibility for calculating the time for cross-flooding over to MSC.245(83) and we also agree that this is the resolution’s primary function. From studying the resolution with the help of the clearer diagrams in Appendix 1, it seems that time zero (T=0, the commencement) for calculating the time for equalization occurs when the ship is at θo degrees as shown in Fig 1c. The impacted spaces and the cross-flooding pipe are assumed to be instantaneously filled, an assumption not mentioned in SOLAS or the EN as far as we can see. We thank the US for the historical note explaining the background to this assumption in MSC.245; it does seem a little arbitrary and may need re-visiting to harmonize better with SOLAS / EN. If the cross-flooding device is not open and passive and contains valves, it conflicts directly with the last sentence of EN5. Paragraph 2.1 of MSC.245(83) then gives a formula for calculating the total cross-flooding time from T=0 until final equilibrium at angle θf degrees. If this is less than 60 seconds EN 5 states that complete fluid equalization is assumed to be instantaneous and no intermediate stage flooding calculations are needed. Also, instantaneous flooding may be assumed if sfinal achieves a value of 1 in 60 seconds or less and does not subsequently reduce. Only if equalization from T=0 is greater than 60 seconds and

213 10/01/2012

sfinal is less than 1 after 60 seconds from T=0 is stage flooding assumed to occur and the first intermediate stage of flooding is as defined above in EN 5. At this point it would seem to us that the regulations, EN and MSC.245(83) are reasonably consistent and there would be little need to further clarify or define what is meant by “first intermediate stage” - as long as we accept the “definition” of T=0 as depicted in Fig 1c. The problem arises firstly (as we think Germany has pointed out), with the assumption of instantaneous cross-flooding of the pipe or duct which could give rise to an optimistic scenario. If the cross-flooding device is a large duct, the weight of floodwater in the duct itself will help the equalization process by transferring weight to the other of the ship, as shown in fig 1c. A worst case scenario, which could happen particularly where manual cross-flooding valves are fitted, occurs where water is contained on the damaged side for a considerable time until the valve is opened. An even worse case scenario may be transient asymmetrical flooding which could result in a large water load at the outboard side of the damage space before equalisation within the damaged compartment occurs. This, rejected at Malmo in December 2003, may be something for future consideration, Secondly, we are puzzled by what seems to be an anomaly in MSC.245 whereby considerable parts of it are concerned with the fluid mechanics of flooding through ducts, friction losses, air pipe venting, factor F etc and yet fig. 1c assumes that flooding through the cross-flooding device itself is instantaneous. Therefore it appears that no account need be taken in the overall flooding calculation of the time for floodwater to pass through the duct or pipe - surely a crucial factor in duct design and general safety? Or are we missing something obvious here? France has some ideas on this (below). To the co-ordinators, and, we think, Germany for different reasons, it would therefore seem more conservative to take T=0 as the time when the damaged tank is full but the cross-flooding pipe/duct is empty. This would mean either specifying T=0 in this way in the regulations and/or in the EN and in MSC.245 (by removing the shading in the pipe in fig.1c, for example). We thank the US for raising new issues with EN 6, 7 and 8 - we will open a new question box below. Denmark advises us that calculations with U-shaped tanks using MSC.245(83) often result in T>60 secs. It would be interesting to know whether this is based on the scenario in Fig 1c or whether allowances have been made for losses through the duct. Could Denmark please let us know, if possible? If we put T=0 before the duct/pipe is cross-flooded then the time to achieve equalisation would be even greater, making Denmark’s “problem” worse. Perhaps the flow rate formulae in Section 2 of MSC.245(83) are too conservative? We recall that Japan did some related research on duct and pipe flow rates recently (ref. SLF53/INF.6) and we understand that research is continuing. Could Japan possibly update us on this work? Germany still thinks that the EN 5 for 7-2.2 should be updated and that we need to decide in the WG which is the most conservative interpretation of the regulations. France makes some interesting points - arguing that if a cross-flooding duct is “large” then it could be considered as a “room” defined separately from the connected compartments in the computer model. France makes a distinction between a cross-flooding pipe (as shown in the figures in Appendix 1 of MSC.245) and a duct. The volume of a pipe is so small as to be negligible and it would therefore not matter, (from the “worst case” heeling moment point of view), whether the pipe was full or empty.

214 10/01/2012

However, from the “time to equalize” point of view, we co-ordinators would guess that flow through a pipe would be slower than through a duct leading to more cases with T>60 secs (that is, if we assume T=0 before any cross-flooding occurs through the pipe). Also MSC.245 contains illustrations of friction losses through both pipes and ducts suggesting that different flow rates will apply to each type of device. It is not totally clear to us how France would determine the rate of filling of the duct – when defined as a “room”. Would this be a separate procedure from para. 2.1 of resolution MSC 245(83)? Also we don’t think that it is necessarily the case that pipes are always manually controlled with valves as, we think, France may be suggesting. SUMMARY: We invite your comments on:

1) the issue of whether T=0 should occur:- (a) just before water enters the cross-flooding pipe/duct OR, (b) as is currently shown in MSC.245 fig 1c, just before water enters the opposite tank or space. For (a) allowances for friction losses in the pipe/duct would be needed when using the formulae in MSC.245(83). For (b) cross-flooding through the pipe/duct would be assumed to be instantaneous with no friction losses. 2) if you prefer 1(a) could we define T=0 in EN 5 by adding, for example, the

following text as highlighted in green at the end of the first sentence?

The cross-flooding time should be calculated in accordance with the Recommendation on a standard method for evaluating cross-flooding arrangements (resolution MSC.245(83)) with the commencement of the cross-flooding time being when the damaged spaces are assumed to be filled to the outside water level but the cross-flooding device is empty. 3) also, if you agree with option 1(a) then we would also need to seek permission

to change fig 1c in MSC.245(83) to remove all shading in the pipe. 4) if we obtain permission from the sub-committee to change MSC.245(83) should

we make it clear that the diagrams apply equally to cross-flooding ducts or other devices by changing the title and amending the arrowed reference to “cross-flooding pipe” in Fig 1a of Appendix 1.

5) Do you support France’s suggestion that cross-flooding ducts should be treated

as “rooms” whereas the volume of pipes can be ignored and that this should be included in the EN? We cannot really use the word “large” as it may be complicated to define so would we also need to define “ducts” in the EN?

Q33D (for Round 6 questionnaire). Can you please indicate your preferences to the numbered issues raised in the above summary? 1) Do you support option (a) Y/N? Comments?

Yes: Japan (supports option (a)), RINA, Norway, Denmark, China, US (support option a), UK (we support the assumption for T=0 just before water enters the cross-flooding device to account for the most conservative scenario. Consequently, designers will be encouraged to implement more effective arrangements.) No: Finland, Germany, Italy Other: France (see comments below)

1) OR do you support option (b) Y/N?

Yes: Finland, Germany, Italy No: Norway, US, Denmark

215 10/01/2012

Comments?

2) If you support 1(a) do you agree to amend EN5 Y/N?

Yes: Japan, RINA, Norway, US, Denmark, China, UK (to the proposed EN 5 enhancement).

3) If you support 1(a) do we need to change fig 1c in MSC.245 Y/N?

Yes: Japan, RINA, Norway, US, UK, Denmark, China

4) Should we clarify fig 1a in MSC.245 Y/N?

Yes: Japan, RINA, Finland, Norway, Germany, Poland, US (generally), UK, France, Denmark, China No: Italy

5) Should ducts be treated as “rooms” Y/N?

Yes: Poland, US (conceptually) No: RINA, Norway, Denmark, Italy, China, Finland (Definitions; pipe, small duct and large duct are dependent of ship size. Administrations should decide case by case the proper definitions), Germany (no, as the boundary between a pipe or a small duct and a room cannot be defined, it is up to the administration to decide on case by case basis), UK (No, at this stage we do not think that there is any need to specify an agreed lower limit for the suggested “room” treatment of the arrangement. In reality, it is up to the flag administration to accept if the duct is large enough to consider it instantaneous anyway.) Comment: France (see below)

5) If “yes” should we define “large ducts” Y/N?

No: Poland, US, Denmark Comment: France (see below)

Further Comments:- Japan: Sorry we have not finalized the updated research of friction coefficients in cross-flooding yet but have a plan to submit the report (INF paper) to SLF 54. [Co-ordinator’s Note:- See SLF 54/4/2 and .INF14] CLIA: No further comments France on 1): The answer to question 1) depends on the volume of the cross flooding duct/pipe. Option “a” of 1) would apply if this volume is such that it is necessary to describe it as a room. If cross flooding pipe is not described as a room, the question is irrelevant. France on 5): Usual practice is to define volume of duct as a room only if it is made of structural elements. A clearer criterion to define if duct is large (has to be described as a room) would be to define a minimum volume by reference to ship’s moulded displacement per centimetre. For calculation of cross flooding time, if pipe is not described as a room, it will not be possible to take into account the time necessary to fill the pipe. If pipe/duct is defined as a room, its volume will be taken into account in the cross-flooded volume. If its volume remains small in comparison with cross-flooded compartment, “k” factor will be calculated for the situation after filling of the duct which is pessimistic as actual k factor

216 10/01/2012

will be less during the phase of filling of the duct. If volume of duct is large, two successive cross flooding stages will be considered with specific “k” factors.

Q33 R7-2.2 EN5 Summary of outcome of Q33D on text of EN:

5. The cross-flooding time should be calculated in accordance with the Recommendation on a standard method for evaluating cross-flooding arrangements (resolution MSC.245(83)) [with the commencement of the cross-flooding time being when the damaged spaces are assumed to be filled to the outside water level but the cross-flooding device is empty]. [Q33D(2); 7 support this] If complete fluid equalization occurs in 60 s or less, it should be treated as instantaneous and no further calculations need to be carried out. Additionally, in cases where sfinal = 1 is achieved in 60 s or less, but equalization is not complete, instantaneous flooding may also be assumed if sfinal will not become reduced. In any cases where complete fluid equalization exceeds 60 s, the value of sintermediate after 60 s is the first intermediate stage to be considered. Only passive open cross-flooding arrangements without valves should be considered effective for instantaneous flooding cases. [Coordinator’s Note: linked to this is the question of possible changes to MSC.245(83), in particular the cross-flooding figures and whether the cross-flooding pipe/duct should be assumed to be flooded instantaneously. [Q33D(1) (7 in favour 3 against);(3)(7 support) (4) (11-1 in favour] and France’s proposal to treat cross-flooding ducts as rooms [Q33D(5); 2 support, 8 against].

TO BE DISCUSSED FURTHER AT SLF 54.

6. If complete fluid equalization can be finalized in 10 min or less, the assessment of survivability can be carried out for passenger ships as the smallest values of sintermediate or sfinal .

7. In case the equalization time is longer than 10 min, sfinal is calculated for the floating position achieved after 10 min of equalization. This floating position is computed by calculating the amount of flood water according to resolution MSC.245(83) using interpolation, where the equalization time is set to 10 min, i.e. the interpolation of the flood water volume is made between the case before equalization (T = 0) and the total calculated equalization time.

8. In any cases where complete fluid equalization exceeds 10 min, the value of sfinal used in the formula in paragraph 1.1 should be the minimum of sfinal at 10 min or at final equalization.

R7-2.2 EN6-8 (NEW ITEM INTRODUCED BY USA IN THEIR RESPONSE TO ROUND 4 QUESTIONNAIRE) Separate / new issue regarding cross-flooding and regulation 7-2.2 EN 6: EN 6 for reg 7-2.2 does not seem consistent with regulation 7-2.1.1 (i.e. according to reg 7-2.1.1 it is not the smallest value of sintermediate or sfinal, as is indicated in EN 6). In addition, an EN in this context seems unnecessary (i.e. the “normal” case that is compliant with the 10 minute time limit in reg 7-2.2) and should be deleted. Then we propose combining EN 7 and 8 as follows: In any cases where complete fluid equalization exceeds 10 min, the value of sfinal used in the formula in regulation 7-2.1.1 should be the minimum of sfinal at 10 min or at final equalization. The sfinal at 10 min is calculated for the floating position achieved after 10 min of equalization. This floating position is computed by calculating the amount of flood water according to

217 10/01/2012

resolution MSC.245(83) using interpolation, where the equalization time is set to 10 min, i.e. the interpolation of the flood water volume is made between the case before equalization (T = 0) and the total calculated equalization time. Note: it is questionable whether the approach in EN 7 and 8 are actually permitted by reg 7-2.2. Coordinator’s Comments: We are not totally certain about the first statement from the US as reg. 7-2.1.1 appears to us to indicate that si is to be taken as the minimum of sint or sfinal.smom which does not conflict with EN 6. However, at this stage we will simply invite general comments on the US proposals, which may need further discussion at SLF 54. For easy reference the existing EN’s 6-8 are included below:- 6. If complete fluid equalization can be finalized in 10 min or less, the assessment of survivability can be carried out for passenger ships as the smallest values of sintermediate or sfinal .

7. In case the equalization time is longer than 10 min, sfinal is calculated for the floating position achieved after 10 min of equalization. This floating position is computed by calculating the amount of flood water according to resolution MSC.245(83) using interpolation, where the equalization time is set to 10 min, i.e. the interpolation of the flood water volume is made between the case before equalization (T = 0) and the total calculated equalization time.

8. In any cases where complete fluid equalization exceeds 10 min, the value of sfinal used in the formula in paragraph 1.1 should be the minimum of sfinal at 10 min or at final equalization. Q67D (for Round 6 Questionnaire). Do you agree with the above statements from the US and their proposal to delete EN 6 and combine EN 7 and 8?

Yes Japan, Finland, Germany (Yes, the US proposal for EN 7 and 8 seems to be clearer), US, UK, EC (At least US has a point to question the approach taken in EN 7 and 8, which do not seem to be in line with Reg. 7-2.2.), France (see comment)

No Italy, Denmark, China

Further Comments:- Japan: Has no strong position. US: Regarding the Co-ordinator’s Comments: “We are not totally certain about the first statement from the US as reg. 7-2.1.1 appears to us to indicate that si is to be taken as the minimum of sint or sfinal.smom which does not conflict with EN 6.” We apologize that our original comment was not very clear or explicit on what we meant. All we were trying to point out is an apparent typo in that the reg 7-2.2 EN 6 indicates the smallest value of sintermediate or sfinal, but in regulation 7-2.1.1 it is the smallest value of sintermediate or sfinal.smom (i.e. product of sfinal x smom). France: If paragraph 6 is kept, it should be amended by replacing sfinal by sfinal * smom.

Q67. SEVEN MEMBERS SUPPORTED THE US PROPOSAL TO DELETE EN6 AND MERGE EN7 AND 8. THREE OPPOSED AND FRANCE HAS A FURTHER COMMENT.

DISCUSS FURTHER AT SLF 54

218 10/01/2012

9. As an alternative to the procedure described above a time-domain flooding simulation [,computational fluid dynamics (CFD) or model testing][CLIA Q10D(2); 10-1 in favour; recommend change]may be carried out to assess the smallest values of [sintermediate (for situations within 600s) or][US propose deletion, see Q33C] sfinal (for situation after 600s).

Cargo ships

[9][10]. If the Administration considers that the stability in intermediate stages of flooding in a cargo ship may be [insufficient] [Q34 awaiting outcome of Q32D], it may require further investigation thereof. [Need to discuss all these EN’s together at SLF 54 once we agree to Q32D]

Regulation 7-2.2 (ref. SLF 51/3/2 Annex – US and Sweden) Stability in intermediate stages of flooding for cargo ships: Although it was decided not to include a requirement for cargo ship intermediate stage flooding calculations in regulation 7-2.2, there were views that this important issue should be revisited in the future (see SLF 47/WP.6, paragraph 6 below).

“6 Several delegations believed that intermediate stages of flooding should be considered for some cargo ships and that this issue should be revisited in any future revision of the regulations. The draft text of regulation 4, paragraph 2, permits some flexibility by the Administrations and there was general support to include the following in the Explanatory Notes:

“If the Administration considers that the stability in intermediate stages of flooding may be insufficient, it may require further investigation thereof”.”

[Coordinator’s Note: The underlined sentence is included in the current text of the EN]. R7-2.2 EN9 (Should reference to cargo ships remain as an EN?) . Q34. Do you think that this issue should remain fairly general, as in current

Explanatory Note 9, or should it be included as an amended regulation 7-2.2 as proposed by Norway (see Q32)?

Yes (leave as EN9): China, Finland, Germany, Japan, MI, CLIA, Italy, UK,

France

No

(need amendments to Reg 7-2.2): Norway, Spain, Denmark, US, Sweden

Comments / Alternatives?:- China: China reserve the position that for cargo ships the stability in intermediate stage of flooding need not be considered. Norway: “insufficient” is a vague expression not suitable for an EN. Spain: Explanatory notes are not mandatory. It should be mandatory to evaluate intermediate stages of flooding for some cargo vessels. Denmark: Clear guidance as to what is considered insufficient and how it should be investigated would be preferable. US: As indicated in Q32, this issue requires further consideration. France: (comment added after Round 2) If this issue was included into regulation 7-2.2, wording should be more precise. ( see comment to Q32).

219 10/01/2012

Round 1 Discussion: As this issue has already been discussed in detail under Q32, we propose to await your responses to Q32A above which should determine our future action. Any further comments?:- France: This question is linked to Q32A. Round 2 Discussion: Await response to Q32B.

Post SLF 53 Comment:- This item was discussed under Q32B above and, as reported by the WG to plenary, option 2 from the Round 1 discussion notes was preferred (i.e. leave the regulation and EN unchanged, thereby allowing the Administration to decide if further investigation is needed for cargo ships). However, the WG chairman said that because of the variety of views expressed this issue could be re-opened in the 2011 CG. So, does anybody in the 2011 SDS CG have any further comments?:- Q34:- For Round 4 CG, see Q32C above. CLIA Q10C, above, may also be affected by the response to Q32C, relating to stage flooding for cargo ships. Further Comments?:- US: We don’t really understand the question/issue; our position is per Q32C. Norway: As mentioned in Q32 we propose changes to the regulation. However, if the regulation remains unchanged we need to change the EN due to the vague expression “insufficient” which is not suitable for an EN. RINA: Intermediate stage flooding should be considered for cargo ships see RINA response to Q32C and CLIA Q10C. Denmark: No comments. Germany: Keep EN9 as it is. Finland: EN9 shall be in line with Q32C acc. to proposal from Norway. Italy: NO FURTHER AMENDMENTS TO 7-2.2 ARE NECESSARY. Round 6 Discussion: We apologise that the question was not clear. The future of old EN9 (new EN10) depends on the outcome of Q32 as to whether or not we apply intermediate stage flooding to cargo ships: Cargo ships

9 10. If the Administration considers that the stability in intermediate stages of flooding in a cargo ship may be insufficient, it may require further investigation thereof.

If, as Norway says, we decide to keep the present text of reg. 7-2.2 as being applicable only to passenger ships then new EN 10 will remain in place but it may need to be changed (for example, by clarifying “insufficient”). So it is proposed that we leave this question open pending the outcome of Q32D, which may not be resolved until SLF 54.

Q34 AWAIT OUTCOME OF Q32D AT SLF 54 BEFORE TAKING FURTHER ACTION.

3 The factor sfinal,i shall be obtained from the formula:

where:

220 10/01/2012

GZmax is not to be taken as more than 0.12 m;

Range is not to be taken as more than 16°; [Coordinators Note: PLEASE NOTE ERROR IN FOLLOWING INEQUALITIES (see S2009 consolidated errata sheet)

[Should read] K = 1 if θe ≥ θmin

[Should read] K = 0 if θe ≤ θmax ] [New Notes for Round 2: JAPAN in Round 1 thinks that the original text is correct, i.e.

K = 1 if θe ≤θmin K = 0 if θe ≥ θmax

US confirms that the original formulae taken from MSC.216(82) are correct, as shown in the original text above. Both the 2009 Consolidated Edition and the accompanying errata sheet are therefore incorrect. The SLF Secretariat has been informed. Also see SLF 53/14 paragraph 12.4.] [AT SLF 54 – NFA; LEAVE IT TO SECRETARIAT]

4 The factor smom,i is applicable only to passenger ships (for cargo ships smom,i shall be taken as unity) and shall be calculated at the final equilibrium from the formula:

where:

Displacement is the intact displacement at the subdivision draught; Mheel is the maximum assumed heeling moment as calculated in accordance with subparagraph 4.1; and

Regulation 7-2.4

1. The displacement is the intact displacement at the subdivision draught in question (ds, dp and dl ).

221 10/01/2012

2. The calculations should be based on the same hull form as for intact stability calculations (including appendages and shell plating). 3. The stability levers (GZ) and centre of gravity positions (KG) for judging the final survival conditions should be calculated by the constant displacement (lost buoyancy) method. 4. The calculations should be done for the ship freely trimming. [Q35] Regulation 7-2.4 (ref. SLF 51/3/2 Annex – US and Sweden) Clarify the item that is now addressed in the Explanatory Notes: “The displacement is the intact displacement at the subdivision draught in question (ds, dp and dl).” Regulation 7-2.4 (ref. SLF 52/17/5 Annex – Norway) Document SLF 51/3/2 contains a request that the meaning of the first sentence, “The displacement is the intact displacement at the subdivision draught in question (ds, dp and dl )” in the EN be clarified. This Administration believes that this text must be seen in connection with paragraph 3 in regulation 7: “That is, the constant displacement method of calculation should be used.” It is proposed that these paragraphs be harmonized with the following principles in MSC/Circ.406/rev.1: “3.1 The calculations should be based on moulded lines and include large appendages such as shaft bosses, skegs and bow thrusters. 3.2 The metacentric heights (GM), stability levers (GZ) and centre of gravity positions (KG) for judging the final survival conditions should be calculated by the constant displacement (lost buoyancy) method. 3.3 The calculations should be done for the ship freely trimming.”

[Coordinators Note: The above principles can be found, for example, in the BCH Code 2008 Edition. Can Norway please confirm the MSC/Circ.406 reference? It is entitled Annex “Guidelines on Interpretation of the IBC Code and the IGC Code and Guidelines for the Uniform Application of the Survival Requirements of the IBC and IGC Codes” and does not appear to contain the text quoted?].

R7-2.4 (Clarify definition of displacement in EN) . Q35. Do you agree that the underlined text should be added to the EN, as

proposed by Norway? Yes

Finland, Germany, Japan, Norway, CLIA, Spain, Denmark, UK, US, Sweden

No

Reasons / Comments / Alternatives?:- China, MI: No comments. Finland: Method how to notice free surfaces during intermediate stages and phases to be also clearly defined. This may require further studies. If damage is considered to have a very large number of intermediate stages the stability curve of the last intermediate stage must be practically the same as the stability curve of the final stage (calculated with the lost buoyancy method) since in reality the flooding is a continuous process. Also the spirit of the rule concerning the damage

222 10/01/2012

extents should not be violated. Germany: Intermediate phases have to be calculated by “added weight” method. Norway: Please note that the Norwegian paper refers to MSC/Circ.406/Rev.1, i.e. the 1990 version. The paragraphs in question will be found under “GUIDELINES FOR THE UNIFORM APPLICATION OF THE SURVIVAL REQUIREMENTS OF THE BULK CHEMICAL CODE AND THE GAS CARRIER CODE” in the annex to that document. Denmark: We support additional detail in the EN, however we note that 3.1 should probably read “shaft bossing.” Round 1 Discussion: There are 10 in favour of this proposal, 2 “no comments” and 1 no vote. Thanks to Norway for clarifying the source of the text; Denmark suggests replacing “shaft bosses” with “shaft bossing”, which seems reasonable. Finland and Germany raise interesting comments on use of the added weight method and calculation of free surfaces during intermediate stages (IS) of flooding, issues which we discuss in detail under Q27. This matter is quite complex so we will await your responses to Q27A to see how to take it further with the SLF sub-Committee. If we set that to one side for now, can we then agree to Norway’s proposal on the understanding that more text may be needed later to cover the calculation of IS flooding? . Q35A. Do you agree that the underlined text should be added to the EN, as

originally proposed by Norway and amended by Denmark, in the knowledge that more text may be needed later to cover IS flooding, MFS and use of added weight during IS flooding?

Yes

MI (agree), Germany, Finland, Italy, Japan, RINA, France (but with proposed amendments – see comments below), Norway (with comments), CLIA, UK, US, Sweden, Denmark

No

Comments / Alternatives?:- France: 3.1 : Line should be the same as for intact stability ( normally including all appendages and shell plating,) otherwise draft in intact condition will not correspond to this calculated from hydrostatics elements. That is the usual practice. So if comment is add in explanatory notes, it should be said : The calculations should be based on the same hull form as for intact stability calculations (including appendages and shell plating) 3.2 : Comment on GM and GZ should apply to paragraph 2, 3 and 4 of regulation 7-2. For intermediate stages, added weight method has to be used ( or combination of added weight and lost buoyancy). The physical parameter is the righting moment from which is derived the GZ (GM is no more used as a criterion and anyway it may be calculated from the slope of GZ curve). So what is important to say is that GZ must be calculated (from inclining moment) assuming a constant displacement equal to intact displacement. KG is a basic data, which represent the vertical position of ship centre of gravity in intact condition. So a preferable wording applicable to all these paragraph would be : Righting levers (GZ) for judging the survival conditions should be calculate referring to the displacement in intact condition at the draft in question. 3.3 Proposed formulation is accepted. : The calculations should be done for the ship freely trimming.” Norway: Using constant displacement in this context where no initial masses are considered lost (as opposed to cargo in MARPOL etc) will normally be slightly conservative with respect to the effect on the righting lever. We are not sure if the wording in regulation 7.3 was included for this reason. Please note that our proposal and MSC/Circ.406/rev.1 relates to the “final survival conditions”. We agree that the question on whether to disregard the transient added mass in partially flooded spaces not communicating directly with the sea as well as handling of free

223 10/01/2012

surface effects in these spaces should be discussed further. Round 2 Discussion: There is full support for Norway’s proposal, as amended by Denmark. (Also see Q27B for MFS and use of added weight method for stage-flooding). France has some alternative proposals. All the proposals are repeated below for easy reference:- Norway “1 The calculations should be based on moulded lines and include large appendages such as shaft [bosses][bossing], skegs and bow thrusters. 2 The metacentric heights (GM), stability levers (GZ) and centre of gravity positions (KG) for judging the final survival conditions should be calculated by the constant displacement (lost buoyancy) method. 3 The calculations should be done for the ship freely trimming.” France “1 The calculations should be based on the same hull form as for intact stability calculations (including appendages and shell plating). 2 Righting levers (GZ) for judging the survival conditions should be calculated referring to the displacement in the intact condition at the draft in question. 3 The calculations should be done for the ship freely trimming.” Proposed revisions to reg. 7.3 (see Q27B) “3 When determining the positive righting lever (GZ) of the residual stability curve [in the final stage of flooding], the displacement used should be that of the intact condition. That is, the constant displacement method of calculation should be used.[During intermediate stages of flooding the added weight method should be used ].”

We must say that we are now slightly confused as to whether this proposal should be fitted in as extra EN’s to reg. 7-2.4 or new EN’s to reg. 7.3 (see Norway’s comment after round 1, above) so we suggest this should be discussed at the WG. Q35B (for the SLF 53 WG). Please state (a) whether you prefer Norway’s original proposal as modified by Denmark or France’s new proposal and (b) whether your preferred proposal should appear as three extra ENs to reg. 7-2.4 or three new ENs to reg. 7.3? (a) Do you prefer proposal from Norway or France?

(b) EN for reg. 7.3 or reg. 7-2.4.

Comments / Alternatives?:- Post SLF 53 Comment:- In the end, France’s proposals in the Round 2 discussion were favoured by the WG (with very minor modifications) - see above. Note that we have re-numbered the EN’s for consistency, giving the existing EN number 1. Q35. AT SLF 54 RECOMMEND EN FOR R7-2.4 BE ALTERED AS SHOWN BELOW AS AGREED AT SLF 53:-

224 10/01/2012

Regulation 7-2.4

1. The displacement is the intact displacement at the subdivision draught in question (ds, dp and dl ).

2. The calculations should be based on the same hull form as for intact stability calculations (including appendages and shell plating). 3. The stability levers (GZ) and centre of gravity positions (KG) for judging the final survival conditions should be calculated by the constant displacement (lost buoyancy) method. 4. The calculations should be done for the ship freely trimming. 4.1 The heeling moment Mheel is to be calculated as follows:

Mheel = maximum {Mpassenger or Mwind or MSurvivalcraft}

4.1.1 Mpassenger is the maximum assumed heeling moment resulting from movement of passengers, and is to be obtained as follows:

Mpassenger = (0.075 · Np) · (0.45 · B) (tm)

where:

Np is the maximum number of passengers permitted to be on board in the service condition corresponding to the deepest subdivision draught under consideration; and

B is the beam of the ship breadth of the ship as defined in Regulation 2.8. [Q36]

Alternatively, the heeling moment may be calculated assuming the passengers are distributed with 4 persons per square metre on available deck areas towards one side of the ship on the decks where muster stations are located and in such a way that they produce the most adverse heeling moment. In doing so, a weight of 75 kg per passenger is to be assumed.

[Coordinator’s Note for Round 2:-: MSC.272(85), which came into force on 1st July, 2010, has increased the average passenger mass to 82.5 kg for certain LSA applications. For consistency, should we also consider increasing this figure where highlighted in yellow in Reg 7-2.4.1.1 above? The 2008 IS Code uses 75 kg as a minimum to be assumed. Comments Invited: Germany: No. the mean weight of 75kg seems still be applicable for stability calculations. Japan: Supports coordinator’s proposal to change “75 kg” to “82.5 kg”. CLIA: Consistency with the IS Code is needed, so both would need to change to 82.5 Kg. UK: The average passenger weight seems to be increasing. However, within the damage stability regulations we could consider with immediate affect adding [“as a minimum”] to promote voluntary use of larger figures for special operational conditions until such time as we are presented with a supporting data set including relevant passenger profiles for different ship sizes and types. US: We support updating the reg 7-2.4.1.1 text to reflect the increased passenger weight. (This should also be done in the 2008 IS Code.)

225 10/01/2012

Coordinator’s Note for Round 3:-: Propose we discuss this at the SLF 53 WG to obtain the views of other members and to decide the best course of action. Post SLF 53 Note:- There was no support in the WG for increasing the assumed weight or for changing the wording, therefore leave unchanged. NFA at SLF 54. ] Regulation 7-2.4.1.1

The beam B used in this paragraph means breadth as defined in regulation 2.8.

Regulation 7-2.4.1.1 (ref. SLF 51/3/2 Annex – US and Sweden) Clarify the item that is now addressed in the Explanatory Notes: “The beam B used in this paragraph means breadth as defined in regulation 2.8.” R7-2.4.1.1 (Clarification of B definition) R7-2.4.1.1 (Delete EN?) . Q36. Do you agree that further clarification of the EN is needed? Yes

Norway, Denmark, Sweden

No

China, Finland, Germany, MI, CLIA, Italy, UK, US

Comments / Proposed wording?:- Japan: No comments. Norway: It would perhaps be a better option to delete “B is the beam of the ship” from the regulation since the definition in regulation 2.8 makes it redundant. Spain: Probably further explanation is needed. Maybe the intention is to permit the use of another beam in special cases (e.g. accommodation deckhouses with a beam significantly lower than the maximum breadth of the vessel). Denmark: We should perhaps use ‘B is the breadth of the ship as defined in Regulation 2.8’ to avoid introducing new terms. US: The definition of B in regulation 7-2.4.1.1 should be revised directly (i.e. “B is the breadth as defined in regulation 2.8”); then the EN can be deleted. Round 1 Discussion: It would seem that the best solution is to simply state in the Regulation that “B is the breadth of the ship as defined in Regulation 2.8” and remove the EN altogether. Q36A. Do you agree that we define B in the regulation using the US/Denmark’s text (‘B is the breadth of the ship as defined in Regulation 2.8’) and delete the EN as proposed by the US? Yes

MI, Germany, Finland, Italy, Japan, RINA, Norway (with comment), CLIA, UK, US, Sweden, Denmark

No

Comments / Alternatives?:- Japan does not have a strong position. France: This proposal is acceptable, but present wording of regulation + EN seems equivalent. Norway: Denmark/US proposals are OK, but we think the sentences in the regulation and the EN are redundant given the definition in 2.8. Round 2 Discussion: There is unanimous support for the additional text in the regulation as proposed by US/Denmark and for deleting the EN although Norway and France think that we could omit both anyway as “B” is already defined. It just seems that because we are defining the other term in the formula for Mpassenger (Np) it may look slightly better to define B as well?

226 10/01/2012

Q36B (for SLF 53 WG). Do you agree to change reg. 7-2.4.1.1 to read “B is the breadth of the ship as defined in regulation 2.8.” and to delete the EN? Yes

No

Further Comments?:- Post SLF 53 Note:- The WG agreed to change Reg. 7-2.4.1.1 and delete the EN. Note that the regulation for the definition of B is now 2.7.

SLF 54 Accept changes agreed at SLF 53 but ensure the cross-reference is correct, (depending on outcome of Q66). 4.1.2 Mwind is the maximum assumed wind force acting in a damage situation:

Mwind = (P · A · Z) / 9,806 (tm)

where:

P = 120 N/m2;

A = projected lateral area above waterline;

Z = distance from centre of lateral projected area above waterline to T/2; and T = ship’s draught, di.

Regulation 7-2.4.1.2

The parameter A (projected lateral area) used in this paragraph does not refer to the attained subdivision index. 4.1.3 MSurvivalcraft is the maximum assumed heeling moment due to the launching of all fully loaded davit-launched survival craft on one side of the ship. It shall be calculated using the following assumptions:

.1 all lifeboats and rescue boats fitted on the side to which the ship has heeled after having sustained damage shall be assumed to be swung out fully loaded and ready for lowering;

.2 for lifeboats which are arranged to be launched fully loaded from the stowed position, the maximum heeling moment during launching shall be taken;

.3 a fully loaded davit-launched liferaft attached to each davit on the side to which the ship has heeled after having sustained damage shall be assumed to be swung out ready for lowering;

.4 persons not in the life-saving appliances which are swung out shall not provide either additional heeling or righting moment; and

.5 life-saving appliances on the side of the ship opposite to the side to which the ship has heeled shall be assumed to be in a stowed position.

227 10/01/2012

5 Unsymmetrical flooding is to be kept to a minimum consistent with the efficient arrangements. Where it is necessary to correct large angles of heel, the means adopted shall, where practicable, be self-acting, but in any case where controls to equalization devices are provided they shall be operable from above the bulkhead deck. These

fittings together with their controls shall be acceptable to the Administration.* Suitable

information concerning the use of equalization devices shall be supplied to the master of the ship.

_______________ * Reference is made to the “Recommendation on a standard method for establishing

compliance with the requirements for cross-flooding arrangements in passengers ships”, adopted by the Organization through resolution [A.266(VIII), as may be amended]. [MSC.245(83), on 12th October, 2007 to replace resolution A.266(VIII)].

[Coordinator’s Note:- The existing footnote in the SOLAS2009 Consolidated Edition refers to A.266 “as may be amended”. Should we now refer specifically to the new resolution “as may be amended”? MSC. 245 (83) is included below for easy reference. Comments invited:- Finland: Reference to new resolution is needed. The FLOODSTAND is investigating these matters and there might be a reason to return to it later on. Germany: Reference to new resolution preferred. Denmark: Yes, we should amend this footnote for clarity. US: The footnote should reference both A.266 and MSC.245(83), as there was resistance to superseding A.266. ] [Coordinator’s Note for Round 2:- Those who responded agree that reference should be made here to the latest MSC resolution but the US would prefer references to both A.266 and MSC.245. Is it true to say that A.266 should continue to be applied to ships constructed before 1/1/2009 and MSC.245 to “new” ships built under S2009 constructed on or after 1/1/2009 and that we should make this clear in the revised footnote or was this not the intention of MSC83? Comments invited:- France: It would be better to have the correct reference. UK: In the light of MSC.245(83) we do not see the need to make further clarification. US: We would like to retract our previous comment to also include A.266. As indicated in your summary, S2009 Chapter II-1 applies to ships constructed on or after 1/1/2009 and they should only use MSC.245. Therefore we now agree with the others that the footnote should be updated to only include reference to MSC.245. Note: the resolution title has also changed slightly. ] [Coordinator’s Note for Round 3:- Thank you US. So we can agree to change the footnote to read:- _____________ * Reference is made to the Recommendation on a standard method for evaluating cross-flooding arrangements, adopted by the Organization by resolution MSC.245(83), as may be amended. ] This change to the footnote was agreed by the WG at SLF 53. ]

228 10/01/2012

RESOLUTION MSC.245(83) (adopted on 12 October 2007)

RECOMMENDATION ON A STANDARD METHOD FOR EVALUATING CROSS-FLOODING ARRANGEMENTS

THE MARITIME SAFETY COMMITTEE,

RECALLING Article 28(b) of the Convention on the International Maritime Organization concerning the functions of the Committee,

RECALLING ALSO resolution A.266(VIII) entitled "Recommendation on a standard method for establishing compliance with the requirements for cross-flooding arrangements in passenger ships", adopted by the Assembly at its eighth session,

NOTING that the above Recommendation does not include provisions for cross-flooding arrangements other than pipes (i.e., cross-flooding times through ducts) or a provision to ensure adequate air ventilation for efficient cross-flooding (i.e., to account for the restrictive effect of air counter pressure during cross-flooding),

NOTING ALSO the revised SOLAS chapter II-1 subdivision and damage stability requirements for passenger and cargo ships, adopted by resolution MSC.216(82),

RECOGNIZING the need to establish a methodology for evaluating cross-flooding arrangements on ships subject to the applicable subdivision and damage stability requirements of SOLAS chapter II-1 to ensure uniform treatment of cross-flooding and equalization arrangements,

HAVING CONSIDERED the recommendations made by the Sub-Committee on Stability and Load Lines and on Fishing Vessels Safety at its fiftieth session,

1. ADOPTS the Recommendation on a standard method for evaluating cross-flooding arrangements, the text of which is set out in the Annex to the present resolution;

2. INVITES Governments to apply the annexed Recommendation to cross-flooding calculations and to bring the Recommendation to the attention of all parties concerned.

229 10/01/2012

Resolution MSC.245(83) 12 October 2007

Page 2

230 10/01/2012


Page 3

231 10/01/2012


Page 4

[Coordinator’s Note for SLF 54:- SLF 54/4 para. 3.1 states that the formula in 2.5 above is incorrect and should read as shown in Eq. 2 of the Annex to that paper.]

232 10/01/2012


Page 5

[Coordinator’s Note for SLF 54:- SLF 54/4 para. 3.2 proposes to replace the text under “4 Alternatives”, above, with “Values for k can be obtained from appendix 2 or other appropriate sources. Also CFD (computational fluid dynamics) can be used to evaluate the discharge coefficient for the whole cross duct.” ]

233 10/01/2012


Page 6

[Coordinator’s Note:– could something be done to improve the clarity of these diagrams – increase size and turn through 90 degrees clockwise, for example? Comments? China: The diagrams on Page 6 of annex to MS.245(83) are too small, I cannot see the text clearly. It’s better to be updated. Finland: It is desirable to improve the clarity of figures on p. 6

234 10/01/2012

CLIA: Yes. Denmark: Yes, agreed. US: Yes – if someone will volunteer to do it! ][Co-ordinator’s Note Round 2: We will try. France: Diagram could be improved, but this is not a major point.]

Post SLF 53 Note:- It was agreed that the diagrams need improving but we need to ask the sub-committee for authorization to make these changes under a new work item.]

Fig 1(a) Section showing cross-flooding pipe and compartments

Location of damage

Flooded Compartments

cross-flooding pipe

Equalizing Compartment

Tank Top

Main Deck

Upper Deck

235 10/01/2012

Fig 1(b) Different stages of cross-flooding

Fig 1(c) Situation after damage but before cross-flooding

H0 Before cross flooding θ θf θ0

Maximum allowable angle of heel for final stage of flooding

Equilibrium flooding position

Hθ

hf

θ0

H0

Anticipated closing device

Before cross flooding

Water on flooded side before cross flooding

236 10/01/2012

Fig 1(d) Situation at maximum allowable angle of heel

θ

Hθ

Maximum allowable angle of heel for final stage of flooding

Water inflow until the maximum allowable angle of heel is achieved

Wθ = Volume of water to bring the ship from θ to θf

237 10/01/2012

Fig 1(e) Situation at final equilibrium

θf

Equilibrium floating position

Water inflow until the equilibrium floating position is achieved

Wf = Volume of water to bring the ship from θ0 to θf

hf

238 10/01/2012


Page 7

239 10/01/2012


Page 8

240 10/01/2012


Page 9

[Coordinator’s Note for SLF 54:- SLF 54/4 para. 3.3 proposes removal of figures 13 and 14 with explanations from the resolution. The paper states that the current methods in Res MSC.245(83) “may result in a significant under-estimation of the cross-flooding time ….”. See SLF 54/8/1 para 15.11 for a proposal to ask the S/C for a new agenda item to update MSC.245(83) as it is not within the current ToR of the SOLAS updates AI.]

241 10/01/2012


Page 10

242 10/01/2012


Page 11

243 10/01/2012

Regulation 7-2.5

In cargo ships where cross flooding devices are fitted, the safety of the ship should be maintained in all stages of flooding. The Administration may request for this to be demonstrated. Cross-flooding equipment, if installed, should have the capacity to ensure that the equalization takes place within 10 min.

5.1 Tanks and compartments taking part in such equalization shall be fitted with air pipes or equivalent means of sufficient cross-section to ensure that the flow of water into the equalization compartments is not delayed. 5.2 In all cases, si is to be taken as zero in those cases where the final waterline, taking into account sinkage, heel and trim, immerses:

.1 the lower edge of openings through which progressive flooding may take place and such flooding is not accounted for in the calculation of factor si. Such openings shall include air-pipes, ventilators and openings which are closed by means of weathertight doors or hatch covers; and


Unprotected openings

1. The flooding angle will be limited by immersion of such an opening. It is not necessary to define a criterion for non-immersion of unprotected openings at equilibrium, because if it is immersed, the range of positive GZ limited to flooding angle will be zero so “s” will be equal to zero.

2. An unprotected opening connects two rooms or one room and the outside. An unprotected opening will not be taken into account if the two connected rooms are flooded or none of these rooms are flooded. If the opening is connected to the outside, it will not be taken into account if the connected compartment is flooded. An unprotected opening does not need to be taken into account if it connects a flooded room or the outside to an undamaged room, if this room will be considered as flooded in a subsequent stage.

Openings fitted with a weathertight mean of closing (“weathertight openings”)

3. The survival “s” factor will be “0” if any such point is submerged at a stage which is considered as “final”. Such points may be submerged during a stage or phase which is considered as “intermediate”, or within the range beyond equilibrium.

4. If an opening fitted with a weathertight means of closure is submerged at equilibrium during a stage considered as intermediate, it should be demonstrated that this weathertight means of closure can sustain the corresponding head of water and that the leakage rate is negligible.

244 10/01/2012

5. These points are also defined as connecting two rooms or one room and the outside, and the same principle as for unprotected openings is applied to take them into account or not. If several stages have to be considered as “final”, a “weathertight opening” does not need to be taken into account if it connects a flooded room or the outside to an undamaged room if this room will be considered as flooded in a successive “final” stage.

.2 any part of the bulkhead deck in passenger ships considered a horizontal evacuation route for compliance with chapter II-2. [Q37D – see below]

[.3 for ro-ro passenger ships, when damaged above the bulkhead deck, any part of the bulkhead deck in way of the damage opening in which the residual freeboard is less than [x] metres.

This could also apply to conventional passenger ships with large, un-subdivided spaces near the equilibrium waterplane. Proposal to be discussed under ro-ro damage stability agenda item] [Q37D– see below].


1. Partial immersion of the bulkhead deck may be accepted at final equilibrium. The new This [CLIA Q11 CG agreed to retain original text] provision is intended to ensure that evacuation along the bulkhead deck to the vertical escapes will not be impeded by water on that deck. A “horizontal evacuation route” in the context of this regulation means a route on the bulkhead deck connecting spaces located on and under this deck with the vertical escapes from the bulkhead deck required for compliance with SOLAS chapter II-2.

Regulation 7-2.5.2.2 EN 1 CLIA Q11: Comments received from CLIA/CCSF between round 1 and 2: Some small improvements have been made to clarify the definition of horizontal evacuation routes. 1. Partial immersion of the bulkhead deck may be accepted at final equilibrium. The [new] provision is intended to ensure that evacuation along the bulkhead deck to the vertical escapes will not be impeded by water on that deck. A “horizontal evacuation route” in the context of this regulation means a route on the bulkhead deck connecting spaces located on and under this deck with the vertical escapes from the bulkhead deck required for compliance with SOLAS chapter II-2. Coordinator’s Comments: CG Member’s Comments?:- MI: Concur. Germany: Yes. China: 1. China has no objection to the word “[new]” inserted before “provision”. 2. However, for ro-ro passenger ships, the requirement that the evacuation route on bulkhead deck cannot be immersed is a big problem. Only crew evacuate from the machinery spaces below along the ro-ro deck (bulkhead deck) and passengers are not allowed to access into the ro-ro space at sea. Therefore the above text is suggested to be amended as follows: “1. Partial immersion of the bulkhead deck may be accepted at final equilibrium.

245 10/01/2012

The [new] provision is intended to ensure that evacuation along the bulkhead deck to the vertical escapes will not be impeded by water on that deck. A “horizontal evacuation route” in the context of this regulation means a route intended for the evacuation of passengers on the bulkhead deck connecting spaces located on and under this deck with the vertical escapes from the bulkhead deck required for compliance with SOLAS chapter II-2. ” Finland: Support. Italy: Agreed. France: OK US: It doesn’t seem the text in question (The new provision is...) is the actual text from reg 7-2.5.2.2 EN1. The actual text in MSC.281(85) reads: This provision is...; so we think ok as is. Round 2 Discussion:- Thank you US – a typing error when transposing MSC.281(85) must have crept in. Apologies. So we go back to the original text “This provision …etc.”. Meantime China has come up with a good point which illustrates the difference between conventional passenger ships and ro-pax ships. The problem for ro-pax ships is that partial immersion of the bulkhead deck in way of the damage opening at final equilibrium usually leads to the capsize of the ship (s=0) due to the WOD effect. So we suggest that China’s proposed amendment should only apply to the EN for regulation. 7-2.5.2.2 and we should consider introducing a new regulation specifically for ro-pax ships to account for the WOD effect:- 5.2

.3 for ro-ro passenger ships, when damaged above the bulkhead deck, any part of the bulkhead deck in way of the damage opening in which the residual freeboard is less than [x] metres.

This could also apply to conventional passenger ships with large, un-subdivided spaces near the equilibrium waterplane. CLIA Q11 (for SLF53 WG). Can we (a) agree that the original text is satisfactory and (b) that a new regulation may be needed for ro-ro passenger ships to ensure that si is zero if the residual freeboard in way of the damage opening when the ro-ro vehicle space is damaged is less than [x] metres? (a) Yes/No?

(b) Yes/No?

Further Comments / Alternative proposals?:- Post SLF 53 Notes:-

1. The WG agreed that the original text of EN 1 for Reg. 7-2.5.2.2 should remain unchanged (see above).

2. Proposed new Regulation 7-2.5.2.3 relating to residual freeboard and the “s” factor for ships with large, un-subdivided spaces near the equilibrium waterplane (see Round 2 Discussion) was put in the ToR for the 2011 SDS correspondence group (see SLF 53/9 paragraph 14.10.3) and will be dealt with by the Ro-Ro branch of the SDS CG (see SLF 54/8/1 paragraph 14.3).

246 10/01/2012

AT SLF54

1) NFA on Reg. 7-2.5.2.2. 2) Discuss under Ro-Ro damage stability (Agenda Item 6) in the context of other ongoing research projects. 2. Horizontal evacuation routes on the bulkhead deck include only escape routes (designated as category 2 stairway spaces according to SOLAS regulation II-2/9.2.2.3 or as category 4 stairway spaces according to SOLAS regulation II-2/9.2.2.4 for passenger ships carrying not more than 36 passengers) used for the evacuation of undamaged spaces. Horizontal evacuation routes do not include corridors (designated as category 3 corridor spaces according to SOLAS regulation II-2/9.2.2.3 or as category 2 corridor spaces according to SOLAS regulation II-2/9.2.2.4 for passenger ships carrying not more than 36 passengers) or escape routes within the damaged space. Landing areas and half landings of a staircase are part of the vertical escape way and not part of a horizontal escape route. [Q37D] [Coordinator’s Note: the CG in round 4 expressed some dissatisfaction with these EN changes which were agreed at SLF 53. Now we are awaiting responses to various options in the Round 6 questionnaire which may also involve changing the wording of the regulation itself. Discuss at SLF 54] No part of a horizontal evacuation route serving undamaged spaces should be immersed. Regulation 7-2.5.2 and 7-2.5.3 (ref. SLF 51/3/2 Annex – US and Sweden) The fact that part of escape routes or control systems of watertight doors or valves may be within the damage extent is not taken into account. It is specified in the explanatory notes that “Horizontal evacuation routes do not include corridors within the damaged spaces.” Is this acceptable if the corridor within the damaged space is used for evacuation from another undamaged space? R7-2.5.2.2 (Clarification of “horizontal evacuation routes”) . Q37. Do you agree that a change to the EN is needed? Yes

China, Spain, Denmark, UK, Sweden

No

Finland, Germany, Japan, MI, Norway, Italy, US

Comments / Proposals?:- Norway: The current wording is a result of extensive discussions during previous sessions. A revisit should not be given priority at the moment. CLIA: see CSSF paper. Denmark: This EN will benefit from redrafting to improve clarity. US: Note: This SLF 51/3/2 item was made before the Explanatory Notes were finalized at SLF 51 and the space categories were added. Therefore this item does not account for the final discussions/decisions made at SLF 51. Round 1 Discussion: Based on the comments received, it would seem that there is a slight majority (7/5) in favour of keeping the EN as they stand. However, if there are ways in which the text can easily be improved and clarified, as hinted at by Denmark, may we invite specific proposals? Q37A. In the light of the comments received in Round 1, should we keep the EN relating to horizontal evacuation routes as they are? Please note the proposals by CLIA/CSSF below.

247 10/01/2012

Yes

MI, Germany, Finland, Japan, RINA, Norway, US (with comment), Sweden, Denmark

No

France (with comments), CLIA (see proposals), UK (with comment)

If “No” do you have specific proposals for improving the text?:- China:- For ro-ro passenger ships, the requirement that the evacuation route on bulkhead deck cannot be immersed is a big problem. Only crew evacuate from the machinery spaces below along the ro-ro deck (bulkhead deck) and passengers are not allowed to access into the ro-ro space at sea. Therefore the above text is suggested to be amended as follows: “1. Partial immersion of the bulkhead deck may be accepted at final equilibrium. The [new] provision is intended to ensure that evacuation along the bulkhead deck to the vertical escapes will not be impeded by water on that deck. A “horizontal evacuation route” in the context of this regulation means a route intended for the evacuation of passengers on the bulkhead deck connecting spaces located on and under this deck with the vertical escapes from the bulkhead deck required for compliance with SOLAS chapter II-2. ” Italy: CLIA comment is agreed. RINA: Sketches describing the acceptable and non-acceptable arrangements would assist the understanding of the requirements. France: It seems that the intent is to exclude corridors designated as category 3 corridor spaces according to SOLAS regulation II-2/9.2.2.3 or as category 2 corridor spaces according to SOLAS regulation II-2/9.2.2.4 for passenger ships carrying not more than 36 passengers. To clarify this it may be sufficient just to delete “within the damaged spaces”. (Anyway, situation outside flooded spaces is not considered). This could be considered as not acceptable if escape route from an undamaged space go through such corridors and if there is no alternative way. So, alternative interpretation may be to consider that such corridors may be excluded only if they are used for evacuation of the space where they are (above the bulkhead deck). If evacuation route from undamaged spaces below the bulkhead deck go through such corridors, they should not be excluded. Alternative wording may be : “Horizontal evacuation routes do not include corridors (designated as category 3 corridor spaces according to SOLAS regulation II-2/9.2.2.3 or as category 2 corridor spaces according to SOLAS regulation II-2/9.2.2.4 for passenger ships carrying not more than 36 passengers) within the damaged space, except if they are used for escape from undamaged spaces below the bulkhead deck.” CLIA: CLIA - See CLIA/SSF proposals. UK: CLIA/CSSF proposed modifications can be implemented. US: Accept as noted in response to second CLIA proposal below. Round 2 discussion of EN 2 follows CLIA’s additional comments, below. Additional comments received from CLIA/CCSF between round 1 and 2: Regulation 7-2.5.2.2 EN 2 2. Horizontal evacuation routes on the bulkhead deck include only escape routes (designated as category 2 stairway spaces according to SOLAS regulation II-2/9.2.2.3 or as category 4 stairway spaces according to SOLAS regulation II-2/9.2.2.4 for passenger

248 10/01/2012

ships carrying not more than 36 passengers) used for the evacuation of undamaged spaces. Horizontal evacuation [routes] do not include corridors (designated as category 3 corridor spaces according to SOLAS regulation II-2/9.2.2.3 or as category 2 corridor spaces according to SOLAS regulation II-2/9.2.2.4 for passenger ships carrying not more than 36 passengers) [or escape routes] within the damaged space. [Landing areas and half landings of a staircase are part of the vertical escape way and not part of a horizontal escape route.] No part of a horizontal evacuation route serving undamaged spaces should be immersed. Coordinator’s Comments: “Routes” and “escape routes” is made bold for emphasis. Please consider these modifications in your reply to Q37A, above. CG Member’s Comments?:- Germany: CSSF proposals help to clarify. Finland: Proposal will help to clarify more precisely. France: It should be necessary to define what a vertical escape route is. US: We do not agree to the proposed additions. Round 2 Discussion:- There is good support for CLIA’s proposed amendments but the US is opposed. China’s comments regarding ro-ro passenger ships are noted and have been discussed under EN 1, above. RINA’s request for explanatory sketches is also noted (we are not sure whether the sketch provided for EN 4, below would be enough?). France would like a definition of “vertical escape route” and also has two alternative proposals:- (1) 2. Horizontal evacuation routes on the bulkhead deck include only escape routes (designated as category 2 stairway spaces according to SOLAS regulation II-2/9.2.2.3 or as category 4 stairway spaces according to SOLAS regulation II-2/9.2.2.4 for passenger ships carrying not more than 36 passengers) used for the evacuation of undamaged spaces. Horizontal evacuation routes do not include corridors (designated as category 3 corridor spaces according to SOLAS regulation II-2/9.2.2.3 or as category 2 corridor spaces according to SOLAS regulation II-2/9.2.2.4 for passenger ships carrying not more than 36 passengers) [within the damaged space]. No part of a horizontal evacuation route serving undamaged spaces should be immersed. (2) 2. Horizontal evacuation routes on the bulkhead deck include only escape routes (designated as category 2 stairway spaces according to SOLAS regulation II-2/9.2.2.3 or as category 4 stairway spaces according to SOLAS regulation II-2/9.2.2.4 for passenger ships carrying not more than 36 passengers) used for the evacuation of undamaged spaces. Horizontal evacuation routes do not include corridors (designated as category 3 corridor spaces according to SOLAS regulation II-2/9.2.2.3 or as category 2 corridor spaces according to SOLAS regulation II-2/9.2.2.4 for passenger ships carrying not more than 36 passengers) within the damaged space, [except if they are used for escape from undamaged spaces below the bulkhead deck]. No part of a horizontal evacuation route serving undamaged spaces should be immersed. It would seem that this question will need to be discussed further by the SFL 53 WG when the views of the other members can also be obtained. Q37B (for the SLF 53 WG). In the light of the comments now received in Round 2, do you prefer to keep the EN relating to horizontal evacuation routes unchanged or do you prefer the amendments proposed by CLIA or France (1 or 2)?

249 10/01/2012

No change?

CLIA?

France (1)?

France (2)?

Further comments / alternatives?:- Post SLF 53 Note:- The WG, after considerable discussion, agreed to amend EN2 as shown above. Q37C Any final comments (for Round 4 questionnaire)?:- Comments?:- US: We are not satisfied with this result and strongly prefer the original version of EN 2. A particular concern is the combination of adding “or escape routes” with the deletion of “within the damaged space” in the second sentence. This combination of different proposals cannot be correct because it would seem to exempt all escape routes and therefore contradict the first sentence. However, as a general comment we think it is important to keep in mind that the intent of regulation 7-2.5.2.2 is to cover the significant “non-stability” benefits of a margin line. With a margin line it didn’t matter whether the bulkhead deck escape routes/ corridors/stair landings were within the damage extent or not because the bulkhead (or where it used to be) had to remain dry. Norway: Having considered this matter in depth, Norway is very concerned about totally ignoring corridors from the term – horizontal evacuation routes. On larger vessels, a serious physical obstruction may occur in corridors (3 m head of water on 42 m beam vessel). Norway therefore proposes to keep the original EN (MSC 85/26/Add. 1 Annex 22, page 25) text. With regards to proposal of specifying landings and half-landings as “not part of a horizontal escape route” we cannot see the need for this. The start of a staircase at the bulkhead deck level will be defined as a flooding point, and any landing or half-landing will be above this level, and are thus governed by the flooding point at the bulkhead deck level. China: No comments. RINA: It is not clear as to why “or escape routes” at the beginning of the new text has been added? Denmark: Unable to understand the sentence ending with “or escape routes”; we still need to retain the words “within the damaged space”. Germany: No comments. Italy: The deleted part “within the damaged space” should be maintained. With ref. to the attached figures, supposing that the spaces are damaged below and also above the bhd. deck, with transversal extension of the damage up to B/2, the horizontal evacuation route would not be available (destroyed) – therefore a verification is not needed. AMENDMENT TO EN2 BY THE WG IS AGREED, AS SHOWN ABOVE. France: In the second sentence, is it correct to exclude “escape route”? What is the meaning of escape route in this sentence? It should be necessary to define what are a “landing area” and “half landing of a stair case”. Round 6 Discussion: Strictly speaking, this item was finalised by the SLF 53 WG but although it was discussed in detail there were a variety of options on the table and the outcome was, as we recall, decided by majority rather than unanimously. It is possible

250 10/01/2012

that the alterations in grey and the strikeout (taken from SLF.53/WP.6 Annex 5, page 79) do not correctly reflect what was finally agreed which is why we asked for comments in Q37C. The US points out that the agreed text as highlighted in grey above is not self-consistent. It would make more sense if the words “within the damaged spaces” were retained (Denmark, France, RINA and Italy agree). Norway has problems with totally ignoring corridors and also with including stairways in escape routes; Norway and the US prefer the original EN. The US points out that the underlying purpose of reg. 7-2.5.2.2 is to mitigate the loss of the concept of non-immersion of the old margin line in S90. The co-ordinators have always had some difficulties in understanding this regulation and accompanying EN so we thought we would break the latter into simpler sections to understand the implications more clearly (and to try to explain it better to ourselves!). To start with here is the relevant part of the original regulation for easy reference:- 5.2 In all cases, si is to be taken as zero in those cases where the final waterline, taking into account sinkage, heel and trim, immerses:

.2 any part of the bulkhead deck in passenger ships considered a horizontal evacuation route for compliance with chapter II-2.

Simplifying the original EN by cutting out the bracketed designations for “escape routes” and “corridors” it states:- 2. (a) Horizontal evacuation routes on the bulkhead deck include only escape routes used for the evacuation of undamaged spaces. (b) Horizontal evacuation routes do not include corridors within the damaged space. (c) No part of a horizontal evacuation route serving undamaged spaces should be immersed. Implication (a) is that a designated horizontal evacuation route on the bulkhead deck used as an escape route from a damaged space does not count as a horizontal evacuation route for the purpose of reg. 5.2.2; therefore in such damage cases si may be non-zero and contribute to A. Implication (b) is that corridors initially considered to form part of a horizontal evacuation route on the bulkhead deck but lying within a damaged space on the bulkhead deck in fact no longer count as horizontal evacuation routes for the purpose of reg 5.2.2; therefore in such damage cases si may be non-zero and contribute to A. This also implies that corridors on the bulkhead deck initially considered to form part of horizontal evacuation routes serving an undamaged space (on the bulkhead deck? anywhere?) and not themselves lying within a damaged space on the bulkhead deck may always be considered to be horizontal evacuation routes but if they become immersed si is to be taken as zero. This would be consistent with (c). Implication (c) is that if any part of the bulkhead deck containing a horizontal evacuation route serving an undamaged space becomes immersed si is to be taken as zero.

251 10/01/2012

The first text change agreed at SLF 53 was for (b) to read:- (b) Horizontal evacuation routes do not include corridors or escape routes. This implies that corridors or escape routes are not considered to be horizontal evacuation routes; therefore in all damage cases involving corridors or escape routes si may be non-zero and contribute to A. This seems clearly wrong! If we leave in the struck out words “within the damaged spaces” we get:- (b) Horizontal evacuation routes do not include corridors or escape routes within the damaged spaces. The implications here are similar to implication (b) above except that “corridors” is replaced with “corridors or escape routes”. The second text change agreed at SLF 53 was to introduce a new sentence:- Landing areas and half landings of a staircase are part of the vertical escape way and not part of a horizontal escape route. This implies in effect that staircases are not considered to be part of the horizontal escape route; therefore in all damage cases involving staircases si may be non-zero and contribute to A. As Norway points out, however, it is hard to see the need for this. Co-ordinator’s Comments:

1) We think that the original intent of reg. 7-2.5.2.2 is simply, as the US pointed out, to replace the concept of margin line non-immersion. We now allow partial flooding of the bulkhead deck up to the waterline at which the designated passenger escape routes (or the openings defined in reg. 7-2.5.2.1 or the stairways mentioned in EN 3) become immersed. If the minimum of two such designated routes required by SOLAS CH II-2 Part D Reg. 13.2 are placed as near to the centreline as is reasonably allowed by the term “widely separated” or indeed are not placed on the bulkhead deck at all then, in theory, considerable (or total?) flooding of the bulkhead deck on passenger ships is now permissible.

2) The resulting complexity of the EN is obvious. Of course, simplification could be

achieved by shortening reg. 7-2.5.2.2 to read:- 5.2 In all cases, si is to be taken as zero in those cases where the final

waterline, taking into account sinkage, heel and trim, immerses: .2 any part of the bulkhead deck in passenger ships [considered

a horizontal evacuation route for compliance with chapter II-2]. This is clearly no longer possible as we would effectively have re-introduced the

margin line!

3) We do not really understand why reg. 7-2.5.2.2 refers to complex fire regulations in chapter II-2, especially those involving stairway and corridor spaces (in the

252 10/01/2012

EN). For stability purposes we are surely not interested in fire-proofed stairways or corridors but only in how far the damage waterline extends over the bulkhead deck and whether the designated escape routes are immersed. Incidentally, in the event of there being several escape routes must all of them be immersed for s=0 or only one?

4) We could therefore simply define the two (or all) approved escape routes

required by Ch II-2 Part D Reg. 13.2 (but only where they involve evacuation along the bulkhead deck) in terms of (x,y,z) co-ordinates (similar to unprotected openings). Only the “outboard” co-ordinates would be needed for input to the probabilistic damage calculations.

5) Any damage case resulting in immersion of any part of any of the defined

escape routes would be assigned s=0. The issue of whether all escape routes lie within the extent of a given damage scenario should not arise. We should only be penetrating to B/2 so there ought always to be an alternative escape route on the other side of the bulkhead deck. The software could be programmed to discount all escape route co-ordinates lying within the extent of damage of a particular case (just as for other openings) but if floodwater extends across the bulkhead deck past B/2 submerging the “non-discounted” co-ordinates then the case would be assigned as s=0.

The co-ordinator’s experience of the complexity of passenger ship evacuation regulations and procedures is, however, very limited so we apologise if the above makes no sense! If a procedure like this does make sense, however, and is acceptable to the group we could amend the regulation by specifically quoting SOLAS CH II-2 Part D Reg. 13.2 and by simplifying EN 2, 3 and 4 considerably. EN 4 is discussed in CLIA Q12C, below. Q37D (for Round 6 questionnaire). Considering all the above points would you

a) Consider clarifying reg. 7-2.5.2.2 by referring to Ch II-2 part D Reg. 13.2 and simplifying the EN by using the procedure outlined in the co-ordinator’s comments? OR

b) prefer to leave the regulation alone but modify part of the EN to read:- Horizontal evacuation routes do not include corridors (designated as category 3 corridor spaces according to SOLAS regulation II-2/9.2.2.3 or as category 2 corridor spaces according to SOLAS regulation II-2/9.2.2.4 for passenger ships carrying not more than 36 passengers) or escape routes within the damaged space. Landing areas and half landings of a staircase are part of the vertical escape way and not part of a horizontal escape route. ? OR

c) prefer to keep everything as agreed at SLF 53 (ref. SLF.53/WP.6, Annex 5)? d) prefer to revert to the original reg. and EN?

Prefer a) Y/N?

Yes: RINA, Denmark, China No: Finland, Norway, Germany, France Comment: US (Although we are not necessarily opposed to this general approach, it would represent a significant departure from that negotiated in the current EN approach (as it is much closer to a complete escape route margin line)

253 10/01/2012

Prefer b) Y/N?

Yes: CLIA, Norway, UK No: Finland, Germany, US (but much better than option c), France, Denmark

Prefer c) Y/N?

Yes: Finland, Germany, France (but see comment) No: Norway, US, Denmark

Prefer d) Y/N?

Yes: Norway (but see comment), US No: Finland, Germany, France, Denmark

Further comments / alternatives?:- Norway to d): prefer the amendments shown under b). Italy: “Horizontal evacuation routes do not include corridors (designated as category 3 corridor spaces according to SOLAS regulation II-2/9.2.2.3 or as category 2 corridor spaces according to SOLAS regulation II-2/9.2.2.4 for passenger ships carrying not more than 36 passengers) or escape routes within the damaged space. Landing areas and half landings of a staircase are part of the vertical escape way and not part of a horizontal escape route.” (i.e. text without deleting any part of the sentence and, in particular, maintaining “within the damaged spaces”) France: In wording agreed at SLF53, France would delete [or escape routes] in the second sentence and the third sentence in square bracket (otherwise, landing area and half landing area of a staircase should be defined.)

Q37 There is no general preference for options a) through d), therefore we can only refer the various issues and proposals to SLF 54 for further discussion, also bearing in mind the link to CLIA Q12.

DISCUSS FURTHER AT SLF 54 3. si = 0 where it is not possible to access a stair leading up to the embarkation deck from an undamaged space as a result of flooding to the “stairway” or “horizontal stairway” on the bulkhead deck.

4. Horizontal escapes situated in way of the damage extent may remain effective, therefore si need not be taken as zero. Contributions to the attained index A may still be gained. [CLIA Q12] [Coordinator’s Note: At SLF 53 it was agreed to replace the text of EN4 with a new diagram and introductory text, below. However some members did not accept this and so the entire question of EN’s 2,3 and 4 has been transferred to Q37.]:-

R 7-2.5.2.2 EN 4

CLIA Q12: Additional comments received from CLIA/CCSF between round 1 and 2:

Regulation 7-2.5.2.2 EN 4 4. Horizontal [and vertical] escapes situated in way of the damage extent may remain effective, therefore si need not be taken as zero. Contributions to the attained index A may still be gained.

254 10/01/2012

[Example for horizontal escape routes:]

Coordinator’s Comments: Please consider these proposed modifications in your reply to Q37A, above. CG Member’s Comments?:- Germany: CSSF proposals help to clarify. Finland: Proposal will help to clarify more precisely. Italy: CLIA comments are agreed. US: We can accept this proposed change (i.e. the addition of [and vertical]). Note: for the example shown we understand this to be an s=0 case; if example is included this should be indicated. We propose that “if not immersed” be added after “remain effective” to clarify this point. Round 2 Discussion:- Three members support CLIA’s proposal and the US can accept provided the example is identified as an “s=0” situation and some clarification is added:- 4. Horizontal [and vertical] escapes situated in way of the damage extent may remain effective [if not immersed], therefore si need not be taken as zero. Contributions to the attained index A may still be gained. It seems that this should be put to the SLF WG for a final decision and to allow more members to contribute.

Evacuation route from undamaged space

"horizontal escape way"to be kept dry

damaged compartments

255 10/01/2012

CLIA Q12 (for SLF53 WG). Can you accept CLIA’s proposal as it stands (including the diagram) or do you prefer to include the US’ amendments? CLIA only?

CLIA + US?

Further comments / alternatives?:- Post SLF 53 Note:- The WG decided to delete the EN altogether (believing it could be confusing) but to include an updated version of the sketch to try to show more clearly the difference between damaged and flooded compartments. Germany agreed to improve CLIA’s sketch and forward it to the CG for consideration and inclusion in the EN. CLIA Q12C (for Round 4 Questionnaire):- Is Germany able to improve the above drawing as agreed at the SFL 53 WG to better reflect the difference between “flooded” and “damaged” compartments/spaces? Space for Revised Drawing / Further Comments?:- US: In line with our comments in Q37C above, we are generally not in favour of deleting EN 4. It may need some clarification/revision but we see this EN as trying to replicate the margin line concept that during stability calculations we ignore potential damage to the bulkhead deck. China: No comments. Denmark: No comments. Germany: (Has provided a new diagram – see below. Many thanks. However it is rather blurred – can the quality be improved a little?)

256 10/01/2012

Round 6 Discussion: The US would prefer to retain the EN for the reasons stated. We suggest that the future of EN’s 2, 3 and 4 will now depend on what is decided in response to Q37D, above. So we propose in future to link any action on CLIA Q12C to Q37D. Further Comments / alternatives?:- Coordinator’s Note: New diagram provided by Germany in round 6 response (below). MANY THANKS!

257 10/01/2012

Denmark: No further comments. China: No (comments).

CLIA Q12 Some CG members are not in favour of deleting the original text so the whole question of the EN’s for reg. 7-2.5.2.2 is to be re-examined under Q37D.

DISCUSS AT SLF 54

5.3 The factor si is to be taken as zero if, taking into account sinkage, heel and trim, any of the following occur in any intermediate stage or in the final stage of flooding:

.1 immersion of any vertical escape hatch in the bulkhead deck intended for compliance with chapter II-2;


1. The purpose of this paragraph is to provide an incentive to ensure that

258 10/01/2012

evacuation through a vertical escape will not be obstructed by water from above. The paragraph is intended for smaller emergency escapes, typically hatches, where fitting of a watertight or weathertight means of closure would otherwise exclude them from being considered as flooding points.

2. Since the probabilistic regulations do not require that the watertight bulkheads be carried continuously up to the bulkhead deck, care should be taken to ensure that evacuation from intact spaces through flooded spaces below the bulkhead deck will remain possible, for instance by means of a watertight trunk.

.2 any controls intended for the operation of watertight doors, equalization devices, valves on piping or on ventilation ducts intended to maintain the integrity of watertight bulkheads from above the bulkhead deck become inaccessible or inoperable;

.3 immersion of any part of piping or ventilation ducts carried through a

watertight boundary that is located within any compartment included in damage cases contributing to the attained index A, if not fitted with watertight means of closure at each boundary.

.3 immersion of any part of piping or ventilation ducts [that is] located within the assumed extent of damage and carried through a watertight boundary if this can lead to the progressive flooding of compartments not assumed as flooded. Coordinator’s Note:- See below for reason for square brackets in amended text.

R7-2.5.3.3 (Clarification of “boundary”)

CLIA Q13

Comments received from CLIA/CCSF between Round 1 and Round 2:

Regulation 7-2.5.3 Watertight closure of open pipes: The wording “boundary” in para 3 could be interpreted as “boundary of the compartment”. It is our understanding that this is not the intention of the regulation.

259 10/01/2012

Therefore following change is proposed:- .3 immersion of any part of piping or ventilation ducts carried through a watertight boundary that is located within any compartment included in damage cases contributing to the attained index A, if not fitted with watertight means of closure at each boundary. Coordinator’s Comments: Can we agree to this modification to Reg. 7-2.5.3.3? CG Member’s Comments?:- MI: Concur. Germany: CSSF proposals help to clarify. Finland: Proposal will help to clarify more precisely. Italy: Agreed. France: The objective is to prevent progressive flooding of other compartment through pipes or ventilation ducts which may be broken by damage extent. Alternatively, progressive flooding may be taken into account in calculations. Other proposal may be .”3 immersion of any part of piping or ventilation ducts that is located within the assumed extent of damage and carried through a watertight boundary if this can lead to the progressive flooding of compartments not assumed as flooded.” UK: prefer to add “watertight” to enhance the addressing rather then removing it. [Coordinator – does UK mean to say “at each watertight boundary” at end of sentence – please clarify]. US: Not sure completely understand the concern; therefore abstain from comments. Round 2 Discussion:- There is good support for CLIA’s proposed amendment to the regulation amongst those who commented but the US and UK have reservations and France has an alternative proposal. We therefore suggest that this be discussed at the SLF 53 WG to allow others to contribute. CLIA Q13 (for SLF53 WG). Do you prefer “no changes” to the regulation or CLIA’s proposal or France’s alternative version? No change?

CLIA?

France? Further comments / alternatives?:- Post SLF 53 Note:- The WG preferred France’s revision of Reg. 7-2.5.3.3:- . 3 immersion of any part of piping or ventilation ducts that is located within the assumed extent of damage and carried through a watertight boundary if this can lead to the progressive flooding of compartments not assumed as flooded. We have re-read this text and would like to propose a very minor change, if still possible, for language reasons:- . 3 immersion of any part of piping or ventilation ducts that is located within the assumed extent of damage and carried through a watertight boundary if this can lead to the progressive flooding of compartments not assumed as flooded. CLIA Q13C (for Round 4 Questionnaire). Although the revised text for Reg. 7-2.3.3.3 was agreed by the SLF 53 WG the coordinators propose to remove the words “that is” as shown within square brackets (for language reasons only). Are you happy with this minor edit (assuming we are still permitted to change it)?

260 10/01/2012

Yes

Vanuatu, US, Sweden, Norway, Japan, RINA, Denmark, France, Germany, Finland, Italy, EC, UK, CLIA, ICS, MI (agree proposed editorial change), Spain

No

China

Final Comments?:- Denmark: Progressive flooding can be accepted according to EN Reg. 7-2, para. 3 provided that the calculation of the damage with and without progressive flooding is carried out and the damage giving the smaller s included in the index calculation. Round 6 Discussion. A large majority are in favour of this minor editorial change so we will report it to the sub-committee accordingly. We hope that the honourable delegation from China can accept the views of the majority? Denmark’s comments on reg 7-2 EN 3 are duly noted.

CLIA Q13 CONCLUDED; R7-2.5.3.3 TEXT CHANGED TO READ . 3 immersion of any part of piping or ventilation ducts that is located within the assumed extent of damage and carried through a watertight boundary if this can lead to the progressive flooding of compartments not assumed as flooded.

WE RECOMMEND THIS MODIFICATION BE ACCEPTED AT SLF 54 5.4 However, where compartments assumed flooded due to progressive flooding are taken into account in the damage stability calculations multiple values of sintermediate,i may be calculated assuming equalization in additional flooding phases. 5.5 Except as provided in paragraph 5.3.1, openings closed by means of watertight manhole covers and flush scuttles, small watertight hatch covers, remotely operated sliding watertight doors, side scuttles of the non-opening type as well as watertight access doors and hatch covers required to be kept closed at sea need not be considered. 6 Where horizontal watertight boundaries are fitted above the waterline under consideration the s-value calculated for the lower compartment or group of compartments shall be obtained by multiplying the value as determined in paragraph 1.1 by the reduction factor vm according to paragraph 6.1, which represents the probability that the spaces above the horizontal subdivision will not be flooded. Regulation 7-2.6

The sketches in the figure illustrate the connection between position of watertight decks in the reserve buoyancy area and the use of factor v for damages below these decks.

261 10/01/2012

262 10/01/2012

Regulation 7-2.6.1

The parameters x1 and x2 are the same as parameters x1 and x2 used in regulation 7-1. [New Co-ordinator’s Note for Round 2: It is proposed that we delete this EN and change the subscripts in this Reg. to match those in Reg 7-1 as this would involve the least number of changes. Comments invited: US: Unsure; recommend following whatever “standard convention” for subscript formatting is. Question: x1 and x1 are defined differently; is that an issue? Co-ordinator’s comment: Many thanks, US. For simplicity, we could just leave the EN as it stands. POST SLF 53 Note:- No further action needed] [NFA at SLF 54]

263 10/01/2012

Regulation 7-3

Permeability

1 For the purpose of the subdivision and damage stability calculations of the regulations, the permeability of each general compartment or part of a compartment shall be as follows:

Spaces PermeabilityAppropriated to stores Occupied by accommodationOccupied by machinery Void spaces Intended for liquids

0.60 0.95 0.85 0.95

0 or 0.95*

* Whichever results in the more severe requirement. 2 For the purpose of the subdivision and damage stability calculations of the regulations, the permeability of each cargo compartment or part of a compartment shall be as follows:

Spaces Permeability at

draught ds Permeability at

draught dp Permeability at

draught dl

Dry cargo spaces Container spaces Ro-ro spaces Cargo liquids

0.70 0.70 0.90 0.70

0.80 0.80 0.90 0.80

0.95 0.95 0.95 0.95

Regulation 7-3.2 1. The following additional cargo permeabilities may be used:

Spaces Permeability at

draught ds Permeability at

draught dp Permeability at

draught dl

Timber cargo in holds 0.35 0.70 0.95 Wood chip cargo 0.60 0.70 0.95

264 10/01/2012

2. Reference is made to MSC/Circ.998 (IACS Unified Interpretation regarding timber deck cargo in the context of damage stability requirements) regarding timber deck cargo. [Coordinator’s Note: included below for easy reference].

265 10/01/2012

266 10/01/2012

267 10/01/2012

3 Other figures for permeability may be used if substantiated by calculations. Regulation 7-3.3

1. Concerning the use of other figures for permeability “if substantiated by calculations”, such permeabilities should reflect the general conditions of the ship throughout its service life rather than specific loading conditions. 2. This paragraph allows for the recalculation of permeabilities. This should only be considered in cases where it is evident that there is a major discrepancy between the values shown in the regulation and the real values. It is not designed for improving the attained value of a deficient ship of regular type by the modification of chosen spaces in the ship that are known to provide significantly onerous results. All proposals should be considered on a case-by-case basis by the Administration and should be justified with adequate calculations and arguments.

268 10/01/2012

Regulation 8 Special requirements concerning passenger ship stability EITHER (US Proposal to delete reg. 8.1):-

[1 A passenger ship intended to carry 400 or more persons shall have watertight subdivision abaft the collision bulkhead so that si = 1 for the three loading conditions on which is based the calculation of the subdivision index and for a damage involving all the compartments within 0.08L measured from the forward perpendicular.]

OR:-

[1 A passenger ship intended to carry 400 or more persons shall have watertight subdivision abaft the collision bulkhead so that si = 1 for a damage involving all the compartments within 0.08L measured from the forward perpendicular for the three loading conditions upon which is based the calculation of [the] [a] subdivision index.]

Regulation 8.1 The intention of this regulation is to prevent the fitting of a large compartment aft of the collision bulkhead. [Q39-41D]

Regulation 8.1 (ref. SLF 52/17/6 - Norway) Paragraph 1 is inconsistent with paragraph 3, 3.2 and 3.4 in the same regulation. In this case it is proposed that the damage length should be relative to L in order to coincide with the damage length implied in regulation 12.1 on location of the collision bulkhead. Ls should then be replaced with L in the following paragraphs: Regulation 8.3 Regulation 8.3.2 Regulation 8.3.4 [Coordinator’s Note – indicated in square brackets below.] R8.1 (Inconsistent use of Ls) . Q38. Do you agree that the changes proposed by Norway are needed for

consistency? Yes

China, Germany, Japan, MI, Norway, CLIA, Italy, Spain, Denmark, UK, US, Sweden

No

Finland

Comments / Alternatives?:- Round 1 Discussion: A large majority is in favour (12/1). Can Finland accept the majority’s view?

IT IS PROPOSED TO ACCEPT THESE AMENDMENTS SUBJECT TO ANY FINAL COMMENTS FROM FINLAND

Comments?:- Finland: Can accept.


269 10/01/2012

(See SLF 53/14 para 12.6).

POST SLF 53 Note:- The changes were accepted in plenary at SLF 53; they are shown highlighted in red below.

AT SLF 54 RECOMMEND ACCEPTANCE OF NORWAY’S PROPOSALS

--------------------- It has been concluded at several sessions that the revised SOLAS chapter II-1 must contain a requirement for full survivability (s = 1) in cases of damages forward of the collision bulkhead. This Administration shares this concern and proposes that appropriate amendments be included in regulation 12 as shown below [see Reg 12.1 for details]. Depending on the outcome of that discussion paragraph 8.1 may then become redundant. Otherwise paragraph 8.1 should be amended as follows [underlined]: “1 A passenger ship intended to carry 400 or more persons shall have watertight subdivision abaft the collision bulkhead so that si = 1 in all service conditions used for calculation of a subdivision index assuming a damage involving all the compartments within 0.08L measured from the forward perpendicular.” R8.1 (and proposed new R12.2) covering fore end damages R8.1 (possible new EN) . Q39. Bearing in mind that Regulation 8 refers specifically to passenger ship

stability only, and Reg 8.1 currently only applies to passenger ships carrying 400 or more persons, do you agree that s should be equal to 1 for cases of damage involving all the compartments within 0.08L measured from the FP for this specified class of ship only, as in current Reg. 8.1? The question of s = 1 in other forward damage cases, as raised by Japan in SLF 51/3/2, would then be covered by Regulation 12 (please also refer to Reg. 12).

Yes

Finland, Germany with comments (Q41 is preferred), Japan, Norway, CLIA, Italy, Spain, Denmark, Sweden

No

China, US

Comments?:- China: The proposed replacement of “3 loading conditions” with “all service conditions” implies that the damage stability of all real loading conditions in the loading manual should calculated, which leads to a huge volume of calculation in comparison with “3 loading conditions”. Finland: s=1 to be applied for all ships under SOLAS2009. Germany: Requirement s=1 shall be applicable for all vessels covered by SOLAS2009. Norway: If there is general agreement that regulation 12 should make this a universal requirement for all ships we can withdraw this proposal. UK: See Q41. US: With the proposed addition to regulation 12, regulation 8.1 should be deleted. Note: this also would solve what seems to be awkward text in regulation 8.1; it indicates “watertight subdivision abaft the collision bulkhead so that s=1” but it is addressing damage forward of the collision bulkhead.

Please see Q41 for discussion.

270 10/01/2012

. Q40. If you answered “yes” to Q39 do you then agree with Norway’s clarifying amendment to Reg. 8.1, underlined in bold above?

Yes

Finland, Germany with comments (Q41 is preferred), Japan, Norway, CLIA, Spain, Denmark, Sweden

No Italy Comments?:- China: See comments to Q39. Germany: Requirement s=1 shall be applicable for all vessels covered by SOLAS2009 Norway: If there is general agreement that regulation 12 should make this a universal requirement for all ships we can withdraw this proposal. Italy: Text to be modified as follows : “…watertight subdivision abaft the collision bulkhead so that si = 1 for the loading conditions on which is based the calculation of a subdivision index …” Denmark: The service conditions used for calculation of the index don’t cover the permissible trim range (which is probably what this wording is trying to achieve), but rather 0.5%L less (or whatever the interval is going to be revised to). Surely the maximum trim(s) would be the limiting condition(s) to be checked? As to whether the intervening conditions less than this need to be checked as well is less clear. UK: See Q41. US: N/A; delete regulation 8.1.


. Q41. Norway proposes as an alternative that Reg 8.1 could be deleted altogether and the general issue of s = 1 for forward damages, as raised by Japan in SLF 51/3/2, could be dealt with under Regulation 12 with a new paragraph 12.2:- “2 The ship shall be so designed that si calculated in accordance with regulation 7-2 will not be less than 1 for all service conditions if [the whole portion] [any part] of the ship forward of the collision bulkhead is flooded without vertical limits.” Given that Regulation 12 applies to all vessels – passenger and cargo ships without any size limitations – do you agree with this proposal by Norway and their proposed wording of new Reg. 12.2? (The main implication seems to be that the s=1 requirement for forward damages would now apply to all sizes and classes of ship). Yes

Finland, Germany, Japan, Norway, Italy, Spain, UK, US, Sweden

No

China, Denmark

Comments?:- China: The proposal by Japan of full damage fwd of collision bulkhead is taken from the old SOLAS Reg.25-6.2 which applies to cargo ships of over 80m in Ls. For passenger ships, Reg.8 of SOLAS 2009 is enough. Norway: We support this as an alternative to amending regulation 8. CLIA: Other ship types. Italy: Agreed in principle, but subject to further verification.

271 10/01/2012

Spain: We think that 8.1 and new 12.2 are not equivalent. We prefer to maintain both regulations. Denmark: We agree with the principle that all damages in all likely service conditions forward of the collision bulkhead should be survived, however we would like to see some studies showing the implications of this requirement on vessels which have never been required to comply, in order to minimise unintended consequences. At the same time, the new wording has the effect of relaxing the existing requirements for passenger ships since the 0.08L length would for some vessels mean the damaging of compartments aft of the collision bulkhead. Discussion on Q39-41 and Reg. 12.1: There seems to be strong but not total support for applying s=1 to forward damages in both cargo ships and passenger ships by deleting Reg 8.1 altogether and introducing a new Reg. 12.2 with the text as proposed above by Norway (square brackets to be resolved). For ease of reference, here are the proposals for dealing with Reg. 12:- “Regulation 12 (ref. SLF 51/3/2 Annex – US and Sweden) New paragraph? Japan would again like to draw attention to the issue that the revised SOLAS chapter II-1 does not contain a requirement for full survivability (s = 1) in case of damages forward of the collision bulkhead; this should be identified for future improvement of the SOLAS text (see SLF 49/17, paragraph 3.5.3). Also see SLF 49/3, paragraph 10 below:

“10 In addition, Japan provided further information to the group regarding the issue that the new revised SOLAS chapter II-1 does not contain a requirement for full survivability (s = 1) in case of damages in front of the collision bulkhead (see SLF 48/21, paragraph 3.35). This information was circulated to the group and comments were requested. From the group‘s comments, there were three general conclusions: (1) there was general agreement that s = 1 for damages forward of the collision bulkhead should be a basic SOLAS chapter II-1 requirement for all ships; (2) this chapter II-1 regulatory omission is generally not viewed as a serious weakness/problem; and (3) this problem cannot be addressed in the Explanatory Notes; it will require a SOLAS amendment (consistent with the SLF 48 view).”

Note: This is already covered by damage of 0.08L from the forward perpendicular for passenger ships carrying more than 400 persons.

Regulation 12 (ref. SLF 52/17/6 - Norway) As pointed out above [Coordinator’s note: see Regulation 8.1 and 8.2] the revised chapter does not contain a requirement for full survivability (s = 1) in case of damages forward of the collision bulkhead. This Administration proposes to amend the regulation by adding a new paragraph 2: “2 The ship shall be so designed that si calculated in accordance with regulation 7-2 will not be less than 1 for all service conditions if [the whole portion] [any part] of the ship forward of the collision bulkhead is flooded without vertical limits.” Below is a brief summary of the advantages and disadvantages of deleting Reg. 8.1 and introducing a new Reg. 12.2:- Advantages. 1) It introduces harmonisation of the regulations for cargo ships with L>=80 m

272 10/01/2012

and passenger ships of all sizes and passenger numbers, based on the principle that damage forward of the collision bulkhead shall not result in loss of the vessel in any service condition. 2) As pointed out by the US, it resolves issues surrounding the rather awkward wording of Reg 8.1, particularly if the unambiguous text “…..the whole portion of the ship forward of the collision bulkhead….” is adopted in proposed Reg. 12.2. 3) We no longer need to revise the wording of Reg. 8.1 as proposed by Norway (see Q39 and 40). 4) As Japan has pointed out (ref. SLF 51/3/2), omission of something equivalent to SOLAS90 Reg. 25-6.2 in S2009 during the harmonisation process may have been an oversight which can only be properly corrected now:-

This regulation is necessary because survival of damages forward of the collision bulkhead would have been achieved automatically under the previous deterministic system of floodable lengths and 1 or 2 compartment damages for passenger ships whereas under a probabilistic system, it would be permissible for a ship to meet overall safety standards, such as A>=R but not survive a fore end collision. 5) It removes the 400 person and 0.08L thresholds in Reg. 8.1. Disadvantages. 1) China is concerned that applying the standards in proposed Reg. 12.2 to all service conditions could result in a large volume of extra calculations. 2) It would introduce step changes in safety standards resulting in a class of “pre-removal of Reg. 8.1 and introduction of Reg 12.2” S2009 ships. For example, passenger ships carrying 399 persons or less would now be required to meet s=1 for fore end collisions as would new cargo ships. Denmark suggests there may be a relaxation for some passenger ships where the existing regulations require damages up to 0.08L to achieve s=1; in some cases this could mean investigating damages aft of the collision bulkhead whereas the new proposal would only require s=1 for damages forward of the collision bulkhead. As Denmark and Italy point out, verification of these changes would be needed to ensure that there are no further unintended consequences. 3) Paragraph re-numbering and consequent revision of cross-references would be needed in Regs. 8 and 12. Further Comments 1) Spain does not believe that Reg. 8.1 and proposed Reg. 12.2 are equivalent and would prefer to keep them both. 2) China would prefer to keep the passenger ship elements of the regulations as they are. 3) There is some concern over the draughts and trims to be assumed or whether actual service conditions should be used to demonstrate s=1 for damages forward of the collision bulkhead. For example, SOLAS90 Reg 25-6.2 only requires examination at the deepest subdivision load line

273 10/01/2012

(no mention of trim). S2009 Reg. 8.1 requires use of “the 3 loading conditions on which is based the calculation of the subdivision index……” (presumably this would be for ds and dp at level trim and dl at service trim, but there is no mention of further conditions if trim exceeds 0.5% of L, a point mentioned by Denmark in their response to Q40). The proposal for new Reg 12.2 by Norway suggests that “all service conditions” should be examined whereas in their original proposal for updating Reg. 8.1 they referred to examination in all service conditions used for calculation of a subdivision index. Italy in responding to Q40 preferred the wording “for the loading conditions on which is based the calculation of a subdivision index” in updating Reg. 8.1. See also responses to Q42, below. 4) We wondered, if new Reg 12.2 is adopted, whether the word “flooded” should be replaced by “damaged” as the flooding would be naturally limited by the equilibrium waterline whereas the vessel could be damaged without vertical limits:- “2 The ship shall be so designed that si calculated in accordance with regulation 7-2 will not be less than 1 for all service conditions if [the whole portion] [any part] of the ship forward of the collision bulkhead is [flooded][damaged] without vertical limits.” Q39A - 41A Whilst recognising that further consideration of the full consequences is still needed and that the text of proposed Reg.12.2 may need to be adjusted slightly, would you agree that the advantages of deleting Reg. 8.1 and introducing a new Reg. 12.2 outweigh the disadvantages? Yes

MI (with comments), Germany, Finland, Japan, Norway (with comment), CLIA (but this seems to be a cargo ship issue), UK, US, Sweden, Denmark

No

Further Comments?:- MI: Concur, but the proposed text would need to be harmonised with that of 8.2 to read ‘in all service conditions used for calculation of a subdivision index.’ France: Proposed amendment to regulation 12 is not equivalent to paragraph 1 of regulation 8 which generally consider damage cases extending aft from collision bulkhead. The intention was to avoid a large compartment aft from the collision bulkhead. It is assumed that for a damage forward from the collision bulkhead, any ship will survive. Is it really necessary to verify this? For bottom damages, no calculation is required if minimum double bottom height is fulfilled. Norway: Further consideration needed regarding deleting Reg. 8.1. Round 2 Discussion:- Support for deleting regulation 8.1 and introducing a new regulation 12.2 seems unanimous but we had no reply from Spain (who were opposed after round 1) and now France and Norway have expressed concerns in their comments. Many thanks to France for their explanation of reg. 8.1 for which the intent has never been very clear to us. If we do decide to retain this regulation it would seem that a new EN along the lines of France’s comment would be very helpful. We can only suggest that we discuss all this again in the WG at SLF 53. Q39B – 41B. In the light of France’s new explanation of reg. 8.1 do you still favour deleting this regulation and inserting a new regulation 12.2? Yes

No

274 10/01/2012

Further Comments?:- POST SLF 53 Note:- Q39B – 41B were discussed in detail in the WG on Thursday afternoon (following completion of the WG paper). It was agreed that all WG discussions from this point onwards at SLF 53 would form the contents of a session document to be prepared and submitted to SLF 54 (ref. SLF 53/19 paragraph 14.9). The conclusion of the debate in the WG was that the issues relating to Reg 8.1 and proposed new Reg. 12.2 should be re-considered by the 2011 CG. Denmark was particularly concerned about the consequences of new Reg. 12.2 on smaller cargo vessels and advised the WG that they would send in some information for consideration by the 2011 CG. Here are some further discussion points for consideration by the 2011 CG as background to the round 4 questionnaire: 1) There now seems to be an increasing feeling that we need both Reg. 8.1 and a new 12.2. Norway originally wanted to delete Reg. 8.1 and introduce a more general requirement covering all ship types under new Reg. 12.2 to the effect that “s” must equal 1 for all damages forward of the collision bulkhead in all loading conditions used in the calculation of an index A. However, Norway now doubts whether we should delete 8.1; Spain and France agree. 2) France has clarified for us the intention of Reg. 8.1 which is to avoid the fitting of a large compartment aft of the collision bulkhead. However, given that several members and the co-ordinators were not clear that this was the intention of this regulation, we decided to look again to see if the wording could be improved. Perhaps simply changing the words around may help? For example we could change from:- 1 A passenger ship intended to carry 400 or more persons shall have watertight subdivision abaft the collision bulkhead so that si = 1 for the three loading conditions on which is based the calculation of the subdivision index and for a damage involving all the compartments within 0.08L measured from the forward perpendicular.

to 1 A passenger ship intended to carry 400 or more persons shall have watertight subdivision abaft the collision bulkhead so that si = 1 for a damage involving all the compartments within 0.08L measured from the forward perpendicular for the three loading conditions upon which is based the calculation of [the] [a] subdivision index.

It may also be advisable to add a new EN to explain the intention of this regulation:- Regulation 8.1 The intention of this regulation is to prevent the fitting of a large compartment aft of the collision bulkhead. 3) Japan’s original problem was that the requirement that si = 1 for damages forward of the collision bulkhead in SOLAS90 had not been transferred to SOLAS 2009. This applied only to cargo vessels in the probabilistic regulations within SOLAS90 (Reg. 25) but also was indirectly covered for passenger ships through compliance with at least a 1-compartment subdivision standard and specific damage stability criteria. Japan’s problem could then be solved for both cargo and passenger ships by Norway’s proposed new Reg. 12.2:-

275 10/01/2012

2 The ship shall be so designed that si calculated in accordance with regulation 7-2 will not be less than 1 [for all service conditions] [for the loading conditions on which is based the calculation of a subdivision index] if [the whole portion] [any part] of the ship forward of the collision bulkhead is [flooded] [damaged] without vertical limits. 4) It would seem from this that both Reg. 8.1 and Reg. 12.2 may be necessary and we simply need to decide on the final wording of Reg. 12.2 (see square brackets above), remembering also that we need to renumber the remaining paragraphs under Reg. 12. 5) Several countries, particularly Germany and Denmark expressed some reservations in the WG about applying proposed new Reg. 12.2 to smaller cargo vessels – we await their comments / data. Q39C – 41C. In the light of the discussion above and at SLF 53, would you agree with the proposed changes to Reg. 8.1 (including the new EN) and the introduction of a new Reg. 12.2 as shown? Yes

Vanuatu, Norway, Japan, RINA, Denmark (with comments), Germany, Italy, Finland, UK, France, CLIA, EC (ongoing research might have a bearing on this. Results should be taken into account), Spain (with comments below).

No

US, China

Further Comments / preferred wording for Reg. 12.2 / other alternatives?:- US: We fully agree with introducing new regulation 12.2, but with the addition of that new requirement we continue to believe regulation 8.1 is unnecessary and should be deleted. Our rationale is as follows: It is reasonable for all ships required to have a collision bulkhead that there is also a SOLAS requirement that s = 1 for any damage forward of the collision bulkhead; new reg 12.2 will accomplish that. With that addition there will now be a deterministic/ prescriptive requirement for a collision bulkhead and related damage stability survivability for extreme forward damages. Additionally regulation 8.3.2 requires s = 0.9 survivability for a damage case across the collision bulkhead. Under a probabilistic concept, we believe these two additional deterministic/prescriptive requirements in combination are sufficient. Note: reg 8.1 seems to have originated from SOLAS 90 reg II-1/7.3, and is not directly related to the collision bulkhead or 400 persons. Japan: With regard to the words in square brackets, Japan prefers “for the loading conditions on ...”, “the whole position” and “flooded”. RINA: [Preferred wording] The ship shall be so designed that si calculated in accordance with regulation 7-2 will not be less than 1 for the loading conditions on which is based the calculation of a subdivision index if any part of the ship forward of the collision bulkhead is flooded without vertical limits. The reservations regarding the application of this regulation to smaller cargo ships deserve further examination. See RINA comments in Q6C. Denmark:- Trim range to be covered. This could be outlined in EN. Agree to new EN Reg. 12.2 for cargo ships having a length L > 80 m but we still have reservations on Reg. 12.2 for the very small cargo ships being in mind that this can be cargo ships down to a length of 24 m. Germany: The wording “for the loading conditions on which is based the calculation of a subdivision index” does not apply to vessels which are not subject to B-1, thus should not be used. Generally, throughout SOLAS, the wordings “initial loading conditions di”, “all service conditions”, “all three loading conditions” should be revisited with respect to vessels not subject to B-1 (small cargo and pax vessels, bulker). We suggest using “initial loading conditions di” as

276 10/01/2012

used in Reg. 7-2.1.1 throughout SOLAS and to specify what is meant by this for vessels not subject to B-1. Finland: We prefer “for the loading conditions on which is based the calculation of a subdivision index if any part of the ship forward of the collision bulkhead is flooded without vertical limits.” Italy: The ship shall be so designed that si calculated in accordance with regulation 7-2 will not be less than 1 for the loading conditions on which is based the calculation of a subdivision index if any part of the ship forward of the collision bulkhead is damaged without vertical limits. France: For regulation 8.1, we cannot see a real difference with the previous wording? Spain: Support Germany and Denmark - reservations in the WG about applying proposed new Reg. 12.2 to smaller cargo vessels. Round 6 Discussion: We must firstly point out that the WG discussions on this and subsequent questions at SLF 53 now form the contents of a report submitted to SLF 54 (ref. SLF 54/8 dated 30 June 2011) by the Chair of the WG. You are invited to refer to this document when considering the remaining questions. In response to Q39-41C there is now a large majority (13-2) in favour of the proposed changes to reg. 8.1 (including the new EN) and the introduction of a new reg. 12.2. However, there are many comments, some questions and a strong argument for deleting reg. 8.1 altogether. So we will look at all your comments in turn:- The US supports new reg. 12.2 but still believes that reg. 8.1, should be deleted because its provisions are covered by reg. 8.3.2 (both are shown below for comparison purposes – amendments already agreed elsewhere in 8.2 and 8.3 are highlighted in red; the proposed amendment for reg. 8.1 with EN is shown ):- 8.1 A passenger ship intended to carry 400 or more persons shall have watertight subdivision abaft the collision bulkhead so that si = 1 for a damage involving all the compartments within 0.08L measured from the forward perpendicular for the three loading conditions upon which is based the calculation of [the] [a] subdivision index.

Regulation 8.1 The intention of this regulation is to prevent the fitting of a large compartment aft of the collision bulkhead. 8.2 A passenger ship intended to carry 36 or more persons is to be capable of withstanding damage along the side shell to an extent specified in paragraph 3. Compliance with this regulation is to be achieved by demonstrating that si, as defined in regulation 7-2, is not less than 0.9 for the three loading conditions on which is based the calculation of the subdivision index. If the subdivision index is calculated for different trims, this requirement must also be satisfied for these loading conditions.

8.3 The damage extent to be assumed when demonstrating compliance with paragraph 2, is to be dependent on both N as defined in regulation 6 the total number of persons carried, and Ls L as defined in regulation 2, such that:

…….. .2 where 400 or more persons are to be carried, a damage length of 0.03 Ls L, but

277 10/01/2012

not less than 3 m is to be assumed at any position along the side shell, in conjunction with a penetration inboard of 0.1B but not less than 0.75 m measured inboard form the ship side, at right angle to the centerline at the level of the deepest subdivision draught; New reg. 12.2 applies to all cargo and passenger ships forward of the collision bulkhead whereas reg. 8.1 only applies to passenger ships carrying 400 or more passengers and is designed to ensure that the subdivision is sufficient to ensure that s=1 is achieved at the three standard draughts following damage immediately aft of the collision bulkhead. We are not totally convinced that reg. 8.3.2 is equivalent to reg. 8.1, as the US argues:-

1) Reg. 8.3.2 covers minor damage only whereas reg. 8.1 covers “all compartments” lying within 0.08L abaft of the forward perpendicular – clearly a major damage scenario with unlimited penetration depth. We think it may be there in case the collision bulkhead is destroyed after a large fore end damage.

2) The required standard for reg. 8.3.2 is si = 0.9 for the 3 standard loading conditions whereas reg. 8.1 requires si = 1 for the same 3 conditions – a significantly higher standard.

So reg. 8.1 overall represents a higher safety standard than reg. 8.3.2 for spaces immediately aft of the collision bulkhead. Whether this was the intention is not certain. In this respect we thank the US for drawing our attention to SOLAS 90 reg. II-1/7.3 which is a special requirement concerning passenger ship subdivision:- 7.3 In ships of 100 m. in length and upwards, one of the main transverse bulkheads abaft the forepeak shall be fitted at a distance from the forward perpendicular which is not greater than the permissible length. Although we agree with the US that the collision bulkhead is not referred to directly here, it is often the case that the after bulkhead of the forepeak is the collision bulkhead so there may be some correlation here between the intent of II-/7.3 in SOLAS90 and II-1/8.1 in SOLAS2009. There does not appear to be any equivalent provision for cargo ships in SOLAS90 – only that s=1 following damage to all compartments forward of the collision bulkhead with unlimited vertical extent, a requirement which we now propose to cover in reg. 12.2. Japan supports the proposal and prefers the following text for new Reg. 12.2: 12.2 The ship shall be so designed that si calculated in accordance with regulation 7-2 will not be less than 1 [for all service conditions] [for the loading conditions on which is based the calculation of a subdivision index] if [the whole portion] [any part] of the ship forward of the collision bulkhead is [flooded] [damaged] without vertical limits. RINA wants further examination of the application of this regulation to smaller cargo ships and prefers the following text: 12.2 The ship shall be so designed that si calculated in accordance with regulation 7-2 will not be less than 1 [for all service conditions] [for the loading conditions on which is based the calculation of a subdivision index] if [the whole portion] [any part] of the ship forward of the collision bulkhead is [flooded] [damaged] without vertical limits.

278 10/01/2012

Denmark asks for trim range to be covered in reg. 8.1 (perhaps in an EN). However we could imply this by deleting [the] below as is already done in some other regulations where calculation of the effect of trim is required:- 8.1 A passenger ship intended to carry 400 or more persons shall have watertight subdivision abaft the collision bulkhead so that si = 1 for a damage involving all the compartments within 0.08L measured from the forward perpendicular for the three loading conditions upon which is based the calculation of [the] [a] subdivision index.

Denmark also shares RINA’s concern on applying reg. 12.2 to small cargo ships which can go down to 24 m in length. We will discuss this below. Germany in reg. 12.2 argues that for the loading conditions on which is based the calculation of a subdivision index could only apply to vessels subject to probabilistic damage stability analysis in part B-1 and suggests that “initial loading conditions di” as used in reg. 7-2.1.1 should be applied throughout SOLAS to replace “all service conditions” and “all three loading conditions” for vessels not subject to the full probabilistic damage analysis (such as small cargo ships etc). We will ask for the views of the group on this idea. Finland prefers the following text for reg. 12.2:- 12.2 The ship shall be so designed that si calculated in accordance with regulation 7-2 will not be less than 1 [for all service conditions] [for the loading conditions on which is based the calculation of a subdivision index] if [the whole portion] [any part] of the ship forward of the collision bulkhead is [flooded] [damaged] without vertical limits. Italy prefers the following text for reg. 12.2:- 12.2 The ship shall be so designed that si calculated in accordance with regulation 7-2 will not be less than 1 [for all service conditions] [for the loading conditions on which is based the calculation of a subdivision index] if [the whole portion] [any part] of the ship forward of the collision bulkhead is [flooded] [damaged] without vertical limits. France asks why we changed reg. 8.1 FROM 8.1 A passenger ship intended to carry 400 or more persons shall have watertight subdivision abaft the collision bulkhead so that si = 1 for the three loading conditions on which is based the calculation of the subdivision index and for a damage involving all the compartments within 0.08L measured from the forward perpendicular.

TO

8.1 A passenger ship intended to carry 400 or more persons shall have watertight subdivision abaft the collision bulkhead so that si = 1 for a damage involving all the compartments within 0.08L measured from the forward

279 10/01/2012

perpendicular for the three loading conditions upon which is based the calculation of [the] [a] subdivision index. This originated from the co-ordinators because, until France explained the true intention of this regulation in round 1, several of us could not really understand the sentence properly. So we proposed the above change to the order of the words to try to remove the word “and” between “subdivision index” and “for a damage” which we felt may have been causing some confusion. We hope the new word order now makes it clearer by putting emphasis on the damage and its extent rather than on the three loading conditions. But we agree – the difference is very small! Spain shares the concerns of Germany, Denmark and RINA about applying new Reg. 12.2 to smaller cargo vessels. SUMMARY

1) We hope that we have been able to convince the US that we still need reg. 8.1 but we will nevertheless ask the group’s opinion.

2) The concerns regarding the applicability of reg. 12.2 to small cargo ships are addressed elsewhere in the wider context of reg. 4.1 (in particular see Q6D).

3) Germany’s proposal to use “initial loading conditions di” wherever the probabilistic damage regulations do not apply would need to be carefully considered in the context of each regulation. We ask the group below whether they approve of this in principle before we highlight all the necessary changes.

4) Regarding text in square brackets:- (a) If we agree to retain reg. 8.1 we suggest that we delete [the] and use [a]

to denote that trim calculations may be involved. (b) For the square brackets in new reg. 12.2:-

All 4 members who expressed a preference wanted to delete “for all service conditions”; 3 out of 4 wanted to delete “the whole portion” and 3 out of 4 wanted to delete “damaged”.

5) We include the text changes to reg. 8.1 and 12.2 agreed by the majority below but we recognise that some wider issues, such as the applicability to small cargo ships, US proposal to remove reg. 8.1 (1) and Germany’s proposal (3) still need to be resolved if necessary by the WG at SLF 54.

8.1 A passenger ship intended to carry 400 or more persons shall have watertight subdivision abaft the collision bulkhead so that si = 1 for a damage involving all the compartments within 0.08L measured from the forward perpendicular for the three loading conditions upon which is based the calculation of [the] [a] subdivision index.

Regulation 8.1 The intention of this regulation is to prevent the fitting of a large compartment aft of the collision bulkhead. 12.2 The ship shall be so designed that si calculated in accordance with regulation 7-2 will not be less than 1 [for all service conditions] [for the loading conditions on which is based the calculation of a subdivision index] if [the whole portion] [any part] of the ship forward of the collision bulkhead is [flooded] [damaged] without vertical limits.

280 10/01/2012

Q39D – 41D (for Round 6 questionnaire). 1) Do you agreed with the US in (1) above that reg. 8.1 should be deleted? 2) Do you agree in principle with Germany’s proposal in (3) to use “initial

loading conditions di” where appropriate throughout SOLAS? 3) Do you accept the square bracket deletions for reg. 8.1 and 12.2 at the end

of the above summary? (1) Y/N?

Yes: US (please see comments) No: Japan, CLIA, RINA, Finland, Norway, Germany, Poland, Italy, UK, EC, France, Denmark, China

(2) Y/N?

Yes: Japan, CLIA, Finland, Norway, Germany, Italy, Denmark, UK (In principle “yes”, however it is not clear to us what benefits the full proposed changes will bring.) No: US, China No comment: RINA

(3) Y/N?

Yes: Japan (see comments below), CLIA, RINA, Finland, Norway, China, Germany, EC, France (see comments) No: Italy, Denmark Comment: US (Subject to decision on deleting reg 8.1 - Yes Note: in reg 12.2 we question whether “without vertical limits” is necessary if the text “any part” is added?)

Further Comments?:- Japan: It is difficult to apply the requirement to small cargo ships because such ships are not applied to Part B-1 and not required to calculate si.. US: Regarding the Round 6 Discussion on keeping or deleting reg 8.1: Although reg 8.3.2 is referred to as “minor damage”, we think that a 0.1B transverse extent and a 0.03L longitudinal extent are less minor in the bow area under consideration. But more significantly, we are not trying to say that reg 8.3.2 is completely equivalent to reg 8.1. What we are saying is that with reg 8.3.2 and the new requirement in reg 12.2, we believe reg 8.1 adds very little additional safety value and is therefore not necessary (i.e. it seems to us that 3 different deterministic regs to cover damage stability in this area is overkill!) France: Cargo ships which are shown to comply with subdivision and damage stability regulation in other instrument will not have subdivision index calculated. So it would be preferable to refer to “all service conditions”. For ships which have to fulfil the stability requirements of part B-1, it will be sufficient to made calculations for the loading conditions on which is based the calculation of a subdivision index.

Q39-41D – proposed new EN - see also proposal for reg. 12.2

(1) There was voting of 13-1 against the US proposal to delete Reg 8.1;

(2) 8-2 were in favour of Germany’s proposal and

(3) 9-2 were in favour of the proposed bracket deletions in reg. 8.1 and new 12.2.

IF GERMANY’s PROPOSAL IS ACCEPTED, IT WILL BE NECESSARY TO IDENTIFY WHERE THE PHRASE “INITIAL LOADING CONDITIONS di” SHOULD BE

EMPLOYED

NOT UNANIMOUS - SO DISCUSS AT SLF 54.

281 10/01/2012

2 A passenger ship intended to carry 36 or more persons is to be capable of withstanding damage along the side shell to an extent specified in paragraph 3. Compliance with this regulation is to be achieved by demonstrating that si, as defined in regulation 7-2, is not less than 0.9 for the three loading conditions on which is based the calculation of the subdivision index. If the subdivision index is calculated for different trims, this requirement must also be satisfied for [these loading conditions][all loading conditions used for the calculation of the subdivision [indexes][indices]]. [Q42]

Regulation 8.2 (ref. SLF 52/17/6 - Norway) Replace the text in paragraph 8.2 to take into consideration that the principle must apply to all calculated trims for the purpose of this paragraph as well: “2 A passenger ship intended to carry 36 or more persons is to be capable of withstanding damage along the side shell to an extent specified in paragraph 3. Compliance with this regulation is to be achieved by demonstrating that si, as defined in regulation 7-2, is not less than 0.9 in all service conditions used for calculation of a subdivision index. R8.2 ( Need to emphasize multiple trims) . Q42. Do you agree to the changes to Reg. 8.2 proposed by Norway, as

underlined above? Yes

Germany (with comments), Japan, Norway, CLIA, Spain, Denmark, UK, US, Sweden, France (added after Round 2 – with comments)

No

China, Finland, Italy (with comments)

Comments?:- China: See comments to Q39. Germany: We support a revised wording as follows “for the three loading conditions on which is based the calculation of a subdivision index”. Italy: Text to be modified as follows : “…by demonstrating that si, as defined in regulation 7-2, is not less than 0.9 for the loading conditions on which is based the calculation of a subdivision index.” France: More general wording applicable if several A index are calculated. Round 1 Discussion: We will need to harmonize the text of Reg. 8.2 either with modified Reg. 8.1 or with new Reg. 12.2, depending on the outcome of Q39A – 41A. Q42A. Any further comments at this stage?:- RINA: We can find no definition of service conditions or understand the intent of loading conditions. Both refer to actual ship operational conditions; consequently should they be used in probabilistic calculations. As an alternative we would prefer to use the subdivision draughts ds, dp and dl, all of which are defined in Reg. 2. Note: Service conditions appear throughout this paper. France: Different wording will be necessary for regulation 8 and for possible additional reg. 12.2. Round 2 Discussion: For information, the term “service conditions” is defined in the EN for reg. 9.8:-

1. The term “all service conditions” used in this paragraph means the three loading conditions used to calculate the attained subdivision index A.

282 10/01/2012

RINA is correct in saying that the term “service conditions” appears in many places in the regulations, sometimes in different contexts, so perhaps it does merit a definition under regulation 2? Apart from that, we now have 3 proposals for changing reg. 8.2:- Original …… is not less than 0.9 for the three loading conditions on which is based the calculation of the subdivision index. 1) Norway …….is not less than 0.9 in all service conditions used for calculation of a subdivision index. 2) Germany …… is not less than 0.9 for the three loading conditions on which is based the calculation of [the] [a] subdivision index. 3) Italy …… is not less than 0.9 for the [three] loading conditions on which is based the calculation of [the] [a] subdivision index. Also, as France says, we will still need to harmonize the text of Reg. 8.2 either with modified Reg. 8.1 or with new Reg. 12.2, depending on the outcome of Q39B – 41B. Q42B (for SLF 53 WG). Please indicate which alternative you prefer and whether you think we need a definition of “service conditions” in reg. 2

No change?

1) Norway?

2) Germany?

3) Italy?

New definition of service conditions?

POST SLF 53 Note:- Q42B (see working document for background) was discussed in detail in the WG on Thursday afternoon (following completion of the WG paper).The conclusion of the debate was to add the following extra sentence at the end of the regulation If the subdivision index is calculated for different trims, this requirement must also be satisfied for these loading conditions. Q42C (for Round 4 Questionnaire). Have you any final comments on the above? Further Comments?:- China: No comments. RINA: No further comment. Denmark: No further comments. Germany: We suggest using “… for these initial loading conditions di” as in reg. 7-2.1.1 to achieve a uniform use of this terminology throughout SOLAS.

283 10/01/2012

EC: Ongoing research might have a bearing on this. Results should be taken into account. France: Would it be possible to replace “must also be satisfied for these loading conditions” by “must be satisfied for all loading conditions used for the calculation of the attained indexes”. Round 6 Discussion: The WG discussions on this and subsequent questions at SLF 53 now form the contents of a report submitted to SLF 54 (ref. SLF 54/8 dated 30 June 2011) by the Chair of the WG. Germany’s point is noted and is dealt with under Q39D-41D (Q2), above for which we await the outcome. The EC’s comment is also noted – any change agreed now may have to be altered again following completion of the current research projects, which may be another reason for asking the S/C to extend the deadline for this agenda item. France prefers the following wording:- 2 A passenger ship intended to carry 36 or more persons is to be capable of withstanding damage along the side shell to an extent specified in paragraph 3. Compliance with this regulation is to be achieved by demonstrating that si, as defined in regulation 7-2, is not less than 0.9 for the three loading conditions on which is based the calculation of the subdivision index. If the subdivision index is calculated for different trims, this requirement must be satisfied for all loading conditions used for the calculation of the attained indexes. We will ask the group for their preference; the coordinators’ only comment is that “indexes” should read “indices”, which is, very strictly speaking, the correct plural of index!! Sorry! Q42D (for Round 6 questionnaire). Do you prefer France’s alternative for the last sentence of reg. 8.2 but using “indices” instead of “indexes”? Yes

Japan, CLIA, RINA, Norway, Italy, UK, EC, France, Denmark, China

No

Finland, Germany, Poland, US

Further Comments?:- Germany: How to deal with different trims in various locations of the regs and EN has been discussed in round 5. The result is pending. Poland: Subdivision indexes might be [Could Poland please clarify this? – coordinators]

Q42 Voting was 10-4 in favour of France’s proposed deletions

and use of “indices” instead of “indexes”. NOT UNANIMOUS SO DISCUSS AT SLF 54

3 The damage extent to be assumed when demonstrating compliance with paragraph 2, is to be dependent on both N as defined in regulation 6 the total number of persons carried [Q43C], and Ls L [Q38] as defined in regulation 2 [Q43C], such that:

.1 the vertical extent of damage is to extend from the ship’s moulded baseline to a position up to 12.5 m above the position of the deepest subdivision draught as defined in regulation 2, unless a lesser vertical extent of damage were to give a lower value of si, in which case this reduced extent is to be used;

.2 where 400 or more persons are to be carried, a damage length of 0.03 Ls

L [Q38], but not less than 3 m is to be assumed at any position along the side shell, in conjunction with a penetration inboard of 0.1B but not less than 0.75 m measured

284 10/01/2012

inboard form the ship side, at right angle to the centerline at the level of the deepest subdivision draught;

.3 where less than 400 persons are carried, damage length is to be

assumed at any position along the side shell between transverse watertight bulkheads provided that the distance between two adjacent transverse watertight bulkheads is not less than the assumed damage length. If the distance between adjacent transverse watertight bulkheads is less than the assumed damage length, only one of these bulkheads shall be considered effective for the purpose of demonstrating compliance with paragraph 2;

.4 where 36 persons are carried, a damage length of 0.015 Ls L [Q38] but

not less than 3 m is to be assumed, in conjunction with a penetration inboard of 0.05B but not less the 0.75 m; and

.5 where more than 36, but fewer than 400 persons are carried the values of

damage length and penetration inboard, used in the determination of the assumed extent of damage, are to be obtained by linear interpolation between the values of damage length and penetration which apply for ship carrying 36 persons and 400 persons as specified in subparagraphs .4.and .2. Regulations 8.3.2 to 8.3.5

The number of persons carried, which is specified in these paragraphs, equals the total number of persons the ship is permitted to carry (and not N = N1 + 2 N2 as defined in regulation 6).

Regulation 8.3.2 to 8.3.5 (ref. SLF 51/3/2 Annex – US and Sweden) Clarify the item that is now addressed in the Explanatory Notes: “The number of persons carried, which is specified in these paragraphs, equals the total number of persons on board (and not N = N1 + 2N2 as defined in regulation 6)” ----------------------------- Note: See regulation 12 regarding the issue of a requirement for full survivability (s = 1) in case of damages forward of the collision bulkhead (which is an issue for both passenger and cargo ships).[Co-ordinator’s Note:- See Q39-41, above, for this item.] Regulation 8.3.2 to 8.3.5 (ref. SLF 51/17/5 Annex – Norway) Document SLF 51/3/2 requests a clarification on the following text in the Explanatory Notes “The number of persons carried, which is specified in these paragraphs, equals the total number of persons on board (and not N = N1 + 2N2 as defined in regulation 6)” In the opinion of this Administration the 400 persons is an equivalent to old regulation II-1/8-3, which did not take lifeboat capacity into account. The text in the EN is appropriately included to avoid a too stringent application by ensuring that the multiplier 2 will be disregarded for the purpose of this regulation. It is proposed that the text remains as it is.

285 10/01/2012

R8.3 (Minor damage)

R8.3.2 to 8.3.5 EN

. Q43. Do you agree with Norway that the current EN does not need amending? Yes

China, Finland, Germany, Japan, MI, Norway, CLIA, Italy, Spain, Denmark

No

Sweden

Comments?:- UK: We need further explanation of the intended reason for clarification from ref. SLF 51/3/2 Annex – US and Sweden. US: Sorry but there is a big misunderstanding regarding the intention of this item in SLF 51/3/2. This holding file item was intended to initiate a future amend / fix directly to regulation 8.3, so that the EN could be deleted altogether. i.e. regulation 8.3 should read: “The damage extent... ...is to be dependent on the total number of persons carried and Ls, such that:” Round 1 Discussion: Many thanks to the US for clearing this up. So the proposal now is to change the opening sentence of Reg 8.3 as shown below and delete the EN covering Regs. 8.3.2 to 8.3.5: 3 The damage extent to be assumed when demonstrating compliance with paragraph 2, is to be dependent on [both N as defined in regulation 6] [the total number of persons carried], and [Ls][L] as defined in regulation 2, such that:

Q43A. Following the clarification by the US do you now agree to the change in text shown above in Reg. 8.3 and deletion of the EN covering Regs. 8.3.2 to 8.3.5? Yes

MI, Germany, Finland, Italy, Japan, France, Norway, CLIA, UK, US (with comment), Sweden, Denmark

No

Comments?:- US: Don’t think we need “as defined in regulation 2”. (This was included before because “N” was defined in reg 6 and therefore needed special reference). Round 2 Discussion: Support is unanimous for this amendment but the US proposes another change which would make the regulation read: 3 The damage extent to be assumed when demonstrating compliance with paragraph 2, is to be dependent on [both N as defined in regulation 6] [the total number of persons carried], and [Ls][L] [as defined in regulation 2], such that:

Do you agree to this further amendment? Q43B (for SLF 53 WG). Do you agree that “as defined in regulation 2” can also be deleted along with the EN for reg. 8.3.2 to 8.3.5? Yes

No

286 10/01/2012

POST SLF 53 Note:- Q43B was discussed in the WG on Thursday afternoon (following completion of the WG paper). The conclusion of the debate was to accept the amendments to the opening sentence of regulation 8.3 and delete the EN for Regs. 8.3.2 to 8.3.5 as highlighted above. Q43C (for Round 4 Questionnaire). Have you any final comments on the above amendments? Further Comments?:- China: No comments. RINA: No further comment. Denmark: No further comments. France: No further comment.

Q43. CONCLUDED AMENDMENT OF REG 8.3 AND DELETION OF EN8.3.2 TO 8.3.5

TO BE RECOMMENDED AT SLF 54.

287 10/01/2012

Regulation 8-1 [Note: changes highlighted below agreed at MSC 89/25 (9.10-9.13)] System capabilities and operational information after a flooding casualty on passenger ships

1 Application This regulation applies to passenger ships constructed on or after 1 July 2010 to which regulation II-2/21 applies. Passenger ships having a length, as defined in regulation II-1/2.5, of 120 m or more or having three or more main vertical zones shall comply with the provisions of this regulation. .[Note: check cross-reference – await outcome of Q66D under reg. 2.26] 2 Availability of essential systems in case of flooding damage * A passenger ship constructed on or after 1 July 2010 shall be designed so that the systems specified in regulation II-2/21.4 remain operational when the ship is subject to flooding of any single watertight compartment. Regulation 8-1.2 1. In the context of this regulation, “compartment” has the same meaning as defined under regulation 7-1 of these Explanatory Notes (i.e. an onboard space within watertight boundaries). 2. The purpose of the paragraph is to prevent any flooding of limited extent from immobilizing the ship. This principle should be applied regardless of how the flooding might occur. Only flooding below the bulkhead deck need be considered. 3 Operational information after a flooding casualty For the purpose of providing operational information to the Master for safe return to port after a flooding casualty, passenger ships constructed on or after 1 January 2014 shall have: .1 onboard stability computer; or .2 shore-based support, [in accordance with] guidelines developed by the Organization** [Note: for further consideration and possible adoption at MSC90] _______________________

* Refer to the Performance standards for the systems and services to remain operational on passenger ships for safe return to port and orderly evacuation and abandonment after a casualty (MSC.1/Circ.1214) [Coordinator’s Note: included below for easy reference].

** Refer to the Guidelines on operational information for masters of passenger ships for safe return to port by own power or under tow (MSC.1/Circ.1400).

288 10/01/2012

POST SLF 53 Note:- The changes highlighted in red, above, were agreed at SLF 53 and approved at MSC 89 in May 2011. The new guidelines on operational information for Masters of Passenger ships are included below for easy reference. Note that the cross-reference to regulation II-1/2.5 under “Application” will have to be checked depending on the outcome of Q66D under reg. 2.26

289 10/01/2012

290 10/01/2012

291 10/01/2012

292 10/01/2012

Note: The following is from SLF 53/WP.6 Annex 3

(now adopted at MSC89 as MSC.1/Circ.1400)

293 10/01/2012

294 10/01/2012

Part B-2 Subdivision, watertight and weathertight integrity

Regulation 9 Double bottoms [in passenger ships and cargo ships other than tankers] [Q6D(4)[1]; discuss at SLF 54]

1 A double bottom shall be fitted extending from the collision bulkhead to the afterpeak bulkhead, as far as this is practicable and compatible with the design and proper working of the ship.

Regulation 9.1

1. This regulation is intended to minimize the impact of flooding from a minor grounding. Special attention should be paid to the vulnerable area at the turn of the bilge. When justifying a deviation from fitting an inner bottom an assessment of the consequences of allowing a more extensive flooding than reflected in the regulation should be provided.

2. Except as provided in regulations 9.3 and 9.4, parts of the double bottom not extended for the full width of the ship as required by regulation 9.1 should be considered an unusual arrangement for the purpose of this regulation and is to be handled in accordance with regulation 9.7. Double bottom arrangements as shown in the example below are to be considered as “unusual”, requiring compliance with regulation 9.8.

B/20

295 10/01/2012

R9.1 EN2 (Unusual DB tanks)

CLIA Q14

Additional comments received from CLIA/CCSF between round 1 and 2:

Regulation 9.1 EN 2 Additional Explanation: [Double bottom arrangements as shown in the example are to be considered as unusual double bottom arrangement and require compliance with regulation 9.8.2]

Coordinator’s Comments: Should Reg. 9.8.2 not be Reg. 9.8? CLIA to clarify. Are members happy that the diagram is self-explanatory? CG Member’s Comments?:- Germany: Acceptable. Finland: Support. France: Correct reference is Reg 9.8. Term “unusual” is perhaps not adapted for this example. Norway: Supports the clarification if it refers to Reg. 9.8. CLIA: Yes, 9.8 is correct. Round 2 Discussion: There is good support for this proposal from those who responded provided we change the reference to 9.8, although France is not convinced. So, if agreed, EN 2 would now read:- 2. Except as provided in regulations 9.3 and 9.4, parts of the double bottom not extended for the full width of the ship as required by regulation 9.1 should be considered an unusual arrangement for the purpose of this regulation and is to be handled in accordance with regulation 9.7.

[Double bottom arrangements as shown in the example [below] are to be considered as [an] unusual [double bottom] arrangement [and require][requiring] compliance with regulation 9.8[.2]]

B/20

296 10/01/2012

[Co-ordinator’s Note: One or two minor changes are suggested for your consideration as shown in square brackets].

CLIA Q14. CONCLUDED - PROPOSAL ACCEPTED BY CG. AWAIT APPROVAL BY SUB-COMMITTEE AT SLF 53.

(See SLF 53/14 para. 12.7). POST SLF 53 Note: CLIA’s proposal (as amended) was accepted in plenary at SLF 53 (see SLF 53/WP.6 para. 21) and is shown highlighted in grey above. CLIA Q14 (for Round 4 Questionnaire). The coordinators shortened the agreed text from “unusual [double bottom] arrangement [and require][requiring] compliance with regulation 9.8” to that shown above. Is this simplification acceptable? Final Comments?:- US: It seems in reality that reg 9.1 EN2 is actually misplaced as it addresses issues related to regulation 9.2 (not regulation 9.1). Further, it seems the sketch is just an example of what the existing EN2 is describing. So we suggest simply indicating “an example is provided below”. Therefore, our proposal is as follows: 1. Relocate and edit current regulation 9.1 EN2 as follows: Regulation 9.2 1 Except as provided in regulations 9.3 and 9.4, parts of the double bottom not extended for the full width of the ship as required by regulation 9.2 should be considered an unusual arrangement for the purpose of this regulation and should is to be handled in accordance with regulation 9.7. An example is provided below. 2. Renumber the existing regulation 9.2 EN to EN 2. China: No comments. Denmark: Simplification is acceptable. Germany: Yes. Finland: Agree. Italy: Agreed. France: Agreement on coordinators’ modification. Round 6 Discussion: There seems to be acceptance amongst those who responded for the slight change to the text but the US would like to relocate EN2 as follows:- Currently agreed reg. 9.1 and 9.2 with EN:- 1 A double bottom shall be fitted extending from the collision bulkhead to the afterpeak bulkhead, as far as this is practicable and compatible with the design and proper working of the ship.

B/20

297 10/01/2012

Regulation 9.1


2. Except as provided in regulations 9.3 and 9.4, parts of the double bottom not extended for the full width of the ship as required by regulation 9.1 should be considered an unusual arrangement for the purpose of this regulation and is to be handled in accordance with regulation 9.7. Double bottom arrangements as shown in the example below are to be considered as “unusual”, requiring compliance with regulation 9.8.

2 Where a double bottom is required to be fitted the inner bottom shall be continued out to the ship's sides in such a manner as to protect the bottom to the turn of the bilge. Such protection will be deemed satisfactory if the inner bottom is not lower at any part than a plane parallel with the keel line and which is located not less than a vertical distance h measured from the keel line, as calculated by the formula:

h = B/20

However, in no case is the value of h to be less than 760 mm, and need not be taken as more than 2,000 mm.

Regulation 9.2

If an inner bottom is located higher than the partial subdivision draught dp, this should be considered an unusual arrangement and is to be handled in accordance with regulation 9.7.

US Proposal (text changes highlighted in green): 1 A double bottom shall be fitted extending from the collision bulkhead to the afterpeak bulkhead, as far as this is practicable and compatible with the design and proper working of the ship.

B/20

298 10/01/2012

Regulation 9.1


2 Where a double bottom is required to be fitted the inner bottom shall be continued out to the ship's sides in such a manner as to protect the bottom to the turn of the bilge. Such protection will be deemed satisfactory if the inner bottom is not lower at any part than a plane parallel with the keel line and which is located not less than a vertical distance h measured from the keel line, as calculated by the formula:

h = B/20


Regulation 9.2

1. Except as provided in regulations 9.3 and 9.4, parts of the double bottom not extended for the full width of the ship as required by regulation 9.[1][2] should be considered an unusual arrangement for the purpose of this regulation and [should] [is to] be handled in accordance with regulation 9.7. Double bottom arrangements as shown in the example below are to be considered as “unusual”, requiring compliance with regulation 9.8. An example is provided below.

2. If an inner bottom is located higher than the partial subdivision draught dp, this should be considered an unusual arrangement and is to be handled in accordance with regulation 9.7. CLIA Q14D (for Round 6 Questionnaire). Do you prefer the changes proposed above by the US or those agreed at SLF 53? US?

Japan, Norway, Germany, Denmark, China, US, RoK (prefer the proposed changes), UK, France (see comment), RINA (There is not a great deal of difference but prefer the US proposal),

B/20

299 10/01/2012

SLF 53? CLIA, Finland, Poland, Italy

Comments? France: We don’t see a significant difference

CLIA Q14 8 members fully support the US proposal and another 2 support it but do not see much difference with the other alternative. 4 members prefer to keep the text and diagrams agreed at SLF 53.

NOT UNANIMOUS - FINAL DECISION TO BE MADE AT SLF 54 2 Where a double bottom is required to be fitted the inner bottom shall be continued out to the ship's sides in such a manner as to protect the bottom to the turn of the bilge. Such protection will be deemed satisfactory if the inner bottom is not lower at any part than a plane parallel with the keel line and which is located not less than a vertical distance h measured from the keel line, as calculated by the formula:

h = B/20


Regulation 9.2

If an inner bottom is located higher than the partial subdivision draught dp, this should be considered an unusual arrangement and is to be handled in accordance with regulation 9.7.

3 Small wells constructed in the double bottom in connection with drainage arrangements of holds, etc., shall not extend downward more than necessary. In no case shall the vertical distance from the bottom of such a well to a plane coinciding with the keel line be less than 500 mm. A well extending to the outer bottom is, however, permitted at the after end of the shaft tunnel. Other wells (e.g., for lubricating oil under main engines) may be permitted by the Administration if satisfied that the arrangements give protection equivalent to that afforded by a double bottom complying with this regulation. In no case shall the vertical distance from the bottom of such a well to a plane coinciding with the keel line be less than 500 mm.

[Post SLF 53 Note:- The above changes were initiated by the SLF 53 WG and later approved in plenary (Ref:- SLF 53/WP.6 paragraphs 27 and 28 for the rationale)]. [Co-ordinator’s Note:- NEW QUESTION FROM GERMANY FOR 2011 CG] R9.3 (Proof of “equivalent protection” is needed) Post SLF 53 Comments:- Clarification regarding “equivalent protection” as mentioned in Reg. 9.3 was verbally agreed by the SDS-WG in SLF 53, namely to show compliance with the requirements laid down in Reg. 9.8.

300 10/01/2012

Germany proposes adding the following sentence in Reg. 9.3 (new text highlighted). Other wells (e.g. for lubricating oil under main engines) may be permitted by the Administration if satisfied that the arrangements give protection equivalent to that afforded by a double bottom complying with this regulation. Proof of equivalent protection is to be shown by demonstrating that the vessel is capable of withstanding bottom damages as specified in paragraph 8. Q65D. Do the members agree to adding this sentence?

Yes?

France, CLIA, Finland, Norway, Germany, US, UK, China, Denmark, RoK (agree), EC (Seems OK), IACS (can generally support the German proposal. However, “small wells” should be clarified in the same way "other wells" have been clarified)

No?

Japan (see comments below), RINA (see comments), Italy

Comments:- Japan: Japan in general agrees with the concept made by Germany to require the compliance with Reg. 9.8, as the proof of equivalent protection, for well with vertical height between the well bottom and baseline less than 500mm. Small ships normally can not provide with other wells complying with the minimum height of 500mm as required by Reg. 9.3. Subsequently, SDS WG in SLF53 agrees to amend Reg. 9.3 to limit the 500mm clearance restriction to small double bottom well. Actually, even any size of ships do not have other well only for LO Sump tank with vertical height of greater than B/20 (min. 760mm / max.2000mm) as required by Reg. 9.2. In the same manner as the problem caused in small ships, such a well less than 500 mm in height should be demonstrated to withstand bottom damages as specified Reg.9.8. Based on above, Japan would propose further modification to Reg. 9.3 as follows; “Small wells constructed in the double bottom in connection with drainage arrangements of holds, etc., and other wells (e.g. for lubricating oil under main engines) shall not extend downward more than necessary. In no case shall the vertical distance from the bottom of such a well to a plane coinciding with the keel line be less than 500 mm. However, in case that the vertical distance from the bottom of such a well to a plane coinciding with the keel line is less than 500 mm, proof of equivalent protection is to be shown by demonstration that the vessel is capable of withstanding bottom damages as specified in paragraph 8. A well extending to the outer bottom is, however, permitted at the after end of the shaft tunnel. Other wells (e.g. for lubricating oil under main engines) may be permitted by the Administration if satisfied that the arrangements give protection equivalent to that afforded by a double bottom complying with this regulation. In no case shall the vertical distance from the bottom of such a well to a plane coinciding with the keel line be less than 500 mm.” RINA: We prefer that the requirements for equivalent protection / not impair the safety of the ship in 9.3/9.4 are incorporated in the proposed amendment to 9.8 below: 9.8. Compliance with paragraphs 3, 4, 6, or 7 is to be achieved by demonstrating that si, when calculated in accordance with regulation 7-2, is not less than 1 for all service conditions when subject to a bottom damage assumed at any position along the ship’s bottom and with an extent specified in subparagraph .2 for the affected part of the ship:

301 10/01/2012

Q65 Voting was 12-3 in favour of the proposal by Germany.

Japan, RINA and IACS all have significant comments, however. FURTHER DISCUSSION NEEDED AT SLF 54

Regulation 9.3 (ref. SLF 51/3/5 – IACS) [Coordinator’s Note:- This paper, proposing a basis for an interpretation to the requirement for the DB height under the main engine, was not supported (ref. SLF51/WP.1 paragraph 6)]. 4 A double bottom need not be fitted in way of watertight tanks, including dry tanks of moderate size, provided the safety of the ship is not impaired in the event of bottom or side damage.

[New Coordinator’s Note for SLF53:- Concern has been expressed that LO drain tanks or sump tanks may have open tops, often not clearly marked on drawings. How should these be treated?]. [Post SLF 53 Note:- The above was discussed by the WG. Germany showed slides, highlighting the design difficulties for smaller vessels with low double bottom heights. ] 5 In the case of passenger ships to which the provisions of regulation 1.5 apply and which are engaged on regular service within the limits of a short international voyage as defined in regulation III/3.22, the Administration may permit a double bottom to be dispensed with if satisfied that the fitting of a double bottom in that part would not be compatible with the design and proper working of the ship.

[Q6D(3)] [Asks members’ opinion in general on the degree to which regs. 9.6 through 9.8 should be applied to small dry cargo ships – various options are given. Option(a) reduce s=1; 5 in favour; (b) introduce flexibility; 3 in favour (c) do not apply to small cargo vessels; 2 in favour US and Japan comments; Option (d) other alternatives from RINA and Norway. See SLF 54/8/1 para. 14.2. Discuss at SLF 54]

6 Any part of a passenger ship or a cargo ship that is not fitted with a double bottom in accordance with paragraphs 1, 4 or 5 shall be capable of withstanding bottom damages, as specified in paragraph 8, in that part of the ship. [This does not apply to small dry cargo ships.] [Q6D(4)[2]; discuss at SLF 54.]

Regulation 9.6

1. Any part of a passenger ship or a cargo ship where a double bottom is omitted in accordance with regulation 9.1, 9.4 or 9.5 shall be capable of withstanding bottom damages, as specified in regulation 9.8. The intent of this provision is to specify the circumstances under which the Administration should require calculations, which damage extents to assume and what survival criteria to apply when double bottoms are not fitted. [This does not apply to small dry cargo ships.] [Q6D(4)[2] discuss at SLF 54]

302 10/01/2012

2. The definition of “watertight” in regulation 2.17 implies that the strength of inner bottoms and other boundaries assumed to be watertight should be verified if they are to be considered effective in this context. 7 In the case of unusual bottom arrangements in a passenger ship or a cargo ship, it shall be demonstrated that the ship is capable of withstanding bottom damages as specified in paragraph 8. [This does not apply to small dry cargo ships.] [Q6D(4)[4] discuss at SLF 54]

Regulation 9.7

The reference to a “plane” in regulation 9.2 does not imply that the surface of the inner bottom may not be stepped in the vertical direction. Minor steps and recesses need not be considered unusual arrangements for the purpose of this paragraph as long as no part of the inner bottom is located below the reference plane. Discontinuities in way of wing tanks are covered by regulation 9.4.

8 Compliance with paragraphs 6 or 7 is to be achieved by demonstrating that si, when calculated in accordance with regulation 7-2, is not less than 1 for all service conditions when subject to a bottom damage assumed at any position along the ship's bottom and with an extent specified in subparagraph .2 below for the affected part of the ship:

.1 Flooding of such spaces shall not render emergency power and lighting, internal communication, signals or other emergency devices inoperable in other parts of the ship.

.2 Assumed extent of damage shall be as follows: For 0.3 L from the forward

perpendicular of the ship Any other part of the ship

Longitudinal Extent

1/3 L2/3 or 14.5 m, whichever is less

1/3 L2/3 or 14.5 m, whichever is less

Transverse Extent

B/6 or 10 m, whichever is less B/6 or 5 m, whichever is less

Vertical Extent, measured from the keel line

B/20 or 2 m, whichever is less B/20 or 2 m, whichever is less

303 10/01/2012

.3 If any damage of a lesser extent than the maximum damage specified in sub-paragraph .2 would result in a more severe condition, such damage should be considered.

Regulation 9.8 (ref. SLF 51/3/2 Annex – US and Sweden) The assumed extent of damage; the longitudinal and vertical extent is the same all along the ship. This should be verified referring to damage statistics. R9.8 R9.8 EN . Q44. Do you think that the extents of damage in this Regulation need to be re-

checked? Yes

Japan (but see proposal), Norway, Spain (see comment), UK, Sweden, France (added after Round 2)

No

Finland, MI, CLIA, Italy, Denmark

Comments?:- China: The damage extent of Reg.9.8 is similar to the bottom damage extent of IBC, IGC and MARPOL. Finland: Not until verified damage statistics are available. Refer to GOALDS. Germany: No, until other evidence is available (results GOALDS). Japan: Japan concurs with this proposal. The requirement “si is not less than 1” should also be re-considered referring to the statistics. Japan also thinks that the alternative regulation regarding bottom damage could be accepted like as side damage (paragraph 4.1). Please find attached file (Q44 proposal.doc, included below for easy reference):- Japan proposes amendments of SOLAS II-1/9.8 and EN as follows. Proposal amendment of SOLAS II-1 Add following sentences as footnote in SOLAS II-1/9.8. ----- * In the case of ships which comply with the regulations shown in the footnote of paragraph 4.1, the

assumed bottom damage as specified in paragraph 9.8.2 shall be applied to all conceivable locations along the length of the ship between adjacent transverse bulkheads. Where the damage between adjacent transverse watertight bulkheads is envisaged, no main transverse bulkhead or a transverse bulkhead bounding side tanks or double bottom tanks shall be assumed damaged, unless:

.1 the spacing of the adjacent transverse bulkhead is less than the longitudinal extent of

assumed damage specified in regulation 9.8.2; or .2 there is a step or recess in a transverse bulkheads of more than 3.05m meters in length,

located within the extent of penetration of assumed damage. ----- Proposal amendment of Explanatory Note Add the following sentences (underline) to the explanation in paragraph 9.8.2 of EN.

304 10/01/2012

---- 2. The damage extents specified in this paragraph should be applied to all parts of the ship where no double bottom is fitted, as permitted by regulations 9.1, 9.4 or 9.5, and include any adjacent spaces located within the extent of damage. Small wells in accordance with regulation 9.3 do not need to be considered damaged even if within the extent of the damage. Possible positions of the damages are shown in an example below (parts of the ship not fitted with a double bottom are shaded; the damages to be assumed are indicated by boxes).

In the case of ships which comply with the regulations shown in the footnote of paragraph 4.1, the term “at any position” used in this paragraph means anywhere in the ship’s length between adjacent transverse bulkheads, unless:

.1 the spacing of the adjacent transverse bulkhead is less than the longitudinal extent of assumed damage specified in regulation 9.8.2; or

.2 there is a step or recess in a transverse bulkheads of more than 3.05m meters in length, located within the extent of penetration of assumed damage. Possible positions of the damages are shown in an example below (parts of the ship not fitted with a double bottom are shaded; the damages to be assumed are indicated by boxes).

Background SOLAS II-1/4.1 accepts the regulations listed in the footnote, ex. MARPOL 73/78 etc., as alternative regulations in part B-1 (side damage stability). Regarding the tank shown below, side damage indicated by blue boxes would cause the same flooding caused by bottom damage indicated by red boxes. Accordingly, in the case of ships which comply with the regulations shown in the footnote of paragraph 4.1, the same assumptions in accordance with MARPOL / LL could also be accepted in the case of bottom damage (paragraph 9.8).

305 10/01/2012

End of Japan’s Proposals Norway: A further investigation could be useful to clarify the extent of damage. Please note that the distribution shown on page 3 of Annex 1 to SLF 47/INF.4 indicates that a change could be justified. The number of data points in these statistics is perhaps too low to draw firm conclusions. Spain: It could be verified referring to damage statistics. Anyway, if the damage statistics confirm the suggested differences, we think that it is better to define only two zones (forward part and rest of the ship), for simplicity reasons. UK: We support re-checking, and consider that in particular the vertical extent needs to be revised. US: Only if additional information is available; we believe the GOALDS project is looking at this issue. Round 1 Discussion: Opinion on the issue of carrying out further investigations into the statistics underlying the extent of bottom damage regulations is evenly divided (5/5) – many thanks for the comments and proposals received, in particular the detailed ideas for an additional footnote and extended EN from Japan. Several members think that we need further investigation if additional information becomes available (perhaps via the GOALDS project) whereas Norway thinks that change may be justified on the basis of the distribution in Annex 1 of SLF 47/INF.4 if more data points are now available. Proposed Action: As it seems that there is sufficient concern for this matter to be taken further but some consider that we need more data to do this properly, it is proposed that we flag up the issue to the SLF sub-committee recommending further discussion either at SLF 54 or when more statistical data becomes available (perhaps via GOALDS). In the meantime we invite your thoughts and comments on Japan’s proposals which could perhaps be used as an interim measure. Q44A Do you agree with the proposed action, above?

Yes

MI, Germany, Finland, Japan, France (with comments), Norway, CLIA, UK, US, Sweden, Denmark

No Comments (particularly on Japan’s proposal) / Alternatives?:- Italy: Further input may come from GOALDS. However we do not support any interim measure. France: GOALDS project effectively deals with this question. Japanese proposal would lead to consider the flooding of only one compartment which is not equivalent to present reg 9. According to Q6A, ship of less than 80m may be excluded.

306 10/01/2012

Round 2 Discussion: Support was unanimous for the proposed delay, which has been included in the CG report (ref. SLF 53/14 paragraph 13.5) so we will await the decision of the S-C. We could, however, discuss Japan’s proposed amendments to the EN further with the other members in the WG (France and Italy do not fully support it). Q44B (for SLF 53 WG) Whilst we await the decision of the S-C regarding the proposed delay to discussion of this item until more bottom damage data is available do you in the meantime support Japan’s proposed amendments to the EN? Yes

No

Post SLF 53 Notes:- There was considerable debate in the WG on Reg. 9.8, especially now that it has been agreed that regulation II-1/9 applies to cargo ships of less than 80 m in length. In the end the matter was returned to us in the 2011 CG (ref. SLF 53/WP.6 paragraph 26) with the following ToR:- SLF 53/WP.6 paragraph 32.5 - “consider the validity of applying sub-paragraph 9.8 to smaller ships and, if necessary, suggest appropriate amendments”. Discussion also turned to the phrase “for all service conditions”. Germany and Denmark were concerned that this could involve undertaking the calculation for scores of conditions; both members stated that they would submit papers either to the CG or to SLF 54. Discussion Notes for 2011 SDS CG: 1) With regard to the original request for confirmation of the extents of damage we will continue to await the conclusions of the GOALDS project but we may need to find out from the project leaders when we can expect this work package to be completed so that we can conclude our deliberations in time for SLF 54, in Jan 2012. Norway mentioned that we may be able to do some work on this ourselves using the distribution in Annex 1 of SLF 47/INF.4 if more data points are now available. Could Norway take this any further for us? 2) We need to ask your opinion on the phrase [for all service conditions]. Denmark, we believe, has an alternative proposal (and Germany?). 3) Can we apply Reg. 9.8 to cargo vessels of less than L = 80 m? 4) Recalling the amendments now agreed to Reg. 4.1 which now only relate to Part B-1 (see Q6B):- 1 [In Part B-1, .1 regulation 5 shall apply to passenger ships of all sizes and every cargo ship having a length (L) of 24 m and upwards (including tankers covered by MARPOL Annex 1, the IBC and IGC Code). .2 regulation 5-1 shall apply to passenger ships of all sizes and every cargo ship having a length (L) of 24 m and upwards including those vessels which are shown to comply with stability regulations in other instruments* developed by the Organization but shall not apply to tankers covered by MARPOL Annex 1, the IBC and IGC Code. .3 the remaining regulations in Part B-1 shall apply to passenger ships of all sizes and, with the exception of regulations 8 and 8-1, to cargo ships having a length (L) of 80 m and upwards but they shall not apply to any vessels which are shown to comply with subdivision and damage stability regulations in other instruments* developed by the Organization.]

307 10/01/2012

__________________ Do you think that a footnote of some sort is now needed for Part B-2 to clarify the application, once we decide on the appropriate length for dry cargo vessels? The footnote proposed below was rejected at SLF 53 but it is still felt that something similar may be necessary. [* The regulations in Part B-2 apply to passenger ships regardless of length and to cargo ships of [24][80] m in length (L) and upwards but shall not apply to those cargo ships which are shown to comply with subdivision and damage stability regulations in other instruments developed by the Organization (Ref. footnote to Regulation 4.1).]

Q44C (for Round 4 Questionnaire):-

a) Can we do anything ourselves about the extents of damage before GOALDS reports its findings?

b) Should we change “for all service conditions”?

c) Should we apply Reg. 9.8 to cargo vessels of less than 80 m in length L? d) Do we need a new footnote to Part B-2 clarifying the application, similar to that

in Part B-1? Bear in mind the Germany/UK paper to MSC (Ref. MSC 89/22/8).

e) Are there any further comments on Japan’s proposals for changing the EN? France stated under Q44A that “the Japanese proposal would lead to consider the flooding of only one compartment which is not equivalent to present reg. 9.”

Please comment on each question below.

a)

US (No comment), Vanuatu (No opinion) Norway (The database material in SLF 47/INF.4 is probably to small to complete a probabilistic revision for the double bottom damage. Norway invites the members of the correspondence group to submit any data that they may have that can contribute to the SLF 47/INF.4 sample). Japan (Yes. We could consider the scope to be applied reg 9.8). Sweden, UK, Spain and RINA (Prefer to await the results of the GOALDS report). Denmark (For small cargo ships we can investigate if existing designs being built within the last 5 years have a double bottom fitted according to Reg. 9 requirements and, if not, whether they fulfil Reg. 9.8. Further, have a look on the existing damage statistics). Germany, Finland, France, Italy: (No).

308 10/01/2012

b)

Vanuatu (phrase seems clear enough) US (Yes; the reg 9.8 text “all service conditions” should be revised to reflect the existing EN1 text “the three loading conditions used to calculate the attained subdivision index A”. Then reg 9.8 EN 1 can be deleted). Norway (Propose to change from “all service conditions” to “the three loading conditions used to calculate the attained subdivision index A” and delete the EN). Japan, France (No) China (There is no need to change it). RINA (Note that the term is already explained in EN 1:- “The term “all service conditions” used in this paragraph means the three loading conditions used to calculate the attained subdivision index A.”) Denmark (It must be outlined that the conditions should cover the operational trim range). Germany (We suggest using “initial loading conditions di“ as used in Reg. 7-2.1.1 throughout SOLAS and to specify what is meant by this for vessels not subject to B-1). Finland (Prefer to use instead of “for all service conditions”, “the loading conditions on which is based the calculation of a subdivision” index.”) Italy (Keep the term as already explained in EN1). UK (Would prefer to solve this probabilistically, where possible i.e. avoid use of any other prescriptive loading conditions).

c)

Vanuatu (No. As previously stated, we believe application of 9.8 to beamy vessels would not benefit the process). US (No; this would not seem consistent as there is no collision/side damage requirement for these cargo ships). Norway, UK (Yes). Japan (thinks that it seems difficult for cargo ships with L <80m to calculate si because these ships need not to be applied Part B-1. The scope of reg 9.6 to reg.9.8 should be considered carefully). China (Agreed). RINA (See comments in Q6C. There will be some parts of 9.8 that will be applicable to ships less than 80 m in length). Denmark (Before acceptance we should thoroughly investigate the effect on all kinds for small cargo ships between 24 m and 80 m in length, e.g. tugs, workboats and other cargo vessels. For information dredgers do not fulfil Reg. 9 due to their design). Germany (Generally yes, however the requirements for Reg. 9 should be adjusted to those small ships after further investigations. We suggest using “initial loading conditions di“ as used in Reg. 7-2.1.1 throughout SOLAS and to specify what is meant by this for vessels not subject to B-1). Finland (Refer to Q6C, cargo vessels more than 24 m. Impact of reg. 9.8 to be further studied for ships with L<80 m.). Italy, Spain (No). France (see comment).

309 10/01/2012

d)

Vanuatu (We would prefer the approach suggested to revise regulation 4 to include the footnote within the text of regulation to avoid future repetition). US (No; we do not support a footnote for this purpose. In light of MSC 89/22/8 and the new approved SLF output, we believe the MSC 89/22/8 proposed text should be combined with the SLF 53 WG agreed text. The end result should be a regulation 4 that is sufficiently clear that there is no need for any footnotes or EN's). Norway (No, any amendment/clarification should be made in regulation 4.1). China (Agreed). RINA (Prefer to see the table EN 4.1 extended to indicate the application of regulations to the applicable ship types and any size criteria). Denmark, Italy, UK (Yes). France (see comment). Spain (Yes, a footnote is useful).

e) US (In the context of our concern noted below for OSVs, Japan’s proposal has some merit. (In Japan’s proposed new EN DB example sketch included on page 235 of the master working document, we note that the damage boxes have been accidentally shifted from what Japan actually submitted/proposed)). Norway (Do not support the proposal). Japan (As suggested by the coordinator at previous discussion, our proposal should be treated just as an interim measure. The proposed footnote is deterministic approach and we support developing of probabilistic bottom damage requirements, as stated in paragraph SLF 53/14/2). China: (No comments). RINA: (No comment). Denmark: (The damage extent must be verified against damage statistics). Germany: (No support for Japan’s proposal). Finland: (Support Japan’s proposal). UK: (This may require further investigation before implementing any change).

Further suggestions / alternatives? Vanuatu: See response to d). US: In addition to our response in paragraph c above, even for some cargo ships greater than 80m (such as OSVs) we have concerns that regulation 9.8 may not be appropriate due to damage extents and/or hull characteristics. Denmark: There is an error in the figure in the EN Reg. 9.8.2 showing double bottom damage extent. A damage combination in the forward part is missing – see below:

France: a) Damage extent is defined in regulation 9.8. Amendment to this extent should be documented.

310 10/01/2012

b) If the intention is to extend the application of this regulation to cargo ships of less than 80m, it is preferable to refer to all service conditions. Anyway this regulation may apply to ships fulfilling other IMO instruments. In explanatory notes it could be specified that for ships fulfilling stability requirements of part B-1, compliance is to be verified for all loading conditions used for calculation of the attained index. c) Reg.9.8 to be applied to ships of L < 80 m, but the damage definition and the required s factor need to be further investigated / proposed for small ships. d) Is the foot note the best way for clarification? e) No additional comment. Round 6 Discussion: We will take your responses to each question in turn:- (a) Can we do anything ourselves about the extents of damage before GOALDS reports its findings? Of the 13 members who responded, 8 expressed a preference to wait for GOALDS to complete its work and 2 were neutral. Norway invited CG members to provide any data they may have to supplement existing data in SLF 47/INF.4. Denmark will look at cargo ships built within the last 5 years to see if they are fitted with a DB and if not whether they comply with reg. 9.8. Japan says that before GOALDS reports to us the CG could consider the scope of the problem. For your information, the leaders of the GOALDS project have very kindly agreed that we can reproduce the conclusions of a recent paper from some of the research team presented at the 12th International Ship Stability Workshop in Washington in June 2011 entitled "GOALDS - Goal-Based Damaged Stability: Collision and Grounding Damages" (by Papanikolaou, Bulian and Mains):- “CONCLUSIONS On the basis of the findings from the analyses carried out so far it is possible to provide some recommendations on the way ahead. There are, indeed, basically, two ways for implementing the results (within further refinements) obtained up to now for the groundings, i.e. by following a probabilistic approach or by following a deterministic approach. In case the “probabilistic way” would be followed, this could mean a fully probabilistic model for grounding damages characteristics, conceptually similar to that presently in SOLAS 2009 for collision (side) damages. Such an approach could be derived in the framework of research applications on the basis of available data. The quality of the database seems to be, however, not sufficiently high for deriving a robust detailed probabilistic approach for bottom damage for regulatory purposes at this stage. In case the “deterministic way” would be followed, this could mean modifying the regulation 9 assumptions. This “global” approach could be more robust than the fully probabilistic approach and less affected by the problems identified in the undertaken analyses. Probabilities of exceedance of SOLAS bottom damage characteristics have been found to be, overall, quite in line with those estimated at the time of development of Reg. 9. Hence, the present analyses would not call for immediate and significant revisions of Reg. 9 unless different acceptable probabilities of exceedance are set. There are, however, some indications that the present Reg. 9 requirements could be more conservative for large ships and less conservative for small ships, and this aspect deserves additional attention. [Co-ordinator’s emphasis] [Gabriele Bulian in later correspondence expanded a little on this. “Of course this sentence is a global summary, but behind it there is some more, and this "more" is contained in the full GOALDS reports. Indeed, first, the

311 10/01/2012

mentioned "indications" are based on a quite limited number of data therefore caution shall be exercised in drawing definite conclusions. Then, different behaviours can be seen depending on what we are considering, i.e. double bottom requirements or just Reg.9.8. In case of Reg 9.8, in addition, the outcome depends on which damage characteristic is considered (e.g. length, width, penetration). For example, width and penetration follows what is contained in the quoted statement, but the damage length has an opposite behaviour in case of small ships. Considering only the height of the double bottom, then results follow the content of the statement since. Hence, the statement reflects the overall behaviour, but it may miss useful/important details, for which reference should be made to the global analysis and global set of conclusions”.]. In general, it seems that for research purposes, the probabilistic approach could be suitable and should be pursued in the framework of the GOALDS project, and possibly, in the long term for regulatory implementation. The possibility of using direct Monte Carlo simulations in a probabilistic framework should also be considered as a step forward with respect to present formulations based on p-factors.” There is a statement earlier in the paper which seems significant for us when looking at smaller ships:- “Data for ships below about 80 m in length show, however, some different behaviour, with a tendency towards shorter damages. On a conservative basis, it is suggested to develop the model for the distribution of the dimensionless damage length by neglecting data for ships below 80 m in length (which are anyway not addressed by the SOLAS Ch. II-1 damage stability provisions).” A summary of the GOALDS findings up to June 2011 would seem to be that :-

• There may not be enough bottom damage statistical data to develop probabilistic regulatory regulations at present

• In terms of a deterministic solution the present method in reg. 9.8 adequately reflects the extended bottom damage database as long as we wish to maintain the currently assumed acceptable “probability of exceedance”.

• There are different characteristics in the damage statistics for smaller ships under 80 m in length (generally shorter damage lengths) and GOALDS should therefore concentrate on ships > 80m.

[Gabriele Bulian commented on this: “In the analysis of grounding damages, there was no detailed analysis only for ships in the referred range, also because most of the interest was on larger ships (say above 80m). Nevertheless, also data for ships below L=80m were part of the global analysis of Reg.9 and therefore some information can be drawn, which is, again, along the lines outlined in the point highlighted above.] It is understood that the work is still in progress – perhaps some of our CG members who are in the GOALDS research teams could advise us of the latest progress before we take any final decisions on whether reg. 9.8 should be applied to ships with L < 80 m.? (b) Should we change “for all service conditions”? From 12 responses received there are 3 (US, Norway and Finland) who think we should change the term “for all service conditions” to “the three loading conditions used to calculate the attained subdivision index A” (taken from EN 1) and delete EN 1. Italy and RINA point out that “for all service conditions” is already explained in EN 1. The UK prefers not to introduce further prescriptive loading conditions (so presumably would opt for the change proposed by the US et al?). China, Vanuatu and Japan would prefer to keep “for all service conditions.” France points out that if reg. 9.8 is to be applied to cargo ships of less than 80 m in length which are not subject to the full probabilistic damage analysis of Part B-1 then it would be more logical to use “all service conditions” and not the three “probabilistic” loading conditions. France proposes that the EN could be used to specify this difference (Co-ordinator’s Note: perhaps as shown highlighted in green below, for example?).

312 10/01/2012

Regulation 9.8

1. [For dry cargo ships of L = 80 m and upwards] the term “all service conditions” used in this paragraph means the three loading conditions used to calculate the attained subdivision index A. For smaller dry cargo vessels the regulation should be applied to all service conditions.]

Denmark says that the operational trim range should be covered. (Co-ordinator’s Note: Presumably we could change the original EN as highlighted below – the method used to denote trim elsewhere in the regulations? This could also apply to France’s proposal.) 1. The term “all service conditions” used in this paragraph means the three loading conditions used to calculate [an] [the] attained subdivision index A.

Germany’s point is noted and is dealt with under Q39D-41D (Q2), above for which we await the outcome. France also states that reg. 9.8 may apply to ships fulfilling other IMO instruments. SUMMARY Although overall opinion appears to be slightly in favour of changing “for all service conditions” to “the three loading conditions used to calculate the attained subdivision index A” and deleting EN1, the proposal from France does seem to be logical but only if reg. 9.8 applies to dry cargo ships of all sizes, which is discussed under Q6D. (c) Should we apply Reg. 9.8 to cargo vessels of less than 80 m length L? This is the key question which addresses the new ToR (ref. SLF 53/WP.6, para 32.5). As many have noted there is a great deal of overlap between this question and Q6D which covers the overall applicability of Part B-2 as specified in reg. 4.1. The issues are quite complex, as the discussion for Q6 shows. It is therefore proposed that, to avoid duplication, we now refer back to Q6 to assess question (c) in the wider context of the general applicability of Part B-2. This also applies to the next question (d), concerning how and where we should specify the applicability of B-2. We will take into account your responses to questions (c) and (d) under Q6. The voting on (c) was as follows:- Yes: we should apply reg. 9.8 to cargo vessels with L< 80. Norway, UK, China 3 No: Vanuatu, US, Italy, Spain 4 More Consideration: Japan, RINA, Denmark, Germany, Finland, France 6 (d) Do we need a new footnote to Part B-2 clarifying the application, similar to that in Part B-1? Bear in mind the Germany/UK paper to MSC (Ref. MSC 89/22/8). As mentioned under (c) we will now deal with this question under Q6D. The voting on (d) was as follows:- Yes: in favour of a new footnote. China, Denmark, Italy, UK, Spain 5 No: Vanuatu, US, Norway 3 Other: RINA (extend table EN 4.1), France (not convinced) 2

313 10/01/2012

(e) Are there any further comments on Japan’s proposals for changing the EN? France stated under Q44A that “the Japanese proposal would lead to consider the flooding of only one compartment which is not equivalent to present reg. 9.” First of all many thanks to the US and Denmark for spotting transmission errors in two of the DB damage extent diagrams – the US noted that the second diagram in Japan’s proposal was incorrect in the large working document. It has now been corrected:-

The diagram in EN 9.8.2 has also been corrected in the large working document and will be transmitted to the Secretariat. However, we are not sure how the difference between the red and green boxes will look when printed in black and white in the final revised EN. Maybe the green boxes should be drawn with dotted lines? What is the difference between the red and green boxes anyway – the text does not explain? The green boxes do not appear to show up in the current EN (MSC.281(85)). Can anybody help us out here? We need to refer to Japan’s interim proposal (made in Round 1 of the SOLAS updates CG) as it clearly has some support. For easier reference we attach to the end of this document. The basic change proposed by Japan is to re-interpret the words “at any position” in reg. 9.8 to mean “between transverse bulkheads” (unless they are spaced too closely or have steps and recesses over 3.05 m in length) for ships compliant with the regulations listed in the footnotes to Reg. 4.1. As the footnotes stand at the moment, ILLC Reg. 27 compliant dry cargo ships do not need to meet the probabilistic damage regulations in part B-1 but at present must comply with parts B-2 to B-4, including the DB regulations. We have noted that standard designs for very large ore carrier are now being considerably influenced by the new SOLAS 2009 regulations. The sketch below illustrates the problem such ships have in complying with the requirement that s=1 in regions not fitted with a double bottom when subject to prescribed bottom damage at any position:-

314 10/01/2012

It is believed that Japan’s interim proposal would mean (as France points out) that only a “one compartment” bottom damage standard would apply and it therefore becomes easier for the s=1 criterion to be complied with. So it would be an extremely important amendment for this class of dry cargo ship – one needing careful consideration. The voting on (e) was as follows:- Yes: the interim proposal has some merit: US (e.g. for OSV’s), Finland, Japan 3 No: Norway, Germany, France 3 No Comment: China, RINA 2 Other: Denmark (damage extent to be verified against statistics) 1 SUMMARY Voting is fairly even but we feel that France’s point is very important since there is a danger that the safety standard originally intended in reg. 9 would be considerably reduced for all dry cargo vessels by implementing Japan’s interim proposal. However, in the light of the difficulties being experienced by designers of very large ore carriers, for example, perhaps the CG would like to review the regulation as applied to this class of ship along the lines proposed by Japan until such time as a probabilistic solution emerges? Q44 – Overall Summary

(a) If it is confirmed that GOALDS is concentrating on ships with L>80 m then we may need to re-examine reg. 9.8 for smaller vessels ourselves using the extended bottom damage statistics (if we can obtain this data).

(b) France’s proposal to modify the EN for reg. 9.8 depends of the outcome of Q6D. (c) and (d) will also depend on the outcome of Q6D. (d) We need help with the green boxes in the diagram for EN 9.8.2. Do we need to re-

consider reg. 9 as applied to B-60 Reg. 27 large dry cargo ships? Q44D (for Round 6 Questionnaire). Whilst we await the outcome of Q6D before completing questions b, c and d, we must consider the following:-

1) More bottom damage statistics are needed for smaller cargo ships. Can anybody in the CG who is part of the GOALDS project supply this extra data?

315 10/01/2012

2) The diagram for EN 9.8.2 needs attention. Can the originator please explain the green boxes and suggest how the diagram can best be clarified so that it is comprehensible in black and white when finally printed?

3) Do we need to re-visit reg. 9 for dry cargo vessels compliant with ILLC reg. 27

and OSV’s in the light of Japan’s interim proposal? 1) Y/N?

Yes: France No: RINA (No access to data), Germany, Denmark (Unfortunately Denmark does not have the resources for doing so for the time being).

2) Comments?

Germany: (Green boxes by France correctly supplement the sketch prepared by GL end of 2007 by two more possible damage positions. GL updated the original sketch and attach it to our reply. There is no need to show differently coloured red and green boxes, the green was supposedly chosen to highlight against the red. Thanks to France). Denmark: (The green colour for the boxes was only used to outline the missing damages. All boxes should be red on the final diagram (perhaps shading can be used for black and white printing).

3) Y/N?

Yes: Japan (see comments below), US No: RINA, Norway, Germany, Denmark, China

Any further comments? Japan: Japan concurs with coordinator’s suggestion. As coordinator pointed out, we do not intend to apply our interim proposal to ships which are applied to Part B-1 but just certain ships which are applied to MARPOL/ICLL and are caused same flooding by side damage and by bottom damage. CLIA: N/A – cargo ship issue RINA: Chapter I Part A, Reg. 3 (a) (ii) states that the present regulations, unless expressly provided otherwise, do not apply to cargo ships of less than 500 gross tonnages. Why do we need to re-visit regulation 9 to assess compliance with ICLL? Germany: Considering that Reg. 9.8 was introduced mainly to avoid Rocknes-incidents in the future and Rocknes was a Bulk-Carrier, we think the requirements should under no circumstances be reduced particularly for these vessels (even more so as acc. Japan VLOC-design is considerably influenced by this). UK: More background data on this is needed. AT SLF 54:

1) We need to discuss whether the “extent of damage” table in R9.8.2 should be revised in the light of the GOALDS research or Japan’s proposal. If GOALDS data is not available for smaller ships we may need to consider revising it ourselves. Japan, in papers SLF 54/8/4 and INF papers /.15 and /.16, is proposing how this can be done probabilistically and this needs our serious consideration.

2) The issue of the green boxes in the EN diagram has been explained. NFA. 3) Japan’s proposal for modifying R9.8 EN 2 is supported by the US but opposed

by 5 members.

Further discussion is therefore needed.

316 10/01/2012

Regulation 9.8

1. The term “all service conditions” used in this paragraph means the three loading conditions used to calculate the attained subdivision index A.

2. The damage extents specified in this paragraph should be applied to all parts of the ship where no double bottom is fitted, as permitted by regulations 9.1, 9.4 or 9.5, and include any adjacent spaces located within the extent of damage. Small wells in accordance with regulation 9.3 do not need to be considered damaged even if within the extent of the damage. Possible positions of the damages are shown in an example below (parts of the ship not fitted with a double bottom are shaded; the damages to be assumed are indicated by boxes).

9 In case of large lower holds in passenger ships, the Administration may require an increased double bottom height of not more than B/10 or 3 m, whichever is less, measured from the keel line. Alternatively, bottom damages may be calculated for these areas, in accordance with paragraph 8, but assuming an increased vertical extent.

Regulation 9.9

1. For the purpose of identifying “large lower holds”, horizontal surfaces having a continuous deck area greater than approximately 30% in comparison with the waterplane area at subdivision draught should be taken located anywhere in the affected area of the ship. For the alternative bottom damage calculation, a vertical extent of B/10 or 3 m, whichever is less, should be assumed.

2. The increased minimum double bottom height of not more than B/10 or 3 m, whichever is less, for passenger ships with large lower holds, is applicable to holds in direct contact with the double bottom. Typical arrangements of ro-ro passenger ships may include a large lower hold with additional tanks between the double bottom and the lower hold, as shown in the figure below. In such cases, the vertical position of the double bottom required to be B/10 or 3 m, whichever is less, should be applied to the lower hold deck, maintaining the required double bottom height of B/20 or 2 m, whichever is less (but not less than 760 mm).

317 10/01/2012

Typical arrangement of a modern ro-ro passenger ferry

Regulation 10 Construction of watertight bulkheads [Q6D(4)[5]][ Discuss at SLF 54]

1 Each watertight subdivision bulkhead, whether transverse or longitudinal, shall be constructed having scantlings as specified in regulation 2.17. In all cases, watertight subdivision bulkheads shall be capable of supporting at least the pressure due to a head of water up to the bulkhead deck. [in passenger ships and freeboard deck in cargo ships]. [Q6D(4)[6]] [ Discuss at SLF 54]

Regulation 10.1

For the treatment of steps in the bulkhead deck of passenger ships see Explanatory Notes for regulation 13. For the treatment of steps in the freeboard deck of cargo ships see Explanatory Notes for regulation 13-1.

2 Steps and recesses in watertight bulkheads shall be as strong as the bulkhead at the place where each occurs.

Regulation 11 Initial testing of watertight bulkheads, etc. [Q6D(4)[7]] [ Discuss at SLF 54]

1 Testing watertight spaces not intended to hold liquids and cargo holds intended to hold ballast by filling them with water is not compulsory. When testing by filling with

318 10/01/2012

water is not carried out, a hose test shall be carried out where practicable. This test shall be carried out in the most advanced stage of the fitting out of the ship. Where a hose test is not practicable because of possible damage to machinery, electrical equipment insulation or outfitting items, it may be replaced by a careful visual examination of welded connections, supported where deemed necessary by means such as a dye penetrant test or an ultrasonic leak test or an equivalent test. In any case a thorough inspection of the watertight bulkheads shall be carried out.

2 The forepeak, double bottom (including duct keels) and inner skins shall be tested with water to a head corresponding to the requirements of regulation 10.1.

3 Tanks which are intended to hold liquids, and which form part of the watertight subdivision of the ship, shall be tested for tightness and structural strength with water to a head corresponding to its design pressure. The water head is in no case to be less than the top of the air pipes or to a level of 2.4 m above the top of the tank, whichever is the greater.

4 The tests referred to in paragraphs 2 and 3 are for the purpose of ensuring that the subdivision structural arrangements are watertight and are not to be regarded as a test of the fitness of any compartment for the storage of oil fuel or for other special purposes for which a test of a superior character may be required depending on the height to which the liquid has access in the tank or its connections.

Regulation 12 Peak and machinery space bulkheads, shaft tunnels, etc. [Q6D(4)[8]] [ Discuss at SLF 54] 1 A collision bulkhead shall be fitted which shall be watertight up to the bulkhead deck [in passenger ships and freeboard deck in cargo ships] [Q6D(4)[9]] [ Discuss at SLF 54]. This bulkhead shall be located at a distance from the forward perpendicular of not less than 0.05L or 10 m, whichever is the less, and, except as may be permitted by the Administration, not more than 0.08L or 0.05L + 3 m, whichever is the greater.

Regulation 12 (ref. SLF 51/3/2 Annex – US and Sweden) New paragraph? Japan would again like to draw attention to the issue that the revised SOLAS chapter II-1 does not contain a requirement for full survivability (s = 1) in case of damages forward of the collision bulkhead; this should be identified for future improvement of the SOLAS text (see SLF 49/17, paragraph 3.5.3). Also see SLF 49/3, paragraph 10 below:

“10 In addition, Japan provided further information to the group regarding the issue that the new revised SOLAS chapter II-1 does not contain a requirement for full survivability (s = 1) in case of damages in front of the collision bulkhead (see SLF 48/21, paragraph 3.35). This information was circulated to the group and comments were requested. From the group‘s comments, there were three

319 10/01/2012

general conclusions: (1) there was general agreement that s = 1 for damages forward of the collision bulkhead should be a basic SOLAS chapter II-1 requirement for all ships; (2) this chapter II-1 regulatory omission is generally not viewed as a serious weakness/problem; and (3) this problem cannot be addressed in the Explanatory Notes; it will require a SOLAS amendment (consistent with the SLF 48 view).”

Note: This is already covered by damage of 0.08L from the forward perpendicular for passenger ships carrying more than 400 persons. [Coordinator’s note (see Regulation 8.1)].

Regulation 12 (ref. SLF 52/17/6 - Norway) As pointed out above [Coordinator’s note: see Regulation 8.1 and 8.2] the revised chapter does not contain a requirement for full survivability (s = 1) in case of damages forward of the collision bulkhead. This Administration proposes to amend the regulation by adding a new paragraph 2: “2 The ship shall be so designed that si calculated in accordance with regulation 7-2 will not be less than 1 for all service conditions if [the whole portion] [any part] of the ship forward of the collision bulkhead is flooded without vertical limits.” [Coordinator’s notes: (1) For the discussion and questions relating to this issue, please refer to Q39 – Q41 under Regulation 8.1, above. (2) If this new paragraph 12.2 is accepted the remaining paragraphs of this regulation (shown in blue) will have to be re-numbered]. [Post SLF 53 Note:- Please see Q39 – 41C for new discussion and question re 12.2, the proposed wording of which is shown below, with square brackets still to be resolved in round 6 or at SLF 54:- 2 The ship shall be so designed that si calculated in accordance with regulation 7-2 will not be less than 1 [for all service conditions] [for the loading conditions on which is based the calculation of a subdivision index] if [the whole portion] [any part] of the ship forward of the collision bulkhead is [flooded] [damaged] without vertical limits. ] [Post Round 6 Note:- In the responses to Q39-41D the CG expressed some preference for the following strike-outs:- [2 The ship shall be so designed that si calculated in accordance with regulation 7-2 will not be less than 1 [for all service conditions] [for the loading conditions on which is based the calculation of a subdivision index] if [the whole portion] [any part] of the ship forward of the collision bulkhead is [flooded] [damaged] without vertical limits.] [See also reg. 8.1. If new 8.2 is accepted subsequent paragraph numbers will change. Final decision on square brackets and strike-outs to be made at SLF 54]. ]

320 10/01/2012

2 Where any part of the ship below the waterline extends forward of the forward perpendicular, e.g., a bulbous bow, the distances stipulated in paragraph 1 shall be measured from a point either:

.1 at the mid-length of such extension;

.2 at a distance 0.015L forward of the forward perpendicular; or

.3 at a distance 3 m forward of the forward perpendicular,

whichever gives the smallest measurement.

3 The bulkhead may have steps or recesses provided they are within the limits prescribed in paragraph 1 or 2.

4 No doors, manholes, access openings, ventilation ducts or any other openings shall be fitted in the collision bulkhead below the bulkhead deck [in passenger ships and freeboard deck in cargo ships] [Q6D(4)[10]] [ Discuss at SLF 54].

5.1 Except as provided in paragraph 5.2, the collision bulkhead may be pierced below the bulkhead deck [in passenger ships and freeboard deck in cargo ships] [Q6D(4)[11]] [Discuss at SLF 54] by not more than one pipe for dealing with fluid in the forepeak tank, provided that the pipe is fitted with a [screw-down] [Q45D] [Most support is for a new EN with diagrams from SLF 51/3/4; 9-1 in favour; discuss at SLF 54] valve capable of being operated from above the bulkhead deck [in passenger ships and freeboard deck in cargo ships] [Q6D(4)[12]] [ Discuss at SLF 54], [the valve chest being secured inside the forepeak to the collision bulkhead][ [Q45D(6)][1 in favour of retaining “valve chest”, 3 against; Discuss at SLF 54]. The Administration may, however, authorize the fitting of this valve [on the after side of the collision bulkhead] [Q45D(8)] [Opinion evenly divided on France’s proposal;discuss at SLF 54] provided that the valve is readily accessible under all service conditions and the space in which it is located is not a cargo space. All valves shall be of steel, bronze or other approved ductile material. Valves of ordinary cast iron or similar material are not acceptable. Regulation 12.5.1 (ref. SLF 51/3/4 – IACS) IACS presented a paper (ref. SLF 51/3/4) in which they argue (paragraph 6) that: “ … unless some justification for the use of screw-down valves can be provided, butterfly valves provide a means as effective as screw-down valves to ensure the integrity of pipes piercing the ship’s collision bulkhead below the bulkhead deck.” It was agreed at SLF 51 that this issue should added to the list of regulations needing future amendment (along with those in SLF 51/3/2 and SLF 51/3/3). Ref. SLF 51/17 Report to MSC, Annex 3. R12.5.1 (remove “screw-down”?) . Q45. Do you agree with IACS’ argument that butterfly valves are just as effective

as screw-down valves for pipes piercing the collision bulkhead and that the word “screw-down” in square brackets above can therefore be removed?

321 10/01/2012

Yes

China, Finland, Japan, MI, Norway, Italy, Spain, Denmark, US, Sweden, France (added in Round 2 response)

No

CLIA, UK

Comments?:- China: Butterfly valves have been effectively used for many years; the regulation should not prohibit such a successful and effective arrangement. CLIA: Unless there is a positive means of locking and monitoring the valve. Denmark: We agree that butterfly valves can replace screw down valves; however we are concerned that fig 3 in the paper shows a more vulnerable arrangement of valves as the other 2 because the valve is not connected to the stronger distance piece, and you effectively do not have a ship’s side valve. France: Other types of valves may also be used. Round 1 Discussion: There are 10 votes in favour and 2 opposed to this proposal, but Denmark (for) and CLIA (against) each have safety concerns. Before accepting the majority view therefore it is proposed that we ask for comments from IACS to see if they consider that the wording needs to be changed in the light of these concerns. Also could the UK perhaps explain their objections to the IACS proposal in case there are any other specific safety concerns? Q45A. Do you agree that we should ask IACS for comments on the safety concerns raised by CLIA and Denmark or should we simply adopt their proposal on a majority verdict? Ask IACS?

MI (with comment), Germany, RINA (with comment), Norway (with comment), CLIA, UK (with comment), US, Sweden, Denmark

Accept majority?

Finland, Italy, Japan, France

Further Comments?:- MI: No objection to this action [asking IACS] but equally happy to proceed on the majority verdict. RINA: It should be confirmed that all safety critical valves, such as this, are remotely operated and in the event of failure of the operating system will fail safe closed or/open, as appropriate, dependant on the system requirements. Norway: Ask IACS for rephrasing. The conditional acceptance reflected by CLIA and Denmark seem relevant. UK: We would like to see some means tested life-cycle performance comparison. Round 2 Discussion: IACS have been requested to review their proposal in the light of the comments received and will report their conclusions to us. Q45B (for SLF 53 WG). IACS’ comments are awaited.

Post SLF 53 Comments:- There was some discussion on this issue during the Thursday afternoon session of the WG (to be reported in the session document being prepared by IMO). IACS read out a statement:- “Regarding the safety concerns raised in the correspondence group by Denmark, we have no objections to withdraw the proposed arrangement illustrated in Figure 3 of document SLF51/3/4. The concern expressed by CLIA regarding means of locking and monitoring of valves is not clear to us as this is not required by Regulation 12.5.1. Also, it is not believed to be prudent for these valves to be Locked.”

322 10/01/2012

The US explained that this regulation was taken from the previous version of SOLAS and was specifically for passenger ships. They expressed some reservations on the issue and said they would provide comments to the 2011 CG. The UK also expressed concern over possible damage to butterfly valves. The Chairman therefore proposed that we retain “screw-down” for now and re-open this question for the 2011 CG. So we return to the original question …... . Q45C (for Round 4 Questionnaire). Do you agree with IACS’ argument that

butterfly valves are just as effective as screw-down valves for pipes piercing the collision bulkhead and that the word “screw-down” in square brackets above can therefore be removed?

Yes

Vanuatu, Norway, Japan, China, RINA (see comments), IACS, Denmark, France, Germany, Finland, Italy, Spain, US (but replace “screw-down” with “suitable”)

No

UK

Comments?:- Vanuatu: Both types of valve can be obstructed by debris; however only with a butterfly would the obstruction actually be apparent from the position of an operating handle. So from the stand point of better control of matters the butterfly is both quicker to activate and better for providing feed-back that the piping has been positively secured. US: We generally agree with the points noted by IACS in paragraph 5 of SLF 51/3/4, and we note that the passenger ship screw-down valve requirement dates back to SOLAS 1929. We can therefore accept deleting the prescriptive screw-down valve requirement, but our preference is to replace “screw-down” with “suitable”. This aligns with the previous terminology used for cargo ships in SOLAS 90 reg II-1/11.4 and may give some protection against the use of unusual/inappropriate valves. We also question whether the term “valve chest” is still used/necessary ----------------------------------------------------------------------------------------------- SOLAS 1929 Regulation IX paragraph (3)(b): The collision bulkhead may be pierced below the margin line by not more than one pipe for dealing with fluid in the forepeak tank, provided that the pipe is fitted with a screwdown valve capable of being operated from above the bulkhead deck, the valve chest being secured inside the forepeak to the collision bulkhead. Norway: However, further specification regarding the agreed standard should be discussed for possible inclusion in the EN. Japan: We do not have a strong position. RINA: It should be confirmed that all safety critical valves, such as this, are remotely operated and in the event of failure of the operating system will fail safe closed or/open, as appropriate, dependent on the system requirements IACS: a) With respect to the UK's reluctance to accept butterfly valves as these valves are more vulnerable to misalignment in case of a structural damage (which is very likely to be only as a consequence of collision or bottom damage), given the vicinity of the valve to the collision bulkhead, structural damage causing misalignment of a butterfly valve is likely to also cause a breach in the watertight boundary between the collision bulkhead and the pipe, or the pipe itself, thereby negating the purpose of the valve. Also, it would seem that a damage causing misalignment of a butterfly valve would likely damage the stem of a typical screw-down valve rendering it inoperable. However, IACS would propose that at the collision bulk head a flanged type butterfly valve shall be provided; lug type butterfly valve (1 centre flange) could be accepted as well. Butterfly valves mounted between the pipe flanges should not be accepted.

323 10/01/2012

(b) SOLAS Chapter II-1 Regulation 12.5.1 requires screw-down valve be provided for peak bulkheads (because a butterfly valve does not give positive closure unless the closing/opening arrangement is assisted by gearing). However, IACS is of the opinion that there is no significant difference if a globe valve or a butterfly valve will be used at the collision bulkhead.To underscore paragraph 5(4) of IACS submission SLF 51/3/4, several IACS Members have been informed by shipyards that they cannot find suitable screw-down valve (i.e., valve size is of 350A) for this purpose in the market. (c) Another problem with requiring screw-down valves is that it prevents the valve from being remotely operated (due to size, complexity and cost of actuators). Accordingly, current designs normally have manually operated collision bulkhead valves. This requires crew to access the forward spaces to close the collision bulkhead valve. If manual operation is by extension spindles, experience indicates that these are exposed to failure due to corrosion of spindles and joints. If a butterfly valve is accepted, remote operation is simplified and thus perceived to increase the overall safety and response time in the event of collision. CLIA: Our original point was that butterfly valves are not as safe as screw-down valves, unless they can be positively held in the closed position and monitored as such. But we acknowledge that alternative arrangements are sometimes applied and offer some benefits, such as the replacement of an extended spindle with hydraulic actuation. MI: In light of the US comments in the working group at the last session of SLF, the Marshall Islands has reviewed the regulatory development history. In the original SOLAS 74, Part B of Ch II-1 was only applicable to passenger ships, which contained the screw-down valve provision in Regulation 13. With the 1983 amendments, certain regulations in Part B were extended to other ship types, which then created dual regulations for certain requirements - in this case, Regulation 11 applied to cargo ships, and specified that pipes piercing the collision bulkhead be fitted with "suitable valves", whereas Regulation 15 was only applicable to Passenger Ships and the requirement was slightly different, including that such pipes be fitted with "screw-down type valves." During the process of harmonizing the probabilistic damage stability regulations for both cargo ships and passenger ships the SDS working group concluded that 'the principles for watertight spaces and openings are similar for passenger ships and cargo ships and wherever possible the provisions should be harmonized in the revised regulations'. This has resulted in the current regulation 12 now being applicable to all ship types and defines “screw-down" valves as per the old passenger ship standard. If there are valid concerns with respect to the use of butterfly valves for this location specifically on passenger ships then perhaps it would be better to consider revising regulation 12 such that 'screw-down' is prescribed for passenger ships and 'suitable valves' for cargo ships. France: Positioning of valve inside the fore peak may be questioned. Most of time the fore peak is a water ballast, which causes maintenance problems and being forward of collision bulkhead, it is more exposed to damage in case of collision. The regulation could be inverted, specifying that valve must be placed aft from the collision bulkhead, and that if this place is a cargo space, the administration may authorize to place it forward from collision bulkhead. UK: Our concerns come from the use of butterfly valves in cargo systems. They have been known to slam shut when cargo is flowing through them at high rates, thereby setting up very large surge pressures which can cause line, hose or metal failure. These failures are usually due to the valve disc not being completely parallel to the flow when in the open position. This can create a closing force that may shear the valve spindle in the case of a butterfly valve. We don't think we have enough information on the issue of transmitted damage after a collision on how a butterfly valve would react to transmitted side or frontal impact damage. We definitely prefer screw-down valves.

324 10/01/2012

Round 6 Discussion: There is a large majority (13-1) in favour of removing “screw-down” in the phrase “……provided that the pipe is fitted with a [screw-down] valve capable of being operated from above the bulkhead deck …..” However there are many comments:- Japan does not have a strong position (voted in favour); CLIA says that screw-down valves are safer but could accept an alternative (did not vote); MI gives a full historical background and proposes “revising regulation 12 such that 'screw-down' is prescribed for passenger ships and 'suitable valves' for cargo ships.” (did not vote); The US also gives a historical background and proposes to use “suitable” instead of “screw-down” (voted in favour); also asked whether the term “valve chest” is still used. Vanuatu gives reasons for preferring butterfly valves and voted in favour; Norway also voted in favour but wants further specification regarding the agreed standard to be discussed for possible inclusion in the EN. RINA wants it confirmed that all such safety critical valves are capable of being remotely operated (Co-ordinator’s note: as stated in the regulations?) and will fail safe in the correct position (voted in favour); UK gives a clear reason for preferring screw-down valves (for cargo systems), questioning how robust butterfly valves would be in resisting transmitted impact loads (voted against): France asks whether the regulation should be inverted so that the valve is normally fitted aft of the collision bulkhead and only as an alternative may it be fitted forward within the fore peak - citing reasons of corrosion and accessibility for this proposal (voted in favour). IACS, voting in favour, argues (1) contrary to the UK that screw-down valves are just as likely to be rendered inoperable by an impact as butterfly valves but they do propose specific arrangements to mitigate the effects of such damage. IACS continues by arguing (2) that they see no significant differences in effectiveness between globe valves and butterfly valves at the collision bulkhead, adding that large screw-down valves are now hard to obtain commercially. Finally IACS argues (3) that butterfly valves are easier to adapt for remote operation whereas screw-down valves for operation from the bulkhead deck (as currently required by the regulation) require spindles, joints etc which may become corroded and inoperable. in practice, current designs often have manually operated collision bulkhead valves requiring local access. (Co-ordinator’s Note: This would seem to be in breach of the current requirement for operation from the bulkhead deck). SUMMARY It would seem that harmonizing the requirements for cargo and passenger ships into one regulation has led in this case to some difficulties over the issue of valves fitted to the collision bulkhead. Screw-down valves were historically the norm for passenger ships whereas butterfly valves are more suitable for cargo ships where access is often difficult. The complex issues surrounding the applicability of reg. 12 (and Part B-2 in general) are still being discussed (see Q6D) so one solution would be either to simply delete “screw-down” and leave interpretation to the Administration based on ship type and location of the valve or, instead, to use the word “suitable” along the lines proposed by the US and MI. If required, this could be further explained in the EN, as outlined by the MI. A new

325 10/01/2012

EN would also allow Norway’s proposal to be included, with suitable wording, and even allow for quite a detailed specification with diagrams as originally advocated by IACS in SLF 51/3/4. We understand that one of those diagrams (fig. 3) anyway may need amending or removing altogether (ref. IACS statement in response to Denmark at the SLF 53 WG) so that could now be done in a new EN. We also need to take into account your views on the term “valve chest” and on whether you support France’s proposal to “invert” the regulation. We will therefore ask a series of questions to try to determine how best to progress with these issues. Q45D (for Round 6 Questionnaire). Please state your preferences for reg. 12.5.1:-

1) Simply remove “screw-down” and leave all interpretation to the Administration?

2) Replace “screw-down” with “suitable” without further explanation? 3) Replace “screw-down” with “suitable” and add a new EN specifying

“screw-down” for passenger ships and “suitable” (with some further detail) for cargo ships?

4) Change only the regulation to specify “screw-down” for passenger ships and “suitable” for cargo ships without further explanation?

5) If you prefer a new EN, do you think it should in addition contain detailed diagrams and notes etc based on IACS’ original proposal (ref. SLF 51/3/4)?

6) Is the use of “valve chest” in the following phrase still relevant? “the [valve chest] being secured inside the forepeak to the collision bulkhead” 7) If not, how should the sentence be changed? (suggestions needed) 8) Do you agree with France that the regulation itself should preferably

require the valve to be fitted aft, rather than forward of the collision bulkhead?

1) Y/N?

Yes: RINA (but with the interpretations in the proposed EN), France No: Finland, Norway, Germany, Poland, US, Italy, Denmark, China, IACS (does not support leaving all interpretation to the Administration. It is important to ensure a harmonized practice on this issue),

2) Y/N?

Yes: CLIA, Italy, Denmark, Finland, US (Yes – but with a new EN generally based on the IACS proposal in SLF 51/3/4 but updated to address “suitable” (e.g. if a butterfly valve then a flanged type or lug type (1 centre flange) are ok, but not a butterfly valve mounted between the pipe flanges; etc.) Maybe IACS can help with this?!) No: RINA, Norway Germany, Poland, China, France, IACS (does not support replacing "screw-down" with "suitable" without further explanation, for the same reason as given in 1) above).

326 10/01/2012

3) Y/N?

Yes: Norway, UK, China No: IACS (does not support replacing “screw-down” with “suitable”, in the regulations or in the EN, as this does not provide for a uniform means of certification. Rather, considering that there was no compelling need to require cargo ships to be fitted with screw-down valves, IACS suggests that the text of SOLAS be revised to retain the screw-down valve as the general requirement, but allow for the use of a butter-fly valve (as opposed to the vague adjective "suitable") as an alternative - for cargo ships only. It should also include a requirement that butterfly valves should have "flanges" or "seats" for the valve to rest against), Germany (No, we do not support replacing “screw-down” with “suitable”, in the regulations or in the EN, as this does not provide for a uniform means of certification. Rather, considering that there was no compelling need to require cargo ships to be fitted with screw-down valves, we suggest that the text of SOLAS be revised to retain the screw-down valve as the general requirement, but allow for the use of a butter-fly valve (as opposed to the vague adjective "suitable") as an alternative - for cargo ships only. It should also include a requirement that butterfly valves should have "flanges" or "seats" for the valve to rest against.) RINA, Finland, Poland, US, Italy, France, Denmark

4) Y/N?

Yes: Japan (prefers (4)) No: RINA, Finland, Norway, Germany, Poland, US, Italy, France, China, Denmark, IACS (does not support "screw-down" for passenger and "suitable" for cargo with no further explanation, for the same reason as given in 3) above).

5) Y/N?

Yes: Finland, Norway, Germany, Poland, US (see 2) above), China, Denmark, IACS (The new explanatory note should include detailed diagrams and notes as per SLF 51/3/4. Any further diagrams which clarify what is acceptable would help), RINA (EN should include comments from all delegates and include diagrams from SLF 51/3/4 as applicable. If the double penetration in SLF 53/3/4 fig 2 is retained then this would require an amendment to Regulation 12.5.1. No: Italy

6) Y/N?

Yes: Norway No: RINA, US, Denmark

7) If N to 6, suggest new text

RINA: 5.1 “Except as provided in paragraph 5.2, the collision bulkhead may be pierced below the bulkhead deck by not more than one pipe for dealing with fluid in the forepeak tank, provided that the pipe is fitted with a screw-down valve capable of being operated from above the bulkhead deck, the valve [chest] being secured inside the forepeak to the collision bulkhead. The Administration may, however, authorize the fitting of this valve on the after side of the collision bulkhead provided that the valve is readily accessible under all service conditions and the space in which it is located is not a cargo space. All valves shall be of steel, bronze or other approved ductile material. Valves of ordinary cast iron or similar material are not acceptable”. US: “...provided that the pipe is fitted with a [suitable] valve capable of being operated from above the bulkhead deck, the valve [being located inside the forepeak immediately adjacent to the collision bulkhead].”

327 10/01/2012

8) Y/N?

Yes: CLIA (It may be preferable and possible in some cases), Finland, France, Germany, Denmark No: RINA (The regulation already gives the option to fit the valve on the after side or inside the collision bulkhead. Which we should keep.), Poland, Italy, China. No Comment: Norway No strong position: US (as reg 12.5.1 already provides the flexibility to locate a valve aft of the collision bulkhead).

Further comments? Finland: Location of valve is better aft of collision bulkhead also due to corrosion (quite often water in forepeak). The valve may locate directly adjacent to the collision bulkhead to prevent progressive flooding into forepeak in case of damage located wt-compartment aft of collision bulkhead.

Q45 FOR SLF 54: IT CAN BE SEEN THAT THERE IS A WIDE RANGE OF OPINION ON THESE ISSUES AND THAT THIS REGULATION IN GENERAL NEEDS ATTENTION (ALSO IN TERMS OF APPLICABILITY). THERE IS A LARGE MAJORITY IN FAVOUR OF A NEW EN (see below) INCORPORATING SOME OF THE DIAGRAMS IN THE IACS PAPER (SLF 51/3/4). WORDING FOR THIS WOULD BE NEEDED.

FURTHER DISCUSSION IS REQUIRED AT SLF 54 [Regulation 12.5.1 Possible new EN for “screw-down” valve.] [Q45D] [ 9-1 in favour; discuss at SLF 54] 5.2 If the forepeak is divided to hold two different kinds of liquids the Administration may allow the collision bulkhead to be pierced below the bulkhead deck [in passenger ships and freeboard deck in cargo ships] [Q6D(4)[13]] [ Discuss at SLF 54] by two pipes, each of which is fitted as required by paragraph 5.1, provided the Administration is satisfied that there is no practical alternative to the fitting of such a second pipe and that, having regard to the additional subdivision provided in the forepeak, the safety of the ship is maintained. 6 Where a long forward superstructure is fitted the collision bulkhead shall be extended weathertight to the deck next above the bulkhead deck [in passenger ships and freeboard deck in cargo ships] [Q6D(4)[14]] [ Discuss at SLF 54]. The extension need not be fitted directly above the bulkhead below provided it is located within the limits prescribed in paragraph 1 or 2 with the exception permitted by paragraph 7 and that the part of the deck which forms the step is made effectively weathertight. The extension shall be so arranged as to preclude the possibility of the bow door causing damage to it in the case of damage to, or detachment of, a bow door.

7 Where bow doors are fitted and a sloping loading ramp forms part of the extension of the collision bulkhead above the bulkhead deck the ramp shall be weathertight over its complete length. In cargo ships the part of the ramp which is more than 2.3 m above the [bulkhead] [freeboard] [Q6D(4)[15]] [ Discuss at SLF 54] deck may extend forward of the limit specified in paragraph 1 or 2. Ramps not meeting the above requirements shall be disregarded as an extension of the collision bulkhead

328 10/01/2012

Regulation 12.7 Reference is made to MSC.1/Circ.1211 (Unified interpretations to SOLAS regulation II-1/10) [see below] and regulation 12 of the revised SOLAS chapter II-1 regarding bow doors and the extension of the collision bulkhead) concerning interpretations regarding bow doors and the extension of the collision bulkhead.

MSC.1/Circ.1211

25 May 2006

UNIFIED INTERPRETATIONS TO SOLAS CHAPTER II-1 REGULATION 12 REGARDING BOW DOORS AND THE EXTENSION OF THE COLLISION

BULKHEAD 1 The Maritime Safety Committee, at its eighty-first session (10 to 19 May 2006), with a view to providing assistance to the Administrations in the implementation of the requirements of the 1974 SOLAS Convention and in order to ensure the uniform application thereof, approved the unified interpretations to regulation 12 of the revised SOLAS chapter II-1 (Resolution MSC.216 (82)), regarding bow doors and the extension of the collision bulkhead, as set out in the annex. 2 Member Governments are urged to:

.1 take note of the annexed unified interpretations and use them when applying the relevant requirements of the 1974 SOLAS Convention; and

.2 bring the annex unified interpretations to the attention of all interested parties.

***

MSC.1/Circ.1211

329 10/01/2012

MSC.1/Circ.1211ANNEX Page 1

ANNEX UNIFIED INTERPRETATIONS TO SOLAS REGULATION 12 OF THE REVISED

SOLAS CHAPTER II-1 REGARDING BOW DOORS AND THE EXTENSION OF THE COLLISION BULKHEAD

By resolution MSC.216(82), amendments to SOLAS chapter II-1 were adopted which are expected to enter into force on 1 January 2009; and paragraphs 3 to 5 of the existing regulation II-1/10 have been transformed into paragraphs 6 and 7 of regulation 12 of the aforementioned revised SOLAS chapter II-1. If ships are to comply with paragraphs 6 and 7 of regulation 12 after the entry-into-force date on 1 January 2009, the following interpretation to SOLAS regulation II-1/12.6 should apply to those ships:

“Where a long forward superstructure is fitted, the collision bulkhead should be extended weathertight to the deck next above the bulkhead deck. The extension need not be fitted directly above the bulkhead below provided that all parts of the extension, including any part of the ramp attached to it are located within the limits prescribed in paragraph 1 or 2 of, with the exception permitted by paragraph 7 in, regulation II-1/12 and that the part of the deck which forms the step is made effectively weathertight. The extension should be so arranged as to preclude the possibility of the bow door or ramp, where fitted, causing damage to it in the case of damage to, or detachment of, a bow door or any part of the ramp.” 8 The number of openings in the extension of the collision bulkhead above the freeboard deck shall be restricted to the minimum compatible with the design and normal operation of the ship. All such openings shall be capable of being closed weathertight.

9 Bulkheads shall be fitted separating the machinery space from cargo and accommodation spaces forward and aft and made watertight up to the bulkhead deck [in passenger ships and freeboard deck in cargo ships] [Q6D(4) [16]] [ Discuss at SLF 54]. In passenger ships an afterpeak bulkhead shall also be fitted and made watertight up to the bulkhead deck. The afterpeak bulkhead may, however, be stepped below the bulkhead deck, provided the degree of safety of the ship as regards subdivision is not thereby diminished.

10 In all cases stern tubes shall be enclosed in watertight spaces of moderate volume. In passenger ships the stern gland shall be situated in a watertight shaft tunnel or other watertight space separate from the stern tube compartment and of such volume that, if flooded by leakage through the stern gland, the bulkhead deck will not be immersed. In cargo ships other measures to minimize the danger of water penetrating into the ship in case of damage to stern tube arrangements may be taken at the discretion of the Administration.

330 10/01/2012

R12.10 – Stern Tubes proposed new EN Discussion for Round 6 Supplementary Questionnaire. IACS will be presenting a paper at SLF with details of three new UI’s (Unified Interpretations) for the above SOLAS 2009 Chapter II-1 regulations. The usual procedure is for the UI’s to be approved by SLF and then MSC whereupon they are issued as MSC/Circulars. We then usually refer to these circulars in the EN as indicated in draft form below. The UI’s in question are:-

• SC93 (Enclosure of stern tubes on cargo ships) [Reg. 12.10] • SC220 (Special requirements for vehicle ferries, ro-ro ships and other ships of

similar type) [Reg. 17-1.1.1] and

• SC81 (Drainage of enclosed spaces situated on the bulkhead deck) [Reg. 35-1.2.6.1]

R6-SQ2 for Round 6 Supplementary Questionnaire. Do you have any comments on the UI’s or any objections to inserting references to the related forthcoming MSC/Circulars in the EN as shown highlighted in draft form below? Further comments / objections?:- Japan: No comments. RINA: Why not add the interpretation directly into the EN rather than refer to a separate document? Norway: Regarding IACS SC93 and SC81: No comments Regarding IACS SC220: The interpretation (a) is identical with IACS LL32 for the ICLL Reg. 21. We can not see that this interpretation has any relevance for SOLAS Reg. II-1/17-1.1. The interpretation (b), first paragraph, seems to introduce an interpretation that is not as restrictive as the SOLAS Reg. 20-2 (94/95 Amendments). If this interpretation refers to doors required for access in accordance with SOLAS Reg. 20-2.2.3 (94/95 Amendments) this should be mentioned in the IACS SC220. Poland: I think that it might be pointed which kind of ships similar type ..like..only vehicle ferries, ro – ro ships ..and….it might be pointed [Poland – please clarify – coordinators.] US: No objection to the general approach; but subject to discussion and acceptance of the IACS UIs at SLF 54. UK: No objections. China: No comments Proposed addition to the Explanatory Notes to reflect new UI’s from IACS to be presented at SLF 54 Regulation 12.10 − Stern Tubes Reference is made to MSC/Circ.[xxxx] (Unified interpretation of SOLAS chapter II-1) regarding enclosure of stern tubes on cargo ships.

DISCUSS AT SLF 54 TOGETHER WITH OTHER PROPOSED EN’s (see SLF 54/8/2)

331 10/01/2012

Regulation 13 Openings in watertight bulkheads below the bulkhead deck in passenger ships

General – Steps in the bulkhead deck

1. If the transverse watertight bulkheads in a region of the ship are carried to a higher deck which forms a vertical step in the bulkhead deck, openings located in the bulkhead at the step may be considered as being located above the bulkhead deck. Such openings should then comply with regulation 17 and should be taken into account when applying regulation 7-2.

2. All openings in the shell plating below the upper deck throughout that region of the ship should be treated as being below the bulkhead deck and the provisions of regulation 15 should be applied. See figure below.

1 Bulkhead deck 2 Considered as located above the bulkhead deck 3 Ship’s side 4 Considered as located below the bulkhead deck

1 The number of openings in watertight bulkheads shall be reduced to the minimum compatible with the design and proper working of the ship, satisfactory means shall be provided for closing these openings. 2.1 Where pipes, scuppers, electric cables, etc., are carried through watertight bulkheads, arrangements shall be made to ensure the watertight integrity of the bulkheads. 2.2 Valves not forming part of a piping system shall not be permitted in watertight bulkheads. 2.3 Lead or other heat sensitive materials shall not be used in systems which penetrate watertight bulkheads, where deterioration of such systems in the event of fire would impair the watertight integrity of the bulkheads.

332 10/01/2012

3 No doors, manholes, or access openings are permitted in watertight transverse bulkheads dividing a cargo space from an adjoining cargo space, except as provided in paragraph 9.1 and in regulation 14. 4 Subject to paragraph 10, not more than one door, apart from the doors to shaft tunnels, may be fitted in each watertight bulkhead within spaces containing the main and auxiliary propulsion machinery including boilers serving the needs of propulsion. Where two or more shafts are fitted, the tunnels shall be connected by an intercommunicating passage. There shall be only one door between the machinery space and the tunnel spaces where two shafts are fitted and only two doors where there are more than two shafts. All these doors shall be of the sliding type and shall be so located as to have their sills as high as practicable. The hand gear for operating these doors from above the bulkhead deck shall be situated outside the spaces containing the machinery. Regulation 13.4 In cases where main and auxiliary propulsion machinery spaces, including boilers serving the needs for propulsion, are divided by watertight longitudinal bulkheads in order to comply with redundancy requirements (e.g., according to regulation 8-1.2), one watertight door in each watertight bulkhead may be permitted, as shown in the figure below.

5.1 Watertight doors, except as provided in paragraph 9.1 or regulation 14, shall be power-operated sliding doors complying with the requirements of paragraph 7 capable of being closed simultaneously from the central operating console at the navigation bridge in not more than 60 s with the ship in the upright position.

5.2 The means of operation whether by power or by hand of any power-operated sliding watertight door shall be capable of closing the door with the ship listed to 15

o

either way. Consideration shall also be given to the forces which may act on either side of the door as may be experienced when water is flowing through the opening applying a static head equivalent to a water height of at least 1 m above the sill on the centreline of the door.

333 10/01/2012

5.3 Watertight door controls, including hydraulic piping and electric cables, shall be kept as close as practicable to the bulkhead in which the doors are fitted, in order to minimize the likelihood of them being involved in any damage which the ship may sustain. The positioning of watertight doors and their controls shall be such that if the ship sustains damage within one fifth of the breadth of the ship, as defined in regulation 2, such distance being measured at right angles to the centreline at the level of the deepest subdivision draught, the operation of the watertight doors clear of the damaged portion of the ship is not impaired.

R13.5.3 (routing of cables inboard of B/5)

Queries received from CLIA/CCSF between Round 1 and Round 2: Regulation 13.5.3 Routing of control cables. From regulation 13, §5.3, it seems that hydraulic piping or control cable so that they would not be damaged by a breach of B/5 penetration. There is no reason to have more stringent criteria for control of valves used to prevent progressive flooding, but this should be clarified

Coordinator’s Comments: Not quite clear what this is saying. Can CLIA please clarify the question?

CG Member’s Comments?:- RINA: See comments to Q45A. France: Sentence has been truncated it should be :

“From regulation 13, §5.3, it seems that hydraulic piping or control cable must be routed so that they would not be damaged by a breach of B/5 penetration. There is no reason to have more stringent criteria for control of valves used to prevent progressive flooding, but this should be clarified”.

The intention is to specify the possible routing of hydraulic piping or control cables (for watertight door or damage control valves referring to reg 7-2.5.3.3) between device and control station to ensure their possible operation after damage.

Norway: CLIA/CCSF’s comment is not clear. The paragraph was carried over from the old text and the contents were probably assumed to be outside the TOR for the harmonization (as a DE responsibility). The scope of that paragraph should not be expanded without further considerations of the implications. CLIA: in regulation 13 §5.3 it is stated that piping and cables for the control of WTD should be arranged in such a way, that they are not damaged from a B/5 damage. Other control valves, which are used to control progressive flooding have more stringent criteria for the location, e.g. within the distance of bulkhead equivalent to the height of the stiffening structure. This is not logical and it should be further clarified.

334 10/01/2012

Round 2 Discussion:- Many thanks for the clarification and comments. It seems that in view of Norway’s comment, this issue would be best dealt with in the SLF 53 WG.

CLIA Q15 (for SLF53 WG). If considered necessary, should we modify this regulation in some way to improve consistency in line with CLIA’s comments or, as Norway suggests, can this only be achieved in co-operation with DE?

SLF only?

SLF+DE?

Post SLF 53 Notes:- This issue was discussed in the Thursday afternoon session of the WG (to be reported in the session document for SLF 54). The US pointed out that historically it was realised that 1 or 2 references to B/5 still remain in SOLAS 2009 and a deliberate decision was taken to leave them in as design requirements without any attempt at harmonisation. Norway said it would investigate further on whether this is for DE or SLF and report to the 2011 CG. Italy considered that WTD could be positioned outside the B/5 line. The chairman considered that this was not a decision for SLF. The question is therefore left open for further comments…...

CLIA Q15C for Round 4 Questionnaire. Are there any further comments on this, particularly from Norway?

Comments? Norway: The deterministic B/5 parameter still applies for watertight doors positioning and bilge non-return valves (Reg. 35-1, paragraph 3.10). In Norway’s opinion these are important safety barriers that must be maintained, if they can not be replaced by an equivalent probabilistic based parameter. We fail to see how a simple deletion of this B/5 safety barrier is in conformity with the overall goal of the Chapter II-1 revision, namely maintaining the level of safety. The SLF should conclude on this matter, and then ask the DE Sub-Committee to provide any comments they may have, for final completion of the matter. Japan: No objection. China: No comments. RINA: No further comments. Denmark: No further comments – B/5 is reasonable. Germany: The regulation is clear enough and the B/5 concept may be kept here as a minimum standard for locating pipes, cables and controls of WTDs. Finland: We prefer to keep reg. 13 par 5.3 as it is. The regulation is clear as such. France: The question is directly linked with the damage stability calculations, so it seems not logical to transfer the question to DE. Anyway, DE will have to give an advice later. Question is about the constraint on routing of control cables or pipes and not on the positioning of doors or valves themselves.

Round 6 Discussion: Of the 8 comments received 7 favour no changes so unless CLIA has any objections we will conclude this item as Norway suggests and invite the sub-committee in our report to ask DE if they may have any issues with consistency between this regulation covering the routeing of control systems for WTD and those for controlling progressive flooding (regs. 7.7, 7-1.1.1 and 7-1.1.2 see CLIA Q6D and CLIA Q17D).

CONCLUDED WE WILL ASK THE SUB-COMMITTEE TO RAISE THIS WITH D.E.

IN THE CG REPORT TO SLF 54.

335 10/01/2012

Are there any final comments, particularly from CLIA and France? US: No.

FOR SLF 54 SUB-COMMITTEE TO DECIDE WHETHER TO REFER THIS MATTER TO DE

(see SLF 54/8/1 paragraph 15.6) 6 All power-operated sliding watertight doors shall be provided with means of indication which will show at all remote operating positions whether the doors are open or closed. Remote operating positions shall only be at the navigation bridge as required by paragraph 7.1.5 and at the location where hand operation above the bulkhead deck is required by paragraph 7.1.4.

7.1 Each power-operated sliding watertight door:

.1 shall have a vertical or horizontal motion;

.2 shall, subject to paragraph 10, be normally limited to a maximum clear opening width of 1.2 m. The Administration may permit larger doors only to the extent considered necessary for the effective operation of the ship provided that other safety measures, including the following, are taken into consideration:

.1 special consideration shall be given to the strength of the door and its closing appliances in order to prevent leakages; and

.2 the door shall be located inboard the damage zone B/5;

.3 shall be fitted with the necessary equipment to open and close the door using electric power, hydraulic power, or any other form of power that is acceptable to the Administration;

.4 shall be provided with an individual hand-operated mechanism. It shall

be possible to open and close the door by hand at the door itself from either side, and in addition, close the door from an accessible position above the bulkhead deck with an all round crank motion or some other movement providing the same degree of safety acceptable to the Administration. Direction of rotation or other movement is to be clearly indicated at all operating positions. The time necessary for the complete closure of the door, when operating by hand gear, shall not exceed 90 s with the ship in the upright position;

.5 shall be provided with controls for opening and closing the door by power from both sides of the door and also for closing the door by power from the central operating console at the navigation bridge;

.6 shall be provided with an audible alarm, distinct from any other alarm in the area, which will sound whenever the door is closed remotely by power and which shall sound for at least 5 s but no more than 10 s before the door begins to move and shall continue sounding until the door is completely closed. In the case of remote hand operation it is sufficient for the audible alarm to sound only when the door is moving. Additionally, in

336 10/01/2012

passenger areas and areas of high ambient noise the Administration may require the audible alarm to be supplemented by an intermittent visual signal at the door; and

.7 shall have an approximately uniform rate of closure under power. The closure time, from the time the door begins to move to the time it reaches the completely closed position shall in no case be less than 20 s or more than 40 s with the ship in the upright position.

7.2 The electrical power required for power-operated sliding watertight doors shall be supplied from the emergency switchboard either directly or by a dedicated distribution board situated above the bulkhead deck. The associated control, indication and alarm circuits shall be supplied from the emergency switchboard either directly or by a dedicated distribution board situated above the bulkhead deck and be capable of being automatically supplied by the transitional source of emergency electrical power required by regulation 42.3.1.3 in the event of failure of either the main or emergency source of electrical power.

7.3 Power-operated sliding watertight doors shall have either:

.1 a centralized hydraulic system with two independent power sources each consisting of a motor and pump capable of simultaneously closing all doors. In addition, there shall be for the whole installation hydraulic accumulators of sufficient capacity to operate all the doors at least three times, i.e. closed-open-closed, against an adverse list of 15º. This operating cycle shall be capable of being carried out when the accumulator is at the pump cut-in pressure. The fluid used shall be chosen considering the temperatures liable to be encountered by the installation during its service. The power operating system shall be designed to minimize the possibility of having a single failure in the hydraulic piping adversely affect the operation of more than one door. The hydraulic system shall be provided with a low-level alarm for hydraulic fluid reservoirs serving the power-operated system and a low gas pressure alarm or other effective means of monitoring loss of stored energy in hydraulic accumulators. These alarms are to be audible and visual and shall be situated on the central operating console at the navigation bridge; or

.2 an independent hydraulic system for each door with each power source consisting of a motor and pump capable of opening and closing the door. In addition, there shall be a hydraulic accumulator of sufficient capacity to operate the door at least three times, i.e. closed-open-closed, against an adverse list of 15

o. This operating cycle shall be capable of being carried

out when the accumulator is at the pump cut-in pressure. The fluid used shall be chosen considering the temperatures liable to be encountered by the installation during its service. A low gas pressure group alarm or other effective means of monitoring loss of stored energy in hydraulic

337 10/01/2012

accumulators shall be provided at the central operating console on the navigation bridge. Loss of stored energy indication at each local operating position shall also be provided; or

.3 an independent electrical system and motor for each door with each power source consisting of a motor capable of opening and closing the door. The power source shall be capable of being automatically supplied by the transitional source of emergency electrical power as required by regulation 42.4.2 – in the event of failure of either the main or emergency source of electrical power and with sufficient capacity to operate the door at least three times, i.e. closed-open-closed, against an adverse list of 15

o.

For the systems specified in paragraphs 7.3.1, 7.3.2 and 7.3.3, provision should be made as follows: Power systems for power-operated watertight sliding doors shall be separate from any other power system. A single failure in the electric or hydraulic power-operated systems excluding the hydraulic actuator shall not prevent the hand operation of any door.

7.4 Control handles shall be provided at each side of the bulkhead at a minimum height of 1.6 m above the floor and shall be so arranged as to enable persons passing through the doorway to hold both handles in the open position without being able to set the power closing mechanism in operation accidentally. The direction of movement of the handles in opening and closing the door shall be in the direction of door movement and shall be clearly indicated. 7.5 As far as practicable, electrical equipment and components for watertight doors shall be situated above the bulkhead deck and outside hazardous areas and spaces. 7.6 The enclosures of electrical components necessarily situated below the bulkhead deck shall provide suitable protection against the ingress of water.

*

[Regulation 13.7.6

The IEC standard referenced in the footnote (IEC publication 529, 1976) has been replaced by the newer standard IEC 60529:2003]. [Coordinator’s Comment: This EN could be deleted as the S2009 Consolidated Edition now has the correct reference?].

_____________ * Refer to the following publication IEC 60529:2003: .1 electrical motors, associated circuits and control components; protected to IPX 7 standard; .2 door position indicators and associated circuit components; protected to IPX 8 standard; and .3 door movement warning signals; protected to IPX 6 standard. Other arrangements for the enclosures of electrical components may be fitted provided the Administration is satisfied that an equivalent protection is achieved. The water pressure IPX 8 shall be based on the pressure that may occur at the location of the component during flooding for a period of 36 h.

338 10/01/2012

7.7 Electric power, control, indication and alarm circuits shall be protected against fault in such a way that a failure in one door circuit will not cause a failure in any other door circuit. Short circuits or other faults in the alarm or indicator circuits of a door shall not result in a loss of power operation of that door. Arrangements shall be such that leakage of water into the electrical equipment located below the bulkhead deck will not cause the door to open. 7.8 A single electrical failure in the power operating or control system of a power-operated sliding watertight door shall not result in a closed door opening. Availability of the power supply should be continuously monitored at a point in the electrical circuit as near as practicable to each of the motors required by paragraph 7.3. Loss of any such power supply should activate an audible and visual alarm at the central operating console at the navigation bridge. 8.1 The central operating console at the navigation bridge shall have a “master mode” switch with two modes of control: a “local control” mode which shall allow any door to be locally opened and locally closed after use without automatic closure, and a “doors closed” mode which shall automatically close any door that is open. The “doors closed” mode shall automatically close any door that is open. The “doors closed” mode shall permit doors to be opened locally and shall automatically re-close the doors upon release of the local control mechanism. The “master mode” switch shall normally be in the “local control” mode. The “doors closed” mode shall only be used in an emergency or for testing purposes. Special consideration shall be given to the reliability of the “master mode” switch. 8.2 The central operating console at the navigation bridge shall be provided with a diagram showing the location of each door, with visual indicators to show whether each door is open or closed. A red light shall indicate a door is fully open and a green light shall indicate a door is fully closed. When the door is closed remotely the red light shall indicate the intermediate position by flashing. The indicating circuit shall be independent of the control circuit for each door. 8.3 It shall not be possible to remotely open any door from the central operating console. 9.1 If the Administration is satisfied that such doors are essential, watertight doors of satisfactory construction may be fitted in watertight bulkheads dividing cargo between deck spaces. Such doors may be hinged, rolling or sliding doors but shall not be remotely controlled. They shall be fitted at the highest level and as far from the shell plating as practicable, but in no case shall the outboard vertical edges be situated at a distance from the shell plating which is less than one fifth of the breadth of the ship, as defined in regulation 2, such distance being measured at right angles to the centreline at the level of the deepest subdivision draught. 9.2 Should any such doors be accessible during the voyage, they shall be fitted with a device which prevents unauthorized opening. When it is proposed to fit such doors, the number and arrangements shall receive the special consideration of the Administration. 10 Portable plates on bulkheads shall not be permitted except in machinery spaces. The Administration may permit not more than one power-operated sliding watertight door

339 10/01/2012

in each watertight bulkhead larger than those specified in paragraph 7.1.2 to be substituted for these portable plates, provided these doors are intended to remain closed during navigation except in case of urgent necessity at the discretion of the master. These doors need not meet the requirements of paragraph 7.1.4 regarding complete closure by hand-operated gear in 90 s. 11.1 Where trunkways or tunnels for access from crew accommodation to the stokehold machinery spaces, for piping, or for any other purpose are carried through watertight bulkheads, they shall be watertight and in accordance with the requirements of regulation 16-1. The access to at least one end of each such tunnel or trunkway, if used as a passage at sea, shall be through a trunk extending watertight to a height sufficient to permit access above the bulkhead deck. The access to the other end of the trunkway or tunnel may be through a watertight door of the type required by its location in the ship. Such trunkways or tunnels shall not extend through the first subdivision bulkhead abaft the collision bulkhead. . Q46. Should “stokehold” be replaced with “engine room”? Yes


No

Comments / Alternatives?:- China: Or “stokehold” be replaced with “stokehold or engine room”. Spain: The term ‘stokehold’ has led to a not totally clear wording in SOLAS Spanish version (‘stokehold’ = ‘cámara de calderas’ – that means ‘boiler room’-, instead of ‘engine room’). Therefore, we support the proposal to avoid misunderstandings. Round 1 Discussion: A unanimous verdict in favour of this amendment, though China proposes an alternative, which raises a question of whether we should use the more general term “machinery spaces” to replace “stokehold”. Q46A. Should we replace “stokehold” with “machinery spaces” or “engine room”? Engine Room?

Finland, RINA (with comment), UK

Machinery Spaces?

MI, Germany (with comment), Italy (with comment), Japan, RINA (with comment), Norway, CLIA, US, Sweden (with comment), Denmark

Comments?:- Germany: Yes (machinery space is defined in Reg. 2.15 and therefore clear). Italy: machinery spaces seems to be more consistent with SOLAS wording. RINA: Propose for consistency that the phrase from regulation 13.4 should be used - “main and auxiliary propulsion machinery including boilers serving the needs of propulsion.” France: No preference. Sweden: Machinery Spaces has a definition which could be used. Round 1 Discussion: There is a majority of 10-3 in favour of replacing “stokehold” with “machinery spaces” (defined in reg. 3.16) but RINA has a more detailed proposal therefore we must take this to the WG to decide. Q46B (for SLF 53 WG). Do we prefer to replace “stokehold” with “machinery spaces” or with RINA’s proposed wording taken from reg. 13.4?

340 10/01/2012

RINA’s proposal?

Machinery Spaces?

Post SLF 53 Comments:- In general it was agreed in the WG on Thursday afternoon that “machinery spaces” was preferred - so the change is highlighted above.

Q46 CONCLUDED RECOMMEND ACCEPTANCE AT SLF 54

11.2 Where it is proposed to fit tunnels piercing watertight bulkheads, these shall receive the special consideration of the Administration. 11.3 Where trunkways in connection with refrigerated cargo and ventilation or forced draught trunks are carried through more than one watertight bulkhead, the means of closure at such openings shall be operated by power and be capable of being closed from a central position situated above the bulkhead deck. Regulation 13-1 Openings in watertight bulkheads and internal decks in cargo ships

[This regulation does not apply to small dry cargo ships.] [Q6D(4)[17]]

[Coordinator’s Note: This has been added because the reg. is taken verbatim from old SOLAS 25-9, applicable only to cargo vessels with L >= 80 m but see also new question Q68D. Perhaps some (or all) of these paragraphs should apply to small dry cargo ships? Comments are invited in [Q6D(4)[17]][Discuss at SLF 54]

1 The number of openings in watertight subdivisions is to be kept to a minimum compatible with the design and proper working of the ship. Where penetrations of watertight bulkheads and internal decks are necessary for access, piping, ventilation, electrical cables, etc., arrangements are to be made to maintain the watertight integrity. The Administration may permit relaxation in the watertightness of openings above the freeboard deck, provided that it is demonstrated that any progressive flooding can be easily controlled and that the safety of the ship is not impaired.

Regulation 13-1.1

1. If the transverse watertight bulkheads in a region of the ship are carried to a higher deck than in the remainder of the ship, openings located in the bulkhead at the step may be considered as being located above the freeboard deck.

2. All openings in the shell plating below the upper deck throughout that region of the ship should be treated as being below the freeboard deck, similar to the bulkhead deck for passenger ships (see relevant figure under regulation 13 above), and the provisions of regulation 15 should be applied

2 Doors provided to ensure the watertight integrity of internal openings which are used while at sea are to be sliding watertight doors capable of being remotely closed

341 10/01/2012

from the bridge and are also to be operable locally from each side of the bulkhead. Indicators are to be provided at the control position showing whether the doors are open or closed, and an audible alarm is to be provided at the door closure. The power, control and indicators are to be operable in the event of main power failure. Particular attention is to be paid to minimizing the effect of control system failure. Each power-operated sliding watertight door shall be provided with an individual hand-operated mechanism. It shall be possible to open and close the door by hand at the door itself from both sides. R13-1.2 (Should all WT doors be sliding even for small cargo ships?) US: New item related to regulation 13-1.2 for consideration under Round 6: SOLAS 2009 regulation 12.9 (SOLAS 90 regulation 11.8) requires watertight bulkheads around machinery spaces. Under SOLAS 90 any watertight doors in cargo ships < 80m could be hinged because the requirement for sliding watertight doors was in Part B-1 regulation 25-9.2 (and only applicable to cargo ships > 80m). However under SOLAS 2009, regulation 13-1.2 requires all watertight doors (if used at sea) to be sliding on all cargo ships (even those < 80m). Our question is basically threefold:

1. Is that a common/correct understanding of the regulations (or have we missed something), and is that how everyone is applying regulation 13-1.2 to cargo ships < 80m?

2. If yes, was this intended or was it an unnoticed product of harmonization?

3. If not necessarily intended, should consideration be given to limiting application of regulation 13-1.2 to cargo ships > 80m?

New Q68D for Round 6 Questionnaire: As this issue has just arisen could we please ask for your opinion on the questions raised by the US:-

1) Do you interpret reg. 13-1.2 as meaning that all watertight doors (if used at sea) for all cargo ships, including those of L < 80 metres are to be of the sliding type?

2) If the answer to 1) is YES, do you believe that this was a) intended or b) was it an unnoticed product of harmonisation? 3) If it was an unnoticed product of harmonisation should consideration be

given to limiting the application of reg. 13-1.2 to cargo ships > 80 m in length?

1) Y / N?

Yes: Japan, RINA (see comments), Norway, Poland, US, UK, EC, France, Denmark, China No: Germany (No, for vessels below 80m no watertight subdivision is required (except for Reg. 9.3))

342 10/01/2012

2) If YES was this a) intended OR b) not intended. Please state a / b?

a): RINA, Poland, EC b): Finland (unnoticed product of harmonisation), US (We do not recall any discussion on this issue during harmonization so believe it was unnoticed.), UK, France, Denmark, China

3) if b) Should the reg. only apply to cargo ships with L > 80m? Y / N?

Yes: Finland (see comments), US, France, Denmark No: UK, EC, China, Norway (This regulation shall apply to all cargo vessels to which damage stability requirements apply. For other cargo vessels where damage stability do not apply reference are made to MSC/Circ.1176 section 8: "SOLAS chapter II-1, parts B . Subdivision and stability - and B1 - Subdivision and damage stability of cargo ships": - Doors in watertight bulkheads of small cargo ships, not subject to any statutory subdivision and damage stability requirements, may be hinged quick acting doors arranged to open out of the major space protected. They should be constructed in accordance with the requirements of the Administration and have notices affixed to each side stating "To be kept

Comments?:- IACS: Please be reminded of the explanations contained in MSC.1/Circ.1176 Ch.8. Please also be informed that IACS UI SC156 “Doors in watertight bulkheads of cargo ships and passenger ships” which the MSC.1/Circ.1176 is based on, is currently being reviewed by IACS. [Coordinator’s Note: An extract from the MSC Circular (p.24) is shown below for easy reference:-

] CLIA: N/A – Cargo ship issue. RINA: Q1 (This regulation is also applicable to ships with a gross tonnage of 500 or greater but

343 10/01/2012

less than 80m in length. The provision of watertight doors to this size of ships would occur where WT bulkheads are required for classification society rules or statutory requirements such as the guidelines for the design and construction of offshore supply vessels, 2006 (MSC.235(82)) or the Code of Safety for Special Purpose Ships, 2008(Resolution MSC.266(84). ) Finland: Openings in watertight bulkheads and internal decks in cargo ships

[This regulation does not apply to small dry cargo ships.] [17] “Small dry cargo ship” is a dry cargo ship with 24<= L<= 80 m. and gross tonnage >= 500.] It has been already proposed title of reg13-1 shown as above and small cargo ship is proposed to mean cargo ship with L< 80 m. Therefore understand that Reg.13-1 is for cargo ship > 80 m.

Q68D. FOR SLF 54:- 10-1 believe that all WT doors for all cargo ships are to be sliding; 6-3 believe this was not planned; 4-4 on question of sliding doors for L<80m; Norway, IACS, RINA have comments.

FURTHER DISCUSSION NEEDED AT SLF 54 3 Access doors and access hatch covers normally closed at sea, intended to ensure the watertight integrity of internal openings, shall be provided with means of indication locally and on the bridge showing whether these doors or hatch covers are open or closed. A notice is to be affixed to each such door or hatch cover to the effect that it is not to be left open. 4 Watertight doors or ramps [Coordinator’s Note: Ramps may be weathertight in reg. 17-1.1.2 – conflict referred to ro-ro CG. See also Q51.] of satisfactory construction may be fitted to internally subdivide large cargo spaces, provided that the Administration is satisfied that such doors or ramps are essential.. These doors or ramps may be hinged, rolling or sliding doors or ramps, but shall not be remotely controlled.

* Should

any of the doors or ramps be accessible during the voyage, they shall be fitted with a device which prevents unauthorized opening. 5 Other closing appliances which are kept permanently closed at sea to ensure the watertight integrity of internal openings shall be provided with a notice which is to be affixed to each such closing appliance to the effect that it is to be kept closed. Manholes fitted with closely bolted covers need not be so marked.

_______________ * Refer to Interpretations of regulations of part B-1 of SOLAS chapter II-1 (MSC/Circ.651).

344 10/01/2012

Regulation 14 Passenger ships carrying goods vehicles and accompanying personnel 1 This regulation applies to passenger ships designed or adapted for the carriage of goods vehicles and accompanying personnel. 2 If in such a ship the total number of passengers which include personnel accompanying vehicles does not exceed 12 + Ad/25, where Ad = total deck area (square metres) of spaces available for the stowage of goods vehicles and where the clear height at the stowage position and at the entrance to such spaces is not less than 4 m, the provisions of regulations 13.9.1 and 13.9.2 in respect of watertight doors apply except that the doors may be fitted at any level in watertight bulkheads dividing cargo spaces. Additionally, indicators are required on the navigation bridge to show automatically when each door is closed and all door fastenings are secured. 3 The ship may not be certified for a higher number of passengers than assumed in paragraph 2, if a watertight door has been fitted in accordance with this regulation. Regulation 15 Openings in the shell plating below the bulkhead deck of passenger ships and the freeboard deck of cargo ships [Coordinator’s Note: We have assumed that the bulkhead deck/freeboard deck terminology is correct throughout this reg. which we think should apply to all cargo ships?][Q6D(4)][Discuss at SLF 54] General – Steps in the bulkhead deck and freeboard deck

For the treatment of steps in the bulkhead deck of passenger ships see Explanatory Notes for regulation 13. For the treatment of steps in the freeboard deck of cargo ships see Explanatory Notes for regulation 13-1.

1 The number of openings in the shell plating shall be reduced to the minimum compatible with the design and proper working of the ship.

2 The arrangement and efficiency of the means for closing any opening in the shell plating shall be consistent with its intended purpose and the position in which it is fitted and generally to the satisfaction of the Administration.

3.1 Subject to the requirements of the International Convention on Load Lines in force, no sidescuttle shall be fitted in such a position that its sill is below a line drawn parallel to the bulkhead deck at side and having its lowest point 2.5% of the breadth of the ship above the deepest subdivision draught, or 500 mm, whichever is the greater. 3.2 All sidescuttles the sills of which are below the bulkhead deck of passenger ships and the freeboard deck of cargo ships, as permitted by paragraph 3.1, shall be of such construction as will effectively prevent any person opening them without the consent of the master of the ship.

345 10/01/2012

4 Efficient hinged inside deadlights so arranged that they can be easily and effectively closed and secured watertight, shall be fitted to all sidescuttles except that abaft one eighth of the ship's length from the forward perpendicular and above a line drawn parallel to the bulkhead deck at side and having its lowest point at a height of 3.7 m plus 2.5% of the breadth of the ship above the deepest subdivision draught, the deadlights may be portable in passenger accommodation other than that for steerage passengers, unless the deadlights are required by the International Convention on Load Lines in force to be permanently attached in their proper positions. Such portable deadlights shall be stowed adjacent to the sidescuttles they serve. . Q47. Do you think we should delete the reference to steerage passengers? Yes

China, Finland, Germany, Japan, MI, Norway, CLIA, Italy, Spain, Denmark, US, Sweden, UK

No

Comments / Alternatives?:- Norway: The term is obsolete today and these principles are covered by ICLL-66 for ICLL ships. Round 1 Discussion: All in favour and thanks to Norway for comment.


(See SLF 53/14 para 12.8). POST SLF 53 Note:- The deletion was accepted in plenary at SLF 53.

FOR SLF 54:- RECOMMEND CHANGE TO BE MADE

5.1 No sidescuttles shall be fitted in any spaces which are appropriated exclusively to the carriage of cargo. or coal . Q48. Do you think we should delete the reference to coal? Yes

China, Finland, Germany, Japan, MI, Norway, Italy, Spain, Denmark, US, Sweden, France

No

CLIA

Comments?:- Q48A. All are in favour except CLIA. Would CLIA be prepared to accept the majority view or are there good reasons for keeping the reference to coal? Comments / CLIA?:- Finland: Support. CLIA: Agree with the deletion. Round 2 Discussion: Support for this proposal is now unanimous but France has made a comment about coal under Q59 so we will now deal with these questions under Q59. Q48B – now see Q59B.

346 10/01/2012

POST SLF 53 Note:- The deletion was accepted in both places.

FOR SLF 54:- RECOMMEND CHANGE TO BE MADE

5.2 Sidescuttles may, however, be fitted in spaces appropriated alternatively to the carriage of cargo or passengers, but they shall be of such construction as will effectively prevent any person opening them or their deadlights without the consent of the master. 6 Automatic ventilating sidescuttles shall not be fitted in the shell plating below the

bulkhead deck of passenger ships and the freeboard deck of cargo ships without the special sanction of the Administration.

7 The number of scuppers, sanitary discharges and other similar openings in the

shell plating shall be reduced to the minimum either by making each discharge serve for as many as possible of the sanitary and other pipes, or in any other satisfactory manner.

8.1 All inlets and discharges in the shell plating shall be fitted with efficient and accessible arrangements for preventing the accidental admission of water into the ship.

8.2.1 Subject to the requirements of the International Convention on Load Lines in force, and except as provided in paragraph 8.3, each separate discharge led through the shell plating from spaces below the bulkhead deck of passenger ships and the freeboard deck of cargo ships shall be provided with either one automatic non-return valve fitted with a positive means of closing it from above the bulkhead deck or with two automatic non-return valves without positive means of closing, provided that the inboard valve is situated above the deepest subdivision draught and is always accessible for examination under service conditions. Where a valve with positive means of closing is fitted, the operating position above the bulkhead deck shall always be readily accessible and means shall be provided for indicating whether the valve is open or closed . 8.2.2 The requirements of the International Convention on Load Lines in force shall apply to discharges led through the shell plating from spaces above the bulkhead deck of passenger ships and the freeboard deck of cargo ships. 8.3 Machinery space, main and auxiliary sea inlets and discharges in connection with the operation of machinery shall be fitted with readily accessible valves between the pipes and the shell plating or between the pipes and fabricated boxes attached to the shell plating. In manned machinery spaces the valves may be controlled locally and shall be provided with indicators showing whether they are open or closed. 8.4 Moving parts penetrating the shell plating below the deepest subdivision draught shall be fitted with a watertight sealing arrangement acceptable to the Administration. The inboard gland shall be located within a watertight space of such volume that, if flooded, the bulkhead deck will not be submerged. The Administration may require that if such compartment is flooded, essential or emergency power and lighting, internal communication, signals or other emergency devices must remain available in other parts of the ship.

347 10/01/2012

8.5 All shell fittings and valves required by this regulation shall be of steel, bronze or other approved ductile material. Valves of ordinary cast iron or similar material are not acceptable. All pipes to which this regulation refers shall be of steel or other equivalent material to the satisfaction of the Administration. 9 Gangway, cargo and fuelling ports fitted below the bulkhead deck of passenger ships and the freeboard deck of cargo ships shall be watertight and in no case be so fitted as to have their lowest point below the deepest subdivision draught. 10.1 The inboard opening of each ash-chute, rubbish-chute, etc., shall be fitted with an efficient cover. 10.2 If the inboard opening is situated below the bulkhead deck of passenger ships and the freeboard deck of cargo ships, the cover shall be watertight and, in addition, an automatic non-return valve shall be fitted in the chute in an easily accessible position above the deepest subdivision draught. Regulation 15-1 External openings in cargo ships [This regulation does not apply to small dry cargo ships?] [Q6D(4)[18]] [Coordinator’s Note: The item in square brackets has been added because the reg. is based on old SOLAS 25-10, applicable only to cargo vessels with L >= 80 m; [Discuss at SLF 54] 1 All external openings leading to compartments assumed intact in the damage analysis, which are below the final damage waterline, are required to be watertight.

Regulation 15-1.1

With regard to air-pipe closing devices, they should be considered weathertight closing devices (not watertight). This is consistent with their treatment in regulation 7-2.5.2.1. However, in the context of regulation 15-1, “external openings” are not intended to include air-pipe openings.

2 External openings required to be watertight in accordance with paragraph 1 shall, except for cargo hatch covers, be fitted with indicators on the bridge.

3 Openings in the shell plating below the deck limiting the vertical extent of damage shall be fitted with a device that prevents unauthorized opening if they are accessible during the voyage.

4 Other closing appliances which are kept permanently closed at sea to ensure the watertight integrity of external openings shall be provided with a notice affixed to each appliance to the effect that it is to be kept closed. Manholes fitted with closely bolted covers need not be so marked.

348 10/01/2012

Regulation 16 Construction and initial tests of watertight doors, sidescuttles, etc. [Default – provided changes are made as shown below] [Q6D(4)[19]] [Discuss at SLF 54] 1 In all ships:

.1 the design, materials and construction of all watertight doors, sidescuttles, gangway and cargo ports, valves, pipes, ash-chutes and rubbish-chutes referred to in these regulations shall be to the satisfaction of the Administration;

.2 such valves, doors and mechanisms shall be suitably marked to ensure that they may be properly used to provide maximum safety; and

.3 the frames of vertical watertight doors shall have no groove at the bottom in which dirt might lodge and prevent the door closing properly.

2 In passenger ships and cargo ships watertight doors shall be tested by water pressure to a head of water [measured from the lower edge of the door opening to the bulkhead deck or the freeboard deck][they might sustain in a final or intermediate stage of flooding] [Q6D(4)[20]]. [Coordinator’s Note: as it stands this is a “deterministic” criterion – would it not be better to simply use a head of water to the bulkhead deck in passenger ships or the freeboard deck in cargo ships? For small dry cargo ships this also avoids the problem of having to undertake a full damage stability analysis simply to determine the test head for a watertight door– see Q6D Round 6 Discussion paragraph 5.4 and 5.5 for more details]. [Discuss at SLF 54]

Regulation 16.2

1. Watertight doors should be tested by water pressure to a head of water measured from the lower edge of the door opening to the bulkhead deck or the freeboard deck[, or to the most unfavourable final or intermediate waterplane during flooding, whichever is greater.] [See coordinator’s note above for reason for proposed deletion. If the above text change to the regulation is approved, EN 1 could be deleted entirely.] [Discuss at SLF 54]

2. Large doors, hatches or ramps on passenger and cargo ships, of a design and size that would make pressure testing impracticable, may be exempted from regulation 16.2, provided it is demonstrated by calculations that the doors, hatches or ramps maintain watertightness at design pressure with a proper margin of resistance. Where such doors utilize gasket seals, a prototype pressure test to confirm that the compression of the gasket material is capable of accommodating any deflection, revealed by the structural analysis, should be carried out. After installation every such door, hatch or ramp should be tested by means of a hose test or equivalent.

Note: See Explanatory Notes for regulation 13 for additional information regarding the treatment of steps in the bulkhead deck of passenger ships. See Explanatory Notes for regulation 13-1 for additional information regarding the treatment of steps in the freeboard deck of cargo ships.

349 10/01/2012

Regulation 16-1 Construction and initial tests of watertight decks, trunks, etc. [Default] [Q6D(4)[21]] [Discuss at SLF 54]

1 Watertight decks, trunks, tunnels, duct keels and ventilators shall be of the same strength as watertight bulkheads at corresponding levels. The means used for making them watertight, and the arrangements adopted for closing openings in them, shall be to the satisfaction of the Administration. Watertight ventilators and trunks shall be carried at least up to the bulkhead deck in passenger ships and up to the freeboard deck in cargo ships.

2 [For passenger ships,] [W][w]here [Q6D(4)[22]] [Discuss at SLF 54]a ventilation trunk passing through a structure penetrates the bulkhead deck, the trunk shall be capable of withstanding the water pressure that may be present within the trunk, after having taken into account the maximum heel angle allowable during intermediate stages of flooding, in accordance with regulation 7-2. [Coordinator’s Note: This paragraph originally came from S2002 II-1/19.2 where it applied only to ro-pax ships. It cannot refer to a cargo ship as it mentions IS flooding. Therefore we propose to add the qualifier at the beginning, as shown.]

3 Where all or part of the penetration of the bulkhead deck is on the main ro-ro deck, the trunk shall be capable of withstanding impact pressure due to internal water motions (sloshing) of water trapped on the ro-ro deck.

4 After completion, a hose or flooding test shall be applied to watertight decks and a hose test to watertight trunks, tunnels and ventilators.

Regulation 17 Internal watertight integrity of passenger ships above the bulkhead deck General – Steps in the bulkhead deck

For the treatment of steps in the bulkhead deck of passenger ships see Explanatory Notes for regulation 13. 1 The Administration may require that all reasonable and practicable measures shall be taken to limit the entry and spread of water above the bulkhead deck. Such measures may include partial bulkheads or webs. When partial watertight bulkheads and webs are fitted on the bulkhead deck, above or in the immediate vicinity of watertight bulkheads, they shall have watertight shell and bulkhead deck connections so as to restrict the flow of water along the deck when the ship is in a heeled damaged condition. Where the partial watertight bulkhead does not line up with the bulkhead below, the bulkhead deck between shall be made effectively watertight. Where openings, pipes, scuppers, electric cables etc. are carried through the partial watertight bulkheads or decks within the immersed part of the bulkhead deck, arrangements shall be made to ensure the watertight integrity of the structure above the bulkhead deck.

*

350 10/01/2012

Regulation 17.1

Watertight sliding doors with reduced pressure head complying with the requirements of MSC/Circ.541 (reproduced below), as may be amended, should be in line with regulation 7-2.5.2.1. These types of tested watertight sliding doors with reduced pressure head could be immersed during intermediate stages of flooding.

_______________ * Refer to the Guidance notes on the integrity of flooding boundaries above the bulkhead deck

of passenger ships for proper application of regulations II-1/8 and 20, paragraph 1, of SOLAS 1974, as amended (MSC/Circ.541, as may be amended). [Included below]

R17.1 EN (removal of the word “sliding”) Additional comments received from CLIA/CCSF between round 1 and 2: Regulation 17.1 EN The watertight integrity above the bulkhead deck should also allow using other than sliding doors as watertight doors here. Watertight [sliding] doors with reduced pressure head complying with the requirements of MSC/Circ.541 (reproduced below), as may be amended, should be in line with regulation 7-2.5.2.1. These types of tested watertight [sliding] doors with reduced pressure head could be immersed during intermediate stages of flooding. Coordinator’s Comments: Do we have anything against this proposal? CG Member’s Comments?:- MI: Difficult to perceive a closing control mechanism for anything other than a sliding door. Germany: Acceptable. Italy: Fully agreed. RINA: It is considered that this proposal allows the use of hinged watertight doors. If this is the case then it needs to be demonstrated that such doors will meet the test requirements in regulation 13. It is concluded that as there are currently fire protected sliding doors meeting the requirements of a watertight sliding door then why would there be a need to provide watertight hinged doors? France: OK : Other types of door than sliding door may fulfil the specified requirements. Norway: Norway can not support this. Doors required to be watertight due to immersion in the final stage of flooding shall be sliding doors as set out in MSC/Circ.541 Annex paragraph 3. Note also the concerns on escape ways in paragraph 4 of the circular. US: MSC/Circ.541 specifies sliding doors; we do not agree to the proposed change without further discussion. Also it seems either a new MSC Circular should be developed to replace MSC/Circ.541 in S2009 or the relevant guidance should be incorporated directly into the EN (and the footnote to MSC/Circ.541 in S2009 should then be deleted). Lastly, the meaning of the wording “should be in line with regulation 7-2.5.2.1” is not clear to us. Round 2 Discussion:- There is some support for CLIA’s proposal to remove “sliding” from the EN for reg. 17.1 but there are considerable reservations. As Norway and the US point out, MSC/Circ.541 clearly requires sliding watertight doors to be fitted. Although the circular applies to the previous version of SOLAS and needs updating for S2009, as stated by the US, it would seem that its provisions are even more necessary now that the new regulations permit submergence of the bulkhead deck up to the immersion limit line at equilibrium. So it is hard to see how we can simply remove “sliding” without at least some discussion. RINA points out that hinged WT doors would need to comply with the test requirements of reg. 17 and also that there are now sliding fire protection doors equivalent to sliding WT doors so cannot see the need for fitting hinged WT doors.

351 10/01/2012

As stated by the US, we also need to re-consider the footnote referring to MSC/Circ.541 and decide whether a new circular should be developed to go with S2009 or whether its provisions should be incorporated into the EN and the footnote deleted. MSC/Circ.541 would then remain applicable to pre-S2009 ships only. Finally the US queries the cross-reference to reg. 7-2.5.2.1 (included here for ease of reference):- 5.2 In all cases, si is to be taken as zero in those cases where the final waterline, taking into account sinkage, heel and trim, immerses:

.1 the lower edge of openings through which progressive flooding may take place and such flooding is not accounted for in the calculation of factor si. Such openings shall include air-pipes, ventilators and openings which are closed by means of weathertight doors or hatch covers; and

CLIA Q16 (for SLF53 WG). In the light of comments from Norway, RINA and the US do you think that:- a) we can safely remove the word “sliding” from the EN as proposed by CLIA b) we should transfer and update the relevant parts of MSC/Circ.541 to the EN and delete the footnote reference to the circular or c) write a new circular to update MSC/Circ.541 for compatibility with S2009? a) remove “sliding” Y/N?

b) transfer 541 to EN + delete footnote Y/N?

c) write new circular +change footnote Y/N?

Further Comments / Why do we need the reference to reg. 7-2.5.2.1?:- Post SLF 53 Comments:- This issue was extensively discussed at the Thursday afternoon session of the WG and there were mixed views – some believed that sliding WTD were needed for maintaining reserve buoyancy as in SOLAS 90 Ch II-1, Reg. 8 whereas others felt that hinged WTD were sufficient as long as they were satisfactorily tested. Whether we need to clarify the reference to Reg. 7-2.5.2.1 was not discussed to our recollection but it was agreed that we should adopt option b), above, and transfer the relevant parts of MSC/Circ.541 into the EN, customizing them for S2009. So there is some work by the CG needed on this item ……. CLIA Q16C for 2011 CG. In the light of comments received to date and views expressed in the WG:- a) Can we can safely remove the word “sliding” from the EN as originally proposed by CLIA.

352 10/01/2012

b) Do we need to improve the wording referring to reg. 7-2.5.2.1 (or remove the reference altogether?) – suggestions would be welcome. c) Can somebody transfer the relevant parts of MSC/Circ.541 to the EN and update them for SOLAS 2009, as agreed by the WG (or is this a job for the coordinator!)? a) remove “sliding” Y/N?

Yes: Vanuatu, Japan, China, Germany, Italy, CLIA, France, ICS No: Sweden, Norway, RINA, Denmark, Finland, UK, US (No; not until this issue is fully considered through the incorporation of relevant parts of MSC/Circ.541 into the EN), Other: EC (A further clarification of the background of this proposal would be welcomed).

b) Suggestions for wording of ref to 7-2.5.2.1

Vanuatu (remove reference). US (Unfortunately we do not have a suggestion here, as it is now very unclear to us what was actually intended with this EN. It seems because of the second sentence (i.e. indicates MSC/Circ.541 compliant WTD can be “immersed” during intermediate stage flooding) that the intention was they can’t be immersed at final equilibrium (otherwise s = 0 per reg 7-2.5.2.1)? This would be consistent with the treatment under SOLAS 90 MSC/Circ.541 where there was still a margin line and WTDs above the bulkhead deck were only for the residual stability range. Maybe we should delineate 2 types of WTDs for use above the bulkhead deck; those that can be submerged in the final equilibrium condition (a “regular” sliding WTD) and those that can only intermittently be submerged in the residual stability range (a quasi-MSC/Circ.541 [sliding] WTD). For this latter door we should carefully consider what is really necessary based on practicality and experience using MSC/Circ.541. Does the FLOODSTAND project provide any help here?). Norway (Not in favour of removing the reference). RINA (No comment). Denmark (Remove reference as it is misleading). France: (Reference to reg 7-2.5.2.1 is not appropriate as this paragraph deals with “watertight doors” so they should be permitted to be immersed at any stage of flooding. It should be just specified that head of water that they have to sustain during any stage of flooding must not be higher than what they can sustain. So proposed wording is the following : “Watertight doors with reduced pressure head complying with the requirements of regulation 13 or 13-1 may be used. These types of tested watertight doors with reduced pressure head must not be immersed at any stage of flooding by a head of water higher than the tested water head.”)

c) Any Volunteers to transfer 541 to EN (+ delete footnote)?

RINA (No comment). France: (Only paragraph 4 and 5 of MSC circular 541 would need to be transferred in addition to previous sentence).

353 10/01/2012

Further Comments?:- Finland: Hinged watertight door is difficult to fulfil requirements related to watertight integrity acc to reg. 7-2.5.2.1 and also to fulfil requirements for pressure testing stated in MSC / Circ. 1176. Spain: We recommend to consider also MSC/Circ.1176 (UNIFIED INTERPRETATIONS TO SOLAS CHAPTERS II-1 AND XII AND TO THE TECHNICAL PROVISIONS FOR MEANS OF ACCESS FOR INSPECTIONS), and in particular item 8. SOLAS CHAPTER II-1, PARTS B AND B-1 DOORS IN WATERTIGHT BULKHEADS OF PASSENGER SHIPS AND CARGO SHIPS. This Circular considers different watertight doors position relative to equilibrium or intermediate waterplane (taking account of flooding due to an assumed damage). Round 6 Discussion: Firstly we will look at the responses to the 3 questions:- For question (a) - removing the word “sliding” from reg. 17.1 EN. 8 were in favour, 7 were opposed and the EC asked for further clarification of the background. To the latter we can only say that the item was introduced by CLIA between round 1 and 2 as shown at the beginning of this question box and the earlier dialogue is in the large working document. We are not sure of the original motive. The US is opposed until the relevant parts of MSC /Circ. 541 are incorporated into the EN. For question (b) – regarding the reference in the EN to reg. 7-2.5.2.1 Of 6 who responded:- Vanuatu and Denmark want the reference removing altogether France do not consider any reference to reg. 7-2.5.2.1 to be appropriate (for reasons given below) Norway wants to keep the reference RINA had no comment US and France have detailed comments which are discussed below. For question (c) – regarding transferring Circ.541 to the EN (as agreed by the WG) There was 1 “no comment” (RINA) but France has a proposal which is discussed below. Under “further comments” Finland points out that hinged doors would not fulfil the watertight integrity requirements of reg. 7-2.5.2.1 (needed to avoid s=0 when immersed) or meet the pressure testing requirements of MSC/Circ.1176. Spain also draws our attention to MSC/Circ.1176, Part 8 for which many thanks. Proposal (1) by France In answering question (b) France has clear proposals for amending the EN by altering the opening sentences and incorporating paragraphs 4 and 5 of MSC/Circ.541 as shown below:-

Regulation 17.1

Watertight sliding doors with reduced pressure head complying with the requirements of MSC/Circ.541 (reproduced below), as may be amended, should be in line with regulation 7-2.5.2.1. These types of tested watertight sliding doors with reduced pressure head could be immersed during intermediate stages of flooding.

354 10/01/2012

1. Watertight doors with reduced pressure head complying with the requirements of regulation 13 or 13-1 may be used. These types of tested watertight doors with reduced pressure head must not be immersed at any stage of flooding by a head of water higher than the tested water head. [Co-ordinator’s Note: The following 2 paragraphs are from MSC/Circ.541 paragraphs 4 and 5:-] 2. The use of watertight sliding doors above the bulkhead deck affects the escape provision of regulation II-2/28. When such doors are used above the bulkhead deck, there should be at least two means of escape from each main vertical zone or similarly restricted space or group of spaces, at least one of which should be independent of watertight doors and at least one of which should give access to a stairway forming a vertical escape. Sliding doors that will be used frequently by passengers must not create a tripping hazard. 3. Doors fitted above the bulkhead deck which are required to meet both fire-protection and watertight requirements shall comply with the fire requirements in regulation II-2/30 and the watertight requirements in [3? – this needs to be clarified] above. Notwithstanding the ultimate sentence of regulation II-2/30.2, watertight doors fitted above the bulkhead deck should be insulated to the standard required by table 26.1 and regulation II-2/24.1.1. The door must be capable of operation using both the remote fire door control circuit and the remote watertight door control circuit. If two doors are fitted, they must be capable of independent operation. The operation of either door separately must not preclude closing of the other door. Both doors must be capable of being operated from either side of the bulkhead. The cross-references highlighted in paragraphs 2 and 3 are to the 2001 Consolidated Version of SOLAS which now seems to have been substantially re-written and re-numbered. Could France help us with the cross-references and confirm that including only the above two paragraphs from Circ.541 is their intention? If France’s proposal is accepted could the footnote reference to MSC/Circ.541 be deleted in line with our new “footnote policy”?

* Refer to the Guidance notes on the integrity of flooding boundaries above the bulkhead deck of passenger ships for proper application of regulations II-1/8 and 20, paragraph 1, of SOLAS 1974, as amended (MSC/Circ.541, as may be amended).

US Comments and Proposal (2) in response to question (b) We wonder whether the above proposal by France would satisfy the points made by the US in their response to question (b), above? It seems to us that the US has identified an underlying problem whereby the new probabilistic damage stability methods clash somewhat with the deterministic methods in use under MSC/Circ.541. Then damage extents were defined and limited in length (usually one or two compartments) and penetration depth (up to B/5). The damage stability criteria were prescriptively specified and, most importantly, immersion of the margin line at final equilibrium was not permitted. The US asks: Maybe we should delineate 2 types of WTDs for use above the bulkhead deck; those that can be submerged in the final equilibrium condition (a “regular” sliding WTD) and those that can only intermittently be submerged in the residual stability range (a quasi-MSC/Circ.541 [sliding] WTD). For this latter door we should carefully consider what is really necessary based on practicality and experience using MSC/Circ.541. Does the FLOODSTAND project provide any help here?

355 10/01/2012

[Co-ordinator’s Note – we will ask the CG members involved with FLOODSTAND]. Some Further Thoughts We guess that MSC/Circ.541 was written to help to determine which portions of the buoyant superstructure above the bulkhead deck could be “included” in the computer model used to determine the damage stability characteristics associated with specific individual deterministic damage cases. The buoyancy of the volume immediately in way of the damage extent was “lost” but the hope was that any water on the bulkhead deck would be “contained” within partial bulkheads or deep webs which usually aligned with the main transverse subdivision bulkheads below the deck. The idea was that the floodwater between the partial bulkheads (or side web frames) extending from the side shell would form a “wedge” shape whose geometry would depend upon the heel and trim. The depth from the side shell of partial bulkheads or webs could then be calculated so as to constrain the “wedge” and prevent water flooding along the bulkhead deck which could therefore be assumed maintain its buoyancy outside the damage zone. Of course, at final equilibrium after damage the regulations did not allow the margin line to be immersed so there would be no water on the bulkhead deck at all. However, to calculate the characteristics of the damage GZ curve beyond equilibrium the computer model was heeled - during which operation water could reach the deck. Such flooding was deemed to be “intermittent” - analogous to a vessel rolling in a seaway. Water could also reach the bulkhead deck during stage flooding where the “equilibrium” angle of heel at any given stage was permitted to exceed that which would immerse the margin line. So the depth of the partial bulkheads or webs from the side shell was designed to contain the intermittent water encroachment during rolling or the “temporary” floodwater arising as a result of stage flooding. The co-ordinates of the partial bulkheads or webs would be defined in the damage run and the GZ curve would be terminated at the heel angle at which any floodwater contained in the “wedge” escaped “around” and past the partial bulkheads or webs. If necessary designers could increase the depth of the partial bulkheads or webs to contain the flood-water and thereby improve the damage GZ characteristics. In Circ.541 openings in partial bulkheads or webs could be weathertight if they were not submerged during any stage of flooding or were only “intermittently” submerged during rolling but had to be watertight if submerged at any time during stage flooding. Such doors, according to paragraph 3 of MSC/Circ.541, must be power-operated sliding watertight doors albeit with scantlings reduced so as to withstand the maximum head of water likely to be encountered in that location. The above describes the situation for compliance with static deterministic damage stability calculations prior to SOLAS 2009. With the introduction of the probabilistic method to passenger ship damage stability the old concepts of margin line non-immersion and fixed damage extents have disappeared making it much harder to “design” partial bulkheads or webs to withstand progressive flooding. Damage cases in which the bulkhead deck suffers considerable flooding (up to the immersion limit lines for final and intermediate stage flooding as defined in reg. 7-2.5.2 and 7-2.5.3 respectively) can still contribute to the attained index A as long as “s” is positive. The maximum head of water at any given location will almost certainly be much greater under the new SOLAS regulations. For example, some vessels can withstand 4, 5 or more compartment damages at the fore or aft end with substantial flooding of the bulkhead

356 10/01/2012

deck and still remain afloat with a positive “s” contributing to the attained index. The head at the deep end of the flooded “wedge” at the fore or aft end of the bulkhead deck in such cases could reach to the next deck above. Given all this it would seem logical that all doors in partial bulkheads or web frames on the bulkhead deck ought to be remotely-operated watertight doors with no distinction between “final”, “stage” or “intermittent” flooding. Also Finland’s statement that hinged doors do not have the watertight integrity of sliding doors and do not easily meet the pressure testing requirements of MSC/Circ. 1176 suggests that for guaranteed safety the watertight doors should be of the sliding type. It also suggests that the assumed head for all watertight doors (above and below the bulkhead deck) should be taken to the next deck above the bulkhead deck. This is because, using the probabilistic method there is no longer one easily identifiable “deepest final waterline” as is the case in deterministic regulations with fixed damage extents. Also abolition of the margin line criterion means that the bulkhead deck may now be flooded at any stage, including final. Proposal (3) by the Co-ordinators For these reasons the co-ordinators would like to propose that MSC/Circ.541 is no longer relevant for probabilistic damage calculations. In addition, some of the internal references within in the circular are out of date (SOLAS 2001) so it is suggested that the footnote referring to the circular be deleted - together with the EN for reg. 17.1. If necessary another sentence could be added to the end of the regulation such as :- “All door openings in partial watertight bulkheads or web frames used to limit progressive flooding are to be closed by remotely-operated sliding watertight doors designed to withstand an assumed head of water taken [at least] to the deck above the bulkhead deck.” The use of “head” in the definition of “watertight” in 2.17 and in regulations such as reg. 16.2 may also need to be re-visited in the light of the above arguments. Study of MSC/Circ. 1176 shows that it is also in need of revision. The SOLAS references in Table 1 are all to the 2004 Consolidated version, for example but more importantly the document takes no account of the changes outlined above resulting from the switch from deterministic to probabilistic damage calculations and the fact that the margin line concept has been abolished. As mentioned by the US it would be extremely helpful if any members involved with the design or approval of passenger ships could outline their own procedures for dealing with flooding boundaries on the bulkhead deck using SOLAS2009. Such information could then be incorporated into the EN to improve consistency of application. CONCLUSION In response to the questions raised by CLIA’s original proposal to remove the word “sliding” from reg 17.1 EN and taking your views into account as far as possible we now have three proposals which we would like you to consider. (1) France proposes to:- (a) remove the reference in the EN to reg. 7-2.5.2.1 (b) replace the existing EN with a new sentence plus two paragraphs from MSC/Circ.541 (c) remove the footnote to reg. 17.1 referring to MSC/Circ.514 (as it is now in the EN).

357 10/01/2012

(2) US wants to (a) consider the possibility of delineating two types of watertight door for use above the bulkhead deck and to re-assess the requirements in the light of practical experience gained in using MSC/Circ.541 (b) find out whether FLOODSTAND can assist us (3) The co-ordinators propose to (a) remove the footnote reference to MSC/Circ.541 (b) remove reg. 17.1 EN altogether (c) add another sentence at the end of current reg. 17.1 (d) re-examine the definition of the term “head” in regs. 2.17 and 16.2 (and elsewhere?) (e) indicate in our report to the sub-committee that MSC/Circ.1176 needs to be updated for use with SOLAS2009 (f) ask CG members for information on how the flooding boundaries on passenger ships are currently determined in practice in the S2009 probabilistic damage analysis. CLIA Q16D. Please state your preferences for the following proposals in the discussion paper.

Proposal 1 Y/N?

Yes: CLIA, US (see comments), Italy, EC (seems OK), France No: RINA, Denmark, China Comment: Germany (basically agreed, but “semi-watertight” doors, which are only weathertight and may not be submerged during any stage of flooding should still be possible).

Proposal 2 Y/N?

Yes: Finland No: CLIA, RINA, Italy, France, Denmark, China Comment: US (see below**)

Proposal 3 Y/N?

Yes: Japan (prefers (3)), RINA, US (see comments), UK, China, Denmark, EC (seems OK) No: CLIA, Germany, Italy, France

Alternative? Norway: Prefer to keep regulation and EN as it is and bring up these questions during an eventual revision of MSC/Circ.541 and MSC/Circ.1176.

Further Comments / FLOODSTAND contributions?:- Finland: We support to transfer contents of MSC/Circ.541 to the revised EN and to delete footnote. We consider; 1. Watertight sliding doors have to fulfil the requirements of regulation 13 or 13-1, if the door is submerged in final or during any intermediate stage of flooding. In an example shown below such doors are defined as watertight or light watertight. Correspondingly MSC.1/Circ. 1380 “Guidance for watertight doors on passenger ships may be opened during navigation” needs to be fulfilled. 2. If a door on a partial watertight bulkhead is located above the worst final and above the worst intermediate damage waterline, but within the area where the door becomes intermittently immersed (fully or partly) at angles of heel in the required range of positive stability beyond the equilibrium position, this door has to fulfil the requirements based on MSC/Circ. 541 and also MSC/Circ. 1176 (in table 1 this door is defined as type B. above). In the example shown below such door is defined as “semi-watertight”. The definition “semi-watertight” is not generally

358 10/01/2012

approved. However, the term “weathertight” is generally used for external doors that are to prevent water to get into vessel and does not properly describe the type of door needed in internal subdivision. Within the EU FP7 project FLOODSTAND (218532) (refer SLF53/INF.2 and SLF53/INF.2/Corr.1), a typical light watertight door was tested. This door was fully watertight to a pressure head of about 3 m. The leakage was very minimal until a notable structural failure under a pressure head of 7.8 m. Even then the leakage was only about 40 l/s. Similar results were also obtained with FEM analysis. Thus the tested door can be considered as watertight until a pressure head of about 3 m and “semi-watertight” until pressure head of about 5.5 m (acc. to Circ. 1176 maximum allowed leakage 0.375 l/min). Results of FLOODSTAND tests seems to be on the same level as results received from tests done by door supplier in official door leakage tests. Based on these results, it seems to be justified to use tested door as sliding light watertight up to the official certified pressure head of 26 kN/m2 in the parts of partial watertight bulkhead that are immersed in any stage of flooding. Further the tested door seems to use as “semi-watertight” door up to 52 kN/m2 in the parts of the bulkheads that are only intermittently immersed. To follow the requirements stated in Circ. 1176 table 1 for “semi-watertight” door located above worst waterline, we support to keep the door as sliding type. We support that “semi-watertight” door may be normally open at sea and according to Circ.541 par. 3 to be closed remotely from bridge. **** We can’t fully accept the comment that using the probabilistic method there is no longer one easily identifiable “deepest final waterline” as in the case of deterministic regulations. We have noticed that it is necessary for other design instructions to determine how different piping, AC- or other systems will be built to fulfil internal watertight integrity. The worst final or intermediate waterline will be controlled by defining relevant openings. If these openings are immersed then the s-value will be zero. Furthermore, the worst intermittently immersed waterline will be controlled by defining relevant unprotected opening, which will truncate the GZ-curve and the s-value is calculated up to this angle. In other words, from practical point of view we have to define the worst immersed limit line and correspondingly the worst intermittently immersed limit line. “The deepest final waterline” is the envelope waterline (V-line) for all damage cases that are contributing to A-index. **** With reference to the comments from US; how it should be carefully considered what is really necessary based on practicality and experience of using MSC/Circ. 541. We have attached an example below, how we have interpreted and applied Circ. 541 by defining different types of flooding devices. Light Watertight sliding door is exactly same as typical watertight sliding door but sustain lesser constant water pressure head (tested constant pressure head = 26 kPa). “Semiwatertight” sliding door is located above worst waterline but within the range of positive residual stability. This door will fulfil Circ. 541 and this door type has also been tested to fulfil requirements of leakage rate according to Circ. 1176. Finland - continued ………..

359 10/01/2012

End of comments from Finland. Germany: The contents of MSC/Circ.541 should be incorporated in the revised EN. However a more detailed discussion considering the results from FLOODSTAND should take place at SLF54. US: We understand the general effect of these 2 proposals to be similar; the primary difference being proposal 1 is via a recommendatory EN and proposal 3 is via a mandatory regulation provision. In addition, proposal 1 includes the MSC/Circ.541 guidance regarding how to satisfy

360 10/01/2012

both WTD and escape/structural fire protection requirements simultaneously (it seems this guidance, modified as necessary, will be needed). **Regarding our suggestion of maybe establishing 2 types of WTDs for use above the bulkhead deck; that was only because we weren’t sure how practical reg 13 compliant sliding WTDs (with reduced pressure head) were for passenger spaces on the bulkhead deck? [Coordinator’s Note for SLF 54: 3 options were given; responses from Round 6 were 5-3 in favour of France; 1-6 support US; 7-4 support coordinators; Norway has an alternative; Finland provides detailed info on semi-watertight doors; Germany says we need to take FLOODSTAND findings into account]

The outcome of the 2011 CG was inconclusive. FURTHER DISCUSSION NEEDED AT SLF 54.

MSC/Circ.541

19 July 1990

GUIDANCE NOTES ON THE INTEGRITY OF FLOODING BOUNDARIES ABOVE THE BULKHEAD DECK OF PASSENGER SHIPS FOR PROPER APPLICATION OF

REGULATIONS II-1/8 AND 20, PARAGRAPH 1, OF SOLAS 1974, AS AMENDED.

. The amendment to regulation II-1/8 of the 1974 SOLAS Convention that came into force on 29 April 1990, concerning the survival of passenger ships after damage, led to uncertainty in the interpretation of regulation II-1/20 on the integrity of flooding boundaries above the bulkhead deck. The Sub-Committee on Stability and Load Lines and on Fishing Vessels Safety, at its thirty-fourth session, developed amendments to regulations II-1/8 and 20 that would ensure a consistent interpretation of the amendment to regulation 8 that came into force on 29 April 1990.

. Recognizing that flooding boundaries also serve as fire protection boundaries, the Maritime Safety Committee, at its fifty-eighth session, referred the amendments proposed by the SLF Sub-Committee to the Sub-Committee on Fire Protection, for its consideration.

. Further recognizing the need for interim guidance, the Maritime Safety Committee, at its fifty-eighth session, adopted a guidance note concerning the integrity of flooding boundaries above the bulkhead deck of passenger ships. The note is annexed for the information of the Member Governments and the commercial shipbuilding industry. ***

361 10/01/2012

MSC/Circ.541

ANNEX

1. Damage stability requirements for passenger ships are set forth in regulation II-1/8 of the International Convention for the Safety of Life at Sea, 1974, as amended. The 1989 amendment to this regulation requires specific stability characteristics at angles of heel beyond the angle of equilibrium. For the purpose of calculating the required righting arms, it is necessary to establish flooding boundaries above the bulkhead deck.

2. Regulation II-1/20 addresses watertight integrity above the margin line, which is effectively equivalent to the bulkhead deck. Although paragraph 1 addresses the spread of water above the bulkhead deck, it is insufficient to establish boundaries for calculation purposes. For the purpose of establishing boundaries to satisfy the residual stability requirements of regulation II-1/8 enclosed spaces included in the damage stability calculations may have weathertight subdivision if they do not become submerged during any stage of flooding, otherwise the subdivision should be watertight. This procedure extends the principle of a weathertight envelope, put forward in paragraph 2, for boundaries which are intermittently submerged.

3. A primary concern with the integrity of boundaries above the bulkhead deck is the design and control of doors. Modern passenger ships often have doors in main vertical zone bulkheads and other bulkheads that are routinely used. Compliance with regulation II-1/8 necessitates that such doors be power operated and remotely controlled sliding watertight doors. Watertight doors installed in the spaces included in the damage stability calculations should meet the requirements of regulation II-1/15 for power operated sliding watertight doors, except that the scantlings and sealing requirements could be reduced to the maximum head of water for their location.

4. The use of watertight sliding doors above the bulkhead deck affects the escape provisions of regulation II-2/28. When such doors are used above the bulkhead deck, there should be at least two means of escape from each main vertical zone or similarly restricted space or group of spaces, at least one of which should be independent of watertight doors and at least one of which should give access to a stairway forming a vertical escape. Sliding doors that will be used frequently by passengers must not create a tripping hazard.

5. Doors fitted above the bulkhead deck which are required to meet both fire-protection and watertight requirements shall comply with the fire requirements in regulation II-2/30 and the watertight requirements in 3 above. Notwithstanding the ultimate sentence of regulation II-2/30.2 watertight doors fitted above the bulkhead deck should be insulated to the standard required by table 26.1 and regulation II-2/24.1.1. The door must be capable of operation using both the remote fire door control circuit and the remote watertight door control circuit. If two doors are fitted, they must be capable of independent operation. The operation of either door separately must not preclude closing of the other door. Both doors must be capable of being operated from either side of the bulkhead.

362 10/01/2012

2 All openings in the exposed weather deck shall have coamings of ample height and strength and shall be provided with efficient means for expeditiously closing them weathertight. Freeing ports, open rails and scuppers shall be fitted as necessary for rapidly clearing the weather deck of water under all weather conditions.

3 The open end of air pipes terminating within a superstructure shall be at least 1 m above the waterline when the ship heels to an angle of 15º, or the maximum angle of heel during intermediate stages of flooding, as determined by direct calculation, whichever is the greater. Alternatively, air pipes from tanks other than oil tanks may discharge through the side of the superstructure. The provisions of this paragraph are without prejudice to the provisions of the International Convention on Load Lines in force.

Regulation 17.3 (ref. SLF 52/17/6 - Norway) This Administration recalls that this paragraph was originally included in the previous chapter to ensure that volumes in the superstructure considered intact after damage would not be flooded through air pipes from damaged tanks below the waterline. These prescriptive requirements do not fit with the probabilistic concept and therefore this paragraph has been the source of some confusion. The intention with the provision is still relevant following the introduction of the “v”-factor also for passenger ships. However, the last two sentences seem to be redundant in the context and are proposed removed as shown. 3 The open end of air pipes terminating within a superstructure shall be [considered as an unprotected opening when applying regulation 7-2.6.1.1.] [at least 1 m above the waterline when the ship heels to an angle of 15º, or the maximum angle of heel during intermediate stages of flooding, as determined by direct calculation, whichever is the greater. Alternatively, air pipes from tanks other than oil tanks may discharge through the side of the superstructure. The provisions of this paragraph are without prejudice to the provisions of the International Convention on Load Lines in force.].

R17.3 (Open end of air pipes) . Q49. Do you agree with the proposed deletion? Yes

China, Finland, Germany, Japan, MI, Norway, Italy, Spain (but see comment), Denmark, UK, US, Sweden, France (added in Round 2 response - with comment)

No

Comments?:- CLIA: Don’t know impact. Spain: We propose to maintain the reference to the International Convention on Load Lines in force. We also prefer to clarify the term ‘open end’ of air pipes. “3 The open end of air pipes terminating within a superstructure shall be considered as an unprotected opening when applying regulation 7-2.6.1.1. at least 1 m above the waterline when

363 10/01/2012

the ship heels to an angle of 15º, or the maximum angle of heel during intermediate stages of flooding, as determined by direct calculation, whichever is the greater. Alternatively, air pipes from tanks other than oil tanks may discharge through the side of the superstructure. The open end of air pipes means pipes without any weathertight valve. The provisions of this paragraph are without prejudice to the provisions of the International Convention on Load Lines in force.” Air pipes are subject to prescriptive regulations contained in regulation 20 of ILLC, and the related interpretations (i.e.: IACS' unified interpretation LL10, IACS' unified interpretation LL36 and IACS' unified interpretation LL49, all of them approved by IMO as an unified IMO interpretations). This modification should be considered in combination with Q50. France (added in Round 2 responses): Corresponding interpretation in explanatory notes should also be deleted.


Regulation 17.3

These provisions regarding the open end of air pipes should be applied only to damages of longitudinal and transverse extent as defined in regulation 8.3 but limited to the bulkhead deck and involving tanks having their open end terminating within the superstructure. Regulation 17.3 (ref. SLF 51/3/2 Annex – US and Sweden) The requirement in this paragraph should be reviewed to determine if it, or a comparable provision, is still necessary under the new probabilistic damage stability methodology. If it is necessary, determine whether it needs revision to properly fit and be consistent with the probabilistic damage stability methodology. (Note: Background information on this item is provided below.) Associated background information: At SLF 48 the prevailing view was to delete this paragraph (see SLF 48/21, paragraph 3.41):

“3.41 The Sub-Committee found that paragraph 3 of regulation 17 was not relevant with respect to the new damage stability requirements. As a temporary solution, the EN should advise that the referenced waterline could be taken from conditions where s = 1.”

As a result, the text was agreed to at SLF 49 and included in the Interim Explanatory Notes (MSC.1/Circ.1226) for regulation 17.3:

“These provisions are generally already accounted for in an alternative probabilistic manner by paragraphs 5.2.1 and 5.3.3 of regulation 7-2. Therefore, instead of the specified waterline, the waterline from conditions where s = 1 can be used. The open end of air pipes means pipes without any weathertight valve.”

364 10/01/2012

Then, based on further discussions at SLF 50, the prevailing view on this item changed (see SLF 50/19, paragraphs 3.15.15 and 3.17.1 below).

“3.15.15 internal watertight integrity of passenger ships above the bulkhead deck “the deterministic way” to be included, replacing the existing text, noting also that regulation 17 has been included in the list of SOLAS regulations to be further considered in the future (SLF 50/3, annex 2).” “3.17.1 it should be reconsidered whether regulation II-1/17.3 should be deleted or not.”

As a result of these decisions at SLF 50, the current text in the draft Explanatory Notes submitted for consideration at SLF 51 is as follows:

“These provisions regarding the open end of air pipes should be applied only to damages of longitudinal and transverse extent as defined in regulation 8.3 but limited to the bulkhead deck and involving tanks having their open end terminating within the superstructure.” [Coordinator’s Note: The underlined sentence is now part of the current EN]

--------------------- Regulation 17.3 (ref. SLF 52/17/6 - Norway) Additionally the following could be added under regulation 17 in the EN: “This paragraph is intended to ensure that flooding of volumes located above a horizontal division in the superstructure will be taken into consideration if a side or bottom damage would cause flooding via tanks or spaces located below the waterline.” R17.3 EN (Open end of air pipes) . Q50. Do you agree with the proposed addition to the EN? Yes

China, Finland, Germany, Japan, MI, Norway, CLIA, Italy, Denmark, UK, US, Sweden

No

Comments?:- Spain: To be considered in combination with Q49. In our opinion, if modification proposed in Q49 is approved, the current text in the Explanatory Notes, and also this proposal, should be reviewed consequently. US: Given the proposed amendment to regulation 17.3, is the existing EN still necessary or valid? (i.e. “These provisions regarding the open end of air pipes should be applied only to damages of longitudinal and transverse extent as defined in regulation 8.3 but limited to the bulkhead deck and involving tanks having their open end terminating within the superstructure.”). France (added in Round 2 responses): This addition is in line with the present explanatory notes, but would be necessary only if paragraph 3 of regulation 17 is not modified (see Q49).

365 10/01/2012

Round 1 Discussion (later modified for round 2): If we look at Q49 and 50 together, and taking into account Spain’s additional text as well as Norway’s proposed deletion of parts of Reg. 17.3, we have the following proposed amendments to the text for the regulation and EN for consideration: “3 The open end of air pipes terminating within a superstructure shall be [considered as an unprotected opening when applying regulation 7-2.6.1.1. (Norway’s proposal for new text, agreed by Spain)] [at least 1 m above the waterline when the ship heels to an angle of 15º, or the maximum angle of heel during intermediate stages of flooding, as determined by direct calculation, whichever is the greater. Alternatively, air pipes from tanks other than oil tanks may discharge through the side of the superstructure](Deletion proposed by Norway, agreed by Spain). [The open end of air pipes means pipes without any weathertight valve. (Spain’s proposed addition, which is a sentence originally appearing in the interim EN, MSC.1/Circ.1226 , not agreed to by Norway)]. [The provisions of this paragraph are without prejudice to the provisions of the International Convention on Load Lines in force](Norway proposes to delete this sentence from the regulations but Spain wishes to keep it in).” Regulation 17.3 “These provisions regarding the open end of air pipes should be applied only to damages of longitudinal and transverse extent as defined in regulation 8.3 but limited to the bulkhead deck and involving tanks having their open end terminating within the superstructure.” Additionally, Norway proposes that the following could be added under regulation 17.3 in the EN: “This paragraph is intended to ensure that flooding of volumes located above a horizontal division in the superstructure will be taken into consideration if a side or bottom damage would cause flooding via tanks or spaces located below the waterline.” One point to note is that Regs. 8.3 and 17 only apply to passenger ships whereas Reg. 7-2.6.1.1 applies to cargo and passenger ships. It seems that we need to clarify what we want to achieve with Reg. 17.3 and then add EN as appropriate. It seems there are at least 4 possibilities:- 1) Do we wish to ensure that any up-flooding via an open-ended air pipe from a tank below the bulkhead deck in a passenger ship subject only to minor damage (as defined by Reg. 8.3) will be taken into account by saying that the space(s) into which the up-flooding occurs will also be considered as damaged and open to the sea? 2) Are we concerned that any water reaching spaces above the bulkhead deck within a superstructure for any reason (e.g. an open bow door, fire-fighting etc) may spread along the bulkhead deck then down-flood into empty tanks via open air pipes of insufficient height, thereby causing progressive flooding? 3) Do we simply want to say that, in a probabilistic sense, if a passenger ship is subject to minor damage (as defined by Reg. 8.3) to a tank or tanks below the bulkhead deck and if such tanks have open-ended air pipes leading to enclosed spaces within the superstructure above the bulkhead deck, which could result in up-flooding followed by water spreading along the bulkhead

366 10/01/2012

deck, then such air pipes should be regarded as unprotected openings when applying Reg. 7-2.6.1.1 to passenger ships. The worst that would happen in this case is that such damage cases would make reduced or zero contribution to “A” via the “s” factor as calculated in Reg. 7-2. 4) We amend Reg. 17.3 as proposed by Norway [and Spain] and replace the old EN (beginning “These provisions”) with the new proposal by Norway (beginning “This paragraph ….”). Q49A – 50A: Can you please consider the above alternatives and state which, if any, of the 4 possibilities you think best represents the intention of Reg. 17.3?

(1)

RINA

(2)

(3)

MI (with comment), Italy, CLIA (Yes, as far as it concerns passenger ships)

(4)

Germany, Finland, Japan, Norway (with comments), CLIA (doesn’t this achieve the objective of 3) for passenger ships?), Denmark

Other

Comments / Further Alternatives?:- MI: This scenario [3] seems to best define the intent of Reg. 17.3 and the action described in (4) seems to adequately address this intent. France: We understand that the proposal is to verify that up-flooding through air pipes terminating within a superstructure is not possible for all studied damage cases. This should apply when studying damages limited by a horizontal watertight boundary as considered in reg 7-2.6. If regulation 17.3 is amended as proposed in Q39 and unanimously agreed, explanatory notes must be amended accordingly. We can propose the following wording : “This paragraph is intended to ensure that volumes located above a horizontal watertight boundary (above the waterline under consideration) will not be flooded in case of damages below this horizontal subdivision, calculated according to Reg 7-2.6” Norway: Without the proposal by Spain. A vent head complying with ICLL can not prevent “upflooding” and a reference to that convention is not relevant. Our principal concern is that allowance for the “v”-factor may not be realistic if partial flooding of a space from below might result in large free surfaces on the otherwise intact volume, hence our reference to regulation 7-2.6.1.1. The contribution to dA in regulation 6.2 will then be 0 if a horizontal subdivision is considered and an air-pipe leads to water accumulating on the deck. This can happen if the upper end comes below the waterplane when the ship rolls. UK: We are of the opinion that the possibility of up-flooding via an open-ended air pipe from a tank below the bulkhead deck must be avoided by checking minor damages only within Regs. 8.3: this keeps somehow SOLAS90 equivalency without introducing further deterministic checks into the probabilistic parts. We could not see any direct link to Reg. 7-2.6.1.1 to refer it in the text of Reg.17.3 . Round 2 Discussion:- We have tried to improve the round 1 discussion to make clearer the origin of the various proposed additions and deletions to reg. 17.3 and the EN and to try to clarify where the link to reg. 7-2.6.1.1 came from. We also now think that it was not Norway’s intention to replace the existing EN but to add another paragraph (see alternative 4, above). We omitted to mention the US’ option of accepting Norway’s proposal for the change to reg. 17.3 but deleting the EN altogether. We suppose that the UK would support Norway’s proposals? There was most support for alternative 4 but we have some comments and a new proposal from France. We therefore summarize the proposals from Norway, US, Spain, and France below:-

367 10/01/2012

1) Norway “3 The open end of air pipes terminating within a superstructure shall be considered as an unprotected opening when applying regulation 7-2.6.1.1. Regulation 17.3 “These provisions regarding the open end of air pipes should be applied only to damages of longitudinal and transverse extent as defined in regulation 8.3 but limited to the bulkhead deck and involving tanks having their open end terminating within the superstructure.” “This paragraph is intended to ensure that flooding of volumes located above a horizontal division in the superstructure will be taken into consideration if a side or bottom damage would cause flooding via tanks or spaces located below the waterline.” 2 US The same as Norway but delete all the EN. 3) Spain “3 The open end of air pipes terminating within a superstructure shall be considered as an unprotected opening when applying regulation 7-2.6.1.1. The open end of air pipes means pipes without any weathertight valve. The provisions of this paragraph are without prejudice to the provisions of the International Convention on Load Lines in force. Regulation 17.3 “These provisions regarding the open end of air pipes should be applied only to damages of longitudinal and transverse extent as defined in regulation 8.3 but limited to the bulkhead deck and involving tanks having their open end terminating within the superstructure.” We are not sure if Spain supports the extra paragraph proposed by Norway:- “This paragraph is intended to ensure that flooding of volumes located above a horizontal division in the superstructure will be taken into consideration if a side or bottom damage would cause flooding via tanks or spaces located below the waterline.” 4) France “3 The open end of air pipes terminating within a superstructure shall be considered as an unprotected opening when applying regulation 7-2.6.1.1.

368 10/01/2012

Regulation 17.3 “This paragraph is intended to ensure that volumes located above a horizontal watertight boundary (above the waterline under consideration) will not be flooded in case of damages below this horizontal subdivision, calculated according to Reg 7-2.6” Co-ordinator’s final comment – would this regulation not read better as follows?- “3 The open end[s] of air pipes terminating within a superstructure shall be considered as [an] unprotected opening[s] when …. etc. Q49B and Q50B (for SLF 53 WG). Which of the above alternatives do you prefer?

(1) Norway

(2) US

(3) Spain

(4) France

Other

Post SLF 53 Comments:- This issue was discussed in detail in the Thursday afternoon session of the WG. It is believed, but should be confirmed by those present, that the following changes were agreed to Reg. 17.3 and the EN:- 3 The open end of Air pipes terminating within a superstructure shall be considered as unprotected openings. at least 1 m above the waterline when the ship heels to an angle of 15º, or the maximum angle of heel during intermediate stages of flooding, as determined by direct calculation, whichever is the greater. Alternatively, air pipes from tanks other than oil tanks may discharge through the side of the superstructure. The provisions of this paragraph are without prejudice to the provisions of the International Convention on Load Lines in force.

Regulation 17.3

These provisions regarding the open end of air pipes should be applied only to damages of longitudinal and transverse extent as defined in regulation 8.3 but limited to the bulkhead deck and involving tanks having their open end terminating within the superstructure. This paragraph is intended to ensure that flooding of volumes located above a horizontal division in the superstructure will be taken into consideration if a side or bottom damage would cause flooding via tanks or spaces located below the waterline.

369 10/01/2012

Q49C and 50C for Round 4 Questionnaire. Do you agree with the above proposals to Reg. 17.3 and the EN? Yes.

Vanuatu (agree with a reservation), US (*), Norway, MI, Japan, China, RINA, UK, Denmark (with comments), Finland (with comments), CLIA (seems reasonable but I wasn’t present)

No. Germany, Italy, France

Further Comments?:- Vanuatu: We can see agreement with such pipes terminating on the 01 level; but not, for example if they were to terminate on higher levels; perhaps in an emergency generator location, for example. This, in our opinion would be in line with the original text specifying heel/list clearance above waterline. US: *My notes were not good on this either, but I had “when applying regulation 7-2.6.1.1” at the end of the reg 17.3 sentence (i.e. Air pipes terminating within a superstructure shall be considered as unprotected openings when applying regulation 7-2.6.1.1.). Denmark: According to our notes from SLF 53 the sentence in the EN starting with “These provisions regarding……” was not deleted. Germany: Possible weathertight closures need to be considered correctly, therefore following additional explanation is proposed: “Air pipes are typically weathertight in direction into the tank and unprotected in direction out of the tank. This different tightness should be considered as such depending on the flooding direction.” Finland: “The open end” to be maintained. In order to apply reg.7-2.6 air pipe terminating within a superstructure is open end. But provided with weathertight closing appliance the air pipe shall apply also reg.7-2.5.2.1 resulting s-value as zero, if submerged in final stage via progressive flooding or when adjacent watertight compartments are damaged. Italy: The first part of the sentence should be maintained, i.e. “The open end of air pipes terminating within a superstructure shall be considered as unprotected openings.”

Air pipes protected by weathertight valves are not to be considered as “unprotected”. France: Agreement on the modification of regulation 17.3. Modification of explanatory notes seems not in line with regulation itself. If unprotected openings are defined at the termination of air pipes, the intention is to verify that up flooding of corresponding room will not occur. Alternatively, progressive flooding of superstructures in which air pipes are terminating may be considered in stability calculations. In this last case, unprotected openings are no more taken into account. Alternative wording for explanatory notes may be : “This paragraph is intended to verify that if spaces within a superstructure not directly within the breach extent will not be flooded through open end of air pipes of damaged compartments.” Round 6 Discussion:- The first point to note is that the co-ordinators did not correctly report what was finally agreed at the SLF 53 WG. Many apologies for this. The WG chairman’s report to SLF 54 is now available and the Annex to SLF 54/8 on page 19 has the following agreed text for the regulation and EN:- 3 Air pipes terminating within a superstructure shall be considered as unprotected opening when applying regulation 7-2.6.1.1. Where Air pipes terminating within superstructure and which are not fitted with the watertight means of closure shall be considered as unprotected openings.

370 10/01/2012

Regulation 17.3 "This paragraph is intended to ensure that flooding of volumes located above a horizontal division in the superstructure will be taken into consideration if a side or bottom damage would cause flooding via tanks or spaces located below the waterline." As co-ordinators we would like to propose some slight adjustments and a simplification to the new text of the regulation for grammatical reasons so that it reads as follows:- 3 Air pipes terminating within a superstructure which are not fitted with watertight means of closure shall be considered as unprotected openings when applying regulation 7-2.6.1.1. The EN would remain as shown: Regulation 17.3 "This paragraph is intended to ensure that flooding of volumes located above a horizontal division in the superstructure will be taken into consideration if a side or bottom damage would cause flooding via tanks or spaces located below the waterline." We must therefore ask again for your opinion on the above texts and hope that these satisfy any points that were raised in response to Q49C and Q50C. Q49D and 50D for Round 6 Questionnaire. Do you agree with the proposals for Reg. 17.3 and the EN as agreed by the WG at SLF 53 (with minor modifications), as shown in blue and red italic above? Yes?

Japan, CLIA, RINA, Finland, Norway, Germany, US, Italy, UK, EC, France, Denmark, China

No?

Further Comments / Alternatives?:-

Q49D and Q50D THE 2011 CG UNANIMOUSLY AGREED TO ALTER THE TEXT OF REG. 17.3 AND THE EN AS SHOWN AT THE END OF THE ROUND 6 DISCUSSION.

RECOMMEND ACCEPTANCE OF THESE DECISIONS AT SLF 54. 4 Sidescuttles, gangway, cargo and fuelling ports and other means for closing openings in the shell plating above the bulkhead deck shall be of efficient design and construction and of sufficient strength having regard to the spaces in which they are fitted and their positions relative to the deepest subdivision draught*

5 Efficient inside deadlights, so arranged that they can be easily and effectively closed and secured watertight, shall be provided for all sidescuttles to spaces below the first deck above the bulkhead deck.

___________ * Refer to the Recommendation on strength and security and locking arrangements of shell doors on ro-ro passenger ships, adopted by the Organization by resolution A.793(19).

371 10/01/2012

Regulation 17-1 Integrity of the hull and superstructure, damage prevention and control on ro-ro passenger ships

1.1 Subject to the provisions of paragraphs 1.2 and 1.3, all accesses that lead to spaces below the bulkhead deck shall have a lowest point which is not less than 2.5 m above the bulkhead deck. R17-1.1.1 proposed new EN Discussion for Round 6 Supplementary Questionnaire. IACS will be presenting a paper at SLF with details of three new UI’s (Unified Interpretations) for the above SOLAS 2009 Chapter II-1 regulations. The usual procedure is for the UI’s to be approved by SLF and then MSC whereupon they are issued as MSC/Circulars. We then usually refer to these circulars in the EN as indicated in draft form below. The UI’s in question are:-


similar type) [Reg. 17-1.1.1] and

• SC81 (Drainage of enclosed spaces situated on the bulkhead deck) [Reg. 35-1.2.6.1]

R6-SQ2 for Round 6 Supplementary Questionnaire. Do you have any comments on the UI’s or any objections to inserting references to the related forthcoming MSC/Circulars in the EN as shown highlighted in draft form below? Further comments / objections?:- Japan: No comments. RINA: Why not add the interpretation directly into the EN rather than refer to a separate document? Norway: Regarding IACS SC93 and SC81: No comments Regarding IACS SC220: The interpretation (a) is identical with IACS LL32 for the ICLL Reg. 21. We can not see that this interpretation has any relevance for SOLAS Reg. II-1/17-1.1. The interpretation (b), first paragraph, seems to introduce an interpretation that is not as restrictive as the SOLAS Reg. 20-2 (94/95 Amendments). If this interpretation refers to doors required for access in accordance with SOLAS Reg. 20-2.2.3 (94/95 Amendments) this should be mentioned in the IACS SC220. Poland: I think that it might be pointed which kind of ships similar type ..like..only vehicle ferries, ro – ro ships ..and….it might be pointed [Poland – please clarify – coordinators.] US: No objection to the general approach; but subject to discussion and acceptance of the IACS UIs at SLF 54. UK: No objections. China: No comments Proposed addition to the Explanatory Notes to reflect new UI’s from IACS to be presented at SLF 54

372 10/01/2012

Regulation 17-1.1.1 − Accesses leading to spaces below the bulkhead deck

Reference is made to MSC/Circ.[xxxx] (Unified interpretation of SOLAS chapter II-1) regarding special requirements for vehicle ferries, ro-ro ships and other ships of similar type.


1.2 Where vehicle ramps are installed to give access to spaces below the bulkhead deck, their openings shall be able to be closed weathertight to prevent ingress of water below, alarmed and indicated to the navigation bridge. Query: Reg 17-1.1.2; Weathertightness of ro-ro deck. [In ro-ro ships, although the enclosed ro-ro deck is protected by a higher weathertight deck, the deck itself must be at least weathertight. In ships with long lower holds, should the ramp opening(s) be made watertight to prevent up-flooding onto the vehicle deck following bottom damage? (see also Regulations 2.19, 9.9 and 17.3)] . Q51. Are there any comments on this specific query which has arisen from

several sources since the 2009 amendments came into force? Comments?:- China: supports the opinion that preventing up-flooding onto the bulkhead deck (other than the wording of “vehicle deck”) after bottom damage is extremely vital for ro-ro passenger ships. However, upgrading the bulkhead deck from weathertightness to watertightness needs to be carefully considered. Finland: This matter should be addressed to RoPax group due to the very complex issue. Germany: This topic is under examination in the RoPax Group. As the issue is very complex we will provide comments within this RoPax Group. Japan: This issue should be considered after discussion about ToR.2, i.e. the Stockholm Agreement. MI: Agree ramps should be WT to prevent up-flooding. Norway: Should not be introduced as a mandatory design requirement, but they must be handled as potential flooding points according to watertightness. A few words to this effect could be inserted in the EN. Italy: To be addressed in the framework of ro-ro / ro-pax damage stability assessment (water on deck). Spain: Due to the specific risks associated to the flooding and the possible water accumulation in the main ro-ro deck, it could be interested to impose a watertight closure for the ramp opening(s) connecting this deck with the long lower hold. Anyway, additional clarification or discussions will be necessary. E.g.: this requirement could be linked or not to specific conditions (i.e.: double bottom and/or double side dimensions, waterline position after flooding, etcetera). It would be also useful to discuss if this requirement should be applied or not, if demonstrated using ‘water on deck’ stability calculations the ship’s capability to survive after flooding and associated ‘water on deck’ accumulation on main ro-ro deck. Denmark: We agree with the principal of preventing up-flooding onto the vehicle deck from the lower holds, but the question is whether the existing weathertight or semi-watertight ramp covers would be capable of preventing up-flooding.

373 10/01/2012

US: No comment. France (added in Round 2 responses):- If the ramp opening is not watertight, possible progressive flooding of lower hold must be considered. For damages limited to ro-ro deck, possible up flooding must also be considered. Round 1 Discussion:- There is a fairly wide range of views on this issue, the most common (4/10) being that it should be discussed by the ro-ro CG. The clear danger is that up-flooding onto the bulkhead deck by any means (open-ended air pipes, non-watertight ramps etc.) could lead to rapid loss via the water-on-deck phenomenon. But the question of whether or not this phenomenon should be included in the SOLAS2009 amendments is still not fully resolved. At this stage it is therefore proposed to raise this issue in the report of the Ro-Ro CG to SLF 53 thereby flagging it up for consideration by the sub-Committee and possible continued discussion by the Ro-Ro CG in the context of the ToR for the next session. Q51A. Any further comments?:- Comments received: RINA: There are a number of issues posed by this question. 1. In considering the up-flooding onto the vehicle deck, both bottom damage and side damages should be considered. 2. Where the LLH is flooded, it is considered that the vehicle ramp require to be sufficiently tight and with adequate strength to withstand the pressure head, due to flooding. Damage stability calculations should indicate that s = 1 for all stages of flooding. Where s=0 then the flooding of this space may result in a rapid capsize, such cases should be investigated for passenger and cargo ships. 3. Regarding the issue of weathertight v watertight this is included in the definitions in Ch. II-1, Reg. 2

“16 Weathertight means that in any sea conditions water will not penetrate into the ship.

17 Watertight means having scantlings and arrangements capable of preventing the passage of water in any direction under the head of water likely to occur in intact and damaged conditions. In the damaged condition, the head of water is to be considered in the worst situation at equilibrium, including intermediate stages of flooding.”

4. The question as posed only refers to up flooding, what about the down flooding? In the Stockholm Agreement it is understood that where the residual freeboard is 2m and above from the damaged ro-ro deck to the final damaged waterline, at the location of the damage, then the requirements of the Stockholm Agreement for water on deck calculations do not need to be carried out. As far as we are aware there are currently no requirements in the current regulation for the residual freeboard to be 2m or above, therefore it may be possible, following a damage, to have flood water on the ro-ro deck but not in the LLH. In such case then the vehicle ramp may be required to be watertight 5. In the case in 2 above the requirements need only be weathertight to prevent up flooding. In the case of 4 above then the requirements need to be watertight to prevent either up or down flooding. France: Agreement to discuss this point within the ro-ro CG.

374 10/01/2012

Round 2 Discussion:- Many thanks to RINA for their detailed comments. Regrettably we did not include this item in the ro-ro CG report as space was restricted but we will raise it at SLF 53 and try to ensure it is transferred to the ro-ro CG for further discussion by the appropriate WG and CG. Regarding RINA’s point 4, we have introduced a proposal on the concept of residual freeboard for ro-pax ships into reg. 7-2.5.2 in response to China’s query about partial submersion of the bulkhead deck. Proposed Action: Request the S-C if this item can be put into the ToR for the next intersessional ro-ro CG. Q51B (for SLF 53 S-C). May we transfer this item to the ro-ro CG and have it included in the ToR? Post SLF 53 comments?:- It was agreed to transfer this item to the ro-ro CG but before any work can be carried out they must await approval from MSC 89 in May 2011 to extend the scope of the ro-ro agenda item to include items other than WOD (see SLF 53/WP.6 paragraph 12 and Annex 4; later modified – see SLF 53/19 paragraph 10.4 and Annex 6 – extract below).

In the meantime the coordinators have contacted a ramp manufacturer who advised that changing “weathertight” to “watertight” would not cause any problems or increased costs as the sealing mechanism would be the same. Co-ordinator’s Note for SLF 54:- See discussion under Reg. 13-1.4 and SLF 54/8/1 paragraph 15.7

375 10/01/2012

1.3 The Administration may permit the fitting of particular accesses to spaces below the bulkhead deck provided they are necessary for the essential working of the ship, e.g. the movement of machinery and stores, subject to such accesses being made watertight, alarmed and indicated on the navigation bridge. 2 Indicators shall be provided on the navigation bridge for all shell doors, loading doors and other closing appliances which, if left open or not properly secured, could, in the opinion of the Administration, lead to flooding of a special category space or ro-ro space. The indicator system shall be designed on the fail-safe principle and shall show by visual alarms if the door is not fully closed or if any of the securing arrangements are not in place and fully locked and by audible alarms if such door or closing appliances become open or the securing arrangements become unsecured. The indicator panel on the navigation bridge shall be equipped with a mode selection function “harbour/sea voyage” so arranged that an audible alarm is given on the navigation bridge if the ship leaves harbour with the bow doors, inner doors, stern ramp or any other side shell doors not closed or any closing device not in the correct position. The power supply for the indicator system shall be independent of the power supply for operating and securing the doors. 3 Television surveillance and a water leakage detection system shall be arranged to provide an indication to the navigation bridge and to the engine control station of any leakage through inner and outer bow doors, stern doors or any other shell doors which could lead to flooding of special category spaces or ro-ro spaces.

376 10/01/2012

Part B-3 Subdivision load line assignment for passenger ships

Regulation 18 Assigning, marking and recording of subdivision load lines for passenger ships 1 In order that the required degree of subdivision shall be maintained, a load line corresponding to the approved subdivision draught shall be assigned and marked on the ship's sides. A ship intended for alternating modes of operation may, if the owners desire, have one or more additional load lines assigned and marked to correspond with the subdivision draughts which the Administration may approve for the alternative service configurations. Each service configuration so approved shall comply with part B-1 of this chapter independently of the results obtained for other modes of operation.

2 The subdivision load lines assigned and marked shall be recorded in the Passenger Ship Safety Certificate, and shall be distinguished by the notation P1 for the principal passenger service configuration, and P2, P3, etc., for the alternative configurations. The principal passenger configuration shall be taken as the mode of operation in which the required subdivision index R will have the highest value.

3 The freeboard corresponding to each of these load lines shall be measured at the same position and from the same deck line as the freeboards determined in accordance with the International Convention on Load Lines in force.

4 The freeboard corresponding to each approved subdivision load line and the service configuration, for which it is approved, shall be clearly indicated on the Passenger Ship Safety Certificate.

5 In no case shall any subdivision load line mark be placed above the deepest load line in salt water as determined by the strength of the ship or the International Convention on Load Lines in force. 6 Whatever may be the position of the subdivision load line marks, a ship shall in no case be loaded so as to submerge the load line mark appropriate to the season and locality as determined in accordance with the International Convention on Load Lines in force. 7 A ship shall in no case be so loaded that when it is in salt water the subdivision load line mark appropriate to the particular voyage and service configuration is submerged.

377 10/01/2012

Part B-4 Stability management

Regulation 19 Damage control information [Default] [Q6D(4)[23]][Discuss at SLF 54]

1 There shall be permanently exhibited, or readily available on the navigation bridge, for the guidance of the officer in charge of the ship, plans showing clearly for each deck and hold the boundaries of the watertight compartments, the openings therein with the means of closure and position of any controls thereof, and the arrangements for the correction of any list due to flooding. In addition, booklets containing the aforementioned information shall be made available to the officers of the ship 2 Watertight doors in passenger ships permitted to remain open during navigation shall be clearly indicated in the ship's stability information. 3 General precautions to be included shall consist of a listing of equipment, conditions, and operational procedures, considered by the Administration to be necessary to maintain watertight integrity under normal ship operations. 4 Specific precautions to be included shall consist of a listing of elements (i.e. closures, security of cargo, sounding of alarms, etc.) considered by the Administration to be vital to the survival of the ship, passengers and crew. 5 In case of ships to which damage stability requirements of part B-1 apply, damage stability information shall provide the master with a simple and easily understandable way of assessing the ship’s survivability in all damage cases [Q52D, see below][6-3 were in favour of Germany amending the Appendix to the EN; 4-4 on Japan’s proposal for consequence diagrams][Discuss at SLF 54]involving a compartment or group of compartments. _____________________ * Refer to the Guidelines for damage control plans (MSC.1/Circ.1245) [Included below].

378 10/01/2012

Ref. T1/2.04 MSC.1/Circ.1245

29 October 2007

GUIDELINES FOR DAMAGE CONTROL PLANS AND INFORMATION TO THE MASTER

1 The Maritime Safety Committee, at its eighty-third session (3 to 12 October 2007), following a proposal by the Sub-Committee on Stability and Load Lines and on Fishing Vessels Safety at its fiftieth session, approved Guidelines for damage control plans and information to the master, set out in the annex, with the objective to provide advice on the preparation of damage control plans and to set a minimum level for the presentation of damage stability information for use on board passenger and cargo ships to which SOLAS regulation II-1/19, as amended by resolution MSC.216(82), applies. 2 Member Governments are invited to use the annexed Guidelines when applying the requirements of SOLAS regulation II-1/19, as amended by resolution MSC.216(82), and to bring the aforementioned Guidelines to the attention of all parties concerned, in particular shipbuilders, shipmasters, shipowners, ship operators and shipping companies.

***

MSC.1/Circ.1245

379 10/01/2012


ANNEX GUIDELINES FOR DAMAGE CONTROL PLANS AND

INFORMATION TO THE MASTER 1 Application

These Guidelines are intended as advice on the preparation of damage control plans and to set a minimum level for the presentation of damage stability information for use on board passenger and cargo ships to which SOLAS regulation II-1/19, as amended by resolution MSC.216(82), applies. 2 General

2.1 The damage control plan and damage control booklet are intended to provide ship’s officers with clear information on the ship’s watertight subdivision and equipment related to maintaining the boundaries and effectiveness of the subdivision so that, in the event of damage to the ship causing flooding, proper precautions can be taken to prevent progressive flooding through openings therein and effective action can be taken quickly to mitigate and, where possible, recover the ship’s loss of stability. 2.2 The damage control plan and damage control booklet should be clear and easy to understand. It should not include information which is not directly relevant to damage control, and should be provided in the working language of the ship. If the languages used in the preparation of the plan and booklets are not one of the official languages of the SOLAS Convention, a translation into one of the official languages should be included. 3 Damage control plans

3.1 The damage control plan should be of a scale adequate to show clearly the required content of the plan. 3.2 Isometric drawings are recommended for special purposes. The plan should include inboard profile, plan views of each deck and transverse sections to the extent necessary to show the following:

.1 the watertight boundaries of the ship; .2 the locations and arrangements of cross-flooding systems, blow-out plugs and

any mechanical means to correct list due to flooding, together with the locations of all valves and remote controls, if any;

.3 the locations of all internal watertight closing appliances including, on ro-ro ships, internal ramps or doors acting as extension of the collision bulkhead and their controls and the locations of their local and remote controls, position indicators and alarms. The locations of those watertight closing appliances which are not allowed to be opened during the navigation and of those watertight closing appliances which are allowed to be opened during navigation, according to SOLAS regulation II-1/22.4, should be clearly indicated;

380 10/01/2012


.4 the locations of all doors in the shell of the ship, including position indicators, leakage detection and surveillance devices;

.5 the locations of all external watertight closing appliances in cargo ships, position indicators and alarms;

.6 the locations of all weathertight closing appliances in local subdivision boundaries above the bulkhead deck and on the lowest exposed weather decks, together with locations of controls and position indicators, if applicable; and

.7 the locations of all bilge and ballast pumps, their control positions and associated valves.

4 Damage control booklets

4.1 The information listed in section 3 should be repeated in the damage control booklet. 4.2 The damage control booklet should include general instructions for controlling the effects of damage, such as:

.1 immediately closing all watertight and weathertight closing appliances;

.2 establishing the locations and safety of persons on board, sounding tanks and compartments to ascertain the extent of damage and repeated soundings to determine rates of flooding; and

.3 cautionary advice regarding the cause of any list and of liquid transfer operations to lessen list or trim, and the resulting effects of creating additional free surfaces and of initiating pumping operations to control the ingress of water.

4.3 The booklet should contain additional details to the information shown on the damage control plan, such as the locations of flooding detection systems, sounding devices, tank vents and overflows which do not extend above the weather deck, pump capacities, piping diagrams, instructions for operating cross-flooding systems, means of accessing and escaping from watertight compartments below the bulkhead deck for use by damage control parties, and alerting ship management and other organizations to stand by and to co-ordinate assistance, if required. 4.4 If applicable to the ship, locations of non-watertight openings with non-automatic closing devices through which progressive flooding might occur should be indicated as well as guidance on the possibility of non-structural bulkheads and doors or other obstructions retarding the flow of entering seawater to cause at least temporary conditions of unsymmetrical flooding. 4.5 If the results of the subdivision and damage stability analyses are included, additional guidance should be provided to ensure that the ship's officers referring to that information are aware that the results are included only to assist them in estimating the ship's relative survivability. 4.6 The guidance should identify criteria on which the analyses were based and clearly indicate that the initial conditions of the ship's loading extents and locations of damage, permeabilities, assumed for the analyses may have no correlation with the actual damaged condition of the ship.

381 10/01/2012

MSC.1/Circ.1245ANNEX Page 3 5 Visual guidance to the master

Visual guidance, such as damage consequence diagrams, may be used to provide the master with a rapid means to evaluate the consequence of damage to the ship. 6 Placement on board the ship 6.1 For passenger ships, the damage control plan should be permanently exhibited or readily available on the navigation bridge, as well as in the ship’s control station, safety centre or equivalent. 6.2 For cargo ships, the damage control plan should be permanently exhibited or readily available on the navigation bridge. Furthermore, the damage control plan should be permanently exhibited or readily available in the cargo control room, all ship’s office or other suitable location. 7 Use of on-board computers Damage control plans and damage control booklets should be in printed form. The use of on-board computers * , with damage stability software developed for the specific ship, and familiar to properly trained ship’s officers can provide a rapid means to supplement the information in the plan and booklet for effective damage control. 8 Shore-based emergency response systems 8.1 A shore-based emergency response system may be used to supplement the damage control booklet referred to in section 4. 8.2 Contact information for gaining access to shore-based facilities together with a list of information required for making damage stability assessments should be readily available. ____________________________ *

Refer to the Guidelines for the on-board use and application of computers (MSC/Circ.891).

382 10/01/2012

Regulation 19 (ref. SLF 52/17/2 – Germany) Germany refers to Regulation 19.5: “……damage stability information shall provide the master a simple and easily understandable way of assessing the ship’s survivability in all damage cases involving a compartment or group of compartments.” ……………… 3 Germany understands that selected damage cases should be included in the Damage Control Booklet which shall be placed on board. The content of such documentation is specified in the appendix to the EN and in MSC.1/Circ.1245. 4 As part of the documentation, sample damage cases should be included. In paragraph 4.5 of MSC.1/Circ.1245, it is specified that if the results of the subdivision and damage stability analyses are included, additional guidance should be provided to ensure that the ship’s officers referring to that information are aware that the results are included only to assist them in estimating the ship’s relative survivability. 5 Noting the theoretical background of the damage stability calculation and the limited transferability to actual loading conditions, it is the understanding of Germany that the focus on simplicity should prevail. Germany also points out that the meaning of “all damage cases” in II-1/19.5 is not clear. Therefore, Germany suggests that the master should be provided with selected sample cases to inform him about the general capability of the vessel. 6 Germany further notes that a clear guidance for preparation of sample damage cases to be included in the Damage Control booklet is presently not available. Proposal 7 Germany proposes to clearly define the sample damage cases and the scope of documentation in order to ensure uniform application. 8 By doing so, the paramount goal of the requirement for damage control documentation, namely to support the crew in case of casualty with easily understandable information, could be achieved. Damage control information for all type of vessels 9 The minimum required scope of sample damage cases should include damage to each main watertight zone in the longitudinal direction. 10 Any main transverse subdivision (such as longitudinal watertight bulkheads) should be considered by additional damage scenarios with transverse extension up to and exceeding such longitudinal bulkhead. The so-defined sample damage cases do not necessarily correspond to the damage stability calculation. 11 For each sample damage case, the final floating position (draft, trim, heel, residual righting lever curve (GZ) and reserve to flooding of opening points should be stated. If in certain damage cases the criteria for the respective damage stability regulation are exceeded, such cases should not be omitted. In such a way, the master could gain valuable information about the capabilities of the vessel.

383 10/01/2012

12 The initial intact condition(s) shall correspond to the applicable damage stability regulation. 13 The permeabilities should correspond to the applicable regulations. Additional damage control information for vessels with [unusual / complex] [compartmentation / watertight subdivision] 14 For vessels with an unusual or a complex watertight subdivision, a more detailed documentation of sample damage cases may be required. 15 In addition to the minimum required scope of documentation of sample damage cases, the documentation of combination of damaged zones should be included. 16 Typical samples with complex [compartmentation/watertight subdivision] are passenger vessels, ro-ro passenger vessels, special purpose ships or any other type of vessel with a specialized watertight subdivision. R19.5 (meaning of “in all damage cases”) Q52. a) Do you agree that increased guidance in preparing the Damage Control

booklet, as outlined by Germany, is necessary? and, if so b) Should such guidance appear in the Regulations or as new Explanatory Notes

or as improvements to MSC.1/Circ.1245? (a) Is increased Guidance necessary? YES or NO:- Yes: Germany, MI, Norway, CLIA (recommended), Spain, Denmark, UK, US, France (added in Round 2 responses) No: China, Finland, Japan, Italy (b) If YES, should this be in the form of new SOLAS regulations, new EN or improvements to MSC.1/Circ.1245? Germany: EN is the preferable place / Content of MSC.Circ1245 should be implemented to the EN. It is our understanding that further guidance for preparation of Damage Control Booklets should lead to clearer presentation of these Booklets and should avoid further confusion of the crew onboard. MI: As improvements to MSC.1/Circ.1245 Norway: Improvements to MSC.1/Circ.1245. CLIA: EN. Denmark: By improvement to MSC.1/Circ.1245 UK: It is preferred to be through MSC.1/Circ.1245. US: Probably in MSC.1/Circ.1245; it should not be scattered between a Circular and the EN. France (added later): MSC.1/Circ.1245 or additional circular.

384 10/01/2012

Comments / suggestions / proposed wording?:- Finland: Damage Control in passenger ships is already very complicated. No additional information is needed. Operational information is needed to comply with SRtP demands and will be “a kind of” supplement to Damage Control Booket. Japan: It would be difficult to define the “sample” damage case to help the judgement by officers. Japan would like to suggest a sample of the information. Please find attached file (Q52 proposal.doc, see below):- Damage Consequence Diagram .1 Initial Condition: d=8.020m Trim(Lpp)=0.000m GM=1.500m

Damage case: Up to HE=1.50m and VE=9.00m

Equilibrium condition Damage Zone

Damage Compartment draught(m) Trim(m) Heel(degree)

Horizontal Extent(m)

Vertical Extent(m)

S-value

1 Compartment flooding 1 APT 8.11 0.15 0 Max Max 1.000 2 E/R 8.50 0.62 0 Max Max 1.000 3 No.2 WBT(S) 8.20 0.10 5.01 1.500 9.000 1.000 4 No.1 WBT(S) 8.34 -0.22 6.22 1.500 9.000 1.000 5 STORE 8.17 -1.22 0 Max Max 1.000 6 FPT 8.10 -2.33 0 Max Max 1.000

1 2 3 4 5 6

1-2 2-32

3-4 4-5 5-6

1-3 2-4 3-5 4-6

1-432

2-5 4-6

1-532

2-6

1-6

APT E/R

Heeling Tank(S)No.2 Cargo Hold No.1 Cargo Hold

No.2 WBT(S) No.1 WBT(S) Store

FPT

APT

E/R No.2 Cargo Hold No.1 Cargo Hold Store

FPT

No.1 WBT(S) No.2 WBT(S)

: Level III : s = 0

: Level II : 0 <s <1: Level I : s = 1

: No calculation

385 10/01/2012

2 Compartments flooding 1-2 APT E/R 8.62 0.81 0 Max Max 1.000 2-3 E/R No.2 WBT(S) 8.72 0.68 3.21 1.500 9.000 0.785 3-4 No.1 WBT(S) No.2 WBT(S) 8.53 -0.12 12.12 1.500 9.000 0.458 4-5 No.1 WBT(S) STORE 8.51 -1.40 5.44 1.500 9.000 0.882 5-6 STORE FPT 8.28 -3.52 0 Max Max 1.000

3 Compartments flooding 1-3 APT E/R No.2 WBT(S) � � No Eq.

Cond. 1.500 9.000 0.0000

2-4 E/R No.1 WBT(S) No.2 WBT(S) � � No Eq. Cond.

1.500 9.000 0.0000

3-5 No.1 WBT(S) No.2 WBT(S) STORE

8.82 -1.66 18.23 1.500 9.000 0.0000

4-6 No.1 WBT(S) STORE FPT 8.73 -4.70 4.80 1.500 9.000 0.0000 Notice: The above damage compartments are the flooding case of the least safety factor within the damage zone.

End of Japan’s Proposed Example. Norway: Principally supports that better guidelines needs to be developed. However, it seems naturally that this discussion is co-ordinated with the work on “safe return to port”. CLIA: This should not be included under “Damage Control Plans/Booklets” – it needs its own name + document eg. “Damage Consequence Diagrams/Booklets/Information.” Spain: As a reflection, it is very important to think about the possible consequences of this information for the master. The only simple way to proceed is to present a very simplified analysis, i.e.: the calculated loading conditions, and assuming the permeabilities corresponding to the applicable regulations (the tanks are assumed empty before damage). The true ‘intact’ loading condition of the ship before damage will be probably not equal to the contained in the information (different draft and trim), and it is possible that some of the tanks affected by the damage were filled with liquid. Then, the true situation after damage probably differs from the calculated (different draft, trim, heel, residual righting lever curve (GZ) and reserve to flooding of opening points). The final decision will be affected also by the true sea conditions after damage. As a conclusion:

- We agree in general with the Germany proposal. - Anyway, it should be clear for the master that this information is only approximate, and

the final decision will be his/her responsibility. The information should not classify the possible situations (‘safe’ or ‘not safe’, specific codes, or similar ways of classification of the possibilities or survival after damage).

- We suggest to consider, in combination with this proposal, the possibility to include a new SOLAS regulation, making mandatory in specific or in all cases, a loading damage stability computer on board, or a shore-based aid, capable to calculate in a emergency scenario the ‘true’ damage case (in a deterministic manner) affecting the ship.

Denmark: We agree with the principal to provide more guidance, but we have to be careful that the amount of information to be presented shall be simple and easy to understand by the crew. Perhaps it would be better to collect a sample of proposals/submissions and compare them for effectiveness, so that we are in a better position to offer more guidance.

386 10/01/2012

Round 1 Discussion: There is a majority of 8 to 4 in favour of Germany’s proposal to try to clarify what is meant by “all damage Cases” in Reg. 19.5 with 5 out of the 8 preferring enhancement of MSC/Circ.1245 as the best means of doing this, though Germany and CLIA prefer use of the EN. Finland is opposed to Germany’s proposal, arguing that for passenger ships there is already a considerable amount of complex information available and anything further could be confusing, a point echoed by Denmark who suggests we should collect samples and select the most effective form of presentation. Finland and Norway, though on opposite sides, both propose that our discussions should be co-ordinated with the Safe RtP CG which will propose the supply of some form of damage information to the master. One problem with this is that Safe RtP only applies to passenger ships whereas the information is equally valuable to the crew of cargo ships. There is also a distinction between the sort of large, complex cruise liners covered by the Safe RtP Guidelines and much smaller passenger ships. For the former, a computerized system would probably be more appropriate with the choice lying between either shore-based support or an onboard stability computer or both. Such a system has the advantage of being able to cover the actual loading/damage scenario with the correct tank-filling depths and load distribution, a point well-made by Spain. There seems to be little doubt that for the crew computers represent the least complex and most accurate solution for covering “all damage cases”. The basis conditions from the approved trim and stability booklet can be “locked” and the loading officer either adjust the nearest intact condition manually or rely on electronic tank gauging to “load” the tanks (or a combination of methods). Then he could either run the condition through a pre-arranged set of damage scenarios to check compliance with the critical GM/KG or, in a real situation, key in his best estimation of the actual damage scenario to obtain guidance information. The system could also be set to “training mode”. Such is the speed of modern computers it may be possible to check all the damage scenarios used in contributing to the “A” index fairly quickly? It is probably too much, given our current capabilities, to require the system to make an allowance for varying sea-states even though such systems are being developed (e.g. FLOODSTAND). The information presented to the Master should be easy to understand and unambiguous but, as Spain suggests, should stop short of providing decision criteria such as “safe” or “unsafe” – the final decision rests with the Master who can take factors other than stability into account, such as the ship’s location, local SAR, structural viability etc. Spain proposes that provision of such a computerized system could be made mandatory in certain cases. It looks as though this will now be happening for Safe RtP ships, but the problem is how far do we go with such a mandatory requirement? Do we include all cargo ships and passenger ships down to quite small sizes? Or for the latter should we simply ask for the sort of damage consequence diagrams proposed in Japan’s submission or even just the basic residual stability data proposed by Germany assuming that “all tanks empty” is the worst case? There is a potential problem with the use of “s” as a survival criterion, as shown in Japan’s diagram since, for example, for ro-pax ships a damage case with s=1 could in theory have very poor survival characteristics if WOD or multiple free surfaces are taken into account. One final point, if a computerized system of some sort is made mandatory for calculating residual damage stability, this should not replace the damage control information (plan / booklet) which will still need to be produced to comply with Regs. 19.1 – 19.4 and MSC/Circ.1245. The computer

387 10/01/2012

system will only be used as a supplement to this basic “paper” information as described in paragraphs 4.5 and 4.6 of the circular for the purpose of trying to resolve the conflicting issues of simplicity, accuracy and comprehensive coverage of “all damage cases” as required by Reg. 19.5. Q52A: Given that passenger ships covered by the new Safe RtP requirements will either be fitted with means to enable shore-based support or an onboard computer system (or both) to provide information to the crew in the event of damage, do you think that such provisions should be extended to all vessels covered by the SOLAS 2009 amendments, including cargo ships, in order to best fulfil the requirements of Reg. 19.5 both for routinely verifying compliance with the intact and damage stability criteria and for use in real damage situations and for training? It is understood that such systems should in no way replace the provision of damage control information and booklets as required by Regs. 19.1 to 19.4 and supplemented by MSC / Circ. 1245. Yes

Italy, Norway (with comments), CLIA

No

MI (with comments), Germany (with comments), Finland, Japan (with comments), RINA (with comments), France (with comments), UK (with comment), US, Denmark

Any further comments?:- MI: The need for the use of shore-based or onboard computer systems has arisen to satisfy the specific Safe RtP provisions of SOLAS and this does not need to be extended to all other ships which do not have to comply with any return to port requirements. Germany: The intention of Germany’s submission was to obtain clear guidance on “which” sample damage cases to be included and “how” to best inform the ship crew on possible deviations to a real case scenario. It is our understanding that information is compulsory for all vessels (inc. dry cargo and small pax) therefore the discussion group of SRtP is no appropriate place. A computer tool on board can only be as good the input information, i.e. in a damage case it is a difficult and sometimes dangerous task to exactly determine which rooms are damaged. Japan: In the case of ships with not complex subdivision, Japan thinks it is possible for the master or officers to assess the ship’s survivability by the booklet-based information. Japan would appreciate it if we could discuss our proposal on 1st round at the CG and/or SLF 53. In the case of ships which the master cannot assess the survivability by booklet due to the complex subdivision and a huge volume of the information, onboard computer and/or shore-based support will be effective. RINA: While the application of the probabilistic damage stability is applicable to all passenger ships it is not necessarily applicable to all cargo ships due to the exclusion clause in regulation 4. For constancy in presentation it is considered, at this point in time, that the provision of shore-based support or an onboard computer system (or both) to provide information to the crew of cargo ships in the event of damage, is not appropriate. The proposal by Japan presents a clear and understandable position, based on the probabilistic damage stability calculation process. After an actual damage and identification of the extent of damages the possible outcomes can be identified and proposed actions considered. Our only concerns are that not all damages have been calculated. In the case shown this may not be of any consequence. However for ro-ro ships, with LLH it is essential that all damage cases are examined, including those where s=0, and the final equilibrium conditions calculated. For all ship types it should be borne in mind that the intermediate damage conditions may be more

388 10/01/2012

onerous than the final equilibrium condition. In such cases the intermediate as well as the final condition should be shown. If there is a requirement for a computer system to provide information and support to the crew, whether provided on the ship or from ashore, then the software should be capable of providing the damage control information and booklets as required by regulations. 19.1 to 19.4 and supplemented by MSC / Circ. 1245. If this is the case why can not the software system be the primary requirement and the paper documents used solely for backup? France: From our understanding, SRTP doesn’t require that ships must be fitted with means to enable shore-based support or an onboard computer system. Such systems not being mandatory on passenger ships, it should be difficult to require them to all ships. Norway: As a long-term goal. Further comments: Similar discussions could also be relevant in discussions under agenda item 8 “Guidelines for verification of damage stability requirements for tankers and bulk carriers”. The use of a loading computer for damage stability information and the use of a shore-based emergency response service (ERS) should not be mutually exclusive. The additional support provided by a professional ERS provider goes way beyond what can be extracted from an ordinary loading computer onboard. UK: The regulations set the minimum required level of subdivision and damage survivability, although very useful to provide some information more advanced and complex processes are required to control and mitigate risks involved in a real damage case. Round 2 Discussion:- Many thanks for all the detailed comments. Overall (9-3) it seems that we are not at present in favour of extending the use of a mandatory onboard computer and/or a shore-based ERS to all ships to fulfil the requirements of Reg. 19.5, as originally suggested by Spain. So we return to Germany’s original proposal, where most favoured enhancements to MSC.1/Circ.1245. Japan has additionally proposed the use of damage consequence diagrams which she would like to be discussed at SLF 53. At this stage we can therefore only suggest that the issue be discussed further by the SLF 53 WG for which it may help if specific text proposals for enhancing Circ.1245 could be prepared. We should also take into account the outcomes of the SRTP and tanker damage stability agenda items (7 and 8) to ensure that the final requirements have some consistency. Q52B (for SLF 53 WG). Given that the majority are not in favour of fulfilling the requirements of Reg. 19.5 through the mandatory use of onboard computers and/or shore based ERS, can we please have suggestions for changing the text of MSC.1/Circ.1245 in line with the original proposals by Germany (9-16), possibly including a section on the use of damage consequence diagrams as suggested by Japan? Further comments / proposals for changing MSC.1/Circ.1245?:- Post SLF 53 Comments:- We now have the new regulations 8-1 and associated operational information for masters. Perhaps with these additions, MSC.1/Circ.1245 and the appendix to the EN there may be some duplication giving a risk of “overload” amongst users of S2009. In the light of these developments can we have further comments from the 2011 CG, especially Germany, who first raised the issue of defining the meaning of “all damage cases” in Reg. 19.5? Do we now have sufficient provision for information to the Master? Maybe we now have too many guidelines and requirements? We did not have time to discuss this at SLF 53. Q52C for Round 4 Questionnaire. Do you agree that increased guidance in preparing the Damage Control booklet, as originally outlined by Germany, is still necessary given the new Reg. 8-1 requirements and associated Guidelines? For earlier discussions please refer to the working document.

389 10/01/2012

Yes

US, Norway, RINA, Denmark, Germany, France

No Vanuatu, Japan, China, Italy, UK, MI

Further comments / specific proposals for changing MSC.1/Circ.1245?:- Japan: Japan would like to show a sample of booklet again, as attached. We think this sample is simple, quickly searchable and understandable for the master.[Coordinators’ Note: -Many thanks for this, Japan. The sample is a 16-page .pdf format file and is not part this document]. RINA: Reg 8-1 only applies to passenger ships having a length, of 120 m or more, or having three or more main vertical zones, shall comply with the provisions of this regulation. Damage control booklets required by Regulation 19 is applicable for all other ships. Denmark: Perhaps increased guidance for preparation of the damage control booklet could be combined with a general revision to eliminate ‘duplication’ and information overload? Germany: The term “in all damage cases” is still not clear. Germany is still of the opinion that the term should be explained as previously proposed. The necessity to include the results of selected damage cases should be limited to vessels subject to B-1. France: Regulation 8-1 only applies to passenger ships of 120m or more or having 3 or more main vertical zones. Draft guideline defines operational information for safe return to port. Intent of regulation 19.5 is more general. Round 6 Discussion:- We are evenly divided on Germany’s proposal to define “in all damage cases” more precisely (6 for, 6 against). To try to find a way forward, we decided to look again at Germany’s original proposal in the large working document. We then wonder how, for example, paragraph 11 differs much from what is already in the Appendix to the EN (paragraph 2.3.1):- 11 For each sample damage case, the final floating position (draft, trim, heel, residual righting lever curve (GZ) and reserve to flooding of opening points should be stated. If in certain damage cases the criteria for the respective damage stability regulation are exceeded, such cases should not be omitted. In such a way, the master could gain valuable information about the capabilities of the vessel. 2.3.1.2 Results for each damage case which contributes to the index A:

.1 draught, trim, heel, GM in damaged condition; .2 dimension of the damage with probabilistic values p, v and r; .3 righting lever curves (including GZmax and range) with factor of

survivability s; .4 critical weathertight and unprotected openings with their angle of

immersion;

.5 details of sub-compartments with amount of in-flooded water/ lost buoyancy with their centres of gravity.

2.3.1.3 In addition to the above requirements in 2.3.1.2, particulars of non-contributing damages (si = 0 and pi > 0.00) should also be submitted for passenger ships and ro-ro ships fitted with long lower holds including full details of the calculated factors.

390 10/01/2012

As it is within our remit to change the EN we would therefore like to suggest that Germany looks again at her original proposal and incorporates as much as necessary into the Appendix to the EN, bearing in mind the existing requirements of MSC.1/Circ.1245 and the new Guidelines for reg. 8-1, which, as France, RINA etc rightly point out only apply to passenger ships of 120 m and above with 3 vertical fire zones. Such passenger ships must still adhere in addition to Circ.1245 and the Appendix to the EN, however, so for these ships at least there may be some risk of “overload” through duplication of requirements. So perhaps Germany can progress this by concentrating on making simple improvements to the Appendix to our own EN which can be accomplished quite easily within our current ToR (see Denmark’s suggestion too). Japan’s proposal is to use damage consequence diagrams which are in fact already mentioned in paragraph 5 of MSC.1/Circ.1245. The dangers of over-reliance on such information has been discussed several times at IMO SLF and indeed is highlighted in the document submitted by Japan:-

That is not to say such diagrams are unreliable but there is a danger that the master will not read the “small print” and conclude either that his ship is safe when it is not or vice versa, neither of which are necessarily good outcomes. The counter argument is, of course, that any information at all is better than none. We will ask the opinion of the CG members. Q52D for Round 6 Questionnaire. Do you agree with:

1. the suggestion that Germany incorporates her original proposal where appropriate into the Appendix to the EN thereby improving its content?

2. Japan’s proposal to use damage consequence diagrams as a means of

complying with the requirements of reg. 19.5 to apply “in all damage cases”?

1) Y/N?

Yes: RINA, Finland, Norway, UK, Denmark, China No: Japan, Italy, France (see comments below) Comment: CLIA (It is only workable if a usable presentation method is used- but that moves towards the Damage Consequence Diagram idea). US (We are not sure that the EN Appendix is directly related to reg 19.5 for this application; the Appendix is referenced from the reg 6.1 EN and provides guidance on submission of calculations for approval. )

391 10/01/2012

2) Y/N?

Yes: Japan (see comments below), Poland, France, China No: Finland, Norway, Italy, UK Comment: CLIA (We agree generally with the concept, but also the reservations stated by the co-ordinators. If such information is to be of use to the master, it must be presented in some usable graphical (or interactive computer based) way. The limitations of any such approach must be made very clear). US (As the Co-ordinator points out, the use of damage consequence diagrams are already allowed by MSC.1/Circ.1245 and this does not really clarify the “in all damage cases” issue.)

Further comments?:- Japan: Japan proposed to use damage consequence diagrams, which is arranged to provide information to ensure orderly evacuation based on the calculation on the safest side. We believe that evacuation based on the proposed diagrams have essentially accounted for “all damage cases” because these diagrams help master’s quick and secure (safe side) judgement in “any flooding cases”. Germany: The meaning of damage control documents on board is limited and might be discussed further. The assumptions (draft, GM, tank filling, permeability, immersion of weathertight openings) made for the damage stability calculation are much too far away form real loading conditions. Also damage consequence diagrams do not improve the situation as they base on the same assumptions. Hence we would like to suggest a further consideration of the installation of a damage stability module for the loading instrument. France: Presentation of results for all damage cases as specified by Germany would lead to a very big document which will not be easily understandable by the captain. In addition, the results which it is possible to produce will be obtained from initial conditions which will not correspond to actual loading conditions. Conclusion of working group at last SLF has been to make mandatory to have an onboard loading computer or shore based support for passenger ships to which regulation 8-1 applies.

Q52 2011 CG OUTCOME NOT CONCLUSIVE - DISCUSS AT SLF 54

Regulation 20 Loading of [passenger] ships [Q53D][ 10-3 in favour of deleting “passenger”] [Discuss at SLF 54] Regulation 20 (ref. SLF 52/17/6 - Norway) The contents of this regulation are operational and only reflect common practice and good seamanship. This Administration can see no reason why its use should be limited to passenger ships. It is proposed to change the title of the regulation to “Loading of passenger ships” R20 (title only – remove “passenger”?) . Q53. Do you agree with the proposed change to the title of this Regulation? Yes


No

392 10/01/2012

Comments?:- Spain: See Q.11.

Round 1 Discussion: All in favour.


(See SLF 53/14 para. 12.9). Note that contents page will need to be changed too.

Post SLF 53 Comments:- As reported in SLF 53/WP.6 paragraph 21, this item was deferred for further consideration by the 2011 CG. It is recalled that in plenary ICS, supported by Greece felt that Reg. 20 should continue to apply specifically to passenger ships. Therefore this item must be opened up for discussion again. Please note that we have agreed to change Reg. 4.1 (See Q6B, above) which now only refers to Part B-1, and not B-2 to B-4. If we do continue to apply Reg. 20 only to passenger ships would we therefore need to introduce something similar specifically for cargo ships and if so how would it differ from the wording for the loading of passenger ships? Q53C for 2011 CG:- Do you agree that we now retain the word “passenger” in the title of Regulation 20? Yes

Vanuatu, RINA

No

US*, Norway, Japan, Denmark, Finland, Italy, UK, ICS (not in isolation)

Comments?:- US: *Although we have no strong position on this item, we did not really follow why applying this to cargo ships would be such a difficult task for them. That said, our general preference would be to “harmonize” the requirement and apply it to cargo ships. Japan: Japan thinks reg.20 is a basic requirement and this regulation should apply to cargo ships stated in reg 4.1. RINA: We would concur with the proposal to amend the title of regulation 20 to cover both cargo and passenger ships. In addition we should retain the table, suitably amended to identify the application to cargo ships and passenger ships. This is particularly relevant with respect to the outcome of the question posed in Q6C. Denmark: I see no reasons why the word “passenger” can not be deleted. ICS: Whilst not fundamentally disagreeing with the position of Norway. ICS considers the simple removal of the word “passenger” has the potential to cause other problems due to the imprecise wording of the regulation. For example “The determination of the ship’s stability shall always be made by calculation.” It is not clear from the wording of the regulation that “equivalent means” may include the use of max KGf / min GMf curves etc. That is obviously understood within the group, but not always in the wider world, and it is not clear from the text. Another issue is the degree of certainty “by calculation” that is available for example for masters of container ships. Round 6 Discussion: This matter is covered in detail under Q6D, above (ref. discussion point 10.2), in the wider context of the general applicability of Parts B2 – B4. We thank ICS for the explanation of their reasons for retaining the word “passenger” in the title of this regulation. Reg. 20.1 is very basic and taken straight from the previous version of SOLAS (reg. 8.7.4). It very clearly applied then only to passenger ships, there being no direct

393 10/01/2012

equivalent in the dry cargo ship probabilistic regulations 25-1 to 25-10. It would however seem sensible to include here the very basic requirement that the master checks and records the stability against all relevant criteria before departure. This would apply to all SOLAS ships – passenger and cargo. It is perhaps surprising that the requirement does not appear elsewhere such as in the 2008 IS Code. Equally the provision in reg. 20.2 requiring that in general water ballast should not be carried in fuel oil tanks is not peculiar to passenger ships and is now, we believe, agreed good practice for most ship types, though the text is taken straight from previous SOLAS Part B reg. 9, which did specifically relate to passenger ships. We think that the phrase “always be made by calculation” may simply mean that it should not be estimated, for example, by assessing the rolling period or sensing how “tender” the ship feels. We also are not sure that “or equivalent means” is referring to limiting KG/GZ curves, which are clearly required by other regulations (SOLAS2009 reg. 5-1, for example) for all ship types. It is simply referring to a physical “device” equivalent to a loading and stability computer. However, we will ask the CG’s opinion again on the title of this regulation in the light of the points made by ICS and the earlier discussions under Q6D. Perhaps ICS could suggest some changes to the text of regs. 20.1 and 20.2 to clarify the regulations for both passenger and cargo ships? Q53D for Round 6 Questionnaire. Do you agree with the arguments put forward by ICS for keeping the word “Passenger” in the title of reg. 20 or do you prefer to delete the word so that the regulation covers both passenger and cargo ships? Keep “passenger”?

Germany, Poland, China

Remove “passenger”

Japan, CLIA, RINA (see comments), Finland, Norway, US, UK (We prefer that the Reg. 20 requirements should still be harmonised), EC (agree), France, Denmark.

Alternative text?

Further Comments? RINA: It is noted that the 2008 IS Code has a requirement in Part A, Chapter 2.1.6. that each ship shall be provided with a stability booklet, approved by the Administration, which contains sufficient information (see part B, 3.6) to enable the master to operate the ship in compliance with the applicable requirements contained in the Code.

Q53 2011 CG OUTCOME NOT CONCLUSIVE - DISCUSS AT SLF 54

Include regulation 20 in the table listing applicable regulations found under Regulation 4.1 in the EN. [Coordinator’s Note:- See Q11]. 1 On completion of loading of the ship and prior to its departure, the master shall determine the ship’s trim and stability and also ascertain and record that the ship is in

394 10/01/2012

compliance with stability criteria in relevant regulations. The determination of the ship’s stability shall always be made by calculation. The Administration may accept the use of an electronic loading and stability computer or equivalent means for this purpose.

Regulation 20.1 (ref. SLF 52/17/6 - Norway) The calculation of the stability limit curves in part B-1 is normally based on the initial transverse centre of gravity (TCG) being zero. Any significant list in the intact condition may invalidate these limit curves. The following sentence, taken from 7.3 of the International Grain Code, is proposed added at the end of the paragraph or as a new paragraph 2:[Coordinator’s Note:- If it is agreed that a new paragraph is needed, the remaining paragraphs will have to be re-numbered.] “After loading, the master shall ensure that the ship is upright before proceeding to sea.” R20.1 (add “upright and”?) . Q54. Do you agree with the proposed addition to this Regulation? Yes

Finland (with comment), Japan, Norway, Spain, UK, US, Sweden

No

China, MI, CLIA, Italy, Denmark

Comments / Should it be an extra sentence in Reg 20.1 or new paragraph 20.2?:- Finland: Word “upright” is not clear. Heeling tolerance to be suggested in EN. Germany: Wording “upright” is not clear. Explicit initial heel range is preferable. Spain: The stability calculations could have been taking into account this initial list. We suggest considering this possibility in this new text. Denmark: This seems unduly restrictive. US: No strong preference, but almost seems like it should be incorporated into regulation 20.1 (i.e. “On completion of loading of the ship and prior to its departure, the master shall [ensure that the ship is upright,] determine the ship’s trim and stability...” Round 1 Discussion: See Q55.

A recommendation on a heel tolerance for validity of the stability calculations could be added to the EN as well. R20.1 EN (heel tolerance to be specified?) . Q55. Do you agree with this proposal for a new EN? Yes

Finland (with comment), Germany (with comment), Japan, Norway, CLIA, US, Sweden, France (added in Round 2 responses)

No

China, MI, Italy, Spain, Denmark, UK

Comments / suggested figure for heel tolerance?:- Finland: Heel tolerance is suggested to be within +/- 0.5 degrees.

395 10/01/2012

Germany: We support the base idea for an upright intact condition. However the EN are primarily addressing “subdivision and damage stability calculation”. Requirements for an intact condition are more appropriate in the IS2008 Code, respectively in MSC.1/Circ.1281. CLIA: Depends on wording – heel tolerance idea could be OK. Spain: It seems to be very difficult to fix an exact figure applicable for all type of ships and situations (stability margins, etcetera). Anyway, we accept to discuss any specific proposal in relation to this matter. Denmark: A heel tolerance would be quite difficult to work out, also considering that the heel angle of a vessel after damage could be quite different from what the damage calculations suggest due to tank filling. In general we think that there are some difficulties in applying the results of a theoretical calculation to an operational/practical situation. US: We are not opposed to this. France (comment added in Round 2 responses): Suggested figure for heel tolerance – 1 degree. Round 1 Discussion (Q54 and Q55): Norway’s point is certainly valid and has good support. We have checked through the IS Code and corresponding EN (MSC.1/Circ.1281) as mentioned by Germany and surprisingly only ships carrying timber deck cargo are specifically required to be “upright” on departure. The IE requirements are for ships to be within +/- 0.5 degrees of upright before commencement of the experiment. Proposed Action: We could simply add the words “upright and” into Reg. 20.1 as follows:- 1 On completion of loading of the ship and prior to its departure, the master shall determine the ship’s trim and stability and also ascertain and record that the ship is [upright and] in compliance with stability criteria in relevant regulations. The determination of the ship’s stability shall always be made by calculation. The Administration may accept the use of an electronic loading and stability computer or equivalent means for this purpose.

Then we could add a new EN something like:- “Upright” means with a maximum list of + / - [0.5] degrees to ensure the validity of compliance with the intact and damage stability regulations. . Q54A and Q55A. Do you agree with the proposed action to include additional

words in Reg. 20.1 and for a new EN? Yes

Germany (with comments), Finland, Italy, Japan, RINA (with comments), France (with comment), Norway (with comments), UK, US (principle), Sweden, Denmark

No

MI, CLIA (with comment)

Comments / Alternatives?:- Germany: We do not support the proposed values of +/- 0.5 deg as this appears to be too strict. According to “good seamanship and practice onboard” the maximum initial heeling angle shall

396 10/01/2012

not exceed [2.0 deg]. This should be incorporated in the regulations. RINA: Agree with the proposal in principle, however any interpretations of upright should be incorporated in the LL requirements i.e. the 2008 IS Code. The concept of upright has been dealt with by mariners for years without clarification, why introduce a tolerance value now? France: Agreement on additional sentence. A limit of 1 deg should be more realistic. Norway: For small ships with a low GM the tolerance required on TCG for observing a strict limitation on heel may not be practicable. The deviations from the limit curve caused by an initial list matters most for larger ships to which damage stability apply. For these ships the GM will be higher and trimming of the ship easier. This is the reason for using the somewhat vague expression “upright”. We would suggest a recommended value of +/- 1 deg. in the EN. CLIA: This is too restrictive and difficult to implement in operation for all ship types. Round 2 Discussion:- There is good support in principle for adding “upright and” to the regulation (11-2 in favour) but there are various views on the tolerance figure in the proposed new EN. RINA suggests that this is a matter for the 2008 IS Code whereas MI and CLIA oppose it altogether. We could leave the EN and use only the vague expression “upright” in the regulation. We list the options below with a request for further discussion at the SLF 53 WG. Option 1:- Do nothing at all. Option 2:- Do nothing in the S2009 regulations but request that the 2008 IS Code includes a requirement for the ship to be upright on departure. Of course, it is just as important to keep the ship upright during the voyage as far as possible, so perhaps this should be made clear in the 2008 IS Code too? Presumably we will leave it to them to set a tolerance as they see fit? Option 3: Include “upright and” in Reg. 20.1 but do not add a new EN with the tolerance. Option 4: Include “upright and” in Reg. 20.1and add a new EN with a tolerance. One degree seems to be the “average” figure suggested. Post SLF 53 Comments:- Time prevented discussion of this item at SLF 53 so could the 2011 CG members please indicate their preferred option, below? Q54C and Q55C (for the Round 4 questionnaire). Please consider which of the above four options you would prefer. 1) Vanuatu (prefer), US, ICS

2) RINA, Germany, CLIA

3) Sweden, Japan, China, RINA, EC (Could be either 3 or 4, with slight tendency towards 3. There seems not to be a strong argument to introduce tolerances).

4) Norway, Denmark (with comments), Finland, Italy, France

397 10/01/2012

Further Comments?:- Vanuatu: We consider that Master might wish to accept a small degree of list or trim on departure; given the effects of BWM convention, to allow for later ballasting/correction in order to avoid taking on particularly fouled local water for ballast (as an example). As long as the effects are minor, these rules should not keep mariners from exercising a degree of holistic control. US: After further consideration of all the good discussion, we have come full circle on this issue and think no action is necessary. Adding “upright” without a heel tolerance seems to have little value and defining a practical tolerance for all ships appears problematic. So without a clear indication that this is really a problem, we are left with RINA’s question “...why introduce a tolerance value now”? And finally as noted by several, this is primarily an intact issue. Sweden: The upright requirement should be handled in the IS code. Japan: Supports to include the word “upright and” and also CLIA’s concern, so Japan prefers option 3. Denmark: Just an open question: how would this be applied in situations where weather conditions and/or cargo exceed the available heel correction; would the vessel be prevented from departure? But in the given case +/-1 degree seems reasonable. Germany: We would prefer to leave such limits out of SOLAS to avoid confusion regarding the initial conditions to be used for the damage stability calculation. Finland: Prefer to add tolerances to EN, because this tolerance for heel is valid also for relevant GM-limiting curve. Italy: A tolerance of +/- 0.5 deg is preferred. CLIA: If a value must be applied in IS, then 1-2 degrees is more reasonable. Even 1 could be difficult for some ships in some circumstances. ICS: This has the potential to create the same sort of problems and confusion that we have seen with damage stability of tankers and the term “in compliance with”. Any “normal” limit would need to be explicitly stated in the regulations as in most cases explanatory notes are only read by stability specialists, not by PSCOs etc. Round 6 Discussion: Of the 16 who responded: 3 were in favour of leaving the regulation unchanged, not adding an EN and taking no further action. 3 were in favour of leaving the regulation unchanged, not adding an EN but asking SLF to ensure that the 2008 IS Code includes a requirement for ships to be “upright” on departure (leaving the tolerance to be set in the Code). 5 were in favour of changing reg. 20.1 to read “……also ascertain and record that the ship is [upright and] in compliance with stability criteria in relevant regulations” but not to add a new EN specifying a tolerance for “upright”. 5 were in favour of changing the regulation as described and adding a new EN such as “Upright” means with a maximum list of + / - [0.5] [1] [2] degrees to ensure the validity of compliance with the intact and damage stability regulations. It could therefore be said that 13-3 are in favour of specifying somewhere that the ship should be “upright” upon departure. Another alternative, not presented for voting, would be to include the tolerance in the reg. 20.1 itself and not add a new EN, for example:- “……also ascertain and record that the ship is [within [0.5] [1] [2] degree(s) of upright and] in compliance with stability criteria in relevant regulations”

398 10/01/2012

We return to Norway’s original point:- The calculation of the stability limit curves in part B-1 is normally based on the initial transverse centre of gravity (TCG) being zero. Any significant list in the intact condition may invalidate these limit curves. We have ourselves observed that a non-zero TCG can significantly change the intact and damage GZ curves and for ships which are marginally compliant with the relevant criteria this could easily be sufficient to make the difference between compliance and non-compliance. It is often the case that the angles of heel used to calculate the intact and damage stability GZ curves are set to 0, 5, 10 degrees etc to reduce calculation time and also that TCG is often not specified when calculating the moments in the loading conditions. Now that computers have speeded up significantly smaller heel angles are readily calculated and the effect of non-zero TCG becomes more apparent. Ships with asymmetrical hull forms (for example with angled stern ramps) with non-zero lightship TCG’s are becoming more common. Also there have been one or two significant casualties arising from ships sailing with non-zero TCG’s so it is a subject which perhaps needs to be more carefully considered in future regulations. PROPOSED ACTION In view of the widely diverging views on this topic, however, and the fact that time prevented it being discussed fully in the SFL 53 WG, we feel that the best course of action is to defer a decision until SLF 54 and ask the Chair of the WG to initiate a debate as a matter of some priority. Q54D and Q55D (for the Round 6 questionnaire). In view of the spread of opinion on the important issue of non-zero TCG’s and initial list on sailing do you agree that this topic is best dealt with by open discussion at SLF 54? Yes? Japan, CLIA, RINA, Finland, Norway, Germany, US, Italy, UK, China,

France, Denmark, EC. No?

Alternative?

Further Comments?

Q54 and 55 DISCUSS AT SLF 54

2 Water ballast should not in general be carried in tanks intended for oil fuel. In ships in which it is not practicable to avoid putting water in oil fuel tanks, oily-water separating equipment to the satisfaction of the Administration shall be fitted, or other alternative means, such as discharge to shore facilities, acceptable to the Administration shall be provided for disposing of the oily-water ballast.

3 The provisions of this regulation are without prejudice to the provisions of the International Convention for the Prevention of Pollution from Ships in force.

399 10/01/2012

Regulation 21 Periodical operation and inspection of watertight doors, etc., in passenger ships

1 Drills for the operating of watertight doors, sidescuttles, valves and closing mechanisms of scuppers, ash-chutes and rubbish-chutes shall take place weekly. In ships in which the voyage exceeds one week in duration a complete drill shall be held before leaving port, and others thereafter at least once a week during the voyage.

2 All watertight doors, both hinged and power operated, in watertight bulkheads, in use at sea, shall be operated daily.

3 The watertight doors and all mechanisms and indicators connected therewith, all valves, the closing of which is necessary to make a compartment watertight, and all valves the operation of which is necessary for damage control cross connections shall be periodically inspected at sea at least once a week.

4 A record of all drills and inspections required by this regulation shall be entered in the log-book with an explicit record of any defects which may be disclosed.

Regulation 22 Prevention and control of water ingress, etc. [in passenger and cargo ships].

Default] [Q6D(4)[24]][Discuss at SLF 54] Regulation 22 (ref. SLF 51/3/2 Annex – US and Sweden) Due to the similarity of headings for regulations 22 and 24, it is proposed to clarify the regulation 22 heading as follows: “Prevention and control of water ingress, etc., in passenger and cargo ships“. R22 (Title change) . Q56. Do you agree with the proposed change to the title of this Regulation? See

also Q58 under Reg. 24. Yes


No

Comments?:- Norway:- For consistency reasons. Round 1 Discussion: All in favour.


(See SLF 53/14 para 12.10). Note that contents page will need to be changed too.

400 10/01/2012

Post SLF 53 Comments:- As reported in SLF 53/WP.6 paragraph 21, this item was not accepted in plenary therefore no changes will be made. New co-ordinator’s note for SLF 54:- See [Q6D(4)[24]] where there remains a question as to whether this regulation applies under the “default” assumption (i.e. to all passenger ships and cargo ships) in which case no further action is needed on changing the title. 1 All watertight doors shall be kept closed during navigation except that they may be opened during navigation as specified in paragraphs 3 and 4. Watertight doors of a width of more than 1.2 m in machinery spaces as permitted by regulation 13.10 may only be opened in the circumstances detailed in that regulation. Any door which is opened in accordance with this paragraph shall be ready to be immediately closed.

2 Watertight doors located below the bulkhead deck [in passenger ships and freeboard deck in cargo ships] [Q6D(4) [25]] [Discuss at SLF 54]having a maximum clear opening width of more than 1.2 m shall be kept closed when the ship is at sea, except for limited periods when absolutely necessary as determined by the Administration.

3 A watertight door may be opened during navigation to permit the passage of passengers or crew, or when work in the immediate vicinity of the door necessitates it being opened. The door must be immediately closed when transit through the door is complete or when the task which necessitated it being open is finished.

4 Certain watertight doors may be permitted to remain open during navigation only if considered absolutely necessary; that is, being open is determined essential to the safe and effective operation of the ship's machinery or to permit passengers normally unrestricted access throughout the passenger area. Such determination shall be made by the Administration only after careful consideration of the impact on ship operations and survivability. A watertight door permitted to remain thus open shall be clearly indicated in the ship’s stability information and shall always be ready to be immediately closed.* [Coordinator’s Note: * Do you think we need to insert a footnote here referring to the “Draft guidance for the determination by Administrations of the impact of open watertight doors on passenger ship survivability under SOLAS Regulation II-1/22.4 and previous SOLAS Regulation II-1/15.9.3” (see SLF 52/19 Annex 3 for details)? The document as agreed at SLF 52 is shown below for easy reference but may be subject to change at DE54 in October 2010.] [Post SLF 53 – now removed as it has been superseded by MSC.1/Circ.1380, which is not included as it is quite large]. R22.4 (new footnote) . Q57. Do you agree that a new footnote is needed? Yes

China, Finland, Japan, Norway, CLIA, Spain, Denmark, UK, US, Sweden, France (added in round 2 responses)

401 10/01/2012

No

Germany, Italy

Comments?:- Germany: The new circular will be guidance for administrations how to allow open water tight doors. No reference to the EN meaningful. Norway: The contents of such a footnote will depend on the outcome of DE 54. Denmark: It is useful to have the reference to hand, and we should update it should it be issued as a circular. UK: Including potential change in October 2010. France: It is necessary to wait for the final version of the MSC circular. Round 1 Discussion: There is strong support for this proposal (10/2). Germany’s comment on the EN is not fully understood, however. Can you explain a little more please, Germany? Obviously we need to see what happens at DE54 so the proposed action is to raise this item for discussion at SLF 53. Q57A. Any further comments at this stage?:-

Round 2 Discussion: We understand there have been considerable developments on this topic at both DE54 and MSC, with some new proposals. We can only await further instructions from the S-C at SLF 53. Q57B. Any further comments at this stage?:-

Post SLF 53 Comments?:- The latest situation with respect to open watertight doors is summarized in the report to MSC (ref. SLF 53/9) paragraph 18. In paragraph 18.5 it is stated

So we will keep the issue of the new footnote on hold until SLF 54 unless anybody has further comments? Q57C for Round 4 Questionnaire. Do you have any further comments on open WT doors at this stage? Should we just include the footnote referring to MSC.1/Circ.1380 anyway? Comments?:- Vanuatu: None US: It is ok to include the footnote to reg 22.4 as the Secretariat will do this anyway in the next publication of SOLAS. Sweden: The footnote referring to the Circ should be included. Norway: No comments. China: We think it is better to just include the footnote referring to MSC.1/Circ.1380 RINA: MSC.1/Circ 1380 Appendix 1 states that: “1.2 Care should be exercised not to confuse the "floatability assessment" criteria used in this procedure (for determining the impact of open watertight doors on survivability) with the requirements in the SOLAS chapter II-1 damage stability regulations, and

402 10/01/2012

2.1 In every case in which a determination that keeping one or more watertight doors open during navigation is absolutely necessary, floatability assessment calculations should be performed.” In which case we agree to add a footnote as proposed. However it is noted that the circular is only guidance and that it may not be applied by some flag administrations. Denmark: Maybe to include a footnote referring to MSC.1/Circ.1380. France: Reference to MSC.1/Circ.1380 should be included. Round 6 Discussion: There is virtual unanimous support for inclusion of a footnote to reg. 22.4 referring to MSC.1/Circ.1380 and we thank the US for pointing out that this will be done automatically by the Secretariat.

Q57. CONCLUDED – a note will be made in the CG report to the sub-committee. (See paragraph 15.8 of SLF 54/8/1).

Requires an * at the end of Reg. 22.4 and the following footnote:- [* Refer to the Guidance for watertight doors on passenger ships which may be opened during navigation (MSC.1/Circ.1380)]

5 Portable plates on bulkheads shall always be in place before the ship leaves port, and shall not be removed during navigation except in case of urgent necessity at the discretion of the master. The necessary precautions shall be taken in replacing them to ensure that the joints are watertight. Power-operated sliding watertight doors permitted in machinery spaces in accordance with regulation 13.10 shall be closed before the ship leaves port and shall remain closed during navigation except in case of urgent necessity at the discretion of the master.

6 Watertight doors fitted in watertight bulkheads dividing cargo between deck spaces in accordance with regulation 13.9.1 shall be closed before the voyage commences and shall be kept closed during navigation; the time of opening such doors in port and of closing them before the ship leaves port shall be entered in the log-book.

7 Gangway, cargo and fuelling ports fitted below the bulkhead deck [in passenger ships and freeboard deck at side in cargo ships] [Q6D(4) [26]] [Discuss at SLF 54], shall be effectively closed and secured watertight before the ship leaves port, and shall be kept closed during navigation.

8 The following doors, located above the bulkhead deck [in passenger ships and freeboard deck at side in cargo ships] [Q6D(4) [27]] [Discuss at SLF 54],, shall be closed and locked before the ship proceeds on any voyage and shall remain closed and locked until the ship is at its next berth:

.1 cargo loading doors in the shell or the boundaries of enclosed superstructures;

.2 bow visors fitted in positions as indicated in paragraph 8.1;

.3 cargo loading doors in the collision bulkhead; and

.4 ramps forming an alternative closure to those defined in paragraphs 8.1 to 8.3 inclusive.

403 10/01/2012

9 Provided that where a door cannot be opened or closed while the ship is at the berth such a door may be opened or left open while the ship approaches or draws away from the berth, but only so far as may be necessary to enable the door to be immediately operated. In any case, the inner bow door must be kept closed.

10 Notwithstanding the requirements of paragraphs 8.1 and 8.4, the Administration may authorize that particular doors can be opened at the discretion of the master, if necessary for the operation of the ship or the embarking and disembarking of passengers when the ship is at safe anchorage and provided that the safety of the ship is not impaired.

11 The master shall ensure that an effective system of supervision and reporting of the closing and opening of the doors referred to in paragraph 8 is implemented.

12 The master shall ensure, before the ship proceeds on any voyage, that an entry in the log-book is made of the time of the last closing of the doors specified in paragraph 13 and the time of any opening of particular doors in accordance with paragraph 14.

13 Hinged doors, portable plates, sidescuttles, gangway, cargo and bunkering ports and other openings, which are required by these regulations to be kept closed during navigation, shall be closed before the ship leaves port. The time of closing and the time of opening (if permissible under these regulations) shall be recorded in such log-book as may be prescribed by the Administration. 14 Where in a between-decks, the sills of any of the sidescuttles referred to in regulation 15.3.2 are below a line drawn parallel to the bulkhead deck at side [in passenger ships and freeboard deck at side in cargo ships] [Q6D(4) [28]] [Discuss at SLF 54], and having its lowest point 1.4 m plus 2.5% of the breadth of the ship above the water when the ship departs from any port, all the sidescuttles in that between-decks shall be closed watertight and locked before the ship leaves port, and they shall not be opened before the ship arrives at the next port. In the application of this paragraph the appropriate allowance for fresh water may be made when applicable.

.1 The time of opening such sidescuttles in port and of closing and locking them before the ship leaves port shall be entered in such log-book as may be prescribed by the Administration.

.2 For any ship that has one or more sidescuttles so placed that the requirements of paragraph 14 would apply when it was floating at its deepest subdivision draught, the Administration may indicate the limiting mean draught at which these sidescuttles will have their sills above the line drawn parallel to the bulkhead deck at side [in passenger ships and freeboard deck at side in cargo ships] [Q6D(4) [29]] [Discuss at SLF 54], and having its lowest point 1.4 m plus 2.5% of the breadth of the ship above the waterline corresponding to the limiting mean draught, and at which it will therefore be permissible to depart from port without previously closing and locking them and to open them at sea on the responsibility of

404 10/01/2012

the master during the voyage to the next port. In tropical zones as defined in the International Convention on Load Lines in force, this limiting draught may be increased by 0.3 m.

15 Sidescuttles and their deadlights which will not be accessible during navigation shall be closed and secured before the ship leaves port.

16 If cargo is carried in spaces referred to in regulation 15.5.2, the sidescuttles and their deadlights shall be closed watertight and locked before the cargo is shipped and such closing and locking shall be recorded in such log-book as may be prescribed by the Administration.

17 When a rubbish-chute, etc. is not in use, both the cover and the valve required by regulation 15.10.2 shall be kept closed and secured. Regulation 22-1

*

Flooding detection systems for passenger ships carrying 36 or more persons constructed on or after 1 July 2010

A flooding detection system for watertight spaces below the bulkhead deck shall be provided based on the guidelines developed by the Organization.*

_______________________ * Refer to the Guidelines for flooding detection systems on passenger ships (MSC.1/Circ.1291) [Included below for easy reference]

405 10/01/2012

406 10/01/2012

407 10/01/2012

408 10/01/2012

409 10/01/2012

Regulation 23 Special requirements for ro-ro passenger ships 1 Special category spaces and ro-ro spaces shall be continuously patrolled or monitored by effective means, such as television surveillance, so that any movement of vehicles in adverse weather conditions and unauthorized access by passengers thereto can be detected whilst the ship is underway.

2 Documented operating procedures for closing and securing all shell doors, loading doors and other closing appliances which, if left open or not properly secured, could, in the opinion of the Administration, lead to flooding of a special category space or ro-ro space, shall be kept on board and posted at an appropriate place.

3 All accesses from the ro-ro deck and vehicle ramps that lead to spaces below the bulkhead deck shall be closed before the ship leaves the berth on any voyage and shall remain closed until the ship is at its next berth.

4 The master shall ensure that an effective system of supervision and reporting of the closing and opening of such accesses referred to in paragraph 3 is implemented.

5 The master shall ensure, before the ship leaves the berth on any voyage, that an entry in the log-book, as required by regulation 22.13, is made of the time of the last closing of the accesses referred to in paragraph 3.

6 Notwithstanding the requirements of paragraph 3, the Administration may permit some accesses to be opened during the voyage, but only for a period sufficient to permit through passage and, if required, for the essential working of the ship.

7 All transverse or longitudinal bulkheads which are taken into account as effective to confine the seawater accumulated on the ro-ro deck shall be in place and secured before the ship leaves the berth and remain in place and secured until the ship is at its next berth.

8 Notwithstanding the requirements of paragraph 7, the Administration may permit some accesses within such bulkheads to be opened during the voyage but only for sufficient time to permit through passage and, if required, for the essential working of the ship.

9 In all ro-ro passenger ships, the master or the designated officer shall ensure that, without the expressed consent of the master or the designated officer, no passengers are allowed access to an enclosed ro-ro deck when the ship is under way.

410 10/01/2012

Regulation 24 [Additional requirements for p][P]revention and control of water ingress, etc., in cargo ships [only] [Q58D] [13-0 in favour; recommend change]

Regulation 24 (ref. SLF 51/3/2 Annex – US and Sweden) Due to the similarity of headings for regulations 22 and 24, it is proposed to clarify the regulation 24 heading as follows: “Additional measures for the prevention and control of water ingress, etc., in cargo ships only“.

R24 (Title change) . Q58. Do you agree with the proposed change to the title of this Regulation? Yes

China, Finland, Germany, Japan, MI, Norway, CLIA, Italy, Spain, Denmark, UK, US, Sweden, France (added in round 2 responses)

No

Comments?:- Norway:- Do not see the need for the latter bracket. France: It seems not necessary to modify the content? Round 1 Discussion:- There is almost unanimous support for this proposal but Norway suggests we could leave out [only] at the end of the title. “Only” was added to emphasize the contrast with the title of Reg. 22 – they are additional measures but only applied to cargo ships:-

Regulation 22

Prevention and control of water ingress, etc [in passenger and cargo ships]. Q58A. On this basis can we accept the word “only” and adopt the proposal as it stands? Yes

MI, Germany, Finland, Italy, Japan, RINA, France, Norway, CLIA, UK, Sweden, Denmark

No US

Further comments?:- US: We agree with Norway; “only” is unnecessary and seems inconsistent with the titling of other regulations in Chapter II-1. Round 2 Discussion:- Further reflection suggests that the US and Norway have a good point here so we are happy to leave out “only” if all agree. Q58B. On reflection “only” is probably superfluous. Are you therefore happy to change the title of Reg. 24 simply to:- “[Additional measures for the] prevention and control of water ingress, etc., in cargo ships” Yes

No

Post SLF 53 Comments:- As reported in SLF 53/WP.6 paragraph 21, this item was not accepted in plenary therefore no changes will be made (see also Q56, above). U.S. comment (to round 4 CG): Maybe we misunderstood the outcome at SLF 53 but it was our understanding that only the proposed reg 22 title change was rejected (i.e. the adding of

411 10/01/2012

“in passenger and cargo ships”) because it is not consistent with the methodology for other regulation titles in Chapter II-1. This is what SLF 53/WP.6 paragraph 21 reflects because SLF 53/14 paragraph 12.10 is only discussing the proposed title change to reg 22. We thought the proposed title change to reg 24 was still “alive”, and we think it both has merit and is generally within the regulation title methodology (except for the “only” text which was already dropped). So if you agree we would request that the following proposed reg 24 title change be circulated for group consideration: [Additional requirements measures for the] prevention and control of water ingress, etc., in cargo ships

Note: Although “measures” is used for SOLAS Chapters X, XI and XII, the term “requirements” seems more consistent with SOLAS Chapter II-1 and is used in the titles for regs 3-1, 8, 30, 53 and Part E. Round 6 Discussion: We thank the US for pointing this out and we apologise for mis-reading SLF 53/WP.6 paragraph 21, which in fact only rejected the proposed change to the title of reg. 22. The US asks for consideration of the following revised title for reg. 24: “Additional requirements for prevention and control of water ingress, etc., in cargo ships”. Acceptance of this revision would also need to be reflected in the contents page. Q58D for Round 6 Questionnaire: Do you accept the proposed revision to the title of reg. 24 shown in blue above? Yes?

Japan, CLIA, RINA, Finland, Norway, Germany, US, UK, EC, France, China, Denmark

No?

Further Comments?:

Q58. UNANIMOUS VERDICT THEREFORE RECOMMEND ACCEPTANCE AT SLF 54

[Coordinator’s Note: if accepted, the contents page will also need to be amended.] 1 Openings in the shell plating below the deck limiting the vertical extent of damage shall be kept permanently closed while at sea.

2 Notwithstanding the requirements of paragraph 3, the Administration may authorize that particular doors may be opened at the discretion of the master, if necessary for the operation of the ship and provided that the safety of the ship is not impaired.

3 Watertight doors or ramps fitted internally to subdivide large cargo spaces shall be closed before the voyage commences and shall be kept closed during navigation; the time of opening such doors in port and of closing them before the ship leaves port shall be entered in the log-book.

412 10/01/2012

4 The use of access doors and hatch covers intended to ensure the watertight integrity of internal openings shall be authorized by the officer of the watch.

Regulation 25 Water level detectors on single hold cargo ships other than bulk carriers 1 Single hold cargo ships other than bulk carriers constructed before 1 January 2007 2007 shall comply with the requirements of this regulation not later than 31 December 2009.

2 Ships having a length (L) of less than 80 m, or 100 m if constructed before 1 July 1998, and a single cargo hold below the freeboard deck or cargo holds below the freeboard deck which are not separated by at least one bulkhead made watertight up to that deck, shall be fitted in such space or spaces with water level detectors

* 3 The water level detectors required by paragraph 2 shall:

.1 give an audible and visual alarm at the navigation bridge when the water level above the inner bottom in the cargo hold reaches a height of not less than 0.3 m, and another when such level reaches not more than 15% of the mean depth of the cargo hold; and

.2 be fitted at the aft end of the hold, or above its lowest part where the inner bottom is not parallel to the designed waterline. Where webs or partial watertight bulkheads are fitted above the inner bottom, Administrations may require the fitting of additional detectors.

3 The water level detectors required by paragraph 2 need not be fitted in ships complying with regulation XII/12, or in ships having watertight side compartments each side of the cargo hold length extending vertically at least from inner bottom to freeboard deck.”

_______________________ * Refer to the Performance standards for water level detectors on bulk carriers and single

hold cargo ships other than bulk carriers, adopted by the Maritime Safety Committee by resolution MSC.188(79).

413 10/01/2012

Part C

(Reg. 35-1 only)

Machinery Installations

(Except where expressly stated otherwise part C applies to passenger ships and cargo ships)

Regulation 35-1 Bilge pumping arrangements [CLIA Q17D][12-0 in favour of discussing B/5 and checking A.265 at SLF 54;] Regulation 35-1 (ref. SLF 51/3/2 Annex – US and Sweden)

Modification may be necessary for application to ships fulfilling the probabilistic damage stability regulations. [Coordinator’s Note:- Are there any specific proposals? Comments? China, Finland, Germany: No comments. US: No proposals; however it is unclear to us whether the treatment of bilge systems for passenger ships in A.265 (regulation 19) was ever considered during the harmonization work? ] [New Coordinator’s Note for Round 2: The US raises a fundamental point as Reg 35-1 is clearly based upon deterministic SOLAS90 II-1/B/Reg. 21 whereas A.265 Reg.19 is probabilistic in approach and may therefore have provided a better starting point for the harmonization process. Time prevents this matter from being taken much further before SLF 53 but do any members remember if use of SOLAS rather than A.265 as the basis for this Reg. was deliberate? Further comments invited:- RINA: Ships complying with Part C may be required to comply with either probabilistic or deterministic damage stability requirements in accordance with Part B, regulation 4, or damage stability may not be required. It is considered that Part C needs to be reviewed to ensure that there is uniformity of application of the regulations when either probabilistic or deterministic damage stability methodologies or there are no damage stability requirements, as applicable.

Norway: It was decided at SLF 43 that the old regulation was a machinery issue and as such belongs in Part C, i.e. not within the scope of the harmonization of Parts B and B-1. Apart from advising DE on the fact that the remnants of the old floodable length principles would be removed from the chapter there were no detailed discussions on a new method in SLF. US: It was not deliberate (updates to reg 35-1 slipped through the cracks and minimum changes were only made at the last second). Round 2 Discussion:- It seems as though some more work may be needed on the background to this regulation. Can we leave this with the SLF 53 WG to discuss and propose a way ahead for the CG? ] Reg 35-1 (Bilge pumping operational for up to B/5 side damage?)

Queries received from CLIA/CCSF between Round 1 and Round 2: Regulation 35-1

414 10/01/2012

Bilge pumping arrangements. This regulation is copied from previous SOLAS. Philosophy seems to be that bilge pumping system should remain operational for breach penetration up to B/5. More explanations are needed.

Coordinator’s Comments:

CG Member’s Comments?:- RINA: See Co-ordinators comment and response to comment under Part C. France: Proposed explanations have not been included in explanatory notes, but this regulation need to be clarified in the context of SOLAS2009. Round 2 Discussions: Thanks to RINA and France for their comments. It seems that more work is needed on this regulation (see previous question). It is proposed that we seek guidance from SLF 53 WG as to how to proceed.

Post SLF 53 Comments:- There was insufficient time for this to be discussed at SLF 53 therefore the item is kept open for discussion by the 2011 CG. We will give it a question number for future reference…...

New CLIA Q17:- Does anybody have any comments on how best to progress this item and whether it is considered that specific changes are needed to Reg 35-1 to answer CLIA’s original question?

Comments?:- Norway: See our comment in “CLIA Q15C for Round 4 Questionnaire”. China: No comments. RINA: No comment at this time. Denmark: No comments at this stage. Germany: Although the B/5 line concept has been removed in B-1 it may still be used for the location of bilge pumping arrangements as a minimum standard. No change to reg 35-1 needed. Finland: Support to keep reg. 35-1 as such as it is. B/5 line concept will give minimum standard as well as for WTD- doors, control cables and also for location of main bilge pipeline (reg. 35-1.10). France: Change in regulation or explanatory notes are needed.

Round 6 Discussion: Most who responded (6 out of 7) seem content with the current text. Norway’s comment to CLIA Q15C is included below for easy reference and is relevant here also:- Norway: The deterministic B/5 parameter still applies for watertight doors positioning and bilge non-return valves (Reg. 35-1, paragraph 3.10). In Norway’s opinion these are important safety barriers that must be maintained, if they can not be replaced by an equivalent probabilistic based parameter. We fail to see how a simple deletion of this B/5 safety barrier is in conformity with the overall goal of the Chapter II-1 revision, namely maintaining the level of safety. The SLF should conclude on this matter, and then ask the DE Sub-Committee to provide any comments they may have, for final completion of the matter. France, however, considers that changes to the regulation or EN are needed. It would seem that the impact on bilge pumping arrangements of removing the B/5 limit

415 10/01/2012

could be quite considerable and changes to the regulations to reflect the deeper side penetrations typical of the probabilistic damage analysis would necessitate a significant re-write of a regulation which a significant number of members are presently happy with. The easy route is to accept the majority verdict and leave things as they are but France has real objections. Not many members responded to the round 4 questionnaire and the issue was not discussed at SLF 53 due to lack of time. PROPOSED ACTION To give more members the opportunity to comment and possibly some additional time for France (CLIA and others?) to suggest specific text changes, we therefore propose that the item be listed for discussion in the WG at SLF 54. In preparation for SLF 54 we could also look again at how this is dealt with IMO Res. A.265 and also consider whether DE should be involved with our discussions (see Norway’s earlier comments). CLIA Q17D for Round 6 Questionnaire: Do you agree with the proposal to delay further action on reg. 35-1 until SLF 54? In the meantime any proposals for specific text changes or a new EN are welcomed. Yes?

CLIA, RINA (see comments), Finland, Norway, Germany, US, Italy, UK, EC, France (see comments), Denmark, China

No?

Alternative?

Comments? RINA: We have reviewed regulation 35-1 and it is considered that within that text there appears to be no major issues whether it is applied to ships which comply with probabilistic stability , deterministic stability one no damage stability al all. The only minor comment would be the deletion coal bunkers in 2.3. Consequently we have reviewed A.265 (VIII) regulation 19, which applies to passenger ships only, and note that amendment may be applied to regulation 35-1.3.2 and 3.4 as follows :

3.2 At least three power pumps shall be fitted connected to the bilge main, one of which may be driven by the propulsion machinery. Where the bilge pump numeral is 30 or more, [or the subdivision index R is more than 0.50 (for ships complying with Part B-1] one additional independent power pump shall be provided.

3.4 On a ship of 91.5 m in length and upwards or having a bilge pump numeral, calculated in accordance with paragraph 3.2, of 30 or more, [or the subdivision index R is more than 0.50 (for ships complying with Part B-1] the arrangements shall be such that at least one power bilge pump shall be available for use in all flooding conditions which the ship is required to withstand, as follows:

Finland: Even that we support to keep reg. 35-1 as such, we think that it would be better to consider this regulation further. In the meantime it is better to have some minimum requirements on the position (= B/5). France: SRTP requirements have a large impact beyond regulation 35-1 on bilge system design, but this applies only to passenger ships of 120m and above.

Q CLIA Q17. DISCUSS COMMENTS FROM RINA, FINLAND AND FRANCE AT SLF 54

416 10/01/2012

1 This regulation applies to ships constructed on or after 1 January 2009.

2 Passenger ships and cargo ships

2.1 An efficient bilge pumping system shall be provided, capable of pumping from and draining any watertight compartment other than a space permanently appropriated for the carriage of fresh water, water ballast, oil fuel or liquid cargo and for which other efficient means of pumping are provided, under all practical conditions. Efficient means shall be provided for draining water from insulated holds.

2.2 Sanitary, ballast and general service pumps may be accepted as independent power bilge pumps if fitted with the necessary connections to the bilge pumping system.

2.3 All bilge pipes used in or under [coal bunkers or] [Q59B]fuel storage tanks or in boiler or machinery spaces, including spaces in which oil-settling tanks or oil fuel pumping units are situated, shall be of steel or other suitable material. . Q59. Do you agree with the deletion of the words “coal bunkers or”, as shown? Yes

China, Finland, Germany, MI, Norway, Italy, Spain, Denmark, UK, US, Sweden

No

CLIA

Comments?:- Japan:- No comments. Round 1 Discussion: There is strong but not unanimous support for this proposal; CLIA would prefer to retain the reference to coal bunkers. Q59A. Would CLIA accept the majority verdict on this or are there strong reasons for keeping the reference to coal bunkers? Yes

CLIA.

No

Further comments?:- France: Not really important, but are we sure that there will be no more coal burning ships? Round 2 Discussion: See also Q48. Maybe France has a point? Or should we delete it now both here and in Reg. 15.5.1 then put it back if coal makes a come-back? Q59B. Do we agree to alter this regulation and also reg. 15.5.1 (see Q48) to remove all references to coal? Yes

No

Final comments post SLF 53:- See also Q48 – the deletion was agreed to as shown above.

NFA at SLF 54

417 10/01/2012

2.4 The arrangement of the bilge and ballast pumping system shall be such as to prevent the possibility of water passing from the sea and from water ballast spaces into the cargo and machinery spaces, or from one compartment to another. Provision shall be made to prevent any deep tank having bilge and ballast connections being inadvertently flooded from the sea when containing cargo, or being discharged through a bilge pump when containing water ballast.

2.5 All distribution boxes and manually operated valves in connection with the bilge pumping arrangements shall be in positions which are accessible under ordinary circumstances.

2.6 Provision shall be made for the drainage of enclosed cargo spaces situated on the bulkhead deck of a passenger ship and on the freeboard deck of a cargo ship, provided that the Administration may permit the means of drainage to be dispensed with in any particular compartment of any ship or class of ship if it is satisfied that by reason of size or internal subdivision of those spaces the safety of the ship is not thereby impaired.* [For the special hazards associated with loss of stability in ships fitted with fixed pressure water-spraying fire-extinguishing systems see II-2/20.6.1.4.] [Q60C][No objections – recommend extra sentence and to ask secretariat to add a footnote reference to MSC.1/Circ.1320 to II-2/20.6.1.4]

[Coordinator’s Note:- Should reference be made in a new footnote to SOLAS II-2 Regulation 20.6.1.4 relating to the drainage of ro-ro spaces fitted with fixed pressure water-spraying fire-extinguishing systems? MSC.1/Circ.1320 is included below]. R35-1.2.6 (new footnote referring to MSC.1/Circ.1320) Q60. (a) Do you think a new footnote referring to SOLAS II-2 Reg. 20.6.1.4 is needed? (b) Reference to the latest circular (MSC.1/Circ.1320) is not included in the SOLAS

2009 Consolidated Edition. If a new footnote is added should a reference to the circular be included as well?

(a) New footnote needed? Yes or No:- Yes: China, Japan, Norway, CLIA, Spain, Denmark, Sweden No: Germany, MI, Italy, US (b) If “yes”, should footnote also refer to MSC.1/Circ.1320? Yes or No:- Yes: China, Japan, Norway, Spain, Denmark, Sweden No: (a) Comments?:- Finland: No special opinion. US: We are not aware of footnotes cross-referencing regulations. If necessary the reference to regulation 20.6.1.4 should be made directly in the regulation 35-1.2.6 text. (note: the MSC.1/Circ.1320 footnote will eventually be added to regulation 20.6.1.4) (b) Comments / proposals for wording?:-

Round 1 Discussion: There is a majority (7/4) in favour of some reference to Reg. 20.6.1.4 in SOLAS II-2 at this point. The US queries whether footnotes cross-reference regulations (there is at least 1 example we found – footnote to SOLAS2009 II-1/C/ Reg. 26.11 cross-references Reg. II-2/4.2) and points out that a footnote referring to MSC.1/Circ.1320 will eventually appear automatically under Reg. II-2/20.6.1.4.

418 10/01/2012

Proposed Action. We could add a sentence at the end of Reg. 35-1.2.6 as follows:-

2.6 Provision shall be made for the drainage of enclosed cargo spaces situated on the bulkhead deck of a passenger ship and on the freeboard deck of a cargo ship, provided that the Administration may permit the means of drainage to be dispensed with in any particular compartment of any ship or class of ship if it is satisfied that by reason of size or internal subdivision of those spaces the safety of the ship is not thereby impaired. [For the special hazards associated with loss of stability in ships fitted with fixed pressure water-spraying fire-extinguishing systems see II-2/20.6.1.4.]. Q60A. Would you accept the proposed action to insert an extra sentence in Reg. 35-1.2.6 as shown, leaving the cross-reference to MSC.1/Circ.1320 to be added as a future footnote to II-2/20.6.1.4 by the Secretariat? Yes

MI, Italy, Japan, RINA (with comment), France, Norway, CLIA, US, Sweden, Denmark

No Further comments / alternatives?:- RINA: See Co-ordinators comment and response to comment under Part C. US: Now that you have pointed out an example of footnotes cross-referencing regulations, we could accept the footnote approach as well. Round 2 Discussion: There is now unanimous support for this proposal and the US will accept either a new footnote or a change to the regulation. Q60B. Do you think it is preferable to change the regulation as shown and leave the secretariat to add a footnote referring to MSC.1/Circ.1320 under II-2/20.6.1.4 or should we add a new footnote referring to Circ.1320 ourselves?

Change reg?

Add footnote ourselves?

Post SLF 53 Comments:- There was insufficient time for this to be discussed at SLF 53 therefore the item is kept open for discussion by the 2011 CG.

Q60C. Could members please indicate their response to Q60B below? Change reg?

US, Norway, Japan, China, Denmark, Germany, Italy, France RINA (Preferred option and Secretariat to add a footnote referring to MSC.1/Circ.1320 under II-2/20.6.1.4).

Add footnote ourselves?

Denmark , UK, CLIA (this seems OK)

Further comments / alternatives?:- Vanuatu: There are implications here where premature dewatering (foam use as an example) might be contra-indicated under some fire-fighting scenarios.

419 10/01/2012

Round 6 Discussion: There is a majority of 9-3 in favour of changing the regulation to:-

2.6 Provision shall be made for the drainage of enclosed cargo spaces situated on the bulkhead deck of a passenger ship and on the freeboard deck of a cargo ship, provided that the Administration may permit the means of drainage to be dispensed with in any particular compartment of any ship or class of ship if it is satisfied that by reason of size or internal subdivision of those spaces the safety of the ship is not thereby impaired. [For the special hazards associated with loss of stability in ships fitted with fixed pressure water-spraying fire-extinguishing systems see II-2/20.6.1.4.]. and leaving the Secretariat to add a footnote referring to MSC.1/Circ.1320 under reg. II-2/20.6.1.4. Would the minority be able to accept this decision? Vanuatu raises a new issue which we think may possibly need discussion in other forum as it seems to indicate that change could be required to reg. II-2/20.6.1.4, which is not within our remit.

Q60. CONCLUDED WE PROPOSE TO CHANGE REG 35-1.2.6 AS SHOWN ABOVE IN SQUARE BRACKETS AND ADVISE THE SUB-COMMITTEE THAT MSC.1/Circ. 1320 SHOULD BE REFERRED TO IN A FOOTNOTE TO II-2/20.6.1.4 Final Comments / Objections?: US: Fully agree with this conclusion. China: No. RECOMMEND ACCEPTANCE AT SLF 54 (Ref. SLF 54/8/1 paragraph 15.8) BUT CHINA MAY HAVE OBJECTIONS

420 10/01/2012

421 10/01/2012

422 10/01/2012

423 10/01/2012

424 10/01/2012

425 10/01/2012

426 10/01/2012

2.6.1 Where the freeboard to the bulkhead deck or the freeboard deck, respectively, is such that the deck edge is immersed when the ship heels more than 5°, the drainage shall be by means of a sufficient number of scuppers of suitable size discharging directly overboard, fitted in accordance with the requirements of regulation 15 in the case of a passenger ship and the requirements for scuppers, inlets and discharges of the International Convention on Load Lines in force in the case of a cargo ship.

R35-1.2.6.1 proposed new EN Discussion for Round 6 Supplementary Questionnaire. IACS will be presenting a paper at SLF with details of three new UI’s (Unified Interpretations) for the above SOLAS 2009 Chapter II-1 regulations. The usual procedure is for the UI’s to be approved by SLF and then MSC whereupon they are issued as MSC/Circulars. We then usually refer to these circulars in the EN as indicated in draft form below. The UI’s in question are:-


similar type) [Reg. 17-1.1.1] and • SC81 (Drainage of enclosed spaces situated on the bulkhead deck) [Reg. 35-1.2.6.1]

R6-SQ2 for Round 6 Supplementary Questionnaire. Do you have any comments on the UI’s or any objections to inserting references to the related forthcoming MSC/Circulars in the EN as shown highlighted in draft form below? Further comments / objections?:- Japan: No comments. RINA: Why not add the interpretation directly into the EN rather than refer to a separate document? Norway: Regarding IACS SC93 and SC81: No comments Regarding IACS SC220: The interpretation (a) is identical with IACS LL32 for the ICLL Reg. 21. We can not see that this interpretation has any relevance for SOLAS Reg. II-1/17-1.1. The interpretation (b), first paragraph, seems to introduce an interpretation that is not as restrictive as the SOLAS Reg. 20-2 (94/95 Amendments). If this interpretation refers to doors required for access in accordance with SOLAS Reg. 20-2.2.3 (94/95 Amendments) this should be mentioned in the IACS SC220. Poland: I think that it might be pointed which kind of ships similar type ..like..only vehicle ferries, ro – ro ships ..and….it might be pointed [Poland – please clarify – coordinators.] US: No objection to the general approach; but subject to discussion and acceptance of the IACS UIs at SLF 54. UK: No objections. China: No comments Proposed addition to the Explanatory Notes to reflect new UI’s from IACS to be presented at SLF 54 Regulation 35-1.2.6.1 − Drainage of bulkhead deck or freeboard deck Reference is made to MSC/Circ.[xxxx] (Unified interpretation of SOLAS chapter II-1) regarding special requirements for vehicle ferries, ro-ro ships and other ships of similar type.


427 10/01/2012

2.6.2 Where the freeboard is such that the edge of the bulkhead deck or the edge of the freeboard deck, respectively, is immersed when the ship heels 5° or less, the drainage of the enclosed cargo spaces on the bulkhead deck or on the freeboard deck, respectively, shall be led to a suitable space, or spaces, of adequate capacity, having a high water level alarm and provided with suitable arrangements for discharge overboard. In addition it shall be ensured that:

.1 the number, size and disposition of the scuppers are such as to prevent unreasonable accumulation of free water;

.2 the pumping arrangements required by this regulation for passenger ships or cargo ships, as applicable, take account of the requirements for any fixed pressure water-spraying fire extinguishing system;

.3 water contaminated with petrol or other dangerous substances is not drained to machinery spaces or other spaces where sources of ignition may be present; and

.4 where the enclosed cargo space is protected by a carbon dioxide fire extinguishing system the deck scuppers are fitted with means to prevent the escape of the smothering gas.

[Coordinator’s Note:- A question was raised by FP (Ref. SLF 52/11) regarding the validity of the 5° heel breakpoint in Reg.2.6.1 and 2.6.2. This was discussed at SLF 52 (Ref SLF 52/19) where it was agreed that 5 degrees was a suitable figure]:-

428 10/01/2012

3 Passenger ships

3.1 The bilge pumping system required by paragraph 2.1 shall be capable of operation under all practicable conditions after a casualty whether the ship is upright or listed. For this purpose wing suctions shall generally be fitted except in narrow compartments at the end of the ship where one suction may be sufficient. In compartments of unusual form, additional suctions may be required. Arrangements shall be made whereby water in the compartment may find its way to the suction pipes. Where, for particular compartments, the Administration is satisfied that the provision of drainage may be undesirable, it may allow such provision to be dispensed with if calculations made in accordance with the conditions laid down in regulations 7 and 8 show that the survival capability of the ship will not be impaired.

3.2 At least three power pumps shall be fitted connected to the bilge main, one of which may be driven by the propulsion machinery. Where the bilge pump numeral is 30 or more, one additional independent power pump shall be provided.

The bilge pump numeral shall be calculated as follows:

where:

[L] [Ls] = the length of the ship (metres), as defined in regulation 2;

M = the volume of the machinery space (cubic metres), as defined in regulation 2, that is below the bulkhead deck; with the addition thereto of the volume of any permanent oil fuel bunkers which may be situated above the inner bottom and forward of, or abaft, the machinery space;

P = the whole volume of the passenger and crew spaces below the bulkhead deck (cubic metres), which are provided for the accommodation and use of passengers and crew, excluding baggage, store, provision and mail rooms;

V = the whole volume of the ship below the bulkhead deck (cubic metres);

429 10/01/2012

P1 = KN,

where:

[N = the number of passengers for which the ship is to be certified]; and

K = 0.056[L] [Ls]

However, where the value of KN is greater than the sum of P and the whole volume of the actual passenger spaces above the bulkhead deck, the figure to be taken as P1 is that sum or two-thirds KN, whichever is the greater.

Regulation 35-1.3.2 (ref. SLF 52/17/6 - Norway) Length is used in paragraphs 3.2, 3.4 and 3.9 of this regulation, but it is not clarified if this is the “load line” length (L) as defined in regulation 2.5 or the subdivision length Ls as defined in paragraph 2.1. The definition of length for the purpose of these provisions in previous SOLAS versions has most in common with the definition of the subdivision length Ls. In paragraph 3.2 the use of the letter “N” as the number of passengers conflicts with the use of N in regulation 6.2. As this regulation is believed to be within the purview of the DE Sub-Committee the Sub-Committee may want to inform DE of these inconsistencies for possible future amendments. R 35-1.3.2 (L or Ls?) . Q61. Do you agree that length L should be Ls and N should be defined as in Reg.

6.2? Should DE be advised to make amendments to this Regulation accordingly?

Yes

China, Japan, Norway, Spain, Denmark, UK, Sweden

No

Finland, Germany (L should be used), MI, CLIA, Italy, US

Comments?:- Finland: “L” should be used, because bilge pump numeral is not based on probabilistic method (old formulation). Germany: Question is not clear / a common approach to use “L” only should be taken. Spain: We agree with the idea that length definition has most in common with the definition of the subdivision length Ls. In relation to the definition of N (‘the number of passengers for which the ship is to be certified’), it is the same wording as in previous SOLAS versions. Anyway, we consider acceptable to use other letter or symbol to designate the number of passengers for which the ship is to be certified, if considered useful to avoid misunderstandings. Additional information:

430 10/01/2012

This regulation was included in previous SOLAS Chapter II-1 (SOLAS 2004, consolidated edition, Chapter II-1 regulation 21.2). The reference was made to ‘criterion numeral’. The criterion numeral was defined in regulation 6.3 of Chapter II-1 (SOLAS 2004, consolidated edition), and the criterion numeral formula is equal to new bilge pump numeral formula. In regulation 6.3 is clearly stated that the length of the ship was defined in regulation 2 and N is the number of passengers for which the ship is to be certified. According regulation 2 of this Chapter "Length of the ship" is the length measured between perpendiculars taken at the extremities of the deepest subdivision load line. Then, definition in line with Ls. US: We prefer length L for this application. Also N was taken from the former “criterion of service” formula/definition. Since N is not defined as a general definition in regulation 2 or 3, we see no real problem here. Round 1 Discussion:- Voting is almost evenly divided on these issues, with good arguments in favour of both L and Ls – those in favour of replacing L with Ls, as proposed by Norway, winning by 7/6. Spain has contributed a detailed argument in favour of using Ls. The “N” term in regulation 35/1.3.2 does have its own definition within the regulation, as pointed out by the US, so it may not be too confusing if it conflicts with the N in Reg. 6.2, which is also clearly defined within that regulation.

Proposed Action: If we accept the small majority verdict, then we replace L with Ls and retain the definition of N:-

[L] [Ls] = the length of the ship (metres), as defined in regulation 2[.1];

……………………………….

P1 = KN,

where:

[N = the number of passengers for which the ship is to be certified]; and

K = 0.056[L] [Ls]

However, where the value of KN is greater than the sum of P and the whole volume of the actual passenger spaces above the bulkhead deck, the figure to be taken as P1 is that sum or two-thirds KN, whichever is the greater. . Q61A. Do you accept the action proposed above (use Ls and remove square

brackets around the definition of “N”) and also that DE be advised to make the amendment to the definition of L in this Regulation accordingly?

Yes

Germany, Finland, Italy, Japan, RINA (with comment), CLIA, UK, Sweden, Denmark

No

MI (with comment), RINA (with comment), France (with comment), Norway (with comment)

431 10/01/2012

Comments / Objections from the minority?:- MI: ‘L’ should be used since this regulation addresses bilge pumping systems and is not dependent on any probabilistic stability parameter. RINA: See response to Q16A. Within the SOLAS regulations “L” has generally been used as the standard definition for length. It is considered that the introduction of Ls, outside of Part B-1 will cause unnecessary confusion. France: This regulation applies to all ships, including ship not complying with probabilistic damage stability requirements of part B-1, so reference to L should be kept. Norway: The formulas in paragraph 3 are based on the old SOLAS assumptions related to coal-fired passenger ships, in particular typical distribution between passenger/crew accommodation, machinery spaces and (implied) cargo holds. US: We can certainly accept this but does it really make a big difference? (and which length is more user friendly?). Round 2 Discussion:- Again opinion is divided on this issue so we propose to take it to the WG at SLF 53 for a final decision. Perhaps, as the US says, it makes very little difference to the calculation of “P1”. Q61B. Should we keep using L in the formula for P1?

Yes

No

Post SLF 53 Comments:- There was insufficient time for this to be discussed at SLF 53 therefore the item is kept open for discussion by the 2011 CG. Q61C. Could members please indicate their response to Q61B below? Yes

US (i.e. make no change), Japan, RINA, Denmark, Germany, Finland, Italy, UK, CLIA, France

No

Vanuatu (agree with US), Norway, China

Further comments / alternatives?:- Norway: We prefer Ls. RINA: Within the SOLAS regulations “L” has generally been used as the standard definition for length. It is considered that the introduction of Ls, outside of Part B-1 will cause unnecessary confusion. Denmark: Ls should only be used in Part B-1. France: This regulation applies to ships not fulfilling stability requirements of part B-1. Round 6 Discussion: Voting was 10-3 in favour of keeping L in the formula for P1 as the regulation may equally apply to vessels which do not comply with part B-1 and will therefore not have an assigned Ls length. We therefore propose to accept the majority verdict but will leave room for Norway, China and Vanuatu to re-open the discussion at SLF 54 if they wish.

Q61 CONCLUDED PROPOSE NO CHANGE TO THE REGULATION PENDING ACCEPTANCE OF MAJORITY VERDICT AT SLF 54 BY NORWAY, CHINA AND VANUATU

432 10/01/2012

Final Comments / Objections?: US: Fully agree with this conclusion. China: No.

Q61. DISCUSS/VOTE AT SLF 54

3.3 Where practicable, the power bilge pumps shall be placed in separate watertight compartments and so arranged or situated that these compartments will not be flooded by the same damage. If the main propulsion machinery, auxiliary machinery and boilers are in two or more watertight compartments, the pumps available for bilge service shall be distributed as far as is possible throughout these compartments.

3.4 On a ship of 91.5 m in length [L] [Ls] and upwards or having a bilge pump numeral, calculated in accordance with paragraph 3.2, of 30 or more, the arrangements shall be such that at least one power bilge pump shall be available for use in all flooding conditions which the ship is required to withstand, as follows:

.1 one of the required bilge pumps shall be an emergency pump of a reliable submersible type having a source of power situated above the bulkhead deck; or

.2 the bilge pumps and their sources of power shall be so distributed throughout the length of the ship that at least one pump in an undamaged compartment will be available.

Regulation 35-1.3.4 (ref. SLF 52/17/6 - Norway) Length is used in paragraphs 3.2, 3.4 and 3.9 of this regulation, but it is not clarified if this is the “load line” length (L) as defined in regulation 2.5 or the subdivision length Ls as defined in paragraph 2.1. The definition of length for the purpose of these provisions in previous SOLAS versions has most in common with the definition of the subdivision length Ls. R 35-1.3.4 (specify length as “L”) . Q62. Do you agree that length L should be changed to Ls in this regulation and

that DE should be advised accordingly? Yes

China, Japan, Norway, CLIA, Spain, UK, Sweden

No

Finland, MI, Italy, Denmark, US

Comments?:- Finland:- “L” should be used. Germany:- A uniform, comprehensive approach shall be taken. Spain:- See Q.61. US:- We prefer length L for this application. Round 1 Discussion: There is a majority of 7 to 4 in favour of using Ls instead of L in this regulation. However, it has been noted that when ship length is being used as a “threshold”, as in this regulation, then it is more consistent with the rest of SOLAS to use L, which is a figure known

433 10/01/2012

earlier in the design phase, than Ls. For this particular regulation we would therefore propose that the regulation be clarified as follows:- 3.4 On a ship of 91.5 m in length [L] [Ls] and upwards or having a bilge pump numeral, calculated in accordance with paragraph 3.2, of 30 or more ……. . Q62A. Conscious that the coordinator is going against the views of the majority

on this issue, do you nevertheless agree that length L in this case should be clarified within this regulation as shown above and that DE should be advised accordingly?

Yes

MI, Germany, Finland, Italy, Japan, RINA, CLIA, UK, US, Sweden, Denmark

No

Norway (with comment)

Comments?:- MI: Yes, ‘L’ should be used. France: To keep L as for Q61. Norway: Affirms the original proposal in SLF 52/17/6. Round 2 Discussion:- There is a large majority in favour of using L but Norway still favours Ls so we propose to take it to the WG at SLF 53 for a final decision. Q62B. Should we use L in defining the length threshold of 91.5 m.?

Yes

No

Further Comments?

Post SLF 53 Comments:- There was insufficient time for this to be discussed at SLF 53 therefore the item is kept open for discussion by the 2011 CG. Q62C for Round 4 Questionnaire. Could members please indicate their response to Q62B below? Yes

Vanuatu, US, Japan, RINA, Denmark, Germany, Finland, Italy, CLIA, France, UK (should retain it unless a clear need to change is demonstrated).

No

Norway, China

Further comments?:- Norway: Ls RINA: Within the SOLAS regulations “L” has generally been used as the standard definition for length. It is considered that the introduction of Ls, outside of Part B-1 will cause unnecessary confusion. France: This regulation applies to ships not fulfilling stability requirements of part B-1. Additional explanations may be necessary concerning the sentence “in all flooding conditions which the ship is required to withstand”. For ship fulfilling damage stability requirements of part B-1, this could mean “damage of minor extent according to regulation 8 and all damages contributing to the attained index”.

434 10/01/2012

Round 6 Discussion: Voting was 11-2 in favour of using L to define the 91.5 metre threshold in this regulation. We therefore propose to accept the majority verdict but will leave room for Norway, and China to re-open the discussion at SLF 54 if they wish. The present regulation does not specify length so the proposal would be to insert L as follows:- 3.4 On a ship of 91.5 m in length [L] [Ls] and upwards or having a bilge pump numeral, calculated in accordance with paragraph 3.2, of 30 or more, the arrangements shall be such that at least one power bilge pump shall be available for use in all flooding conditions which the ship is required to withstand, as follows:

Q62. CONCLUDED PROPOSE TO INSERT “L” AS SHOWN IN SQUARE BRACKETS PENDING ACCEPTANCE OF MAJORITY VERDICT AT SLF 54 BY NORWAY AND CHINA Final Comments / Objections?: US: Fully agree with this conclusion.

New Issue: France thinks that further explanation of the text underlined in the regulation above is needed. Perhaps a new EN is needed, such as:- Regulation 35-1.3.4 For ships required to fulfil the damage stability requirements of part B-1 the words “in all flooding conditions which the ship is required to withstand” should be taken to mean all damages of minor extent according to regulation 8 and all damages contributing to the attained index, A. Q62D for Round 6 Questionnaire: Do you consider that a new EN (similar to that highlighted in green above) is needed, as proposed by France? Yes?

RINA, Finland, Norway, Germany, Poland, US (no objection to this), Italy, China, France, Denmark, UK (We do not have a strong opinion about this, but the proposed EN seems to make sense).

No?

CLIA, EC (text is clear as it stands)

Comments / Alternatives?: Japan: Japan generally supports France’s proposal but has a little concern about the words “and all damages contributing to the attained index, A” because a ship with higher value of attained index is subject to more stringent requirement about the allocation of bilge pump in paragraph 35-1.3.4.2. For example, “all damages contributing to the attained index” in the ship with A=0.95 are wider than those in the ship of the same shape and with A=0.9. In this case, in paragraph 35-1.3.4.2, “undamaged compartment” in the ship with A=0.95 are more limited than those in the ship with A=0.9, in spite of the fact that the safety of the ship with A=0.95 is higher. In addition, the amount of discharged water by “one power bilge pump” is much less than that of inflow water in the serious damage case. Japan thinks that we need to discuss further about the words “and all damages contributing to the attained index, A”

435 10/01/2012

Q62. • PROPOSE TO INSERT “L” AS SHOWN IN SQUARE BRACKETS PENDING

ACCEPTANCE OF MAJORITY VERDICT AT SLF 54 BY NORWAY AND CHINA.

• DISCUSS FRANCE’S PROPOSAL FOR A NEW EN IN VIEW OF JAPAN’S REMARKS.

3.5 With the exception of additional pumps which may be provided for peak compartments only, each required bilge pump shall be so arranged as to draw water from any space required to be drained by paragraph 2.1. 3.6 Each power bilge pump shall be capable of pumping water through the required main bilge pipe at a speed of not less than 2 m/s. Independent power bilge pumps situated in machinery spaces shall have direct suctions from these spaces, except that not more than two such suctions shall be required in any one space. Where two or more such suctions are provided, there shall be at least one on each side of the ship. The Administration may require independent power bilge pumps situated in other spaces to have separate direct suctions. Direct suctions shall be suitably arranged and those in a machinery space shall be of a diameter not less than that required for the bilge main.

3.7.1 In addition to the direct bilge suction or suctions required by paragraph 3.6, a direct suction from the main circulating pump leading to the drainage level of the machinery space and fitted with a non-return valve shall be provided in the machinery space. The diameter of this direct suction pipe shall be at least two thirds of the diameter of the pump inlet in the case of steamships, and of the same diameter as the pump inlet in the case of motorships.

3.7.2 Where in the opinion of the Administration the main circulating pump is not suitable for this purpose, a direct emergency bilge suction shall be led from the largest available independent power driven pump to the drainage level of the machinery space; the suction shall be of the same diameter as the main inlet of the pump used. The capacity of the pump so connected shall exceed that of a required bilge pump by an amount deemed satisfactory by the Administration.

3.7.3 The spindles of the sea inlet and direct suction valves shall extend well above the engine-room platform.

3.8 All bilge suction piping up to the connection to the pumps shall be independent of other piping.

3.9 The diameter d of the bilge main shall be calculated according to the following formula. However, the actual internal diameter of the bilge main may be rounded off to the nearest standard size acceptable to the Administration:

where:

d is the internal diameter of the bilge main (millimetres); [L] [Ls] and B are the length and the breadth of the ship (metres) as defined in regulation 2; and

436 10/01/2012

D is the moulded depth of the ship to the bulkhead deck (metres) provided that, in a ship having an enclosed cargo space on the bulkhead deck which is internally drained in accordance with the requirements of paragraph 2.6.2 and which extends for the full length of the ship, D shall be measured to the next deck above the bulkhead deck. Where the enclosed cargo spaces cover a lesser length, D shall be taken as the moulded depth to the bulkhead deck plus lh/L where l and h are the aggregate length and height respectively of the enclosed cargo spaces (metres). The diameter of the bilge branch pipes shall meet the requirements of the Administration.

Regulation 35-1.3.9 (ref. SLF 52/17/6 - Norway) Length is used in paragraphs 3.2, 3.4 and 3.9 of this regulation, but it is not clarified if this is the “load line” length (L) as defined in regulation 2.5 or the subdivision length Ls as defined in paragraph 2.1. The definition of length for the purpose of these provisions in previous SOLAS versions has most in common with the definition of the subdivision length Ls. R 35-1.3.9 (Continue to use “L” in the formula for “d”?) . Q63. Do you agree that length L should be changed to Ls in this regulation and

that DE should be advised accordingly? Yes

China, Japan, Norway, CLIA, Spain, UK, Sweden

No Finland, MI, Italy, Denmark, US

Comments?:- Germany:- A uniform, comprehensive approach shall be taken. Spain:- See Q61 Round 1 Discussion: The formula for “d” is taken straight from SOLAS90 II-1/B/Reg 21.2.9 where “L” was defined as the length “measured between perpendiculars taken at the extremities of the deepest subdivision load line” which seems to be nearer to “L” (as defined in S2009 Reg 2.5) rather than “Ls”. So even though a small majority is in favour of using “Ls” we would propose that we should instead use “L” as defined in Reg. 2.5 in this instance and clarify the definitions of “L” and “B” accordingly:- where:

d is the internal diameter of the bilge main (millimetres); [L] [Ls] and B are the length and the breadth of the ship (metres) as defined in regulation[s] 2[.5 and 2.8 respectively]; and …………………..

Q63A. Do you agree to this proposed clarification (with DE being notified accordingly)? Yes

MI, Germany, Finland, Italy, Japan, RINA, France, CLIA, UK, US, Sweden, Denmark

No Norway (with comment) Comments?:- France: L should be kept. Norway: Affirms the original proposal in SLF 52/17/6. Round 2 Discussion:- There is a large majority in favour of the proposed clarification but Norway still affirms the original proposal so we suggest we take it to the WG at SLF 53 for a final decision.

437 10/01/2012

Q63B. Should we continue to use L in the formula for “d”? Yes

No Further Comments? Post SLF 53 Comments:- There was insufficient time for this to be discussed at SLF 53 therefore the item is kept open for discussion by the 2011 CG. Q63C for Round 4 Questionnaire. Could members please indicate their response to Q63B below? Yes

Vanuatu, US (i.e. make no change), Japan, China, RINA, Denmark, Finland, Germany, Italy, UK, CLIA, France

No

Norway

Further comments?:- Norway: Ls RINA: Within the SOLAS regulations “L” has generally been used as the standard definition for length. It is considered that the introduction of Ls, outside of Part B-1 will cause unnecessary confusion. France: This regulation applies to ships not fulfilling stability requirements of part B-1. Round 6 Discussion: Voting was 12-1 in favour of keeping L in the formula for d as the regulation may equally apply to vessels which do not comply with part B-1 and will therefore not have an assigned Ls length. We therefore propose to accept the majority verdict but will leave room for Norway to re-open the discussion at SLF 54 if they wish.

Q63. CONCLUDED PROPOSE NO CHANGE TO THE REGULATION PENDING ACCEPTANCE OF

MAJORITY VERDICT AT SLF 54 BY NORWAY Final Comments / Objections?: Poland: I support to continue to use L in the formula of “d” US: Fully agree with this conclusion. China: No.

RECOMMEND ACCEPTANCE AT SLF 54

3.10 Provision shall be made to prevent the compartment served by any bilge suction pipe being flooded in the event of the pipe being severed or otherwise damaged by collision or grounding in any other compartment. For this purpose, where the pipe is at any part situated nearer the side of the ship than one fifth of the breadth of the ship (as defined in regulation 2 and measured at right angles to the centreline at the level of the deepest subdivision [load line] [draught]), or is in a duct keel, a non-return valve shall be fitted to the pipe in the compartment containing the open end.

Regulation 35-1.3.10 (ref. SLF 51/3/2 Annex – US and Sweden) The term “deepest subdivision load line” should be replaced by “deepest subdivision draught.”

438 10/01/2012

R 35-1.3.10 (Replace “Load Line” with “Draught”?) . Q64. Do you agree that the words “load line” should be changed to “draught” in

this regulation and that DE should be advised accordingly? Yes

China, Japan, MI, Norway, CLIA, Spain, Denmark, UK, US, Sweden

No

Finland, Germany, Italy

Comments?:- Germany: Draught is wrong, as the B/5 is measured from the waterline at the subdivision draught, which is the “subdivision load line.” Spain: Probably it is better to use the term deepest subdivision draught instead of deepest subdivision load line to avoid different interpretations. Anyway, in our opinion, ‘one fifth of the breadth’ is in relation to the SOLAS90 damage penetration, and this distance should be reviewed in the future. Additional information: See Q28 Round 1 Discussion:- A large majority (10/3) is in favour of replacing “load line” with “draught”. Germany has strong views against use of “draught”, however. Q64A. Can we accept the majority view and advise DE of the change accordingly?

Yes

MI, Germany, Finland, Japan, France (with comments), Norway, CLIA, UK, US, Sweden, Denmark

No Comments (particularly from Germany) ?:- RINA: See Co-ordinators comment and response to comment under Part C. France: The term “subdivision load line” is correct to define a waterline, but “subdivision draught” is equivalent. In regulation 15.5.3, reference is made to “subdivision draught” for the same purpose. In addition, term duct keel may be replaced by “nearer than 1/20th of the breadth of the ship from base line.” Round 2 Discussion:- Although we have a unanimous vote on this France would like to change the term “duct keel” and has a further comment on draught versus load line. It is therefore proposed to take this to the SLF 53 WG for a final decision. Q64B. Can we agree to replace “load line” with “draught”? Yes

No

Comments?:- Post SLF 53 Comments:- There was insufficient time for this to be discussed at SLF 53 therefore the item is kept open for discussion by the 2011 CG. Q64C for Round 4 Questionnaire. Could members please indicate their response to Q64B below? Yes

Vanuatu, US, Norway, Japan, China, RINA, Denmark, Germany, Finland, Italy, UK, CLIA, France

No

439 10/01/2012

Comments / France on duct keel?:- Norway: Not in favour of replacing “duct keel” with “nearer than 1/20th of the breadth of the ship from base line.” This could lead to a relaxation for smaller ships where minimum double bottom requirement is 760 mm (more than B/20). Also a problem for larger ships where maximum double bottom requirement is 2000 mm (less than B/20). RINA: Noting that there are several references to B/5 in part C it is considered that these and other inconsistencies should be considered in a review of Part C. Denmark: Keep the wording “duct keel”. Round 6 Discussion: There is a unanimous verdict (13-0) in favour of replacing “load line” with “draught” where shown below:- 3.10 Provision shall be made to prevent the compartment served by any bilge suction pipe being flooded in the event of the pipe being severed or otherwise damaged by collision or grounding in any other compartment. For this purpose, where the pipe is at any part situated nearer the side of the ship than one fifth of the breadth of the ship (as defined in regulation 2 and measured at right angles to the centreline at the level of the deepest subdivision [load line] [draught]), or is in a duct keel, a non-return valve shall be fitted to the pipe in the compartment containing the open end.

There appears little support for France’s proposal to replace “duct keel”. Q64. CONCLUDED

PROPOSE TO REPLACE “LOAD LINE” WITH “DRAUGHT” AS SHOWN IN SQUARE BRACKETS IN THE DISCUSSION PAPER

AND MAKE NO CHANGE TO “DUCT KEEL” Final Comments / Objections?: Poland: I am in favour of replacing load line with draught and DE might be advised accordingly. US: Fully agree with this conclusion. China: No.

RECOMMEND ACCEPTANCE AT SLF 54

3.11 Distribution boxes, cocks and valves in connection with the bilge pumping system shall be so arranged that, in the event of flooding, one of the bilge pumps may be operative on any compartment; in addition, damage to a pump or its pipe connecting to the bilge main outboard of a line drawn at one fifth of the breadth of the ship shall not put the bilge system out of action. If there is only one system of pipes common to all the pumps, the necessary valves for controlling the bilge suctions must be capable of being operated from above the bulkhead deck. Where in addition to the main bilge pumping system an emergency bilge pumping system is provided, it shall be independent of the main system and so arranged that a pump is capable of operating on any compartment under flooding condition as specified in paragraph 3.1; in that case only the valves necessary for the operation of the emergency system need be capable of being operated from above the bulkhead deck.

3.12 All cocks and valves referred to in paragraph 3.11 which can be operated from above the bulkhead deck shall have their controls at their place of operation clearly marked and shall be provided with means to indicate whether they are open or closed.

440 10/01/2012

4 Cargo ships

At least two power pumps connected to the main bilge system shall be provided, one of which may be driven by the propulsion machinery. If the Administration is satisfied that the safety of the ship is not impaired, bilge pumping arrangements may be dispensed with in particular compartments.

441 10/01/2012

APPENDIX GUIDELINES FOR THE PREPARATION OF SUBDIVISION AND DAMAGE

STABILITY CALCULATIONS 1 GENERAL

1.1 Purpose of the Guidelines

1.1.1 These Guidelines serve the purpose of simplifying the process of the damage stability analysis, as experience has shown that a systematic and complete presentation of the particulars results in considerable saving of time during the approval process. 1.1.2 A damage stability analysis serves the purpose to provide proof of the damage stability standard required for the respective ship type. At present, two different calculation methods, the deterministic concept and the probabilistic concept are applied. 1.2 Scope of analysis and documentation on board 1.2.1 The scope of subdivision and damage stability analysis is determined by the required damage stability standard and aims at providing the ship’s master with clear intact stability requirements. In general, this is achieved by determining KG-respective GM-limit curves, containing the admissible stability values for the draught range to be covered. 1.2.2 Within the scope of the analysis thus defined, all potential or necessary damage conditions will be determined, taking into account the damage stability criteria, in order to obtain the required damage stability standard. Depending on the type and size of ship, this may involve a considerable amount of analyses. 1.2.3 Referring to SOLAS chapter II-1, regulation 19, the necessity to provide the crew with the relevant information regarding the subdivision of the ship is expressed, therefore plans should be provided and permanently exhibited for the guidance of the officer in charge. These plans should clearly show for each deck and hold the boundaries of the watertight compartments, the openings therein with means of closure and position of any controls thereof, and the arrangements for the correction of any list due to flooding. In addition, Damage Control Booklets containing the aforementioned information should be available. 2 DOCUMENTS FOR SUBMISSION

2.1 Presentation of documents

The documentation should begin with the following details: principal dimensions, ship type, designation of intact conditions, designation of damage conditions and pertinent damaged compartments, KG-respective GM-limit curve.

442 10/01/2012

2.2 General documents

For checking of the input data, the following should be submitted:

.1 main dimensions;

.2 lines plan, plotted or numerical;

.3 hydrostatic data and cross curves of stability (including drawing of the buoyant hull);

.4 definition of sub-compartments with moulded volumes, centres of gravity and permeability;

.5 layout plan (watertight integrity plan) for the sub-compartments with all internal and external opening points including their connected sub-compartments, and particulars used in measuring the spaces, such as general arrangement plan and tank plan. The subdivision limits, longitudinal, transverse and vertical, should be included;

.6 light service condition; .7 load line draught; .8 coordinates of opening points with their level of tightness (e.g. weathertight,

unprotected); .9 watertight door location with pressure calculation;

.10 side contour and wind profile;

.11 cross and down flooding devices and the calculations thereof according to resolution MSC.245(83) with information about diameter, valves, pipes length and coordinates of inlet/outlet;

.12 pipes in damaged area when the destruction of these pipes results in progressive

flooding; and .13 damage extensions and definition of damage cases.

2.3 Special documents

The following documentation of results should be submitted.

2.3.1 Documentation

2.3.1.1 Initial data:

.1 subdivision length Ls;

.2 initial draughts and the corresponding GM-values;

.3 required subdivision index R; and .4 attained subdivision index A with a summary table for all

contributions for all damaged zones.

443 10/01/2012

2.3.1.2 Results for each damage case which contributes to the index A:

.1 draught, trim, heel, GM in damaged condition; .2 dimension of the damage with probabilistic values p, v and r; .3 righting lever curves (including GZmax and range) with factor of

survivability s; .4 critical weathertight and unprotected openings with their angle of

immersion;

.5 details of sub-compartments with amount of in-flooded water/ lost buoyancy with their centres of gravity.

2.3.1.3 In addition to the above requirements in 2.3.1.2, particulars of non-contributing damages (si = 0 and pi > 0.00) should also be submitted for passenger ships and ro-ro ships fitted with long lower holds including full details of the calculated factors. 2.3.2 Special consideration For intermediate conditions as stages before cross-flooding or before progressive flooding, an appropriate scope of the documentation covering the aforementioned items is needed in addition.

THE FOLLOWING APPENDICES RELATE TO REGS 5-1 to 7.2: APPENDIX 1) Norway’s original proposals APPENDIX 2) Current clean text of SOLAS 2009 and EN APPENDIX 3) Alternative proposals by UK APPENDIX 4) Round 5 discussions and questionnaire results APPENDIX 5) Norway’s revised proposals for discussion at SLF 54

444 10/01/2012

APPENDIX 1

[Co-ordinator’s Note: In view of the major re-organisation proposed by Norway to the regulations and explanatory notes covering Regulation 5-1 (Stability Information to be supplied to the master) and Regulation 7 (the attained subdivision index, A) a revised text is shown below with all comments removed for ease of reference. Norway’s proposed changes to the Regulations are shown in blue and alterations to the EN in italic font. Appendix 2 shows the current SOLAS Consolidated Edition 2009 and EN for comparison. Appendix 3 shows an alternative set of proposals].

445 10/01/2012

Regulation 5-1

Stability information to be supplied to the master *



.1 curves or tables of minimum operational metacentric height (GM) and maximum permissible trim versus draught which assures compliance with the relevant intact stability requirements of part A of the 2008 IS Code and relevant damage stability requirements, alternatively corresponding curves or tables of the maximum allowable vertical centre of gravity (KG) versus draught, or with the equivalents of either of these curves;


.3 all other data and aids which might be necessary to maintain the required intact stability according to the requirements of part A of the 2008 IS Code and stability after damage.

Regulation 5-1.2

Any limiting GM (or KG) requirements arising from provisions in regulation 6.1 (regarding partial attained subdivision indices), regulation 8 or regulation 9, which are in addition to those described in regulation 5-1.4, should also be taken into account when developing this information. ________________________ ∗ Refer also to the Guidelines for the preparation of intact stability information (MSC/Circ.456);

Guidance on the intact stability of existing tankers during transfer operations (MSC/Circ.706);[Q6] and the Revised guidance to the master for avoiding dangerous situations in following and quartering seas (MSC.1/Circ.1228).

446 10/01/2012

3 The stability information shall show the influence of various trims in cases where the operational trim range exceeds +/− 0.5% of [Ls] [L]. Applied trim values shall coincide in all stability information intended for use on board. [Coordinator’s Note for Round 2: Not yet finally decided - please see Q20(a)A, Q20(b)A and Q20(c)A for further questions on this Regulation in Round 2] 4 The stability limits intended for use on board shall be presented as consolidated data taken from the applicable intact and damage stability calculations of these regulations. Information not required for determination of stability and trim limits should be separated from this information. 5 If the damage stability is calculated in accordance with part B-1 of these regulations a stability limit curve is to be determined using linear interpolation between the minimum required GM assumed for each of the three draughts ds, dp and dl. When additional subdivision indices are calculated for different trims, a single envelope curve based on the minimum values from these calculations shall be presented. If it is intended to develop curves of maximum permissible KG it shall be ensured that the resulting maximum KG curves correspond with a linear variation of GM. 6 When curves or tables of minimum operational metacentric height (GM) versus draught are not appropriate, the master should ensure that the operating condition does not deviate from a studied loading condition, or verify by calculation that the stability criteria are satisfied for this loading condition.

Regulation 5-1.3, 5-1.4 and 5-1.5



447 10/01/2012

3 If multiple GM limiting curves are obtained from damage stability calculations of differing trims in accordance with regulation 7, an envelope curve covering all calculated trim values should be developed. Calculations covering different trim values should be carried out in steps not exceeding 1% of Ls. The whole range including intermediate trims should be covered by the damage stability calculations. Refer to the example showing an envelope curve obtained from calculations of 0 trim and 1% of Ls.

4 As an alternative to an envelope curve, the calculations for additional trims may be carried out with one common GM for all of the trims assumed at the deepest subdivision draught ds and the partial subdivision draught dp respectively. The lowest values of each partial index As and Ap across trims will then be used in the summation of the attained subdivision index A according to regulation 7.1. At the light service draught the partial index Al is assumed constant. This will result in one GM limit curve based on the GM used at each draught. A trim limit diagram showing the assumed trim range is then developed as shown in the figure.

[Coordinator’s Note:- Is the above diagram understandable to everybody? For example, what does the vertical axis represent – minimum GM? What happens if KG is used?]

448 10/01/2012

5 It is not required that the trim values at ds and dp coincide as long as the limitations with respect to variation between trims are observed at each draught. The applicable trim limits may then be marked at 0.5% Ls [L] in excess of the largest calculated trims as shown in the figure. There will be no trim limits in the draught range between dl and dp unless the limiting GM is governed by other applicable intact or damage stability criteria. ----------------------------------------- Q21. Looking at Regulation 5-1.4 and the EN, it would appear that the amendments proposed in SLF 51/3/2 have been superseded by Norway’s proposals in SLF 52/17/4 and 52/17/6. The EN amendment in 51/3/2 would then be superseded by Norway’s revised EN, which also includes alterations to Reg. 7. A clean copy of all the proposed SOLAS text revisions and the changes to the EN are shown in Appendix 1 at the end of this questionnaire. Taking into account all the comments and notes above would you agree to the amendments to Regulation 5-1 with EN as proposed by Norway and as shown in Appendix 1? Yes

China (but amended diagram needed), Finland (with comment), Germany (with comment), Japan, MI, Norway, Italy (with comment), US (with comment), Sweden

No

CLIA, Spain, Denmark, UK

Comments / Alternative Proposals?:- China: Reference is made to the trim limiting curve on page 3 of the annex of document SLF 52/17/4�Norway�. Following figure is a hard-copy:

This is a good proposal except that the two slope lines should be vertical and the trapezoid

curve should be rectangular as the proposed figure by Norway uses two different sets of trim range

449 10/01/2012

in the calculation of partial index A for draught dp and ds respectively. Paragraph 2 of notes to Regulation 5-1.3 and 5-1.4 of MSC.281(85) says “then additional sets

of GM limit lines should be constructed on the basis of the operational range of trims which is covered by loading condition of partial subdivision draught and deepest subdivision draught ensuring that intervals of 1% Ls are not exceeded”. I interpret this sentence in this way: draught dp and ds represent cargo loading conditions. “Operational range of trims” is the trim range starting from the least trim to the maximum trim on the sorted results of the trims of all cargo loading conditions. For example, if the real trims(i.e., without deduction of ±0.5%Ls for all cargo loading conditions are sorted and listed as below:

-1.7%Ls, -0.4% Ls, 0.8% Ls, 1.6% Ls, 2.4% Ls

Then the real trim range is -1.7% Ls ~2.4% Ls. Trim range of -1.2% Ls ~1.9% Ls. range should

be applied in the calculation of partial index A for both dp and ds. This means the trim range of dp is the same as the trim range of ds. Although for the cargo loading conditions in the loading manual, the range of trims of the loading conditions of which the draft is ds may differ from the trims range of the loading conditions of which the drafts are less than ds, but in real operation the loading conditions may differ from the loading manual and the real trims of ds may exceed the used trim range and run into the trim range of dp. And the same case may occur for the used trim range of dp. Therefore using two separate trim ranges for draught dp and ds respectively is only of theoretical meaning and may not be consistent with the real operation. However, using the same trim range for both draught dp and ds as illustrated above is practical and concords with the explanatory notes. END of CHINA’s PROPOSALS Finland: Reg 5-1.4 (proposed 5-1.5, see Q18). Propose to add ; “If the subdivision index is calculated for different trims, an envelope curve with the highest GM values of the several required GM curves will be established in the same way. Agree with Norwegian proposed text into EN with the exception that calculations for trim variation also include variable trim for dl. Germany: has the following comments (the wording of the proposed text by NOR would need to be revised at several parts (including the diagram)!)

c) We regard it as NOT meaningful that the light service draft dl is “fixed” in draft/trim (as a consequence Al is constant). Such restriction is in conflict with the general methodology of the probabilistic concept

we regard dl as a “design parameter” which can be freely chosen by the designer. This includes that calculations for trim variation also include variable trims for dl. Any load cases need later to be verified to be within the limitations of trim/GM as a result of the damage stability calculation. This allows full flexibility for the designer and also inherits the required safety level

d) With respect to Reg. 5.1.5 and the diagram we have the following comments:

It is proposed that in the draft range between dl and dp NO trim limitation is valid. We are concerned for drafts close below dp as here per proposed definition no limit exists.We regard it as important that the trim limitation of +/- 0.5%L is valid for the entire draft range. This is to be seen in conjunction with our proposal that trim variations for dl are allowed.

MI: Proposals acceptable as a complete package including use of ‘L’.

450 10/01/2012

Norway: It is realised that the second figure may be difficult to explain, however the principle for dealing with draughts below dp can not be dealt with without considering the effect on A and the calibration of the R-formulas. CLIA: This issue and the EN is handled in the CSSF work:- The calculation of different trims as proposed by Norway (SLF52/17/4) is shown below in a slightly simplified way and supported by the group. The concept of fixed trim at the light service draught has been removed and the normal trim range of 0.5% Ls is also applied here. However more examples might be useful in the final EN to illustrate the concept, in particular for trim variations at draughts between dl and dp. “3 If multiple GM limiting curves are obtained from damage stability calculations of differing trims in accordance with regulation 7 an envelope curve covering all calculated trim values should be developed. Calculations covering different trim values should be carried out in steps not exceeding 1% of Ls. The whole range including intermediate trims should be covered by the damage stability calculations 4 As an alternative to an envelope curve the calculations for additional trims may be carried out with one common GM for all of the trims assumed at the deepest subdivision draught ds and the partial subdivision draught dp respectively. The lowest values of each partial index As and Ap across trims will then be used in the summation of attained subdivision index A according to regulation 7 5 It is not required that the trim values at ds, dp and dl coincide as long as the limitations with respect to variation between trims are observed at each draught.” Italy: Yes in principle but the lack of trim limits in the draught range between dl and dp is not acceptable. Spain: We do not agree with the proposal contained in points .4 and .5 (“As an alternative to an envelope curve, the calculations for additional trims may be carried out with one common GM for all of the trims assumed...”). The proposed limiting trim curve is not very clear for us. Anyway, if the group decides to accept the proposal, we have two comments:

3) What are the trim limits between dl and dp? 4) We suggest to change the axis (e.g. draught X axis and trim Y axis):

451 10/01/2012

END of SPAIN’s COMMENTS Denmark: In terms of presentation, I would be concerned that the trim limit diagram will be potentially confusing to ship’s staff, we prefer UK’s proposal for a trim limit diagram. Also Reg 5-1.5 should be the maximum of minimum GM limit curves. EN 3, Ls should be changed to L for consistency? We agree with the principle to clarify the regulations, but think that the presentation of max trim needs to be improved. UK: We are of the opinion that the details of each trim value used in the calculations should be presented as separate curves, alongside with the envelope curve (see Q25). US: Yes in principle; however some details need to be further considered and refined. e.g. The relationship between proposed new regulation 5-1.4 and the existing provision in regulation 5-1.2 is unclear to us; should these paragraphs be consolidated or should paragraph 4 precede paragraph 2? Also as indicated in the Coordinator’s Note, the new figure for EN paragraph 4 needs additional details / clarifications. Round 1 Discussion: See end of Appendix 1 for general discussion on the issues raised by Q21, Q23 and Q25.

452 10/01/2012

Regulation 7

Attained subdivision index A

1 An attained subdivision index A is obtained by the summation of the partial indices As, Ap and Al, (weighted as shown) calculated for the draughts ds, dp and dl defined in regulation 2 in accordance with the following formula:

A = 0.4As + 0.4Ap + 0.2Al


A = Σpi si

where:


pi accounts for the probability that only the compartment or group of

compartments under consideration may be flooded, disregarding any horizontal subdivision, as defined in regulation 7-1,

si accounts for the probability of survival after flooding the compartment or

group of compartments under consideration, and includes the effect of any horizontal subdivision, as defined in regulation 7-2.

Regulation 7.1



A = 0.4As + 0.4Ap + 0.2Al

where the indices s, p and l represent the three loading conditions and the factor to be multiplied to the index indicates how the index A from each loading condition is weighted. 2. The method of calculating the A for a loading condition is expressed by the formula:

i=t Ac = ∑ pi [vi si] i=1

453 10/01/2012








considered damage for a specific initial condition

5. Three initial loading conditions should be used for calculating each index A. The loading conditions are defined by their mean draught d, trim and GM (or KG). The mean draught and trim are illustrated in the figure below. The light service condition will be common for all calculations of index A.

Q23. Do you agree with the proposed changes to Reg 7.1.5 EN (shown in blue)? Yes

China, Finland, Japan, Norway, Spain, Denmark, Sweden

No

Germany, MI, Italy, UK, US

Comments?:- China: Propose to replace “mean draught d” with “correspondent draught d” as color text below:

“5 Three initial loading conditions should be used for calculating each index A. The loading conditions are defined by their meancorrespondent draught d, trim and GM (or KG). The mean draught and trim are illustrated in the figure below. The light service condition will be common for all calculations of index A.”

454 10/01/2012

Germany: Refer to our answer to Q21. CLIA: See CSSF EN for this issue. Italy: Not acceptable because there may be loading conditions corresponding to light service draught with different trims. US: We prefer the original text; this EN is describing the general case. Round 1 Discussion: See end of Appendix 1 for general discussion on the issues raised by Q21, Q23 and Q25. 6. The GM (or KG) values for the three loading conditions could, as a first attempt, be taken from the intact stability GM (or KG) limit curve. If the required index R is not obtained, the GM (or KG) values may be increased (or reduced), implying that the intact loading conditions from the intact stability book must now meet the GM (or KG) limit curve from the damage stability calculations derived by linear interpolation between the three GMs. 7 A previously approved partial index Al may be considered to remain valid for a sister ship and in other cases where differences in light ship particulars result in minor deviations from the assumed draught and trim in the light service condition. It is recommended that the limits for validity of stability documentation in case of lightship deviations set out in regulation 5.2 be applied also for this purpose.[Coordinator’s Note: Please see Q24A for possible amended version of this text]. 2 As a minimum, the calculation of A shall be carried out at level trim for the deepest subdivision draught ds and the partial subdivision draught dp. The [actual] [anticipated] service trim shall be used for the light service draught dl. If in any anticipated service condition within the draught range from ds to dp the trim variation in comparison with the calculated trims is greater than 0.5% of Ls, one or more additional calculations of A are to be performed for the same draughts, but including sufficient trims to ensure that for all intended service conditions the difference in trim in comparison with the reference trim used for one calculation will be less than 0.5% of Ls. The partial index Al is considered constant for the purpose of these calculations.

[Regulation 7.2 EN removed]

3 Each additional value of A calculated in accordance with paragraph 2 shall comply with regulation 6 and 7.1. Q25. Norway proposes to replace the existing text of Reg 7.2 and re-organize and

re-number the remaining regulations and EN in association with Reg 5-1.4 (see Appendix 1 for complete version). It is assumed that these amendments are intended to replace Norway’s earlier proposals in SLF 51/3/2. An alternative proposal from the UK in 51/3/2 suggests that maximum allowable KG’s rather than minimum GM’s should be used and that the limiting curves should be presented as a variation against trim for the 3 specified draughts (assuming linear interpolation between draughts). Combined critical KG curves would then cover all the relevant stability criteria, both intact and damage. No specific

455 10/01/2012

changes to the text of the Regulations or EN were proposed. As this is a fairly complex issue we would simply like to ask if there is support at this stage for Norway’s package of proposals for Reg 7 as shown in Appendix 1; are there any objections, questions or alternative proposals?

Yes (Accept Norwegian proposals in App 1)

China, Finland, Germany, MI (but see comments), Norway, Italy, US

No

Japan, Spain (see comments), Denmark, UK, Sweden

Comments, reasons, alternative proposals?:- Finland: Support Norway. No support for UK proposal. Prefer GM-limiting rather than KG-limiting curves. Germany: Support Norway’s proposal (strong objections against UK proposal!) Japan: It is not clear how to deal the case that the trim in the loading case between Dp and Dl exceeds the range of calculated trim. MI: Could support Norway’s proposals because they are in a package but the UK suggestion of using max allowable KGs and resulting combined critical KG curves has considerable merit and should be further discussed before a final decision is made. CLIA: CSSF EN work. Italy: See also comments on item 21. Spain: We accept the proposals except the trim versus draught graph. As we have explained, it is not very clear in our opinion. We have made one proposal:

- To change the axis (e.g. draught X axis and trim Y axis):

456 10/01/2012

Spain (continued): Regarding UK proposal, we think it is more clear than the other proposed trim limit curve (we can accept it), but we think that for the master is more intuitive to have GM or KG curves versus draught (and different curves depending on trim), e.g.:

Max Allowable KG vs Draught

4

4.5

5

5.5

6

6.5

7

7.5

8

8.5

4 4.5 5 5.5 6 6.5 7

Draught (m.)

Crit

ical

KG

(m.)

Trim Aft Trim 0 Trim Fwd

End of Spain’s Proposals

457 10/01/2012

Denmark: We wonder if it is worth considering whether the trim limits should be restricted to no greater than the calculated conditions, as it is for deterministic damage stability. Consider that if the partial indices are at 0.5R or 0.9R for a particular trim, allowing 0.5%L more trim will most certainly reduce the attained partial indices. US: We support in principle; details subject to further consideration. Round 1 Discussion: See end of Appendix 1 for general discussion on the issues raised by Q21, Q23 and Q25. 4 When determining the positive righting lever (GZ) of the residual stability curve, the displacement used should be that of the intact condition. That is, the constant displacement method of calculation should be used.



Regulation 7.6

1. With the same intent as wing tanks, the summation of the attained index A should reflect effects caused by all watertight bulkheads and flooding boundaries within the damaged zone. It is not correct to assume damage only to the centreline and ignore changes in subdivision that would reflect lesser contributions.


458 10/01/2012

7 In the flooding calculations carried out according to the regulations, only one breach of the hull and only one free surface need to be assumed in the final stage of flooding. The assumed vertical extent of damage is to extend from the baseline upwards to any watertight horizontal subdivision above the waterline or higher. However, if a lesser extent of damage will give a more severe result, such extent is to be assumed.

8 If pipes, ducts or tunnels are situated within the assumed extent of damage, arrangements are to be made to ensure that progressive flooding cannot thereby extend to compartments other than those assumed flooded. However, the Administration may permit minor progressive flooding if it is demonstrated that its effects can be easily controlled and the safety of the ship is not impaired.

Regulation 7.8

1. Pipes and valves directly adjacent to a bulkhead or to a deck can be considered to be part of the bulkhead or deck, provided the separation distance is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc.

2. The provision for allowing “minor progressive flooding” should be limited to pipes penetrating a watertight subdivision with a total cross-sectional area of not more than 710 mm

2 between any two watertight compartments.

General Discussion on Q21, Q23 and Q25 covering:-

1. Reg. 5-1.4 (Stability information to be supplied to the master) and associated EN

2. EN 5 for Reg. 7.1 (Attained subdivision index A) 3. Reg. 7.2 and associated EN for the trims to be used in the calculation of A

As coordinators we have found it quite difficult to draw any firm conclusions from the responses made to date on how best to present the results of the S2009 damage stability analysis to the master although the proposals by Norway have helped greatly in clarifying the issues involved and providing a basis for discussion. In an attempt to try to see more clearly what we are trying to achieve by integrating all the limiting GM/KG curves for intact and damage stability into something understandable for the crew, we have drawn up a table (below) summarizing all the criteria with the appropriate draughts and trims relevant to a passenger ship. It can be clearly seen from the table that in integrating intact and damage stability critical curves we are attempting to combine data from deterministic and probabilistic sources and it may be this that is causing us some difficulty as the two do not really mix very well. For example, when we calculate A to ensure that A>=R, this is not really a stability characteristic comparable, say, with the area under the residual GZ curve. It is really a “spot check” on the overall safety level of this ship in comparison with the safety level of a large fleet of similar vessels. The regulations as they stand require this “spot check” to be carried out at 2 specified draughts at level trim and a light draught at the corresponding service trim. The KG or GM used in these calculations may not necessarily be “critical” such that A=R; in some cases A could be much greater than R, in which case no critical GM/KG can be said to exist for that “criterion” as the choice of input KG/GM can be almost random.

459 10/01/2012

With respect to trim, the regulations currently imply that compliance with A>=R using level trim for ds and dp and service trim for dl can then be assumed across a trim range from +0.5%L to -0.5%L. Only if the operating trim exceeds these limits are further A>=R calculations needed, to ensure that there is no major reduction in safety at operating trims in excess of +/-0.5%L. But this is again a “spot check” and does not readily lend itself to the production of valid GM/KG limit curves interpolated between level trim and the extremes of the operating trim as the choice of input GM/KG can be fairly arbitrary and it is quite possible for A to be much greater than R. In a similar way, the additional requirement in Reg. 6.1 that the partial indices As, Ap and Al are each greater than or equal to 0.9R for pax ships and 0.5R for cargo ships is designed to ensure that there is a significant contribution to A at each of the 3 load draughts, which used to be a problem in SOLAS90 Reg.25 for cargo ships where nearly all the contribution to A could come from the light draught. Again, this is a “spot check” to overcome a specific problem, and is therefore not really amenable to the production of “critical” GM/KG curves interpolated across a range of trims. The regulations within SOLAS2009 which are more amenable to producing meaningful critical KG/GM curves are those requiring “si” to be a certain value (Reg. 8.1, 8.2 and 9.8) although only Reg. 9.8 is stated to be applicable “for all service conditions”. As Denmark suggests, the critical situation for compliance with Reg. 8.1 is likely to be at ds with maximum operational bow trim, whereas for Reg. 8.2 and 9.8 the operational range of trims and draughts should be covered. The above begins to suggest a procedure for the designer to develop useful limiting curves:-

1. First calculate the intact stability limiting GM/KG curves in accordance with 2008 IS Code covering criteria I1 to I8 in the table below at suitable draught and trim increments across the operational ranges.

2. For the same draughts and trims calculate damage criteria for Reg. 8.1, 8.2 & 9.8. 3. Plot minimax critical GM/KG curves across the operational range of draught and

trim for the intact and damage criteria in 1 and 2 only. 4. Using the critical KG/GM’s from these calculations, at the appropriate trim(s)

and ds, dp and dl ensure that A>=R and that the partial indices in Reg. 6.1 are all compliant.

5. If the operational trim range exceeds +/- 0.5%L carry out further spot checks on A>=R and the partial indices using the appropriate critical GM/KG’s derived from 1 and 2 but do not attempt to plot any critical curves based on the “criteria” in Reg. 6.1.

6. Add a statement in the Stability Booklet to say that “Provided the ship is loaded in accordance with the limiting GM/KG curves/tables, the minimum A/R ratio for damage stability will be 1.xxx and the partial indices at ds, dp and dl will be always >= 0.9R (>=0.5R for cargo ships)”.

If the above procedure is agreed to in principle, we could either try to provide appropriate revisions to the Regulations and EN in time for Round 3 or use a drafting group at SLF 53. Appendix 1 Q1. Do you agree in principle with the procedure outlined above

for providing integrated limiting GM/KG curves to the crew whilst verifying that the probabilistic elements of S2009 Reg. 6 and 7 are complied with?

460 10/01/2012

Yes

MI, Japan, Norway, CLIA (Agree in part – see comments), UK, Denmark

No

Germany (with comments), Finland (with comments), Italy (with comments)

Comments?:- MI: Yes, agree in principle with the procedure. Germany:

1) Also for reg 8 and 9 the same initial conditions as for reg 6 (dl, dp, ds) should be used resulting in one GM limit curve for all damage aspects. Trim range of 0.5%Ls should be used for all 3 draughts.

2) The procedure from the coordinator to obtain GM/KG limit curve is technically

meaningful for designers, but this does not solve the problem in application of correct limiting curves covering the relevant parameters draft, trim, GM.Germany understands the damage stability calculation as a “design parameter” that shows the capabilities of a vessel and ensures the required safety level.

Having this in mind the following principles should be incorporated to the EN

1. DRAFT as close as possible” in alignment with the load case “Ballast Arrival” (this ensures that the entire operation scope of the vessel is covered by the limit curve)

2. TRIM trim is a “design parameter” and can freely chosen by the designer (*** see below remark)

3. GM GM is a “design parameter” and can freely chosen by the designer (*** see below remark)

Important remark *** for all load cases it is to be ensured that ALL load cases (incl. “Ballast Departure”) are within the limitation (trim, GM) from the damage stability calculation. This could also mean that additional damage stability calculations with different trim level are to be carried out by the designer We appreciate the proposal by Norway and related technical comments as a good approach to give a general guidance. However, several details need to be clarified such as

- clarity of diagrams related to trim restriction for “easy on-board use - application of +/- 0.5%L trim range also for the light service draft DL, etc).

Further we are concerned that for certain scenarios inappropriate restrictions to designers could occur. Therefore we regard any such proposal as an additional part of the EN only, but such guidance should not be tailored as a compulsory schema. Therefore we regard the methodology of the “GM envelope curve” as the paramount principle. Finland: For all 3 draughts trim range of 0.5 %Ls should be applied. Italy: The procedure outlined above is not acceptable. In particular on item 2 the damage assessments for Reg. 8.1, 8.2 & 9.8 were never intended to be carried out with all drafts and trims of intact stability. Moreover on item 4, if A< R it is not clear what should be done. For these reasons ITALY fully supports the proposal made by CLIA/CSSF, here attached for easy reference :

461 10/01/2012

“This issue and the EN is handled in the CSSF work:- The calculation of different trims as proposed by Norway (SLF52/17/4) is shown below in a slightly simplified way and supported by the group. The concept of fixed trim at the light service draught has been removed and the normal trim range of 0.5% Ls is also applied here. However more examples might be useful in the final EN to illustrate the concept, in particular for trim variations at draughts between dl and dp. “3 If multiple GM limiting curves are obtained from damage stability calculations of differing trims in accordance with regulation 7 an envelope curve covering all calculated trim values should be developed. Calculations covering different trim values should be carried out in steps not exceeding 1% of Ls. The whole range including intermediate trims should be covered by the damage stability calculations 4 As an alternative to an envelope curve the calculations for additional trims may be carried out with one common GM for all of the trims assumed at the deepest subdivision draught ds and the partial subdivision draught dp respectively. The lowest values of each partial index As and Ap across trims will then be used in the summation of attained subdivision index A according to regulation 7 5 It is not required that the trim values at ds, dp and dl coincide as long as the limitations with respect to variation between trims are observed at each draught.” France: Outlined procedure is a possible option but may not be the only one. It should always be possible to study independently intact and damage stability criteria and to combine them in final. One of the problems is that usually much more draft/trim conditions are studied for intact stability criteria than for damage stability criteria. In addition, for some ships, two sets of intact stability curves are presented depending on encountered weather conditions. In the same way, two set of damage stability curves may be provided if several subdivision load lines are assigned. Anyway this principle can help us in the process to define integrated limiting GM/KG curves. CLIA: In our experience, for Cruise Vessels the following is the procedure used in reality and the limit diagrams produced:

1) Calculate the Intact limiting GM/ KG values for a range of draughts at a range of trims. Present them as GM or KG limit curves with an X axis of draught, with a curve for each trim.

2) Calculate limiting GM/ KG values for regulation 6-7 (including partial A indices requirements) for A=R, at dl, dp, ds, then check at the limiting GM values for each of the three conditions, that compliance with regulations 8 and 9 is achieved. Present them as GM or KG limit curves on the same axes as intact limits.

3) If trim is more than 0.5%Ls, then there will need to be Reg 6-7 A=R GM or KG limit curves for each trim (although not normally the case for cruise ships).

4) For a ship where compliance with Reg 8 or 9 is NOT achieved at the Reg 6-7 limiting GM values, then calculate the limiting GM/ KG curve for compliance with Reg 8 (or 9) at the same 3 draughts. At that limit curve, A will be >R and this can be stated on the diagram/ manual.

462 10/01/2012

5) For each of the trims from the Intact limits (it’s assumed that if needed, trims chosen for

damage stability would coincide), overall “envelope” limits for GM or KG for both intact and damage requirements can be drawn, with X axis of draught, making a very simple presentation for the master, equivalent to the limit diagrams from the SOLAS 90 rules.

463 10/01/2012

Criteria to be complied with Code2008 IS CODE INTACT STABILITYRegulation

2.2.1 Area under GZ curve not to be less than 0.055 m-rads up to 30 degrees I1 Operating Range Operating Range2.2.1 Area under GZ curve not to be less than 0.09 m-rads up to 40 deg or downflooding I2 Operating Range Operating Range2.2.1 Area under GZ curve not to be less than 0.03 m-rads between 30 to 40 deg (or d'flood) I3 Operating Range Operating Range2.2.2 GZ shall be at least 0.2 m at an angle of heel equal to or greater than 30 degrees I4 Operating Range Operating Range2.2.3 The maximum righting lever shall occur at an angle of heel not less than 25 degrees I5 Operating Range Operating Range2.3 Severe wind and rolling criterion - area b>=area a I6 Operating Range Operating Range

3.1.1 Angle of heel due to passenger crowding not to exceed 10 degrees I7 Operating Range Operating Range3.1.2 Angle of heel due to turning not to exceed 10 degrees I8 Operating Range Operating Range

S2009 DAMAGE STABILITYRegulation

6.1 Attained Index A not to be less than Required Index R D1 Actual Service dlThe draughts and trims to be used in calculating A are specified in Reg. 7.2:- Level if trim < 0.5%Ls dp"In the calculation of A, the level trim shall be used for dl and dp. The actual service Level if trim < 0.5%Ls dstrim shall be used for dl. If, in any service condition, the trim variation in comparision D1a If trim >=0.5%Ls, A to be calculated againwith the calculated trim is > 0.5%Ls, one or more additional calculations of A are to be at trim = 0.5%Ls & so on until the differencesubmitted for the same draughts but diffeent trims so that, for all service conditions, between the actual and reference trim doesthe difference in trim in comparison with the reference trim used for one calculation will not exceed 0.5%Ls (dp & ds only)be less than 0.5%Ls."

6.1 Partial indices As, Ap and Al are to be each individually >= 0.9R (0.5R for cargo ships) D2 As for A? dlD3 As for A? dpD4 As for A? ds

8.1 si = 1 for damage to all compartments within 0.08L from the FP (>= 400 pax) D5 As for A? dlD6 As for A? dpD7 As for A? ds

8.2 si = 0.9 for minor side damages with penetration depth varying with pax numbers D8 As for A? dlD9 As for A? dp

D10 As for A? ds

9.8 si = 1 when subject to specified bottom damage D11 All service All service

Trims? Draughts?

464 19th September, 2011

APPENDIX 2

[Coordinator’s Note: For information, the current regulations in the SOLAS2009 Consolidated Edition covering Regulation 5-1 (Stability Information to be supplied to the master) and Regulation 7 (the attained subdivision index, A) and the explanatory notes are shown without comments for easier comparison with the proposed changes in Appendix 1.]

Regulation 5-1




.1 curves or tables of minimum operational metacentric height (GM) versus draught which assures compliance with the relevant intact and damage stability requirements, alternatively corresponding curves or tables of the maximum allowable vertical centre of gravity (KG) versus draught, or with the equivalents of either of these curves;


.3 all other data and aids which might be necessary to maintain the required intact and stability after damage.

Regulation 5-1.2

Any limiting GM (or KG) requirements arising from provisions in regulation 6.1 (regarding partial attained subdivision indices), regulation 8 or regulation 9, which are in addition to those described in regulation 5-1.4, should also be taken into account when developing this information. ________________________ ∗ Refer also to the Guidelines for the preparation of intact stability information (MSC/Circ.456);

Guidance on the intact stability of existing tankers during transfer operations (MSC/Circ.706); and the Revised guidance to the master for avoiding dangerous situations in following and quartering seas (MSC.1/Circ.1228).


3 The stability information shall show the influence of various trims in cases where the operational trim range exceeds +/- 0.5% of Ls.

4 For ships which have to fulfil the stability requirements of part B-1, information referred to in paragraph 2 is determined from considerations related to the subdivision index, in the following manner: Minimum required GM (or maximum permissible vertical position of centre of gravity KG) for the three draughts ds, dp and dl are equal to the GM (or KG values) of corresponding loading cases used for the calculation of survival factor si. For intermediate draughts, values to be used shall be obtained by linear interpolation applied to the GM value only between the deepest subdivision draught and the partial subdivision draught and between the partial load line and the light service draught respectively. Intact stability criteria will also be taken into account by retaining for each draft the maximum among minimum required GM values or the minimum of maximum permissible KG values for both criteria. If the subdivision index is calculated for different trims, several required GM curves will be established in the same way.

5 When curves or tables of minimum operational metacentric height (GM) versus draught are not appropriate, the master should ensure that the operating condition does not deviate from a studied loading condition, or verify by calculation that the stability criteria are satisfied for this loading condition.





Regulation 7



A = 0.4As + 0.4Ap + 0.2Al


A = Σpi si

where:


pi accounts for the probability that only the compartment or group of compartments under consideration may be flooded, disregarding any horizontal subdivision, as defined in regulation 7-1,



Regulation 7.1



A = 0.4As + 0.4Ap + 0.2Al

where the indices s, p and l represent the three loading conditions and the factor to be multiplied to the index indicates how the index A from each loading condition is weighted.


2. The method of calculating the A for a loading condition is expressed by the formula:


i=1









6. The GM (or KG) values for the three loading conditions could, as a first attempt, be taken from the intact stability GM (or KG) limit curve. If the required index R is not obtained, the GM (or KG) values may be increased (or reduced), implying that the intact loading conditions from the intact stability book must now meet the GM (or KG) limit curve from the damage stability calculations derived by linear interpolation between the three GMs.


2 In the calculation of A, the level trim shall be used for the deepest subdivision draught and the partial subdivision draught. The actual service trim shall be used for the light service draught. If in any service condition, the trim variation in comparison with the calculated trim is greater than 0.5% of Ls, one or more additional calculations of A are to be submitted for the same draughts but different trims so that, for all service conditions, the difference in trim in comparison with the reference trim used for one calculation will be less than 0.5% of Ls. Regulation 7.2


2. Each combination of the index within the formula given in regulation 7.1 should not be less than the requirement given in regulation 6.2. Each partial index A should comply with the requirements of regulation 6.1.

3. Example:



3 When determining the positive righting lever (GZ) of the residual stability curve, the displacement used should be that of the intact condition. That is, the constant displacement method of calculation should be used.




Regulation 7.5



6 In the flooding calculations carried out according to the regulations, only one breach of the hull and only one free surface need to be assumed. The assumed vertical extent of damage is to extend from the baseline upwards to any watertight horizontal subdivision above the waterline or higher. However, if a lesser extent of damage will give a more severe result, such extent is to be assumed.



Regulation 7.7





APPENDIX 3

[Coordinator’s Note: For information, the current regulations in the SOLAS2009 Consolidated Edition covering Regulation 5-1 (Stability Information to be supplied to the master) and Regulation 7 (the attained subdivision index, A) and the explanatory notes are shown amended in accordance with the method outlined under the discussion at the end of Appendix 1 (Ref. Appendix 1 Q1, above.]

Regulation 5-1




.1 curves or tables of minimum operational metacentric height (GM) versus draught which assures compliance with the relevant intact [stability requirements of part A of the 2008 IS Code] and [relevant] damage stability requirements, alternatively corresponding curves or tables of the maximum allowable vertical centre of gravity (KG) versus draught, or with the equivalents of either of these curves;


.3 all other data and aids which might be necessary to maintain the required intact [stability according to the requirements of part A of the 2008 IS Code] and stability after damage.

[Regulation 5-1.2

Any limiting GM (or KG) requirements arising from provisions in regulation 6.1 (regarding partial attained subdivision indices), regulation 8 or regulation 9, which are in addition to those described in regulation 5-1.4, should also be taken into account when developing this information.] ________________________ ∗ Refer also to the Guidelines for the preparation of intact stability information (MSC/Circ.456)[;

Guidance on the intact stability of existing tankers during transfer operations (MSC/Circ.706)] and the Revised guidance to the master for avoiding dangerous situations in following and quartering seas (MSC.1/Circ.1228).


3 The [intact and damage] stability information [required by regulation 2.1] shall [encompass the operating range of draught and trim.]. [shall show the influence of various trims in cases where the operational trim range exceeds +/- 0.5% of Ls.]

4 For ships which have to fulfil the stability requirements of part[s] B-1 [and B-2, the limiting GM/KG] information referred to in regulation[s] 2[.1] [and 3] is determined from considerations [of the appropriate intact stability criteria in combination with the damage stability criteria in regulations 8.1, 8.2 and 9.8. No limiting GM/KG curves/tables are to be calculated for demonstrating compliance with the criteria in regulations 6.1 and 6.2. Instead a note is to be added to the stability information provided to the master stating the achieved A/R ratio and partial indices at level trim and also at the extremities of the trim ranges forward and/or aft but only if these exceed +/-[0.2][0.5]% of L at any of the three draughts specified in regulation 7.1.]

related to the subdivision index, in the following manner: Minimum required GM (or maximum permissible vertical position of centre of gravity KG) for the three draughts ds, dp and dl are equal to the GM (or KG values) of corresponding loading cases used for the calculation of survival factor si. For intermediate draughts, values to be used shall be obtained by linear interpolation applied to the GM value only between the deepest subdivision draught and the partial subdivision draught and between the partial load line and the light service draught respectively. Intact stability criteria will also be taken into account by retaining for each draft the maximum among minimum required GM values or the minimum of maximum permissible KG values for both criteria. If the subdivision index is calculated for different trims, several required GM curves will be established in the same way.


1. Linear interpolation of the limiting values between the draughts ds, dp and dl is only applicable to minimum GM values. If it is intended to develop curves of maximum permissible KG, a sufficient number of KMT values for intermediate draughts must be calculated to ensure that the resulting maximum KG curves correspond with a linear variation of GM. When light service draught is not with the same trim as other draughts, KMT for draughts between partial and light service draught must be calculated for trims interpolated between trim at partial draught and trim at light service draught 2. In cases where the operational trim range is intended to exceed ±0.5% of Ls, the original GM limit line should be designed in the usual manner with the deepest subdivision draught and partial subdivision draught calculated at level trim and actual service trim used for the light service draught. Then additional sets of GM limit lines should be constructed on the basis of the operational range of trims which is covered by loading conditions of partial subdivision draught and deepest subdivision draught ensuring that intervals of 1% Ls are not exceeded. For the light service draught dl only one trim is to be considered. The sets of GM limit lines are combined to give one envelope limiting GM curve. The effective trim range of the curve should be clearly stated.


[1. The combined intact and damage limiting GM/KG curves/tables may be produced as follows:-

.1 Calculate the limiting GM/KG curves/tables for the appropriate intact stability criteria at suitable draught and trim increments across the operational range.

.2 For the same draughts and trims calculate the limiting GM/KG curves/tables for the damage stability criteria in regulations 8.1, 8.2 and 9.8.

.3 Combine all the results to determine the most onerous criteria across the trim range at specified draughts and produce limiting curves or tables of GM/KG for use by the master.

.4 For the three draughts specified in Regulation 7.1 select, at level trim, the most onerous values of GM or KG at each draught (by linear interpolation if necessary) and use these values to calculate the attained subdivision index, A and the partial indices As, Ap and Al to demonstrate compliance with Regulation 6.1.

.5 If the operating trim range exceeds +/- [0.2][0.5]% of L at any of the 3 draughts specified in Regulation 7.1, then repeat the calculation of A and the partial indices at the extremities of the trim range forward and/or aft using the appropriate limiting GM/KG for each draught / trim (by linear interpolation if necessary) to ensure compliance with Regulation 6.1. 2. If it is found that the attained index or partial indices do not meet the criteria in Regulation 6.1 then the subdivision arrangements must be improved and the procedure repeated until compliance is achieved. Compliance with Regulations 6.1 and 6.2 may not be achieved by increasing the GM (lowering the KG). 3. In addition to the curves/tables of limiting GM/KG the statement below should be added to the stability information booklet giving the calculated values of the A/R and the partial indices ratios to demonstrate compliance with Regulations 6.1and 6.2:- “Provided the ship is loaded in accordance with the limiting GM/KG curves/tables, the ratio of attained / required index (A/R) at level trim for damage stability will be 1.xxx (minimum 1.000). At maximum operational bow trim the A/R ratio increases/decreases to 1.yyy and at maximum operational stern trim the A/R ratio increases/decreases to 1.zzz. At level trim the partial indices As, Ap and Al are x.xxxR, x.xxxR and x.xxxR respectively (minimum 0.9R or 0.5R, as appropriate) changing to x.xxxR, x.xxxR and x.xxxR at maximum operational bow trim and x.xxxR, x.xxxR and x.xxxR at maximum operational stern trim”.] 5 When curves or tables of minimum operational metacentric height (GM) [or maximum operational (KG)] versus draught are not appropriate, the master should ensure that the operating condition does not deviate from a studied loading condition, or verify by calculation that the [intact and damage] stability criteria are satisfied for this loading condition.


Regulation 7



A = 0.4As + 0.4Ap + 0.2Al


A = Σpi si

where:





Regulation 7.1



A = 0.4As + 0.4Ap + 0.2Al





i=1








considered damage for a specific initial condition 5. Three initial loading conditions should be used for calculating the index A. The loading conditions are defined by their mean draught d, trim and GM (or KG) [(refer to the Explanatory Notes for regulations 5-1.3 and 5-1.4 for determination of the GM (or KG) to be used)]. The mean draught and trim are illustrated in the figure below.

6. The GM (or KG) values for the three loading conditions could, as a first attempt, be taken from the intact stability GM (or KG) limit curve. If the required index R is not obtained, the GM (or KG) values may be increased (or reduced), implying that the intact


loading conditions from the intact stability book must now meet the GM (or KG) limit curve from the damage stability calculations derived by linear interpolation between the three GMs. 2 In the calculation of A, [the] level trim shall be used for the [deepest subdivision] [three] draught[s specified in regulation 7.1.] [and the partial subdivision draught. The actual service trim shall be used for the light service draught]. If [, at any of the three draughts,] [in any service condition], the [maximum operational] trim [variation in comparison with the calculated trim is greater than] [exceeds +/-] [0.2][0.5]% of [Ls ][L], [one or more additional] [further] calculations of A are to be submitted for the same [three] draughts [at the maximum operational trim forward and/or aft specific to each draught.] [but different trims so that, for all service conditions, the difference in trim in comparison with the reference trim used for one calculation will be less than 0.5% of Ls.].

[Note: A clean version of the above paragraph is given below for ease of reference:-] 2 In the calculation of A, level trim shall be used for the three draughts specified in regulation 7.1. If, at any of the three draughts, the maximum operational trim exceeds +/- [0.2][0.5]% of L, further calculations of A are to be submitted for the same three draughts at the maximum operational trim forward and/or aft specific to each draught.

Regulation 7.2

1. The calculations for differing trim should be carried out [as described in the Explanatory Notes for Regulations 5-1.3 and 5-1.4.] with the same initial trim for the partial and deepest subdivision draughts. For the light service draught, the actual service trim should be used (refer to the Explanatory Notes for Regulation 2.11).


3. Example:




3 When determining the positive righting lever (GZ) of the residual stability curve, the displacement used should be that of the intact condition. That is, the constant displacement method of calculation should be used.



Regulation 7.5


2. In the forward and aft ends of the ship where the sectional breadth is less than the ship’s breadth B, transverse damage penetration can extend beyond the centreline bulkhead. This application of the transverse extent of damage is consistent with the


methodology to account for the localized statistics which are normalized on the greatest moulded breadth B rather than the local breadth. Where longitudinal corrugated bulkheads are fitted in wing compartments or on the centreline, they may be treated as equivalent plane bulkheads provided the corrugation depth is of the same order as the stiffening structure. The same principle may also be applied to transverse corrugated bulkheads.

6 In the flooding calculations carried out according to the regulations, only one breach of the hull and only one free surface need to be assumed. The assumed vertical extent of damage is to extend from the baseline upwards to any watertight horizontal subdivision above the waterline or higher. However, if a lesser extent of damage will give a more severe result, such extent is to be assumed.


Regulation 7.7





APPENDIX 4

• THIS APPENDIX CONTAINS THE ROUND 5 DISCUSSION ON REGULATIONS 5-1 and 7 AND THE ACCOMPANYING QUESTIONNAIRE, WITH RESPONSES.

• IT CONSISTS OF THREE MAIN SECTIONS AS EXPLAINED AND IS

COLOUR-CODED.

• IT SUPERSEDES APPENDICES 1 to 3, ABOVE WHICH ARE RETAINED FOR REFERENCE ONLY.

• PLEASE NOTE THAT THE SECOND SECTION CONTAINS NORWAY’S

PROPOSALS PRIOR TO SLF 53.

• THESE WERE THEMSELVES SUPERSEDED BY NEW PROPOSALS FROM NORWAY WHICH CAN BE FOUND IN THE ROUND 6 SUPPLEMENTARY DISCUSSION PAPER AND QUESTIONNAIRE IN APPENDIX 5.

• AT SLF 54 IT IS PROPOSED TO CONCENTRATE ON THE LATEST

PROPOSALS FROM NORWAY IN APPENDIX 5 WHICH THE MEMBERS GENERALLY PREFERRED TO THE ALTERNATIVE FROM THE UK IN APPENDIX 3.

• SOME ISSUES WILL NEED TO BE RESOLVED BY DISCUSSION AT SLF 54.


SOLAS Consolidated Edition 2009

with Explanatory Notes

(Res. MSC.281(85))

Applicable to Passenger and Cargo Ships

with keels laid on or after 1st January, 2009

KEY TO COLOUR CODES and FONTS USED IN THIS DOCUMENT SOLAS Consolidated Edition 2009; Current SOLAS text Resolution MSC.281(85); Current Explanatory Notes (EN) Agreed Regulatory Text Changes Changes to SOLAS agreed up to Round 4 Agreed EN Text Changes Changes to EN text agreed up to Round 4 Q21 Reference to question in working document SOLAS Consolidated Edition 2009; Regulation text still under discussion

Resolution MSC.281(85); EN text still under discussion

This document contains Round 5 of the 2011 SDS CG questionnaire covering the following regulations and explanatory notes only:- Regulation 5-1 ...................................................Stability Information to be Supplied to the Master Regulation 7 …....................................................................................Attained Subdivision Index A 1) Comprises the 2009 Consolidated Edition text and EN with text changes etc. as

agreed at SLF 53 in January 2011 using the above colour codes followed by a discussion of the main problems found to date with the above regulations and EN’s.

2) Consists of a series of amendments in blue proposed by Norway prior to SLF 53. 3) An alternative series of amendments in blue proposed by the UK / Co-ordinators. There is a question at the end of each of the three sections for comments, additional items that may have been overlooked or alternative proposals. Please refer to the working document for full background information, including previous questions, discussions and responses.

1) 2009 Consolidated Text & EN with SLF 53 agreed amendments


Regulation 5-1 Stability information to be supplied to the master *



.1 curves or tables of minimum operational metacentric height (GM) [and maximum permissible trim] Q18 versus draught which assures compliance with the relevant intact [stability requirements of part A of the 2008 IS Code] and [relevant] Q19 – proposed inserts not accepted damage stability requirements, alternatively corresponding curves or tables of the maximum allowable vertical centre of gravity (KG) versus draught, or with the equivalents of either of these curves;


.3 all other data and aids which might be necessary to maintain the required intact stability [according to the requirements of part A of the 2008 IS Code] Q19 – proposed inserts not accepted and stability after damage.

Regulation 5-1.2

Any limiting GM (or KG) requirements arising from provisions in regulation 6.1 (regarding partial attained subdivision indices), regulation 8 or regulation 9, which are in addition to those described in regulation 5-1.4, should also be taken into account when developing this information. 3 The stability information shall show the influence of various trims in cases where the operational trim range exceeds +/- 0.5% of Ls

3 The intact and damage stability information required by regulation 5-1.2 shall encompass the operating range of draught and trim. Applied trim values shall coincide in all stability information intended for use on board. Q20 ________________________ ∗ Refer also to the Guidelines for the preparation of intact stability information (MSC/Circ.456)

[; Guidance on the intact stability of existing tankers during transfer operations (MSC/Circ.706)] Q6; and the Revised guidance to the master for avoiding dangerous situations in following and quartering seas (MSC.1/Circ.1228).



4 For ships which have to fulfil the stability requirements of part B-1, information referred to in paragraph 2 is determined from considerations related to the subdivision index, in the following manner: Minimum required GM (or maximum permissible vertical position of centre of gravity KG) for the three draughts ds, dp and dl are equal to the GM (or KG values) of corresponding loading cases used for the calculation of survival factor si. For intermediate draughts, values to be used shall be obtained by linear interpolation applied to the GM value only between the deepest subdivision draught and the partial subdivision draught and between the partial load line and the light service draught respectively. Intact stability criteria will also be taken into account by retaining for each draft the maximum among minimum required GM values or the minimum of maximum permissible KG values for both criteria. If the subdivision index is calculated for different trims, several required GM curves will be established in the same way. Regulation 5-1.3 and 5-1.4 (see also regulation 7.2)


2. In cases where the operational trim range is intended to exceed ±0.5% of Ls, the original GM limit line should be designed in the usual manner with the deepest subdivision draught and partial subdivision draught calculated at level trim and actual service trim used for the light service draught. Then additional sets of GM limit lines should be constructed on the basis of the operational range of trims which is covered by loading conditions of partial subdivision draught and deepest subdivision draught ensuring that intervals of 1% Ls are not exceeded. For the light service draught dl only one trim is to be considered. The sets of GM limit lines are combined to give one envelope limiting GM curve. The effective trim range of the curve should be clearly stated. Q21 – to be considered in Round 5

5 When curves or tables of minimum operational metacentric height (GM) versus draught are not appropriate, the master should ensure that the operating condition does not deviate from a studied loading condition, or verify by calculation that the stability criteria are satisfied for this loading condition.



Regulation 7 Attained subdivision index A

1 The attained subdivision index A is obtained by the summation of the partial indices As, Ap and Al, (weighted as shown) calculated for the draughts ds, dp and dl defined in regulation 2 in accordance with the following formula: Q22 – to be considered in Round 5

A = 0.4As + 0.4Ap + 0.2Al


A = Σpi si

where:





Regulation 7.1



A = 0.4As + 0.4Ap + 0.2Al




i=1











6. The GM (or KG) values for the three loading conditions could, as a first attempt, be taken from the intact stability GM (or KG) limit curve. If the required index R is not obtained, the GM (or KG) values may be increased (or reduced), implying that the intact loading conditions from the intact stability book must now meet the GM (or KG) limit curve from the damage stability calculations derived by linear interpolation between the three GMs. Q23 and Q24 – to be considered in Round 5

2 In the calculation of A, the level trim shall be used for the deepest subdivision draught and the partial subdivision draught. The actual service trim shall be used for the light service draught. If in any service condition, the trim variation in comparison with the calculated trim is greater than 0.5% of Ls, one or more additional calculations of A are to be submitted for the same draughts but different trims so that, for all service conditions, the difference in trim in comparison with the reference trim used for one calculation will be less than 0.5% of Ls.



Regulation 7.2



3. Example:



Q25 and Q26 – to be considered in Round 5 3 When determining the positive righting lever (GZ) of the residual stability curve in the final stage of flooding Q27(2) and see Reg. 7.6 , the displacement used should be that of the intact condition. That is, the constant displacement method of calculation should be used.

Regulation 7.3

“The purpose of calculation of sequential flooding is to ensure that any intermediate flooding stage or phase will not lead to a lower si value. During intermediate phases of flooding, the added weight method is used and only one free surface needs to be



assumed for water in spaces flooded during the current stage. In the final phase (full phase) of each stage the lost buoyancy [constant displacement] method is used, so one free surface is assumed for all flooded spaces.” Q27(3) 4 The summation indicated by the above formula shall be taken over the ship’s subdivision length (Ls) for all cases of flooding in which a single compartment or two or more adjacent compartments are involved. In the case of unsymmetrical arrangements, the calculated A value should be the mean value obtained from calculations involving both sides. Alternatively, it should be taken as that corresponding to the side which evidently gives the least favourable result.


Regulation 7.5

1. With the same intent as wing tanks, the summation of the attained index A should reflect effects caused by all watertight bulkheads and flooding boundaries within the damaged zone. It is not correct to assume damage only [to the centreline] to one half of the ship breadth B CLIA Q2 and ignore changes in subdivision that would reflect lesser contributions.

2. In the forward and aft ends of the ship where the sectional breadth is less than the ship’s breadth B, transverse damage penetration can extend beyond the centreline bulkhead. This application of the transverse extent of damage is consistent with the methodology to account for the localized statistics which are normalized on the greatest moulded breadth B rather than the local breadth. 3. Where longitudinal corrugated bulkheads are fitted in wing compartments or on the centreline, they may be treated as equivalent plane bulkheads provided the corrugation depth is of the same order as the stiffening structure. The same principle may also be applied to transverse corrugated bulkheads.

6 In the flooding calculations carried out according to the regulations, only one breach of the hull and only one free surface need to be assumed [in the final stage of flooding]. Q27(2) and see Reg. 7.3. The assumed vertical extent of damage is to extend from the baseline upwards to any watertight horizontal subdivision above the waterline or higher. However, if a lesser extent of damage will give a more severe result, such extent is to be assumed.




Regulation 7.7

1. Pipes and valves directly adjacent to a bulkhead or to a deck can be considered to be part of the bulkhead or deck, provided the separation distance is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc. Valves which are situated as close as practicable to the bulkhead or deck, but exceeding due to their size the order of the stiffening structure should still be assumed to be part of the bulkhead or deck. CLIA Q3 2. The provision for allowing “minor progressive flooding” should be limited to pipes penetrating a watertight subdivision with a [total] cross-sectional area of not more than [710 mm


compartments. [The total cross-sectional area of all [this] [these] small pipes should [have a cross-sectional area of not more than] [not exceed] [an equivalent pipe diameter of Ls/1000]]. CLIA Q4 Why do we need to consider changes to regulations 5-1 and 7 covering stability information to be supplied to the master? New Discussion for Round 5 of CG. Some of the main reasons why changes have been proposed by Norway and the UK to the above regulations and EN summarized from discussions in earlier rounds of the CG are given below:- 1) Difficulties with integrating KG/GM limit curves for intact and damage criteria 1.1 There are real difficulties in providing the draught/trim/limiting GM/KG curves in a form easily usable on board especially in consolidating all the applicable intact and damage criteria across the operating range of draughts and trims into simple graphs or tables for use by the master. For example there was no requirement in S2009 for a vessel with an operating trim range of < +/- 0.5%L to be provided with anything other than level trim damage critical GM/KG information (see Reg. 7.2). A problem then arises where, according to the 2008 IS Code applied, for example, to a ship with L = 200 m. having an operating draught range of 4.0 to 5.8 m. and trim range just below +/- 0.5%L (= 1 m.) the critical KG information could be presented as shown in Fig. 1 below. Note that each point on the intact stability curves is the lowest of the complete set of applicable intact stability criteria. It is only possible to plot three points from the damage stability criteria - at draughts dl=4.15m (assumed service trim = 0.75 m by stern), dp=5.14m and ds=5.8m (at level trim only) making interpolation of a specific critical KG for a given draught at non-zero trim impossible. The same applies to the next figure (fig. 2) showing critical KG against draught. It is also not clearly stated in the Reg. 7.2 or EN whether the variation of critical KG/GM with trim applies only to the A>R criterion in Reg. 6.1 or also to:- a) partial indices criteria >0.9R (0.5R for cargo ships) in Reg. 6.1 b) fore end damage criteria in Reg. 8.1 c) minor side damage criteria in Reg. 8.2 d) bottom damage criteria in Reg. 9.8 (which are to be calculated for all draughts and trims). For this exercise it is assumed that the damage critical KG’s shown in the figures below are the minima from all the above damage criteria.



Max Allowable Intact + Damage KG vs Trim

8.00

8.50

9.00

9.50

10.00

10.50

-1 -0.5 0 0.5 1

Trim (m.)

Crit

KG

(m.)

dr = 4.0 dr = 4.2 dr = 4.4 dr = 4.6 dr = 4.8dr = 5 dr = 5.2 dr = 5.4 dr = 5.6 dr = 5.8dl = 4.15 dp=5.14 ds = 5.8

Fig. 1 Trim vs Critical KG’s (intact and damage) at specified draughts with Trim Range < 0.5%L



Fig. 2 Max. Allowable Intact + Damage KG vs Draught

8.00

8.50

9.00

9.50

10.00

10.50

4.00 4.50 5.00 5.50 6.00

Draught (m.)

Crit

ical

KG

(m.)

Trim = -1 Trim = 0 Trim = 1

Damage Trim -0.75 Damage Trim = 0 Damage Trim = 0

Fig. 2 Draught vs Critical KG curves (intact and damage)

at specified trims with Trim Range < 0.5%L 1.2 It can be seen from the above that interpolation to determine the damage/intact critical KG for any other than the 3 damage draught/trim combinations shown by the spots is not possible. If the operating trim range in the above example ship was, say, 2.0 m. by the stern and 2.0 m. by the bow, then according to regulations 5-1.3 (before the alterations agreed at SLF 53) and 7.2, further critical KG calculations are required such that the “difference in trim in comparison with the reference trim used for one calculation will be less than 0.5% of Ls.” These extra calculations now make interpolation between trims possible but there are still some uncertainties (see Fig. 3 and Fig.4 below).



Fig. 3 Max Allowable Intact + Damage KG vs Trim

8.00

8.50

9.00

9.50

10.00

10.50

-2 -1.5 -1 -0.5 0 0.5 1 1.5 2

Trim (m.)

Crit

KG

(m.)

dr = 4.0 dr = 4.2 dr = 4.4 dr = 4.6 dr = 4.8dr = 5 dr = 5.2 dr = 5.4 dr = 5.6 dr = 5.8dl = 4.15 dp = 5.14 ds = 5.8

Fig. 3 Trim vs Critical KG curves (intact and damage)

at specified draughts with Trim Range > 0.5%L 1.3 It can be seen that this combined diagram as it stands cannot easily be used for interpolating between intact and damage critical KG’s at specific intermediate draughts and trims. Only by separating the intact and damage curves, interpolating KG for draught and trim for each and then finding the minimum value could any answers be obtained. It would make it easier if the intact criticals could also be calculated at ds, dp and dl. Even so interpolation between dp and dl to find the damage critical KG is not possible as only the service trim is calculated for dl.



Fig. 4 Max. Allowable Intact + Damage KG vs Draught

8.00

8.50

9.00

9.50

10.00

10.50

4.00 4.50 5.00 5.50 6.00

Draught (m.)

Crit

ical

KG

(m.)

Trim = -2 Trim = -1 Trim = 0 Trim = 1

Trim = 2 Damage Trim -2 Damage Trim -1 Damage Trim -0.75

Damage Trim 0 Damage Trim 1 Damage Trim 2

Fig. 4 Draught vs Critical KG curves (intact and damage)

at specified trims with Trim Range > 0.5%L 1.4 Although this diagram is easier to interpret than fig. 3 there is a gap in the damage critical KG curves between dl (4.15 m.) and dp (5.14 m). The current explanatory notes for Reg. 5-1.3 and 5-1.4 are based on linear interpolation between dl, dp and ds but only for limiting GM lines so interpolation using the above KG diagram would not be valid. Under the existing regulations the “gap” between dl an dp must be closed by linear interpolation on limiting GM (as shown in fig. 7 below). The limiting GM curves derived from the above are shown in fig. 6. The assumed KM curves used to convert KG to GM using GM = KM – KG are shown in fig. 5 below for information.



Fig. 5 KM against Draught for various trims

10.00

11.00

12.00

13.00

14.00

15.00

4.00 4.50 5.00 5.50 6.00

Draught m.

KM

m.

Trim = -2 Trim = -1 Trim = 0 Trim = 1 Trim = 2



Fig. 6 Min. Required Intact + Damage GM vs Draught

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

5.00

5.50

6.00

4.00 4.50 5.00 5.50 6.00

Draught (m.)

Min

imum

GM

(m.)




Fig. 6 Draught vs Limiting GM curves (intact and damage)

at specified trims with Trim Range > 0.5%L

1.5 The maximum allowable KG curves in fig. 4 have been converted to minimum required GM curves using GM = KM (from fig. 5) – KG. Fig. 7 below shows how the linear extrapolation between dp and dl is carried out in accordance with the current EN for Reg. 7.1 and 7.2.



Fig. 7 Min. Required Intact + Damage GM vs Draught Showing Linear Extrapolation between dp and dl

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

5.00

5.50

6.00

4.00 4.50 5.00 5.50 6.00

Draught (m.)

Min

imum

GM

(m.)


Trim = 2 Damage Trim -2 Damage Trim -1 Damage Trim -0.75Damage Trim 0 Damage Trim 1 Damage Trim 2


at specified trims with Trim Range > 0.5%L showing linear extrapolation converging to a single value at dl

1.6 How would the Master use the above curves to calculate minimum GM at a specified draught and trim? It can easily be seen that for draughts > approximately 4.72 metres the damage stability limiting GM curves are more onerous than the intact. So if the actual draught is, for example, 5.5 metres and the trim is 1.2 metres by the stern the minimum GM by interpolation is approximately 3.15 metres. At draughts less than 4.72 metres (for example 4.5 metres and trim of -1.2 metres), the intact and damage minimum GM’s would be read off separately with the largest value being the overall critical GM – e.g. damage 3.83 m. intact 3.98 m so critical GM is 3.98 m. According to EN3 for Reg. 7.2 Fig. 7 can be simplified by using an envelope curve:-



Fig. 8 Min. Required Intact + Damage GM vs Draught Showing Envelope Curve

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

5.00

5.50

6.00

4.00 4.50 5.00 5.50 6.00

Draught (m.)

Min

imum

GM

(m.)





at specified trims with Trim Range > 0.5%L showing an envelope curve covering all trims 1.7 Using the above example, the minimum GM for draught 4.5 metres at any trim is 4.05 m. It should be noted that:-

• the current EN’s only show an envelope curve for damage stability limiting GM data. • the EN method will provide a safety margin whenever the actual trim lies within the

extreme limits. • for passenger ships, where the trim range is usually quite small, this method may be

satisfactory but for ro-pax or cargo ships the master may legitimately prefer to use the correct trim curves rather than the envelope, especially if compliance is marginal.



• We are slightly puzzled as to why the critical KG curves show that that the bow trim curves (+2 metres) for intact and damage stability in fig. 4 are the most onerous whereas for the limiting GM curves in fig. 8 the stern trim curves (-2 metres) are more onerous. Of course, we are not using data from an actual ship so that there may be inconsistencies but we wonder whether this may point to the fact that with limiting GM curves another variable has been introduced which varies with trim (i.e. KM). Limiting KG and limiting GM may not therefore be equivalent. This is discussed in more detail below.

2) Are Critical KG Curves and Limiting GM Curves Equivalent? 2.1 The regulations and EN’s would suggest that limiting KG and GM curves are interchangeable and equivalent but the previous calculations (expanded below) appear to indicate otherwise. Beginning with the GM limiting envelope curve (heavy red line in fig. 8) and following the guidance in Reg. 5-1.3 and 5-1.4 EN1:- 1. Linear interpolation of the limiting values between the draughts ds, dp and dl is only applicable to minimum GM values. If it is intended to develop curves of maximum permissible KG, a sufficient number of KMT values for intermediate draughts must be calculated to ensure that the resulting maximum KG curves correspond with a linear variation of GM. When light service draught is not with the same trim as other draughts, KMT for draughts between partial and light service draught must be calculated for trims interpolated between trim at partial draught and trim at light service draught We obtained:-

Fig. 9 Converting GM envelope to KG envelope curve using KM interpolation method in EN1 for Reg. 5-1.3

Draught GM env at Trim? KM at trim KG env4.00 5.65 Intact -2 14.50 8.854.15 5.00 Intact -2 14.20 9.204.20 4.79 Intact -2 14.10 9.314.40 4.29 Intact -2 13.90 9.614.60 3.90 Linear Int* 13.29 9.394.80 3.80 Linear Int* 13.21 9.415.00 3.71 Linear Int* 13.14 9.435.14 3.65 Damage -2 13.10 9.455.20 3.59 Damage -2 13.02 9.435.40 3.35 Damage -2 12.70 9.355.60 3.11 Damage -2 12.10 8.995.80 2.90 Damage -2 11.40 8.50

* Trim obtained by linear interpolation between damage at trim -2 and draught 5.14and damage at trim -0.75 and draught 4.15 metres:-

Draught Trim KM see fig 5

4.15 -0.75 13.974.60 -1.32 13.294.80 -1.57 13.215.00 -1.82 13.145.14 -2.00 13.10

The resulting KG envelope curve is shown below (fig. 10):-



Fig. 10 Max. Allowable Intact + Damage KG vs Draught(Fig. 4 with added KG Envelope Curve derived from GM envelope)

8.00

8.50

9.00

9.50

10.00

10.50

4.00 4.50 5.00 5.50 6.00

Draught (m.)

Crit

ical

KG

(m.)



Damage Trim 0 Damage Trim 1 Damage Trim 2 From GM envelope

2.2 It can be seen that in this case the KG envelope curve is easier to comply with than the lines plotted for each individual trim (in the regions where these can be directly compared). This contrasts with the limiting GM envelope curve which had an increased safety margin compared to the individual trim lines. The above KG envelope curve appears to give optimistic results for critical KG, eg draught 5.5 m. - envelope curve limit is 9.2 m. - level trim limit only 8.8 m. 2.3 Again, we think this may be due to the fact that KM varies with trim at a given draught but it seems to confirm that limiting GM and limiting KG curves may not be equivalent. The problem is made worse where the trim range is less than 0.5%L and only level trim limiting GM/KG curves are calculated for dp and ds. As France stated in an earlier CG discussion:- “If constant GM or KG is kept for a trim range, presentation in max KG is more favourable for trim by bow and presentation in GM is more favourable for trim by stern. Up to 0.20m difference may be observed - so limit of 0.5% of Ls may be questioned”.



3) Choice of initial KG/GM to calculate A – influence on critical KG/GM 3.1 EN5 and 6 for Reg. 7.1 state:- 5. Three initial loading conditions should be used for calculating the index A. The loading conditions are defined by their mean draught d, trim and GM (or KG). The mean draught and trim are illustrated in the figure below.

6. The GM (or KG) values for the three loading conditions could, as a first attempt, be taken from the intact stability GM (or KG) limit curve. If the required index R is not obtained, the GM (or KG) values may be increased (or reduced), implying that the intact loading conditions from the intact stability book must now meet the GM (or KG) limit curve from the damage stability calculations derived by linear interpolation between the three GMs. 3.2 The first point to note with EN’s 5 and 6 is that they only relate to obtaining the required index R at level trim for dp and ds and at the service trim for dl (Reg. 7.2 deals with trim >0.5%L). The procedure for calculating the combined damage/intact GM/KG limit curve in cases where the trim range is <= 0.5%L would then suggest itself as follows (similar to that described by CLIA at the end of Appendix 1 of the working document). 3.3 Use the maximum allowable KG (minimum GM) for intact stability at level trim for ds and dp and the service trim for dl. The example in fig. 11 below uses the same sample data as previously. a) For Reg. 6.1 calculate A. If A>=R go to b) b) For Reg. 6.1 calculate Al, Ap and As. If each >= 0.9R (0.5R for cargo ships) go to c) c) For Reg. 8.1 calculate s for each of the 3 draughts for a damage involving all compartments lying within 0.08L aft of the FP. If s = 1 for each draught go to d) d) For Reg. 8.2 calculate s for each of the 3 draughts for minor damages in Reg. 8.3. If s >=0.9 for each draught go to e) e) For Reg. 9.8 calculate s for “all service conditions” when subject to specified bottom damages. If s = 1 (presumably for all draughts in the range specified for the intact stability calculation at level trim and for dl at the service trim) then the calculation for level trim is finished 3.4 If, at any of the above steps, a criterion is not met then the KG is decreased (GM increased) and the calculation repeated until compliance is achieved for all the damage criteria. This implies that the damage stability limit curve is more onerous than the intact, as explained in EN 6 for Reg. 7.1. If the KG has to be lowered (GM increased) at step b) to e) to achieve compliance, then A will increase as will one or more of the partial indices in step b). It is not clear as to whether step a) and b) should then be repeated using the new lowest KG(s) (highest GM(s)) and the improved “A” and partial indices noted somewhere. This could be clarified in the EN.



Fig. 11 Starting point - Calculate A using Intact Critical KG's at each draught

8.00

8.50

9.00

9.50

10.00

10.50

4.00 4.50 5.00 5.50 6.00

Draught (m.)

Crit

ical

KG

(m.)

Trim = -1 Trim = 0 Trim = 1dl Damage Trim -0.75 dp Damage Trim = 0 ds Damage Trim = 0

3.5 If, at step a) or b), the damage stability criteria for A or the partial indices are not met then the KG must be lowered (GM raised) at one or more of the three draughts dl, dp or ds. Here there is a slight ambiguity. “dl” may be at a different trim from dp and ds – the “actual service trim” which is always fixed. Is the KG/GM for dl also fixed or can it be lowered/raised along with the KG/GM for dp and ds to increase “A” and/or the partial indices? This is not made clear in the regulations or EN. Technically, changing the KG/GM would have a small influence on trim therefore there is a case for saying that trim and KG/GM for dl must be fixed throughout. There is another slight ambiguity here. We have shown in fig. 11 above the KG for dl corresponding to the limiting intact stability KG as suggested in Reg. 7.1 EN6. But what if the KG for the actual light service draught dl is less than the intact critical KG? Must that fixed KG from an actual loading condition be used throughout the damage calculations? Again this is not clear from the regulations or EN.



3.6 Shown below in fig. 12 is one method of increasing A to meet R in step a) if it is found that A<R using the intact critical KG – by lowering the KG at dp. Some software packages claim that they can iterate the step a) calculation to give an A=R limiting KG/GM. How this is done will vary from one system to another as there are several possible methods and no official guidance (e.g. reduce the dp KG significantly but leave the ds KG as it is; reduce both ds and dp etc) even if we assume that the dl KG is fixed. It is interesting to note that there is no requirement to do these critical calculations if A>R in the first iteration of step a) meaning that there would not necessarily be a critical KG/GM value for A=R. Also, perhaps not all software packages are capable of iterating to a solution for A=R. In this case “A”/ “R” simply becomes a number and the limiting KG/GM curves are determined by the intact or other damage stability criteria.

Fig. 12 Increasing "A" so that A=R by lowering KG at dp

8.00

8.50

9.00

9.50

10.00

10.50

4.00 4.50 5.00 5.50 6.00

Draught (m.)

Crit

ical

KG

(m.)


dl Damage Trim -0.75 dp Damage Trim = 0 ds Damage Trim = 0



3.7 If shifting the KG for dp as shown in fig. 12 results in A=R and all the remaining damage criteria in steps a) to e) above are satisfied then the above graph must be converted to show minimum GM rather than maximum KG to allow for linear interpolation for intermediate draughts (see fig. 13 below).

Fig. 13 Increasing "A" so that A=R by increasing GM at dpMinimum Required GM

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

5.00

5.50

6.00

4.00 4.50 5.00 5.50 6.00

Draught (m.)

Min

imum

GM

(m.)


dl Damage Trim -0.75 dp Damage Trim = 0 ds Damage Trim = 0

3.8 Apart from the anomaly mentioned earlier that for the minimum GM intact curves stern trim is more onerous whereas for the maximum allowable KG curves head trim is more onerous a question arises about what to do if the ship is operating at a non-zero trim, bearing in mind that if the trim range is within + / - 0.5%L there is no requirement to calculate trimmed damage curves. CLIA mentions that passenger vessels often operate within these narrower trim limits. In the above example, if the ship is sailing at a draught of 5.7 metres with a stern trim of 0.9 metres how does one interpolate between the level trim damage curve and the intact curves at -0.9 metres trim? The situation is even more confusing if the draught is less than dp as the trim for the



damage critical GM line varies between zero trim at dp and -0.75 metres trim at dl. From fig. 13, how does one interpolate the correct limiting GM for a draught of say 4.5 metres with a stern trim of 0.9 metres, for example? 3.9 Also, if the full S2009 damage calculations were to be carried out specifically at a draught of 5.7 m. and trim -0.9 m. then the minimum allowable GM to comply with all the damage criteria may be, for example, 2.5 metres. In fig. 13, the red damage GM line linearly interpolated at 5.7 metres is only 1.1 metres so there is the potential for a considerable error. If the actual GM for the loading condition lies on the red limit line above at 5.7 metres draught (1.1 m.) the ship would appear to comply with S2009 whereas in reality she could have a GM deficit of up to (2.5 – 1.1 = 1.4 m). All these numbers are hypothetical but it is hoped that the point is made. 3.10 The situation improves somewhat if the operating trim exceeds + / - 0.5%L as further trimmed damage critical GM limit curves are produced at, say, + / - 0.5% L and + / - 1.0% L. There remain presentational problems in integrating the intact and damage limit curves and on interpolating for the actual draught and trim. 4) SUMMARY 4.1 Norway and the UK tried to address some of the issues raised in the above discussion and their proposed amendments are shown in Sections 2 and 3, below. 4.2 Some changes to regulations 5-1 affecting information to the Master have already been agreed at SLF 53 as highlighted at the beginning of this document. 4.3 The main issues to be addressed by further possible changes to Reg. 5-1 and Reg. 7 + EN can be summarized as follows:- a) The operational trim range of +/ 0.5%L within which no trimmed damage stability calculations need to be performed makes integration difficult with the intact stability limit curves from the 2008 IS Code, which cover the entire operating range of draught and trim. The fact that there may be no calculated information on the effect of trim on A could lead to significant underestimation of the safety margin (see example under 3.9, above) The removal at SLF 53 of this range threshold in Reg. 5-1.3 should help this problem but more work is needed on Reg. 7.2. b) Reg. 9.8 requires s=1 to be achieved after specified bottom damage in “all service conditions”, which is the same as the range specified in the 2008 IS Code. So there is a lack of consistency within the S2009 Regs which needs to be considered. c) The specification of a fixed trim for dl makes interpolation almost impossible, especially between the trimmed intact and damage limit curves for draughts between dl and dp. d) There are doubts over the equivalence of limiting GM and KG curves for trimmed conditions as KM, used to calculate GM, varies with trim whereas KG is independent of trim. e) Is there any technical reason why linear interpolation of a limit line between calculated draughts is more valid on the basis of GM than KG? f) There are circumstances in which there is no need to calculate a limiting KG/GM curve for A=R. The actual curve is quite arbitrary - there are many possible ways of varying the KG at dp and ds to achieve A=R.



Round 5 Q1. Do you have any comments etc on the above? Are there any other items that need to be considered? Do you have any alternative thoughts? Please bear in mind that detailed changes to the above regulations to try to rectify some of the problems outlined are shown in Part 3 below, where comments can also be made at the end. Comments: CHINA: China noticed the difficulties with integrating KG/GM limit curves for intact and damage criteria which is caused by Reg. 5-1.3 and 5-1.4 EN1, but changes to regulation 7 may be inappropriate. Great changes will damage the continuity and cause confusion. We propose to just separate the intact and damage curves, and it will also be easy to check loading conditions separately. Using envelope curve may result in some loading conditions which can meet the intact and damage criteria separately failing to meet the requirements. It is our opinion that the envelope curve should be as a reference basis rather than mandatory requirements. Limiting GM curve is more meaningful in practical applications. We propose the master shall be only supplied with curves or tables of minimum operational metacentric height (GM). CLIA: No comments EC: See under Q3 FINLAND:

• Very profound analysis of the current situation regarding reg. 5-1 and 7. In some details the summary seems to be very academic and as such thiswill be difficult to apply in practise with common design process.

• Main purpose to compare GM- or KG-limiting curves we would like to consider that GM limiting curve is the primary curve.

• The trim range of +0.5/-0.5 % Ls m should be maintained. • Same trim range for Dl should be kept and for dp and ds additional calculations

shall be made, if trim range of +0.5/-0.5 % Ls exceeds. • The overall GM-limiting curve shall be derived as proposed by Norway

In general we support changes to apply in reg. 5-1 and 7 proposed by Norway, which are shown in part 2 of this paper. GERMANY:

• A very valuable summary of the current situation and the related difficulties, however the approach shown is in some parts very academic and not in line with the common design practice.

• Many of the difficulties originate from the harmonization between cargo and passenger ship requirements. To keep a harmonized set of rules, some of the issues may remain.

• To overcome the presented difficulties we would propose the following: o GM limiting curves are the primary source. If KG limiting curves are used,

they are to be as such, that the same result can be achieved. o The trim range ±0.5% Ls is to be kept as this has been the basis for the

sample ship calculation. The influence of the trim on the GM is acknowledged and accepted to keep a simple and consistent method for cargo and passenger ships



GERMANY: (continued)

o For Dl the same trim range should be applied o For other trim ranges additional calculations are to be made. Resulting in

a clear determination of allowable trims for each draught o The overall GM limiting curve can be derived in the following ways.

The envelope curve of the most onerous GM for each of the 3 draughts

The calculation of other damage requirements (reg 8, 8.1 9.8) are to be included in these limiting curve. The same trim ranges are to be applied as above.

o The result is one limiting curve for the damage requirements for the specified trims and various GM limiting curves for the different other intact criteria for different trims.

o Modern onboard stability computers are capable to deal with different limiting curves. If a simpler approach is needed, the envelope curve of the most onerous requirements is to be used be used.

• This approach is implemented in the comments and proposals based on the Norwegian text.

ITALY: No further comments at this time. NORWAY: Our opinion is that the amended Norwegian proposal in part 2 will reduce most of problems mentioned in part 1. Please see answer to Q2. We have the following comments to the points raised by UK on page 23: 4 (a) We believe our proposal for a revised text of regulation II-1/5-1.3 and .4 in SLF 52/17/4 would reduce this problem. Part A, chapter 2 paragraph 2.1.7 and part B, chapter 3, paragraph 3.5.1 of the 2008 IS Code are relevant in the context and the need for harmonising a calculation tolerance with the SOLAS limit should be considered. (b) We understand this requirement to be limited to the calculated service conditions referred to in regulation II-1/7.2 (as may be amended). Removing the limitation for one trim only at dl and introducing a trim limit curve would seem to resolve this. (c) Agreed. This is another argument for removing that limitation. (d) Whether an initial KG or GM is selected for a given draught and trim should not matter with respect to the partial indices. As a selected value GM will be independent of KMt. Consistency problems arise in the range between dp and dl if KG is used, since the KMt for the two drafts will not be related at all when the trims are different. (f) For the sake of clarity we would like to recall the background for the envelope curve as discussed at SLF 49: Within the restrictions for partial indices in regulation II-1/6.1 the probabilistic method allows selecting combinations of high and low GMs at will as indicated in the sketch. Within the GM limits derived from these calculations there will be infinite combinations of future loading conditions that may or may not satisfy the required index R. For this reason a limiting GM for an arbitrary loading case cannot be found with absolute certainty by interpolating between discrete curves. The envelope curve assures that any loading within the trim limits defined by regulation II-1/7.2 will not be part of a combination of service condition where A would be less than R.



In this example the trim in loading condition C1 is within the limits defined by trim 1 and 2, but the GM must comply with the envelope curve to ensure that it is part of a combination where A>R. We agree with UK that the EN should be modified to explain how the probabilistic envelope curve should be combined with curves for separate trims based on relevant deterministic regulations such as the IS Code. This could typically be compliance with the weather criterion at light draughts for certain ships. Our opinion is that the traditional interpolation between trims would still be acceptable in the regions where deterministic values govern minimum GM.



POLAND: See under Q3 RINA: With regards to the above summary we would advise as follows: 4.3 a) It is noted that there is an inconsistency between the way current regulations require the results of intact stability and damage stability calculations to be presented differently and the problem this causes when developing a combined intact and damage stability GM/KG curve. It is considered essential that this issue is resolved in order to provide clear and understandable information to the ships Master. 4.3 d) From the consolidated working document it is noted that there a number of correspondence group members who have commented on the significant variation between KG and GM, when trim variation for a particular draught is taken into account. If this is the case is there a case for using either GM or KG, but not both, for the use in the intact and damage stability information? See also comments on Q 2 & 3. SWEDEN: An envelope limit curve can be optimized with the objective to either minimize GM or maximise VCG, whilst still complying with the stability requirements, within the allowed operating trim range. The optimum trim will diverse dependant on which criteria is used, illustrated in Fig A. As a consequence, a GM envelope curve is not relevant in the VCG environment, and if it should be drawn, conservative KMT values should be used, see Fig B MaxVCG(opt GM). Instead the limit curves for each trim curve should be used for transformation and then made into a envelope curve. In Fig B such envelope curve is drawn, MacVCG(opt VCG) on top of fig 10.

Fig A. Trim on x axis, meters on Y axis



SWEDEN: continued

Fig B, parts of fig 10, drawn with the respective GM and VCG envelope limit curves drawn in the VCG environment.

US: General: 1. We think maybe the figure 10 red “envelope curve” that is derived from the GM envelope in figure 8 is not correct for draughts 4.6, 4.8 and 5.0 (i.e. the funny dip in the curve). We think this stems from an error reading the KM values from figure 5 (i.e. the blue box KM figures on page 17). We attribute this to misreading the figure 5 KM scale where each division is .2m vice .1m. 2. We don’t understand the discussion about interpolation in paragraph 3.8 (page 22). We must assume that -0.9m trim is < 0.5% Ls so that the damage line is good for all trims up to whatever the 0.5% Ls limit is. Therefore it seems the -0.9m trim interpolation should be between level trim intact and -1m intact, and then it appears that this intact value will govern over the damage line value. (i.e. not sure why you would interpolate between the damage and intact curves?) 3. We also don’t understand the point being made in paragraph 3.9 (page 23). If the stability information plot GMs are not fully compliant with all the S2009 regulations (we assume this means regs 8 and 9.8?) then they can’t be approved (i.e. under your example the minimum GM at 5.7m draught on the plot would have to be 2.5m, not 1.1m).



US: continued Comments: 1. For sake of simplicity in this discussion we tend to view the intact stability limits separately from the damage stability limits. In this way you can determine a minimum GM for intact requirements and a minimum GM for damage requirements, and then take the governing (highest) GM as the required GM for that specific condition. IS Code reg 2.1.7 requires that intact limit curves must cover the full range of operating trims, so any intermediate trim would be interpolated between the intact trim curve steps. For damage the same general principle would apply, although there are some additional difficulties with interpolation in the draught range between dp and dl, and also if the trim is < 0.5% Ls then we assume level trim is “close enough”. 2. Regarding interpolation for various damaged trim conditions in the draught range between dp and dl: Reg 7.2 requires the actual service trim for the light service draught in the “A” calculation, which in general seems reasonable since that load condition itself is rather fixed.* Given this situation and also the fact that intact stability limits tend to govern at the lighter draughts, we propose that the damage trim limit lines be extended from dp to dl as has been indicated by the dotted lines in figure 7. We think this is accurate enough and would solve the interpolation problem. (note: it seems this would require deleting the last sentence of current reg 5-1.3 and 5-1.4 EN 1) * However, we note several members have indicated that they need some variable trim range at dl (which this wouldn’t provide). We are not opposed to this, and it seems several “optional” dl trim conditions could be incorporated into the process. 3. The general consensus is that the required damage stability information must now encompass the full range of operating trims (already required for intact by reg 2.1.7). Therefore the question seems to be how many additional trim condition calculations are necessary to accomplish this? The current approach of within 0.5% of Ls does not seem sufficient for all ship types. We see potential options as: a. trim calculations (for ds and dp) at 0 trim and the maximum operational trim only (this has some similarity to part of the UK proposal in section 3). b. trim calculations (for ds and dp) at 0 trim and the maximum operational trim, and such additional trim calculations as necessary to ensure that trim calculation steps do not exceed [1%] of Ls. (e.g. if max operating trims were +2.8% and -0.4% of Ls; then option a: trim calculations at 0, +2.8% and -0.4% option b: trim calculations at 0, +1%, +2%, +2.8% and -0.4% of Ls) 4. We think the regulations and EN should allow flexibility to either: (1) interpolate between a series of minimum GM lines at different trims; (2) develop a single GM envelope curve (i.e. as in current EN 3 for reg 7.2); or (3) the Norway proposed alternative shown in EN 4 for reg 5-1.5 of section 2. This would seem to resolve the concern expressed in paragraph 1.7 on page 16. 5. Regarding the difference between min GM and max KG limits: We are not convinced this is a significant problem because reg 5-1.4 specifies the linear interpolation between draughts must be applied to GM values only. Therefore it seems all the limit curves/lines must be calculated with GM and then converted to KG (i.e. the interpolation lines on the



GM plot will be curves on the KG plot). The Norway proposal for new reg 5-1.5 seems to indicate this point more clearly. 6. Also because intact stability tends to govern at lighter drafts, we do not think there is any need for additional damage stability calculations for draughts below the light service draft condition. The light service draft minimum GM should apply to any lesser draughts with respect to damage stability. Note: this comment is specifically related to the TOR .1 “consider what requirements for a minimum GM (or max KG) are applicable at draughts below the light service draught”. VANUATU: Several phrases in the text seem to us to be confusing with respect to full meaning. I wonder if we can use this comment to draw attention to them; 5-1 1 …“accurate guidance as to the stability of the ship under varying conditions of service.” Since this falls under Part B-1 of SOLAS, how would this apply to a heavy lift ship – for example? Are they excluded on the basis of footnote .7 of Regulation 4 as a vessel intended for the carriage of deck cargo? When ballasted down to take cargo aboard, are builders intended to be required to provide guidance to the Master for the loading operation; or are the “varying conditions” intended to describe underway conditions for conventionally designed ships? Para 2 under Regulation 5-1.3 and 5-1.4 for the heavy lift example above; does the phrase “light service draught” have the same meaning as for a conventional cargo ship? Regulation 7.5 para 6; “The assumed vertical extent of damage is to extend from the baseline upwards to any watertight horizontal subdivision above the waterline, or higher.” In a heavy lift’s loading condition, the upwards without limit aspect of this rule would cripple the validity of further flooding considerations, if as it is likely, the crew were to de-ballast the hull in such a situation.

2) 2009 Consolidated Text & EN with SLF 53 agreed amendments Showing amendments proposed by Norway prior to SLF 53 EN changes in italics








Regulation 5-1.2


3 The intact and damage stability information required by regulation 5-1.2 shall encompass the operating range of draught and trim. Applied trim values shall coincide in all stability information intended for use on board. Q20 ________________________ ∗ Refer also to the Guidelines for the preparation of intact stability information (MSC/Circ.456)

[; Guidance on the intact stability of existing tankers during transfer operations (MSC/Circ.706)] Q6; and the Revised guidance to the master for avoiding dangerous situations in following and quartering seas (MSC.1/Circ.1228).



4 For ships which have to fulfil the stability requirements of part B-1, information referred to in paragraph 2 is determined from considerations related to the subdivision index, in the following manner: Minimum required GM (or maximum permissible vertical position of centre of gravity KG) for the three draughts ds, dp and dl are equal to the GM (or KG values) of corresponding loading cases used for the calculation of survival factor si. For intermediate draughts, values to be used shall be obtained by linear interpolation applied to the GM value only between the deepest subdivision draught and the partial subdivision draught and between the partial load line and the light service draught respectively. Intact stability criteria will also be taken into account by retaining for each draft the maximum among minimum required GM values or the minimum of maximum permissible KG values for both criteria. If the subdivision index is calculated for different trims, several required GM curves will be established in the same way. 4 The stability limits intended for use on board shall be presented as consolidated data taken from the applicable intact and damage stability calculations of these regulations. Information not required for determination of stability and trim limits should be separated from this information. 5 If the damage stability is calculated in accordance with part B-1 of these regulations a stability limit curve is to be determined using linear interpolation between the minimum required GM assumed for each of the three draughts ds, dp and dl. When additional subdivision indices are calculated for different trims, a single envelope curve based on the minimum values from these calculations shall be presented. If it is intended to develop curves of maximum permissible KG it shall be ensured that the resulting maximum KG curves correspond with a linear variation of GM. Regulation 5-1.3 and 5-1.4 (see also regulation 7.2) and 5-1.5






4 As an alternative to an envelope curve, the calculations for additional trims may be carried out with one common GM for all of the trims assumed at the deepest subdivision draught ds and the partial subdivision draught dp respectively. The lowest values of each partial index As and Ap across trims will then be used in the summation of the attained subdivision index A according to regulation 7.1. At the light service draught the partial index Al is assumed constant. This will result in one GM limit curve based on the GM used at each draught. A trim limit diagram showing the assumed trim range is then developed as shown in the figure.



5 It is not required that the trim values at ds and dp coincide as long as the limitations with respect to variation between trims are observed at each draught. The applicable trim limits may then be marked at 0.5% Ls [L] in excess of the largest calculated trims as shown in the figure. There will be no trim limits in the draught range between dl and dp unless the limiting GM is governed by other applicable intact or damage stability criteria.

5 6 When curves or tables of minimum operational metacentric height (GM) versus draught are not appropriate, the master should ensure that the operating condition does not deviate from a studied loading condition, or verify by calculation that the stability criteria are satisfied for this loading condition.



Regulation 7 Attained subdivision index A

1 The An attained subdivision index A is obtained by the summation of the partial indices As, Ap and Al, (weighted as shown) calculated for the draughts ds, dp and dl defined in regulation 2 in accordance with the following formula: Q22 – to be considered in Round 5

A = 0.4As + 0.4Ap + 0.2Al


A = Σpi si

where:





Regulation 7.1



A = 0.4As + 0.4Ap + 0.2Al




i=1










considered damage for a specific initial condition 5. Three initial loading conditions should be used for calculating the each index A. The loading conditions are defined by their mean draught d, trim and GM (or KG). The mean draught and trim are illustrated in the figure below. The light service condition will be common for all calculations of index A.




7 A previously approved partial index Al may be considered to remain valid for a sister ship and in other cases where differences in light ship particulars result in minor deviations from the assumed draught and trim in the light service condition. It is recommended that the limits for validity of stability documentation in case of lightship deviations set out in regulation 5.2 be applied also for this purpose. [Coordinator’s Note: please see Q24B in the working document for a possible amended version of this text]. 2 In the calculation of A, the level trim shall be used for the deepest subdivision draught and the partial subdivision draught. The actual service trim shall be used for the light service draught. If in any service condition, the trim variation in comparison with the calculated trim is greater than 0.5% of Ls, one or more additional calculations of A are to be submitted for the same draughts but different trims so that, for all service conditions, the difference in trim in comparison with the reference trim used for one calculation will be less than 0.5% of Ls. 2 As a minimum, the calculation of A shall be carried out at level trim for the deepest subdivision draught ds and the partial subdivision draught dp. The [actual] [anticipated] service trim shall be used for the light service draught dl. If in any anticipated service condition within the draught range from ds to dp the trim variation in comparison with the calculated trims is greater than 0.5% of Ls, one or more additional calculations of A are to be performed for the same draughts, but including sufficient trims to ensure that for all intended service conditions the difference in trim in comparison with the reference trim used for one calculation will be less than 0.5% of Ls. The partial index Al is considered constant for the purpose of these calculations.

Regulation 7.2



3. Example:





Q25 and Q26 – to be considered in Round 5 3 Each additional value of A calculated in accordance with paragraph 2 shall comply with regulation 6 and 7.1.

3 4 When determining the positive righting lever (GZ) of the residual stability curve in the final stage of flooding Q27(2) and see Reg. 7.6 , the displacement used should be that of the intact condition. That is, the constant displacement method of calculation should be used.

Regulation 7.3

“The purpose of calculation of sequential flooding is to ensure that any intermediate flooding stage or phase will not lead to a lower si value. During intermediate phases of flooding, the added weight method is used and only one free surface needs to be assumed for water in spaces flooded during the current stage. In the final phase (full phase) of each stage the lost buoyancy [constant displacement] method is used, so one free surface is assumed for all flooded spaces.” Q27(3) see Round 4 questionnaire 4 5 The summation indicated by the above formula shall be taken over the ship’s subdivision length (Ls) for all cases of flooding in which a single compartment or two or more adjacent compartments are involved. In the case of unsymmetrical arrangements, the calculated A value should be the mean value obtained from calculations involving both sides. Alternatively, it should be taken as that corresponding to the side which evidently gives the least favourable result.

5 6 Wherever wing compartments are fitted, contribution to the summation indicated by the formula shall be taken for all cases of flooding in which wing compartments are involved. Additionally, cases of simultaneous flooding of a wing compartment or group of compartments and the adjacent inboard compartment or group of compartments, but excluding damage of transverse extent greater than one half of the ship breadth B, may



be added. For the purpose of this regulation, transverse extent is measured inboard from ship’s side, at right angle to the centreline at the level of the deepest subdivision draught.

Regulation 7.5 6


2. In the forward and aft ends of the ship where the sectional breadth is less than the ship’s breadth B, transverse damage penetration can extend beyond the centreline bulkhead. This application of the transverse extent of damage is consistent with the methodology to account for the localized statistics which are normalized on the greatest moulded breadth B rather than the local breadth. 3. Where longitudinal corrugated bulkheads are fitted in wing compartments or on the centreline, they may be treated as equivalent plane bulkheads provided the corrugation depth is of the same order as the stiffening structure. The same principle may also be applied to transverse corrugated bulkheads.

6 7 In the flooding calculations carried out according to the regulations, only one breach of the hull and only one free surface need to be assumed [in the final stage of flooding]. Q27(2) and see Reg. 7.3 4. The assumed vertical extent of damage is to extend from the baseline upwards to any watertight horizontal subdivision above the waterline or higher. However, if a lesser extent of damage will give a more severe result, such extent is to be assumed.

7 8 If pipes, ducts or tunnels are situated within the assumed extent of damage, arrangements are to be made to ensure that progressive flooding cannot thereby extend to compartments other than those assumed flooded. However, the Administration may permit minor progressive flooding if it is demonstrated that its effects can be easily controlled and the safety of the ship is not impaired.

Regulation 7.7 8

1. Pipes and valves directly adjacent to a bulkhead or to a deck can be considered to be part of the bulkhead or deck, provided the separation distance is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc. Valves which are situated as close as practicable to the bulkhead or deck, but exceeding due to their size the order of the stiffening structure should still be assumed to be part of the bulkhead or deck. CLIA Q3



2. The provision for allowing “minor progressive flooding” should be limited to pipes penetrating a watertight subdivision with a [total] cross-sectional area of not more than [710 mm


compartments. [The total cross-sectional area of all [this] [these] small pipes should [have a cross-sectional area of not more than] [not exceed] [an equivalent pipe diameter of Ls/1000]. CLIA Q4 see Round 4 questionnaire Round 5 Q2 Do you have any comments etc on the above proposed changes by Norway? Do you have any suggested improvements or an alternative? Comments: CHINA: Please see the comments on Round 5 Q1 CLIA: We question the need for the option of using KG curves. Restricting the limits to be presented only as required minimum GM values would remove some of the issues being debated here. The requirement for use of a single envelope curve is questionable. When compared to using the correct GM minimum value for the actual trim (or interpolated between trims), the envelope will result in less GM margin and is too onerous. If GM limits are to be calculated for different trims (which involves a lot more work for the ship builder), why should they not be used as the GM limits for operation of the ship, with interpolation as required. These issues exist in the current regs// EN and the changes now proposed by Norway don’t address them. EC: See under Q3 FINLAND:

• We support the changes proposed by Norway. • This is good approach to revise regulation 5-1 and 7 and EN. • We don’t have any improvements or an alternative.

GERMANY: Reg 5-1 SOLAS Agreed to delete paragraph 4 The last sentence of the new para 4 should be deleted. New para 4: 4 The stability limits intended for use on board shall be presented as consolidated data taken from the applicable intact and damage stability calculations of these regulations.



GERMANY: (continued) The last sentence of para 5 to be deleted, small modifications in para 5: 5 If the damage stability is calculated in accordance with part B-1 of these regulations a stability limit curve is to be determined using linear interpolation between the minimum required GM assumed for each of the three draughts ds, dp and dl. When additional subdivision indices are calculated for different trims, a single envelope curve based on the minimum values from these calculations shall be presented. If KG limiting curves are used as an alternative presentation, each GM limiting curve for the different trims need to be converted in corresponding KG values to achieve the same result as for interpolation of the GM curves. The KG envelope curve need to be achieved on the basis of these individual KG curves Reg 5-1 EN Para 1. Accepted Para 2: to be modified: 2. In cases where the operational trim range is intended to exceed ±0.5% of Ls, the original GM limit line should be designed in the usual manner with the deepest subdivision draught and partial subdivision draught calculated at level trim and actual service trim used for the light service draught. Then additional sets of GM limit lines should be constructed on the basis of the operational range of trims ensuring that intervals of 1% Ls are not exceeded. Also for the light service draught dl the trim range of ±0.5% of Ls applies and other trim ranges may be calculated. The sets of GM limit lines are combined to give one envelope limiting GM curve. The effective trim range of the curve is achieved by overlapping the calculated trim ranges and should be clearly stated. The figure below shows an example of different trim ranges.

The red lines show the initial trim range, the green lines an alternative, extended trim range, the black lines the envelope trim range.



GERMANY: (continued) The following diagram shows the corresponding GM limiting curves, together with the envelope curve in black

Para 3: Accepted Para 4: Not accepted, to be deleted Para 5: accepted except the last sentence. Slightly modified. 5 It is not required that the trim values at ds and dp coincide as long as the limitations with respect to variation between trims are observed at each draught. The applicable trim limits may then be marked as shown in the figure.

Para 6. Unchanged, only renumbered Reg 7 SOLAS Para 1: Change accepted Para 2: Slightly modified proposal: 2 As a minimum, the calculation of A shall be carried out at level trim for the deepest subdivision draught ds and the partial subdivision draught dp. The [actual] [anticipated] service trim shall be used for the light service draught dl. If in any anticipated service condition within the draught range the trim variation in comparison



GERMANY: (continued) with the calculated trims is greater than 0.5% of Ls, one or more additional calculations of the GM limiting curve are to be performed for the same draughts, but including sufficient trims to ensure that for all intended service conditions the difference in trim in comparison with the reference trim used for one calculation will be less than 0.5% of Ls. . The sets of GM limit lines are combined to give one envelope limiting GM curve.

New para 3: not accepted Para 4 to 5: unchanged, accepted Reg 7 EN Para 1 to 4. Accepted Para 5: changes not accepted. Para 6: all reference to KG should be deleted: 6. The GM (or KG) values for the three loading conditions could, as a first attempt, be taken from the intact stability GM (or KG) limit curve. If the required index R is not obtained, the GM (or KG) values may be increased (or reduced), implying that the intact loading conditions from the intact stability book must now meet the GM (or KG) limit curve from the damage stability calculations derived by linear interpolation between the three GMs Para 7. Accepted Reg 7.2 EN Para 1 to 3: deletion accepted ITALY: No further comments at this time. NORWAY: Reconsideration of the proposals in Norwegian submission SLF 52/17/4 The proposals in that document were based on the assumption that the principle of using only one trim at the light service draught had to be maintained as a consequence of earlier decisions that the safety level must remain unchanged. At SLF 53 it was decided that this limitation need no longer be observed (see SLF 53/WP.1 paragraph 14.5). Consequently Norway is of the opinion that the principle of adding additional trims at the light service draught should be included in the calculation principles. The purpose is to take into consideration that substantial trim changes can occur in the range between dp and dl during normal operations. The notes below highlight what changes could be made to the Norwegian proposals if the trim restriction be lifted.



NORWAY: Continued 1. Disregard paragraph 5 in SLF 52/17/4 2. In the Annex part A (Proposed amendments to regulations in chapter II-1 of SOLAS-74 as amended): Regulation 7 – Attained subdivision index A Instead of the proposal in 2.2 the proposed amendments to 7.2 replace the current text to cover principles discussed above. The word “actual” could be replaced with “estimated” to provide some flexibility if the draught and trim in the final stability calculations deviate moderately from preliminary results due to variations in the lightship particulars:

“2 As a minimum, the calculation of A shall be carried out at level trim for the deepest subdivision draught ds and the partial subdivision draught dp. The estimated service trim may be used for the light service draught dl. If in any anticipated service condition within the draught range from ds to dl the trim variation in comparison with the calculated trims is greater than 0.5% of Ls, one or more additional calculations of A are to be performed for the same draughts, but including sufficient trims to ensure that for all intended service conditions the difference in trim in comparison with the reference trim used for one calculation will be less than 0.5% of Ls.”

3. In the Annex Part C (Proposed changes to the Explanatory Notes): Regulation 5-1.3 and 5-1.4 (see also regulation 7.2) Instead of the proposal in 1.4 of the annex the text of a new note 4 could read:

“4 As an alternative to an envelope curve the calculations for additional trims may be carried out with one common GM for all of the trims assumed at each subdivision draught. The lowest values of each partial index As, Ap and Al across these trims will then be used in the summation of attained subdivision index A according to regulation 7.1. This will result in one GM limit curve based on the GM used at each draught. A trim [limit][envelope] diagram showing the assumed trim range is then developed as shown in the figure.”



NORWAY: Continued Replace the previous figure:

l1

p2p3

l2

s1s2

p1

Dra

ught

Trim

0.5 L 0.5 L 0.5 L0.5 L

Instead of the proposal in 1.5 of the annex the text of a new note 5 could read: “5 It is not required that the trim values at ds, dp and dl coincide as long as the limitations with respect to variation between trims are observed at each draught. The applicable trim limits may then be marked at 0.5% Ls [L] in excess of the largest calculated trims as shown in the figure.” Regulation 7.1 Paragraph 1.5 is replaced with: In the proposal for a modified note 5 the word “each” is retained to cover multiple trims, but the last sentence should be deleted, i.e.: “5 Three initial loading conditions should be used for calculating each index A. The loading conditions are defined by their mean draught d, trim and GM (or KG). The mean draught and trim are illustrated in the figure below.” Regulation 7.2 Note 1 should be deleted and note 2 will be redundant. 4. The other proposals in the annexes to SLF 52/17/4 remain as contained in the document.



POLAND: See under Q3 RINA: Regulation 5-1.4 Agree with the proposal to consolidate intact and damage stability data. Regulation 5-1.5 Agree with the proposal to develop a single envelope limiting curve in the interests of clarity and uniformity. En 4 to regulation 5-1.4. If we are going to opt for a single envelope limiting curve it is not understood why we should want to develop an alternate solution which could cause confusion to the users. See also comments on the United Kingdom proposals. SWEDEN: No comments. US: 1. We generally support the Norway proposal. However, we think the regulations and EN should allow flexibility to either: (1) interpolate between a series of minimum GM lines at different trims; (2) develop a single GM envelope curve; or (3) the Norway proposed alternative shown in EN 4 for reg 5-1.5. Note: the proposed regulation 5-1.5 text currently mandates a single envelope curve only. 2. In the proposed alternative in EN 4 and 5 for reg 5-1.5, it indicates there are no trim limits between dp and dl (unless governed by other intact or damage criteria). Although we expect intact to govern for some or much of this range, this treatment needs more discussion. VANUATU: No comments.








Regulation 5-1.2


3 The intact and damage stability information required by regulation 5-1.2 shall encompass the operating range of draught and trim. Applied trim values shall coincide in all stability information intended for use on board. Q20 ________________________ ∗ Refer also to the Guidelines for the preparation of intact stability information (MSC/Circ.456) [;

Guidance on the intact stability of existing tankers during transfer operations (MSC/Circ.706)] Q6; and the Revised guidance to the master for avoiding dangerous situations in following and quartering seas (MSC.1/Circ.1228).


4 For ships which have to fulfil the stability requirements of part B-1, information referred to in paragraph 2 is determined from considerations related to the subdivision index, in the following manner: Minimum required GM (or maximum permissible vertical position of centre of gravity KG) for the three draughts ds, dp and dl are equal to the GM (or KG values) of corresponding loading cases used for the calculation of survival factor si. For intermediate draughts, values to be used shall be obtained by linear interpolation applied to the GM value only between the deepest subdivision draught and the partial subdivision draught and between the partial load line and the light service draught respectively. Intact stability criteria will also be taken into account by retaining for each draft the maximum among minimum required GM values or the minimum of maximum permissible KG values for both criteria. If the subdivision index is calculated for different trims, several required GM curves will be established in the same way. 4 For ships which have to fulfil the stability requirements of parts B-1 and B-2, the limiting GM/KG information referred to in regulations 2.1 and 2.3 is determined from considerations of the appropriate intact stability criteria in combination with the damage stability criteria in regulations 8.1, 8.2 and 9.8. No limiting GM/KG curves/tables are to be calculated for demonstrating compliance with the criteria in regulations 6.1 and 6.2. Instead a note is to be added to the stability information provided to the master stating the achieved A/R ratio and partial indices at level trim and also at the extremities of the trim ranges forward and/or aft but only if these exceed +/-[0.2][0.5]% of L at any of the three draughts specified in regulation 7.1.






1. The combined intact and damage limiting GM/KG curves/tables may be produced as follows:-

.1 Calculate the limiting GM/KG curves/tables for the appropriate intact stability criteria at suitable draught and trim increments across the operational range.

.2 For the same draughts and trims calculate the limiting GM/KG curves/tables for the damage stability criteria in regulations 8.1, 8.2 and 9.8.

.3 Combine all the results to determine the most onerous criteria across the trim range at specified draughts and produce limiting curves or tables of GM/KG for use by the master.

.4 For the three draughts specified in Regulation 7.1 select, at level trim, the most onerous values of GM or KG at each draught (by linear interpolation if necessary) and use these values to calculate the attained subdivision index, A and the partial indices As, Ap and Al to demonstrate compliance with Regulation 6.1.

.5 If the operating trim range exceeds +/- [0.2][0.5]% of L at any of the 3 draughts specified in Regulation 7.1, then repeat the calculation of A and the partial indices at the extremities of the trim range forward and/or aft using the appropriate limiting GM/KG for each draught / trim (by linear interpolation if necessary) to ensure compliance with Regulation 6.1. 2. If it is found that the attained index or partial indices do not meet the criteria in Regulation 6.1 then the subdivision arrangements must be improved and the procedure repeated until compliance is achieved. Compliance with Regulations 6.1 and 6.2 may not be achieved by increasing the GM (lowering the KG). 3. In addition to the curves/tables of limiting GM/KG the statement below should be added to the stability information booklet giving the calculated values of the A/R and the partial indices ratios to demonstrate compliance with Regulations 6.1and 6.2:- “Provided the ship is loaded in accordance with the limiting GM/KG curves/tables, the ratio of attained / required index (A/R) at level trim for damage stability will be 1.xxx (minimum 1.000). At maximum operational bow trim the A/R ratio increases/decreases to 1.yyy and at maximum operational stern trim the A/R ratio increases/decreases to 1.zzz. At level trim the partial indices As, Ap and Al are x.xxxR, x.xxxR and x.xxxR respectively (minimum 0.9R or 0.5R, as appropriate) changing to x.xxxR, x.xxxR and x.xxxR at maximum operational bow trim and x.xxxR, x.xxxR and x.xxxR at maximum operational stern trim”. 5 When curves or tables of minimum operational metacentric height (GM) [or maximum operational (KG)] versus draught are not appropriate, the master should ensure that the operating condition does not deviate from a studied loading condition, or verify by calculation that the [intact and damage] stability criteria are satisfied for this loading condition.

Regulation 7



1 The attained subdivision index A is obtained by the summation of the partial indices As, Ap and Al, (weighted as shown) calculated for the draughts ds, dp and dl defined in regulation 2 in accordance with the following formula: Q22 – to be considered in Round 5

A = 0.4As + 0.4Ap + 0.2Al


A = Σpi si

where:





Regulation 7.1



A = 0.4As + 0.4Ap + 0.2Al




i=1









considered damage for a specific initial condition 5. Three initial loading conditions should be used for calculating the index A. The loading conditions are defined by their mean draught d, trim and GM (or KG). Refer to the Explanatory Notes for regulations 5-1.3 and 5-1.4 for determination of the GM (or KG) to be used. The mean draught and trim are illustrated in the figure below.



2 In the calculation of A, the level trim shall be used for the deepest subdivision draught and the partial subdivision draught. The actual service trim shall be used for the light service draught. If in any service condition, the trim variation in comparison with the calculated trim is greater than 0.5% of Ls, one or more additional calculations of A are to be submitted for the same draughts but different trims so that, for all service conditions, the difference in trim in comparison with the reference trim used for one calculation will be less than 0.5% of Ls. 2 In the calculation of A, level trim shall be used for the three draughts specified in regulation 7.1. If, at any of the three draughts, the maximum operational trim exceeds +/- [0.2][0.5]% of L, further calculations of A are to be submitted for the same three draughts at the maximum operational trim forward and/or aft specific to each draught.

Regulation 7.2

1. The calculations for differing trim should be carried out as described in the Explanatory Notes for Regulations 5-1.3 and 5-1.4. with the same initial trim for the partial and deepest subdivision draughts. For the light service draught, the actual service trim should be used (refer to the Explanatory Notes for Regulation 2.11).


3. Example:




Q25 and Q26 – to be considered in Round 5 3 When determining the positive righting lever (GZ) of the residual stability curve in the final stage of flooding Q27(2) and see Reg. 7.6 , the displacement used should be that of the intact condition. That is, the constant displacement method of calculation should be used.

Regulation 7.3

“The purpose of calculation of sequential flooding is to ensure that any intermediate flooding stage or phase will not lead to a lower si value. During intermediate phases of flooding, the added weight method is used and only one free surface needs to be assumed for water in spaces flooded during the current stage. In the final phase (full phase) of each stage the lost buoyancy [constant displacement] method is used, so one free surface is assumed for all flooded spaces.” Q27(3) see Round 4 questionnaire 4 The summation indicated by the above formula shall be taken over the ship’s subdivision length (Ls) for all cases of flooding in which a single compartment or two or more adjacent compartments are involved. In the case of unsymmetrical arrangements, the calculated A value should be the mean value obtained from calculations involving both sides. Alternatively, it should be taken as that corresponding to the side which evidently gives the least favourable result.


Regulation 7.5


2. In the forward and aft ends of the ship where the sectional breadth is less than the ship’s breadth B, transverse damage penetration can extend beyond the centreline bulkhead. This application of the transverse extent of damage is consistent with the methodology to account for the localized statistics which are normalized on the greatest moulded breadth B rather than the local breadth.


3. Where longitudinal corrugated bulkheads are fitted in wing compartments or on the centreline, they may be treated as equivalent plane bulkheads provided the corrugation depth is of the same order as the stiffening structure. The same principle may also be applied to transverse corrugated bulkheads.

6 In the flooding calculations carried out according to the regulations, only one breach of the hull and only one free surface need to be assumed [in the final stage of flooding]. Q27(2) and see Reg. 7.3. The assumed vertical extent of damage is to extend from the baseline upwards to any watertight horizontal subdivision above the waterline or higher. However, if a lesser extent of damage will give a more severe result, such extent is to be assumed.


Regulation 7.7

1. Pipes and valves directly adjacent to a bulkhead or to a deck can be considered to be part of the bulkhead or deck, provided the separation distance is of the same order as the bulkhead or deck stiffening structure. The same applies for small recesses, drain wells, etc. Valves which are situated as close as practicable to the bulkhead or deck, but exceeding due to their size the order of the stiffening structure should still be assumed to be part of the bulkhead or deck. CLIA Q3 2. The provision for allowing “minor progressive flooding” should be limited to pipes penetrating a watertight subdivision with a [total] cross-sectional area of not more than [710 mm


compartments. [The total cross-sectional area of all [this] [these] small pipes should [have a cross-sectional area of not more than] [not exceed] [an equivalent pipe diameter of Ls/1000]]. CLIA Q4 see Round 4 questionnaire.


Round 5 Q3 The above proposed amendments are designed to deal with the problems outlines in Part 1. Do you have any comments etc on the above proposed changes by the UK? Do you have any suggested improvements or an alternative? Comments: CHINA: Please see the comments on Round 5 Q1 CLIA: We disagree with the concept given in 5-1.4. For ship designers, builders and operators, the presence of a fixed GM limit curve for ALL SOLAS damage stability criteria is essential, including the GM limit for A=R for reg 6-7. The damage limit curve should be the GM limits for whichever criteria is more onerous (Could be reg 8 if not reg 6-7). If the limiting criteria is Reg 8, then it is acceptable to state in the stability manual the A vs R value achieved at that limit curve. However, if Reg 6-7 is limiting, then the GM limit must be for A=R and the statement in the stability manual will simply state that at these GM values, Reg 8 and 9 are also achieved. The operator often needs to work close to the minimum GM values and needs to have a very clear graphical representation of what those values are. It is difficult to see how the UK proposal could be workable. In the UK suggestions for the EN, the suggestion that “Compliance with reg 6.1 and 6.2 may not be achieved by increasing GM” is not clear. The UK proposal for 7.2, is a good one but the wording needs some adjustment. There should be even keel damage calculations for all 3 draughts. Then, if the max trim is more than a certain % of L, there need to be calculations at the max trim (+/ -), and also intermediate trims such that the increments are not more than a certain % of L. Another way is to simply require damage stability calculations to be done at a range of trims, based on a specified trim increment. EC: Comments CG round 5 Please find below our response to the different questions to be considered in this round. In so doing, it is assumed that this response will also cover questions 1, 2 and 3 for round 5 in the subsequent parts of the questionnaire. Q21 EC could support the proposal from Norway concerning the amendments to Regulation 5-1, except that we have some reservations on par. 4, where it is stated that calculations for additional trims may be carried out with one common GM for all the trims assumed….. We do not understand the reason for using just one common GM and it seems not to be an accurate reflection of the actual situation.


EC: Comments CG round 5 (continued) Q 22 The EC does not support the proposals for Regulation 7.1, but would like to propose the following alternative. We understand this alternative proposal comes at a late stage and is a bit more radical than the proposals so far. This alternative proposal stems from a research project commissioned by EMSA and that was carried out by the University of Strathclyde1 At the stage of submitting these comments the study has almost been finalised and it is expected to have the results presented at SLF 54, either by an INF paper, an oral presentation or both. The EC proposes to delete the formula for calculating the attained index in Regulation 7 for passenger ships. Instead we propose to require (in Regulation 6) each partial index to be not less than the required index R, so As ≥ R, Ap ≥ R and Al ≥ R. This would also make the requirement from Regulation 6.1 that the partial indices are not less than 0,9 R obsolete. The main reason for this proposal is that draught should be considered as a design parameter and for each draught the requirement A ≥ R should be met. For passenger ships we should not work with an 'average' stability'. It should not be allowed to compensate a worse stability at a certain draught with a better stability at another draught, even if there are limitations to what can be compensated. The requirement A ≥ R for each draught only needs to be tested at the 3 different draughts ds, dp and dp. The proposal is different from the earlier proposal from UK to weigh the partial indices equally for passenger ships. In that approach one is still able to compensate for cases with worse stability. More information on the background of the proposal can be found in the final EMSA2 report which will be made available to the CG. The intention is also to submit an INF paper to SLF 54 containing a short summary of the final results. Q 23 The proposal that the light service condition will be common for all calculations is not supported. If there are different trim situations possible at the light service condition, then this should be taken into account. Q24 EC could agree to the proposal to add a new par 7 if we delete the words 'and in other cases'. This latter is too vague and may open up for a lot of creativity. Q25 EC could support the proposal from Norway; we also believe there is some merit to the UK proposal to use max KG curves, which seem to be quite practicable. Q26 EC could support the proposal to add a new paragraph 7.3 1 Study of the specific damage stability parameters of Ro-ro passenger vessels according to SOLAS 2009

including water on deck calculation.


EC: Comments CG round 5 (continued) Other issues In the research commissioned by EMSA some other issues were raised which may have a bearing on other questions that were dealt with in previous rounds, but not in round 5. This concerns: 1. An amendment to the formula for the s factor for ropax ships; and

2. The calculation of the required index; the report proposes to increase the value of R

and use a different formula. This proposal may be combined with a removal of the K factor from the s-formula. By introducing a higher R-factor the safety level will be increased significantly. The question then is if this would fit into the TOR of the agenda item we are dealing with.

More information on the above in the form of the results of the research project will be forwarded to the CG in due time and as stated earlier the EC intends to present the outcome at the next SLF meeting. FINLAND: We do not accept to use the UK approach. GERMANY:

• Not accepted ! • Norwegian proposal is the better basis for additions and reflects the original

agreed contents better. • The UK approach is too prescriptive how the design process should be made.

This is up to the designer and should not be part of the rules. ITALY: No further comments at this time. NORWAY: Please see our answer to Q2. POLAND: I would like to present some comments to round 5 of the 2011 SDS CG questionnaire covering the following regulations and explanatory notes. Regulation 5-1 Stability information to be supplied to the Master. Regulation 7 Attained subdivision Index A. I would like to present some comments to stability Part B-1 Regulation 5-1 information to be supplied to the master Regulation 5-1 point 3. "The stability information shall show the influence of various trims in cases where the operational trim range exceeds +/- 0.5 % of Ls". I think that it is important to supply to the master information in this point connected with combined effect – results and influence of trim and the shape of the hull on GZ curve for the same displacement (forward trim and aft trim) The Master should know on the easy way how will present GZ curve when the trim will occur for different cases of displacement both in operation and in damage condition. This might be useful information for the master to make correct decision in case of damage of the ship.


POLAND: continued As far as I am concerned this information could be applicable to passenger and cargo ships both in operation and taking into consideration stability in damage condition. RINA: EN regulation 5-1.3 & 5-1.4 The proposal usefully combines text from other areas of the document. The only concern that I would raise is that the proposed section looks more like Regulation than Explanatory Notes, which are non mandatory. See also comments on the Norwegian proposals. SWEDEN: The limit curves should cover all applicable stability criteria, including reg. 6.1 & 6.2 US: 1. This proposal is quite different. Conceptually we understand it to be a verification of damage stability compliance at level trim and the max trim conditions of an operating envelope based on the intact stability criteria (and possibly regs 8 and 9.8). 2. However, we question the feasibility of this. In proposed EN 2 for regs 5-1.3 and 5-1.4 it indicates a damage stability compliance failure can only be corrected by improved subdivision arrangements; not GM increases. At the ds condition we think the damage stability criteria is frequently more severe than the intact criteria, and we are not sure it is really feasible to increase the subdivision for compliance. VANUATU: is the intention in para 4, “For ships which have to fulfil the stability requirements of parts B-1 and B-2,” to solely address these requirement to vessels required to comply with both parts, rather than the original meaning that addressed meeting part B-1 only? Para .3 (and .4) under Regulation 5-1.3 and 5-1.4 – we believe the phrase “most onerous criteria” probably needs explanation before a decision can be made. Definition from Webster’s dictionary online defines onerous as involving, imposing or constituting a burden : troublesome – we’ve seen the UK use this word before in their MSC 85 paper on OSVs and simply describing something as “worst-case” may be a better choice of words than something as subjective as a synonym for “troublesome”.


APPENDIX 5

• NORWAY RE-CONSIDERED ITS ORIGINAL PROPOSALS FOR CHANGING REGS. 5-1 THROUGH 7.2 (INCLUDING THE EN) AS DETAILED IN SLF 52/17/4.

• THIS APPENDIX SHOWS THESE REVISED PROPOSALS TOGETHER WITH

SOME COMMENTS ON THEM TAKEN FROM THE ROUND 6 SUPPLEMENTARY QUESTIONNAIRE.

• IN GENERAL THE 2011 CG MEMBERS PREFERRED THESE PROPOSALS

BUT THERE ARE STILL SOME REFINEMENTS NEEDED AS INDICATED IN THE RESPONSES TO THE QUESTIONNAIRE BELOW.

DISCUSS AT SLF 54


SOLAS Updates; SLF 54 Agenda Item 8; CG Round 5 response from Norway Changes to Regulations 5-1 through 7.2 and associated Explanatory Notes KEY TO COLOUR CODES and FONTS USED IN THIS DOCUMENT SOLAS Consolidated Edition 2009; Current SOLAS text Resolution MSC.281(85); Current Explanatory Notes (EN) Agreed Regulatory Text Changes Changes to SOLAS agreed up to Round 4 Agreed EN Text Changes Changes to EN text agreed up to Round 4 Q21 Reference to question in working document SOLAS Consolidated Edition 2009; Regulation text deletions SLF 51/17/4

SOLAS Consolidated Edition 2009; Regulation text additions SLF 51/17/4

Resolution MSC.281(85); EN text deletions SLF 51/17/4

Resolution MSC.281(85); EN text additions SLF 51/17/4 SOLAS Consolidated Edition 2009; Revised Reg. changes Sept. 2011 R5 CG Resolution MSC.281(85); Revised EN changes Sept. 2011 R5 CG


Regulation 5-1 Stability information to be supplied to the master * 1 The master shall be supplied with such information satisfactory to the Administration as is necessary to enable him by rapid and simple processes to obtain accurate guidance as to the stability of the ship under varying conditions of service. A copy of the stability information shall be furnished to the Administration.

2 The information should include: .1 curves or tables of minimum operational metacentric height (GM) [and

maximum permissible trim][Q18] versus draught which assures compliance with the relevant intact and damage stability requirements, alternatively corresponding curves or tables of the maximum allowable vertical centre of gravity (KG) versus draught, or with the equivalents of either of these curves;

.2 instructions concerning the operation of cross-flooding arrangements; and .3 all other data and aids which might be necessary to maintain the required

intact stability and stability after damage. Regulation 5-1.2 Any limiting GM (or KG) requirements arising from provisions in regulation 6.1 (regarding partial attained subdivision indices), regulation 8 or regulation 9, which are in addition to those described in regulation 5-1.4, should also be taken into account when developing this information. 3 The stability information shall show the influence of various trims in cases where the operational trim range exceeds +/- 0.5% of Ls. The intact and damage stability information required by regulation 5-1.2 shall encompass the operating range of draught and trim. Applied trim values shall coincide in all stability information intended for use on board.[Q20] 4 For ships which have to fulfil the stability requirements of part B-1, information referred to in paragraph 2 are determined from considerations related to the subdivision index, in the following manner: Minimum required GM (or maximum permissible vertical position of centre of gravity KG) for the three draughts ds, dp and dl are equal to the GM (or KG values) of corresponding loading cases used for the calculation of survival factor si. For intermediate draughts, values to be used shall be obtained by linear interpolation applied to the GM value only between the deepest subdivision draught and the partial subdivision draught and between the partial load line and the light service draught respectively. Intact stability criteria will also be taken into account by retaining for each draft the maximum among minimum required GM values or the minimum of maximum permissible KG values for both criteria. If the subdivision index is calculated for different trims, several required GM curves will be established in the same way. ________________________ ∗ Refer also to the Guidelines for the preparation of intact stability information (MSC/Circ.456);

Guidance on the intact stability of existing tankers during transfer operations


(MSC/Circ.706);[Q6] and the Revised guidance to the master for avoiding dangerous situations in following and quartering seas (MSC.1/Circ.1228).

4 The stability limits intended for use on board shall be presented as consolidated data taken from the applicable intact and damage stability calculations of these regulations. Information not required for determination of stability and trim limits should be separated from this information. 5 If the damage stability is calculated in accordance with part B-1 of these regulations a stability limit curve is to be determined using linear interpolation between the minimum required GM assumed for each of the three draughts ds, dp and dl. When additional subdivision indices are calculated for different trims, a single envelope curve based on the minimum values from these calculations shall be presented. If it is intended to develop curves of maximum permissible KG it shall be ensured that the resulting maximum KG curves correspond with a linear variation of GM.


1. Linear interpolation of the limiting values between the draughts ds, dp and dl is only applicable to minimum GM values. If it is intended to develop curves of maximum permissible KG, a sufficient number of KMT values for intermediate draughts must be calculated to ensure that the resulting maximum KG curves correspond with a linear variation of GM. When light service draught is not with the same trim as other draughts, KMT for draughts between partial and light service draught must be calculated for trims interpolated between trim at partial draught and trim at light service draught. 2. In cases where the operational trim range is intended to exceed ±0.5% of Ls, the original GM limit line should be designed in the usual manner with the deepest subdivision draught and partial subdivision draught calculated at level trim and actual service trim used for the light service draught. Then additional sets of GM limit lines should be constructed on the basis of the operational range of trims which is covered by loading conditions of partial subdivision draught and deepest subdivision draught ensuring that intervals of 1% Ls are not exceeded. For the light service draught dl only one trim is to be considered. The sets of GM limit lines are combined to give one envelope limiting GM curve. The effective trim range of the curve should be clearly stated. Q21



4 As an alternative to an envelope curve, the calculations for additional trims may be carried out with one common GM for all of the trims assumed at [the deepest][each] subdivision draught [ds and the partial subdivision draught dp respectively]. The lowest values of each partial index As [and][,] Ap [and Al] across [these] trims will then be used in the summation of the attained subdivision index A according to regulation 7.1. [At the light service draught the partial index Al is assumed constant]. This will result in one GM limit curve based on the GM used at each draught. A trim [limit] [envelope] diagram showing the assumed trim range is then developed as shown in the figure. [

]

[Replace the above figure:


l1

p2p3

l2

s1s2

p1

Dra

ught

Trim

0.5 L 0.5 L 0.5 L0.5 L

]

5 It is not required that the trim values at ds [and][,] dp [and dl] coincide as long as the limitations with respect to variation between trims are observed at each draught. The applicable trim limits may then be marked at 0.5% Ls [L] in excess of the largest calculated trims as shown in the figure. [There will be no trim limits in the draught range between dl and dp unless the limiting GM is governed by other applicable intact or damage stability criteria].

5 6 When curves or tables of minimum operational metacentric height (GM) versus draught are not appropriate, the master should ensure that the operating condition does not deviate from a studied loading condition, or verify by calculation that the stability criteria are satisfied for this loading condition.

Regulation 6 Required subdivision index R *

1 The subdivision of a ship is considered sufficient if the attained subdivision index A, determined in accordance with regulation 7, is not less than the required subdivision index R calculated in accordance with this regulation and if, in addition, the partial indices As, Ap and Al are not less than 0.9R for passenger ships and 0.5R for cargo ships. Regulation 6.1

To demonstrate compliance with these provisions, see the Guidelines for the preparation of subdivision and damage stability calculations, set out in the appendix, regarding the presentation of damage stability calculation results.

___________________________ * The Maritime Safety Committee, in adopting the regulations contained in parts B to B-4,


invited Administrations to note that the regulations should be applied in conjunction with the explanatory notes developed by the Organization in order to ensure their uniform application.

2 For all ships to which the damage stability requirements of this chapter apply, the degree of subdivision to be provided shall be determined by the required subdivision index R, as follows:

.1 In the case of cargo ships greater than 100 m in length (Ls):

.2 In the case of cargo ships not less than 80 m in length (Ls) and not

greater than 100 m in length (Ls):

where Ro is the value R as calculated in accordance with the formula in subparagraph .1.

.3 In the case of passenger ships:

where:

N = N1 + 2N2

N1 = number of persons for whom lifeboats are provided

N2 = number of persons (including officers and crew) the ship is permitted to carry in excess of N1.

.4 Where the conditions of service are such that compliance with paragraph

2.3 of this regulation on the basis of N = N1+ 2N2 is impracticable and where the Administration considers that a suitably reduced degree of hazard exists, a lesser value of N may be taken but in no case less than N = N1 + N2

Regulation 6.2.4

Regarding the term “reduced degree of hazard”, the following interpretation should be applied: A lesser value of N, but in no case less than N = N1 + N2, may be allowed at the discretion of the Administration for passenger ships, which, in the course of their voyages, do not proceed more than 20 miles from the nearest land.


Regulation 7 Attained subdivision index A 1 The An attained subdivision index A is obtained by the summation of the partial indices As, Ap and Al, (weighted as shown) calculated for the draughts ds, dp and dl defined in regulation 2 in accordance with the following formula: Q22

A = 0.4As + 0.4Ap + 0.2Al


A = Σ pi si

where:





Regulation 7.1

1. The probability of surviving after collision damage to the ship hull is expressed by the index A. Producing an index A requires calculation of various damage scenarios defined by the extent of damage and the initial loading conditions of the ship before damage. Three loading conditions should be considered and the result weighted as follows:

A = 0.4As + 0.4Ap + 0.2Al



i=t


Ac = ∑ pi [vi si] i=1


2.2 To obtain a maximum index a for a given subdivision, t has to be equal to T, the total number of damages.






considered damage for a specific initial condition 5. Three initial loading conditions should be used for calculating the each index A. The loading conditions are defined by their mean draught d, trim and GM (or KG). The mean draught and trim are illustrated in the figure below. [The light service condition will be common for all calculations of index A].

6. The GM (or KG) values for the three loading conditions could, as a first attempt, be taken from the intact stability GM (or KG) limit curve. If the required index R is not obtained, the GM (or KG) values may be increased (or reduced), implying that the intact loading conditions from the intact stability book must now meet the GM (or KG) limit curve from the damage stability calculations derived by linear interpolation between the three GMs. Q23 and Q24 7 A previously approved partial index Al may be considered to remain valid for a


sister ship and in other cases where differences in light ship particulars result in minor deviations from the assumed draught and trim in the light service condition. It is recommended that the limits for validity of stability documentation in case of lightship deviations set out in regulation 5.2 be applied also for this purpose.

2 In the calculation of A, the level trim shall be used for the deepest subdivision draught and the partial subdivision draught. The actual service trim shall be used for the light service draught. If in any service condition, the trim variation in comparison with the calculated trim is greater than 0.5% of Ls, one or more additional calculations of A are to be submitted for the same draughts but different trims so that, for all service conditions, the difference in trim in comparison with the reference trim used for one calculation will be less than 0.5% of Ls.

2 As a minimum, the calculation of A shall be carried out at level trim for the deepest subdivision draught ds and the partial subdivision draught dp. The [estimated] [actual] [anticipated] service trim [shall][may] be used for the light service draught dl. If in any anticipated service condition within the draught range from ds to dl the trim variation in comparison with the calculated trims is greater than 0.5% of Ls, one or more additional calculations of A are to be performed for the same draughts, but including sufficient trims to ensure that for all intended service conditions the difference in trim in comparison with the reference trim used for one calculation will be less than 0.5% of Ls. [The partial index Al is considered constant for the purpose of these calculations].

Regulation 7.2 1. The calculations for differing trim should be carried out with the same initial trim for the partial and deepest subdivision draughts. For the light service draught, the actual service trim should be used (refer to the Explanatory Notes for Regulation 2.11). 2. Each combination of the index within the formula given in regulation 7.1 should not be less than the requirement given in regulation 6.2. Each partial index A should comply with the requirements of regulation 6.1. 3. Example:

Based on the GM limiting curves obtained from damage stability calculations of each trim, an envelope curve covering all calculated trim values should be developed. Calculations covering different trim values should be carried out in steps not exceeding 1% of Ls. The whole range including intermediate trims should be covered by the damage stability calculations. Refer to the example showing an envelope curve obtained from calculations of 0 trim and 1% of Ls.


Q25 and Q26 3 Each additional value of A calculated in accordance with paragraph 2 shall comply with regulation 6 and 7.1. R5-1 to 7.2 R5-1 to 7.2 EN Discussion for Round 6 Supplementary Questionnaire. Changes to Regulations 5-1 through 7.2 and associated Explanatory Notes NORWAY: Reconsideration of the proposals in Norwegian submission SLF 52/17/4 The proposals in that document were based on the assumption that the principle of using only one trim at the light service draught had to be maintained as a consequence of earlier decisions that the safety level must remain unchanged. At SLF 53 it was decided that this limitation need no longer be observed (see SLF 53/WP.1 paragraph 14.5). Consequently Norway is of the opinion that the principle of adding additional trims at the light service draught should be included in the calculation principles. The purpose is to take into consideration that substantial trim changes can occur in the range between dp and dl during normal operations. R6-SQ1 for Round 6 Supplementary Questionnaire. Given the large support in Round 5 for Norway’s original proposals in SLF 52/17/4 and bearing in mind that some square bracket issues still need to be resolved can you, in general, accept Norway’s revised proposals included in their response to the Round 5 questionnaire (shown below) or do you think these regulations and EN still need to be discussed in detail at SLF 54 before any text changes are finalized? Accept Norway’s new proposal?

CLIA (In general, yes. But we still question the benefit of the option to use KG curves. The proposals to ensure full consistency between GM limit curves and derived KG limit curves are important. The concept of a single envelope curve, even when GM limits have been calculated for different trims still seems to be present. That is unduly onerous. If limits for trims have been calculated, it should be possible to use them in operation. But we believe that these issues actually have little impact on our vessels, which usually have limited trim).


Germany (Yes, but the final clean version should be explained and discussed again at SLF54), Finland, Norway, US (subject to some additional refinements) EC (In general yes, except for the parts on the partial indices and the weighing thereof. The on-going research will result in some proposals for amending SOLAS 2009 on the part of the partial indices, so we think that we should at least have a look what will be presented and discuss. The results of the research will also focus on the R-factor, which we think should also be discussed.)

Wait until SLF 54 to discuss the issues?

RINA, China, Finland (with comment), Poland (Regulations and EN still need to be discussed in detail at SLF54 before any text changes are finalised.), Vanuatu (Prefer this approach for some of the detailed issues), UK, France (see comment)

Further comments / alternatives?:- Japan: No comments. Finland: Even if we accept Norway’s proposal, we wish to discuss it in detail at SLF54 due to the importance of this item. Germany: Reg 5-1.4 The last sentence should be made clearer. Which information should be separated. EN for 5-1.4: here is still mentioned that there is only one trim at Dl. To be changed to trim range Both figures to illustrate the trim ranges are not self explaining and need to be improved. An alternative proposal please find enclosed (shown below):-


New proposal from Germany German proposal for a draft text about extension of the GM-limiting curve up to drafts acc. to tropical freeboard incl. fresh water allowance: “If a vessel is permitted to sail at drafts above the subdivision draft ds, the GM-limiting curve may be extended up to that draft, but not exceeding the tropical freeboard draft, by taking over the GM at the subdivision draft ds as constant for all drafts above ds. The increased draft due to the freshwater allowance may be taken into account the same way.” Vanuatu: We need to fully explore the intent behind SLF 52/17/4 Annex 2 page 2 B proposed change to regulation 4 footnote. Otherwise we are generally in agreement with their proposals. US: We definitely support this approach; it should allow us to refine and finalize this text at SLF 54. UK: Before accepting the proposed method on alternative limiting curve determination, we would like to see sufficient evidence that any condition which falls outside of a calculated point - within the outer side of 0.5%Ls trim variation limit - would not be failing any requirements of part B-1. France: France is of the opinion that, if a common curve for all trim is retained, it would be better to have a maximum KG curve, because GM is too much sensitive to trim variations.

solas explainatory

Documents

agreed en text changes

text round

consolidated text

text unchanged

solas regulations

proposed amendments

solas ch

application para