oss-104_2012-04

DNV-OSS-104: Rules for Classification of Self-Elevating Units

OFFSHORE SERVICE SPECIFICATIONDNV-OSS-104

Rules for Classification ofSelf-Elevating UnitsAPRIL 2012The electronic pdf version of this document found through http://www.dnv.com is the officially binding versionThe content of this service document is the subject of intellectual property rights reserved by Det Norske Veritas AS (DNV). The user accepts that it is prohibited by anyone else but DNV and/or its licensees to offer and/or perform classification, certification and/or verification services, including the issuance of certificates and/or declarations of conformity, wholly or partly, on the basis of and/or pursuant to this document whether free of charge or chargeable, without DNV's prior written consent. DNV is not responsible for the consequences arising from any use of this document by others.

DET NORSKE VERITAS ASFOREWORDDET NORSKE VERITAS (DNV) is an autonomous and independent foundation with the objectives of safeguarding life, property and the environment, at sea and onshore. DNV undertakes classification, certification, and other verification and consultancy services relating to quality of ships, offshore units and installations, and onshore industries worldwide, and carries out research in relation to these functions.

DNV service documents consist of among others the following types of documents:

Service Specifications. Procedural requirements.

Standards. Technical requirements.

Recommended Practices. Guidance.

The Standards and Recommended Practices are offered within the following areas: A) Qualification, Quality and Safety Methodology

B) Materials Technology

C) Structures

D) Systems

E) Special Facilities

F) Pipelines and Risers

G) Asset Operation

H) Marine Operations

J) Cleaner Energy

O) Subsea Systems

Det Norske Veritas AS April 2012

Any comments may be sent by e-mail to [email protected] any person suffers loss or damage which is proved to have been caused by any negligent act or omission of Det Norske Veritas, then Det Norske Veritas shall pay compensation to such person for his proved direct loss or damage. However, the compensation shall not exceed an amount equal to ten times the fee charged for the service in question, provided that the maximum compensation shall never exceed USD 2 million.

In this provision "Det Norske Veritas" shall mean the Foundation Det Norske Veritas as well as all its subsidiaries, directors, officers, employees, agents and any other acting on behalf of Det Norske Veritas.

CHANGESGeneralThis is a new document.

These new rules was approved by the Executive Committee in April 2012. The rules come into force 1 October 2012.

Table of contentsPART 0 INTRODUCTION ..................................................................................... 5CHAPTER 1 INTRODUCTION .........................................................................................................6 CHAPTER 2 CONTENTS IN DETAIL ............................................................................................. 10PART 1 GENERAL REGULATIONS AND CONDITIONS .................................. 18CHAPTER 1 CLASSIFICATION PRINCIPLES ............................................................................... 19CHAPTER 2 PROCEDURES ......................................................................................................... 21CHAPTER 3 PRINCIPLES AND CONDITIONS ............................................................................. 22PART 2 MATERIALS AND WELDING ............................................................... 25CHAPTER 1 METALLIC MATERIALS ........................................................................................... 26CHAPTER 2 STRUCTURAL FABRICATION ................................................................................. 27PART 3 HULL AND EQUIPMENT ...................................................................... 28CHAPTER 1 STRUCTURAL DESIGN ............................................................................................ 29CHAPTER 2 STABILITY AND WATERTIGHT INTEGRITY ........................................................... 36CHAPTER 3 TOWING .................................................................................................................... 40PART 4 MACHINERY SYSTEMS AND EQUIPMENT ........................................ 42CHAPTER 1 MARINE, MACHINERY AND PIPING SYSTEMS ..................................................... 43CHAPTER 2 ELECTRICAL INSTALLATIONS ................................................................................ 55CHAPTER 3 AREA ARRANGEMENTS ......................................................................................... 63CHAPTER 4 CONTROL AND COMMUNICATION SYSTEMS ...................................................... 68CHAPTER 5 FIRE PROTECTION .................................................................................................. 73CHAPTER 6 ENHANCED CONTROL & SAFETY SYSTEMS ....................................................... 77PART 5 CERTIFICATION ................................................................................... 80CHAPTER 1 PROCEDURES ......................................................................................................... 81CHAPTER 2 MACHINERY AND SYSTEM CERTIFICATION ........................................................ 82PART 6 NEWBUILDING SURVEY ..................................................................... 90CHAPTER 1 INTRODUCTION ....................................................................................................... 91CHAPTER 2 SURVEY PLANNING ................................................................................................. 92CHAPTER 3 FABRICATION OF STRUCTURES ........................................................................... 94CHAPTER 4 COMMISSIONING PROCESS .................................................................................. 95CHAPTER 5 DELIVERABLES ........................................................................................................ 97PART 7 CLASSIFICATION IN OPERATION ...................................................... 98CHAPTER 1 INTRODUCTION ....................................................................................................... 99CHAPTER 2 GENERAL PROVISIONS AND REQUIREMENTS FOR SURVEYS ....................... 100CHAPTER 3 PREPARATION AND PLANNING .......................................................................... 104CHAPTER 4 PERIODICAL SURVEYS ......................................................................................... 107CHAPTER 5 OTHER SURVEYS .................................................................................................. 113CHAPTER 6 PERMANENTLY INSTALLED SELF-ELEVATING UNITS ...................................... 115PART 0 INTRODUCTIONDET NORSKE VERITAS ASCHAPTER 1 INTRODUCTIONSection 1. GeneralThe Classification Rules for design and construction of self-elevating units can be found in the applicable requirements of DNV Offshore standards and MODU Rules. Recognizing that these standards are generic in nature, both in the topics covered and in the actual requirement description, there is an opportunity to construct an abstract of these with a focus on self-elevating unit relevant requirements.

Section 2. ObjectiveThe objective of this publication is to give a complete but concise overview of the relevant technical standards and DNVs involvement for building and classing a conventional self-elevating unit. In this objective, the book is to be used in conjunction with DNV Offshore Service Specification OSS-101 and the relevant technical standards as referred to therein.

Section 3. ScopeThis publication describes the technical and procedural requirements for classification of self-elevating units of a conventional design as covered by main class. Both the description of a conventional design and the scope of main class is further detailed in Part 1.

This publication covers the involvement of class for a units different phases during life time, i.e. design, construction, commissioning, delivery and operation.

The publication does not cover the requirements for separate additional class notations, nor the requirements for units of an unconventional design. These are detailed in DNVs Offshore Service Specification OSS-101.

Section 4. StructureTo maintain a clear overview, these rules consist of references to the relevant Offshore Standards, Service Specifications and other DNV Service Documents. The degree of reference detail is depending on the nature of the subject. To improve readability and understanding, the references are completed with a direct description of requirements. In special, a description has been included on topics of a higher complexity or risk.

The first part of these Rules describes the principles of Classification and its procedures in chapter 1 and 2. The third chapter of this part continues thereafter with the overall technical principles as applicable for the design of a self-elevating unit build under DNV Classification.

The technical requirements together with relevant calculations methods are discussed in detail in Parts 2 to 4. The three parts cover the main technical areas of class, subsequently Materials and Welding, Hull and Equipment and Machinery and Systems.

Part 5 to 7 thereafter give a concise overview for specific phases of class involvement, that is respectively in the Component and System Certification process, the new building mechanical completion and commissioning and conclusively survey and test requirements in the operational phase after delivery.

For a clear separation between the content of this publication and other DNV Rules, Standards or other service documents, references to parts, chapters and sections refer this publication if not explicitly stated otherwise.

Section 5. Definitions5.1 Verbal formsShall: Indicates a mandatory requirement to be followed for fulfillment or compliance with the present service specification. Deviations are not permitted unless formally and rigorously justified, and accepted by all relevant contracting parties.

Should: Indicates that among several possibilities one is recommended as particularly suitable, without mentioning or excluding others, or that a certain course of action is preferred but not necessarily required. Other possibilities may be applied subject to agreement.

May: Verbal form used to indicate a course of action permissible within the limits of the service specification.

Will: Indicates a mandatory action or activity to be undertaken by DNV. (Ref. shall for other parties).

5.2 DefinitionsApproval or approved: Denotes acceptance by DNV of documentation showing design solutions, arrangements and equipment that complies with the Rules.

Assessment: An Act of assessing, appraising or evaluating a condition of a product, process or system.

Builder: Signifies the party contracted to build a vessel in compliance with the Society's rules.

Certificate: A document confirming compliance with the Society's rules or with other rules and regulations for which the Society has been authorized to act.

Certification: A service confirming compliance with applicable requirements on the date that the survey was completed.

Certification of materials and components (CMC): The activity of ensuring that materials, components and systems used in vessels to be classed by the Society comply with the rule requirements. The scope of classification re-quires that specified materials, components and systems intended for the vessel are certified. Depending on the categorisation, certification may include both plan approval and survey during production and/or of the final product.

Class: Class is assigned to and will be retained by vessels complying with applicable requirements of the

Society's rules.

Classification: A service which comprises the development of independent technical standards for vessels - class rules and standards, and to verify compliance with the rules and standards throughout the vessels' life.

Close-up examination: An examination where the details of structural components are within the close visual inspection range of the surveyor, i.e. preferably within reach of hand.

Commissioning: A process of assuring that components, equipment and the systems are functioning in accordance with the functional requirements.

Concurrent surveys: Surveys required to be concurrently completed shall have the same date of completion. A survey required to be carried out in conjunction with or carried out as part of another survey shall be completed on or before the completion of the other survey, however, within the time window for that survey.

Condition of Class (CC): Constitutes a requirement that specific measures, repairs or surveys shall be carried out within a specific time limit in order to retain class.

Condition on behalf of the flag administration (CA): Constitutes specific measures, repairs or surveys that shall be carried out within a specific time limit in order to retain the statutory certificate. A CA will be issued only when the Society has been authorised to carry out statutory surveys on behalf of the flag ad-ministration.

Contract: The specific agreement between DNV and the client. It defines the extent of services requested by the customer, and is concerned with:

the classification of vessels or installations, both new buildings and in operation

statutory work carried out on behalf of national maritime authorities

equipment and materials.

Critical structural areas: Areas that have been identified from calculations to require monitoring or from the service history of the subject vessel or from similar or sister vessels to be sensitive to cracking, buckling or corrosion which would impair the structural integrity of the vessel.

Customer: Signifies the party who has requested the Society's service.

Designer: Signifies a party who creates documentation submitted to the Society for approval or information.

Det Norske Veritas (DNV): An autonomous and independent foundation with the purpose of safeguarding life, property and the environment. The foundation operates through the limited company Det Norske Veritas AS, which is registered in Norway and operates through a worldwide network of offices.

ESD: Emergency Shut Down.

Essential services see Safety systemsExceptional circumstances means unavailability of dry-docking facilities; unavailability of repair facilities; unavailability of essential materials, equipment or spare parts; or delays incurred by action taken to avoid severe weather conditions.

Flag administration: The maritime administration of a vessel's country of registry.

FMECA: Failure Mode Effect and Consequence Analysis.

FUI: Fatigue Utilisation Factor.

Contain advice which is not mandatory for the assignment or retention of class, but with which the Society, in light of general experience, advises compliance.

IACS: The International Association of Classification Societies. Unified rules, interpretations, guidelines and recommendations may be found on www.iacs.org.uk.

IMO: The International Maritime Organization.

Independent tank: Self-supporting tank which does not form part of the vessel's hull and does not contribute to the hull strength.

Independent gravity tank is a tank with design vapour pressure not exceeding 0.7 bar. Pressure vessel is a tank with design gas or vapour pressure exceeding 0.7 bar.

ISO: Signifies the International Organisation for Standardization.

HP: High Pressure.

Manufacturer: Signifies the entity that manufactures the material or product, or carries out part production that determines the quality of the material or product, or does the final assembly of the product.

Mechanical Completion (MC): Verification that the components, equipment and the systems are constructed, installed and tested in accordance with applicable drawings and specifications and are ready for testing and commissioning in a safe manner.

Memorandum to Owner (MO): Constitutes information related to the ship, its machinery and equipment or to rule requirements. A MO will be issued in relation to information that does not require any corrective action or survey.

OEM: Original Equipment Manufacturer.

Overall examination: An examination intended to report on the overall condition of the structure.

Plan approval: Signifies a systematic and independent examination of drawings, design documents or records in order to verify compliance with the rules or statutory requirements.

Prompt and thorough repair: A permanent repair completed at the time of survey to the satisfaction of the surveyor, therein removing the need for the imposition of any associated condition of class.

Quality system: Signifies both the quality management system and established production and control procedures.

Quality Survey Plan (QSP): A plan that systematically identifies activities related to the classification project (e.g.,Construction,installation,testing,mechanicalcompletion,pre-commissioning,testingand commissioning) and the extent of involvement each party (i.e., Yard's QC, Yards' QA, DNV and Owners [if desired]) will undertake. Such a plan needs to be submitted to the Society for approval prior to commencement of classification projects.

Reliability: The ability of a component or a system to perform its required function under given conditions for a given time interval.

Representative tanks: Those tanks which are expected to reflect the condition of other tanks of similar type and service and with similar corrosion protection systems. When selecting representative tanks account shall be taken of the service and repair history on board and identifiable critical and/or suspect areas.

Review: Signifies a systematic examination of drawings, design documents or records in order to evaluate their ability to meet requirements, to identify any problems and to pro-pose necessary actions.

Safety systems: Systems needed to be continuous available or available on demand to prevent, to detect, to control or to mitigate the effects of an undesirable event, and to safeguard the personnel, environment and the installation.Sighting survey: A survey to confirm that the relevant construction or the equipment is in a satisfactory condition and, as far as can be judged, will remain so until the postponed survey has been carried out.

Significant repair: A repair where machinery is completely dismantled and re-assembled. Significant repairs will, furthermore, be cases of repairs after serious damage to machinery.

The Society: Signifies Det Norske Veritas AS.

Safety systems: Systems, which are provided to prevent, detect, control or mitigate the effects of an accidental event. Failure of a safety system could lead to the development or escalation of an accidental event.

Spaces: Separate compartments including holds and tanks.

Statement of compliance: A document confirming compliance with specified requirements. Such documents may be issued by the Society in cases where it has not been authorised to certify compliance.

Statutory certificates: IMO convention certificates issued on behalf of, or by, national authorities.

Statutory survey: Survey carried out by or on behalf of a flag administration.

Substantial corrosion: Extent of corrosion such that assessment of corrosion pattern indicates wastage in excess of 75% of allowable margins, but within acceptable limits.

Survey: Signifies a systematic and independent examination of a vessel, materials, components or systems in order to verify compliance with the rules and/or statutory requirements.

Surveys will be carried out on the vessel, at the construction or repair site as well as at sub-suppliers and other locations at the discretion of the Society, which also decides the extent and method of control.

Suspect areas: Areas showing substantial corrosion and/or are considered by the surveyor to be prone to rapid wastage.

Temporary conditions: Design conditions not covered by operating conditions, e.g. conditions during fabrication, mating and installation phases, dry transit phases.

Temporary equipment: equipment intended for use on installations and which is covered by class, requires hook-up to systems covered by class and/or is a significant deck load and/or may pose a risk for fire, explosion and escape routes.

Transit conditions: All wet vessel movements from one geographical location to another.

Transverse section: Section which includes all longitudinal members such as plating, longitudinals and girders at the deck, side, bottom, inner bottom and hopper side plating, longitudinal bulkhead and bottom plating in top wing tanks, as applicable.

For transversely framed vessels, a transverse section includes adjacent frames and their end connections in way of transverse sections.

UT: Ultrasonic Testing.

Verification: A service that signifies a confirmation through the provision of objective evidence (analysis, observation, measurement, test, records or other evidence) that specified requirements have been met.

Witnessing: Signifies attending tests or measurements where the surveyor verifies compliance with agreed test or measurement procedures.

CHAPTER 2 CONTENTS IN DETAILPART 0 INTRODUCTION ..................................................................................... 5CHAPTER 1 INTRODUCTION ............................................................................................ 6

Sec.1General................................................................................................................................ 6Sec.2Objective............................................................................................................................. 6Sec.3Scope .................................................................................................................................. 6Sec.4Structure ............................................................................................................................. 6Sec.5Definitions .......................................................................................................................... 65.1 Verbal forms ............................................................................................................................... 6

5.2 Definitions ................................................................................................................................... 7

CHAPTER 2 CONTENTS IN DETAIL ............................................................................... 10

PART 1 GENERAL REGULATIONS AND CONDITIONS .................................. 18CHAPTER 1 CLASSIFICATION PRINCIPLES ................................................................. 19

Sec.1General.............................................................................................................................. 19Sec.2Application ....................................................................................................................... 19Sec.3Notations .......................................................................................................................... 19CHAPTER 2 PROCEDURES ............................................................................................ 21

Sec.1Plan Approval ................................................................................................................... 211.1 Format ...................................................................................................................................... 21

1.2 Subcontractors ......................................................................................................................... 21

1.3 Plans and data to be submitted ................................................................................................ 21

Sec.2Certification ...................................................................................................................... 21Sec.3Testing and Surveys ........................................................................................................ 21CHAPTER 3 PRINCIPLES AND CONDITIONS ................................................................ 22

Sec.1General.............................................................................................................................. 22Sec.2Principles.......................................................................................................................... 222.1 Classification scope .................................................................................................................. 22

2.2 Safety and important systems .................................................................................................. 22

2.3 Redundancy ............................................................................................................................. 23

2.4 Failure effects ........................................................................................................................... 23

Sec.3Environmental Conditions .............................................................................................. 233.1 Design temperature .................................................................................................................. 23

3.2 Temperature for machinery systems and equipment ............................................................... 23

3.3 Cooling water temperatures ..................................................................................................... 24

3.4 Humidity.................................................................................................................................... 24

3.5 Performance ............................................................................................................................ 24

3.6 Inclinations................................................................................................................................ 24

3.7 Vibrations ................................................................................................................................. 24

PART 2 MATERIALS AND WELDING ............................................................... 25CHAPTER 1 METALLIC MATERIALS ............................................................................. 26

Sec.1General.............................................................................................................................. 26Sec.2Principles ......................................................................................................................... 26CHAPTER 2 STRUCTURAL FABRICATION .................................................................... 27

Sec.1General.............................................................................................................................. 27PART 3 HULL AND EQUIPMENT ...................................................................... 28CHAPTER 1 STRUCTURAL DESIGN .............................................................................. 29

Sec.1General.............................................................................................................................. 291.1 Introduction ............................................................................................................................... 29


Sec.2Principles.......................................................................................................................... 30Sec.3Analysis and Calculations .............................................................................................. 303.1 Fatigue analysis........................................................................................................................ 31

Sec.4Design and Loading Conditions ..................................................................................... 314.1 General ..................................................................................................................................... 31

4.2 Environmental conditions ........................................................................................................ 32

4.3 Accidental conditions ............................................................................................................... 32

Sec.5Loads and Load Effects .................................................................................................. 325.1 Accidental loads ....................................................................................................................... 33

5.2 Load calculations ...................................................................................................................... 33

Sec.6Structural Categorization, Material and Inspection Principles .................................... 336.1 Structural categorization ........................................................................................................... 33

6.2 Material selection...................................................................................................................... 33

Sec.7Structural Strength .......................................................................................................... 347.1 Footing strength........................................................................................................................ 34

7.2 Section scantlings..................................................................................................................... 35

7.3 Fatigue strength ....................................................................................................................... 35

Sec.8Weld Connections............................................................................................................ 35Sec.9Corrosion Control ............................................................................................................ 35CHAPTER 2 STABILITY AND WATERTIGHT INTEGRITY .............................................. 36



Sec.2Stability ............................................................................................................................. 37Sec.3Watertight Integrity, Freeboard and Weathertight Closing Appliances...................... 373.1 Materials ................................................................................................................................... 37

3.2 Watertight integrity.................................................................................................................... 38

3.3 Weathertight closing appliances .............................................................................................. 38

3.4 Freeboard ................................................................................................................................. 38

3.5 Penetrations ............................................................................................................................. 39

CHAPTER 3 TOWING ....................................................................................................... 40



1.3 Principles .................................................................................................................................. 40

Sec.2Towing .............................................................................................................................. 402.1 General ..................................................................................................................................... 40

2.2 Material ..................................................................................................................................... 40

2.3 Strength analysis ...................................................................................................................... 41

PART 4 MACHINERY SYSTEMS AND EQUIPMENT ........................................ 42CHAPTER 1 MARINE, MACHINERY AND PIPING SYSTEMS ........................................ 43


1.2 Application ................................................................................................................................ 43


Sec.2Principles.......................................................................................................................... 452.1 Component design ................................................................................................................... 45

Sec.3Valves................................................................................................................................ 453.1 Design and tests ....................................................................................................................... 45

3.2 Installation ................................................................................................................................ 45

3.3 Operation .................................................................................................................................. 45

Sec.4Piping ................................................................................................................................ 454.1 Design ...................................................................................................................................... 45

4.1.1Materials ....................................................................................................................... 464.2 Platform piping.......................................................................................................................... 46

4.2.1Pre-load/ballast ............................................................................................................ 464.2.2Bilge and drainage ....................................................................................................... 474.2.3Raw water systems ...................................................................................................... 474.2.4Drag chains .................................................................................................................. 474.2.5Air, overflow and sounding ........................................................................................... 484.2.6Storage and transfer systems for helicopter fuels ........................................................ 484.3 Machinery piping ...................................................................................................................... 48

4.3.1Cooling system ............................................................................................................. 484.3.2Lubrication oil system ................................................................................................... 484.3.3Fuel oil system ............................................................................................................. 484.3.4Feed water and condensation systems ........................................................................ 494.3.5Hydraulic systems ........................................................................................................ 494.3.6Pneumatic power supply .............................................................................................. 494.4 Pipe fabrication, workmanship and testing .............................................................................. 49

Sec.5Rotating Machines ........................................................................................................... 495.1 Principles .................................................................................................................................. 49

5.2 Diesel engines .......................................................................................................................... 49

5.3 Starting arrangements .............................................................................................................. 50

5.3.1Capacity ....................................................................................................................... 505.3.2Pneumatic .................................................................................................................... 505.3.3Electric.......................................................................................................................... 505.3.4Emergency generators ................................................................................................. 515.4 Start from dead ship ............................................................................................................... 51

Sec.6Jacking Gear Machinery.................................................................................................. 516.1 General ..................................................................................................................................... 51

6.1.1Application .................................................................................................................... 516.1.2Document and plans to be submitted ........................................................................... 516.2 General .................................................................................................................................... 51

6.3 Materials ................................................................................................................................... 52

6.4 Arrangement ............................................................................................................................. 52

6.5 Gearing ..................................................................................................................................... 52

6.5.1General......................................................................................................................... 526.5.2Pinion rack.................................................................................................................... 536.5.3Gear casings and bearing structure ............................................................................. 536.5.4Shafts and connections ................................................................................................ 536.5.5Bearings ....................................................................................................................... 536.6 Brakes ...................................................................................................................................... 53

6.7 Flexible mountings.................................................................................................................... 53

6.8 Control and monitoring ............................................................................................................. 53

6.9 Testing & inspection ................................................................................................................. 54

6.9.1General......................................................................................................................... 546.9.2Workshop testing.......................................................................................................... 546.9.3Installation inspection ................................................................................................... 546.9.4Testing on board .......................................................................................................... 54CHAPTER 2 ELECTRICAL INSTALLATIONS .................................................................. 55


1.2 Application ................................................................................................................................ 55


Sec.2Principles.......................................................................................................................... 56Sec.3Arrangements and Installation ....................................................................................... 573.1 Arrangement ............................................................................................................................. 57

3.2 Installation ................................................................................................................................ 57

Sec.4Power Supply ................................................................................................................... 574.1 Main .......................................................................................................................................... 57

4.1.1Capacity ....................................................................................................................... 574.1.2Generator prime movers .............................................................................................. 584.1.3System functionality ..................................................................................................... 584.1.4Load shedding and automatic restoration of power ..................................................... 584.2 Emergency power supply systems .......................................................................................... 58

4.3 Battery systems ........................................................................................................................ 59

4.4 Power supply to jacking gear.................................................................................................... 59

Sec.5Electrical Power Distribution .......................................................................................... 59Sec.6Protection ......................................................................................................................... 59Sec.7Control .............................................................................................................................. 60Sec.8Electrical Equipment: ...................................................................................................... 60Sec.9Cables ............................................................................................................................... 609.1 Cable selection ........................................................................................................................ 60

9.2 Cable construction and rating ................................................................................................... 61

9.3 Cable routing and installations ................................................................................................. 61

CHAPTER 3 AREA ARRANGEMENTS ........................................................................... 63

Sec.1General.............................................................................................................................. 631.1 Scope ....................................................................................................................................... 63


Sec.2Arrangements................................................................................................................... 632.1 Electrical installations ............................................................................................................... 64

Sec.3Hazardous Areas Installations........................................................................................ 643.1 Area classification..................................................................................................................... 64

3.2 Battery rooms, paint stores, and welding gas bottle stores ..................................................... 64

3.3 Requirements for specific systems ........................................................................................... 653.3.1Combustion engines..................................................................................................... 653.3.2Electrical installations and cables................................................................................. 65Sec.4Ventilation Systems ......................................................................................................... 65Sec.5Marking and Signboards ................................................................................................. 66CHAPTER 4 CONTROL AND COMMUNICATION SYSTEMS ......................................... 68


1.2 Application ................................................................................................................................ 68


Sec.2Principles.......................................................................................................................... 682.1 Response to failures ................................................................................................................. 68

2.1.1Failure detection ........................................................................................................... 682.1.2Fail-safe functionality.................................................................................................... 69Sec.3System Design ................................................................................................................. 693.1 Additional requirements for computer based systems.............................................................. 69

Sec.4Component Design and Installation............................................................................... 69Sec.5User Interface ................................................................................................................... 69Sec.6Emergency Control .......................................................................................................... 706.1 Emergency shut down .............................................................................................................. 70

6.1.1Additional requirements for notation ES ....................................................................... 706.2 Emergency control.................................................................................................................... 71

6.2.1Additional requirements for notation ES ....................................................................... 716.2.2Emergency control room .............................................................................................. 71Sec.7Communication & Alarms ............................................................................................... 717.1 Communication......................................................................................................................... 71

7.2 Alarms ...................................................................................................................................... 717.2.1Additional requirements for notation ES ....................................................................... 72CHAPTER 5 FIRE PROTECTION ..................................................................................... 73


1.2 Application ................................................................................................................................ 73


Sec.2Principles.......................................................................................................................... 74Sec.3Passive Fire Protection ................................................................................................... 743.1 Additional requirements for notation ES ................................................................................... 74

Sec.4Fire Fighting Systems ..................................................................................................... 744.1 Fire pumps, fire mains, hydrants and hoses............................................................................. 74

4.2 Active fire protection of specific areas ...................................................................................... 75

4.2.1Additional requirements for notation ES ....................................................................... 75Sec.5Fire and Gas Detection Systems .................................................................................... 755.1 Additional requirements for notation ES ................................................................................... 75

Sec.6Escape .............................................................................................................................. 76CHAPTER 6 ENHANCED CONTROL & SAFETY SYSTEMS .......................................... 77

Sec.1Introduction ...................................................................................................................... 771.1 General ..................................................................................................................................... 77

1.2 Objective................................................................................................................................... 77

1.3 Scope ....................................................................................................................................... 77

1.4 Documentation requirements ................................................................................................... 77

Sec.2Control Systems .............................................................................................................. 772.1 Emergency shutdown ............................................................................................................... 77

2.2 Emergency control.................................................................................................................... 78

2.3 Communication......................................................................................................................... 78

Sec.3Fire Protection.................................................................................................................. 783.1 Passive fire protection .............................................................................................................. 78

3.2 Active fire protection of specific areas ...................................................................................... 78

3.3 Fire detectors............................................................................................................................ 79

PART 5 CERTIFICATION ................................................................................... 80CHAPTER 1 PROCEDURES ............................................................................................ 81

Sec.1Introduction ...................................................................................................................... 81Sec.2Certification Types........................................................................................................... 81Sec.3Class Involvement ........................................................................................................... 81CHAPTER 2 MACHINERY AND SYSTEM CERTIFICATION ........................................... 82

Sec.1General.............................................................................................................................. 82Sec.2Principles.......................................................................................................................... 82Sec.3Machinery Systems and Equipment .............................................................................. 823.1 Miscellaneous mechanical components ................................................................................... 83

3.2 Pressure vessels ..................................................................................................................... 843.3 Main power, emergency power, fire water pumps ................................................................... 843.4 Components in marine piping systems..................................................................................... 85

Sec.4Electrical Installations ..................................................................................................... 854.1 Required certificates ................................................................................................................. 85

Sec.5Automation and Control System .................................................................................... 885.1 General ..................................................................................................................................... 88

Sec.6Fire Protection.................................................................................................................. 88Sec.7Watertight/ Weathertight Integrity .................................................................................. 89PART 6 NEWBUILDING SURVEY ..................................................................... 90CHAPTER 1 INTRODUCTION .......................................................................................... 91

Sec.1Overview .......................................................................................................................... 91Sec.2Structure ........................................................................................................................... 91Sec.3Principles.......................................................................................................................... 91CHAPTER 2 SURVEY PLANNING ................................................................................... 92

Sec.1Objective........................................................................................................................... 92Sec.2Scope ................................................................................................................................ 92Sec.3Quality Survey Plan ......................................................................................................... 923.1 Review of the construction facility ............................................................................................ 92

3.2 Kick-off meeting ........................................................................................................................ 92

3.2.1Quality standards ......................................................................................................... 933.3 Survey extent............................................................................................................................ 93

CHAPTER 3 FABRICATION OF STRUCTURES .............................................................. 94

Sec.1Principles.......................................................................................................................... 94Sec.2Technical Provisions ....................................................................................................... 94Sec.3Certification and Classification ...................................................................................... 94CHAPTER 4 COMMISSIONING PROCESS ..................................................................... 95

Sec.1Introduction ...................................................................................................................... 95Sec.2Principles.......................................................................................................................... 95Sec.3Process ............................................................................................................................. 95Sec.4Survey Scope Categories................................................................................................ 95Sec.5Test Requirements related to Marine, Utility and Safety Systems .............................. 95Sec.6Jacking Trials ................................................................................................................... 966.1 Jacking machinery .................................................................................................................... 96

CHAPTER 5 DELIVERABLES .......................................................................................... 97

Sec.1Class Certificate............................................................................................................... 97Sec.2Conditions of Class ......................................................................................................... 97Sec.3Appendix to Class Certificate ......................................................................................... 97Sec.4Additional Declarations ................................................................................................... 97Sec.5Statutory Certificates....................................................................................................... 97PART 7 CLASSIFICATION IN OPERATION ...................................................... 98CHAPTER 1 INTRODUCTION .......................................................................................... 99

Sec.1Introduction ...................................................................................................................... 99Sec.2Objective........................................................................................................................... 99Sec.3Scope ................................................................................................................................ 99CHAPTER 2 GENERAL PROVISIONS AND REQUIREMENTS FOR SURVEYS ......... 100

Sec.1Conditions for Retention of Class ................................................................................ 100Sec.2Class Involvement ......................................................................................................... 1002.1 Damage and repairs ............................................................................................................... 100

2.2 Temporary equipment ............................................................................................................ 100

Sec.3Special Provisions for Ageing Units ............................................................................ 1013.1 Calculation of fatigue life ........................................................................................................ 101

3.2 Follow up ................................................................................................................................ 101

3.3 Additional inspections ............................................................................................................. 102

Sec.4Alternative Survey Arrangements ................................................................................ 102Sec.5Surveys Performed by Approved Companies............................................................. 102CHAPTER 3 PREPARATION AND PLANNING ............................................................. 104

Sec.1Preparation ..................................................................................................................... 104Sec.2Planning.......................................................................................................................... 1042.1 General ................................................................................................................................... 104

2.2 Periodical surveys .................................................................................................................. 104

2.3 Specific surveys...................................................................................................................... 105

2.4 In-service Inspection Program (IIP) ........................................................................................ 105CHAPTER 4 PERIODICAL SURVEYS ........................................................................... 107

Sec.1Annual Survey ................................................................................................................ 1071.1 Structure and equipment ........................................................................................................ 107

1.1.1Hull ............................................................................................................................. 1071.1.2Watertight/ weathertight integrity ................................................................................ 1071.1.3Towing system ........................................................................................................... 1071.1.4Machinery and safety systems ................................................................................... 1071.1.5Jacking system ........................................................................................................... 1071.1.6Hazardous area .......................................................................................................... 1081.1.7Drainage, bilge, pre load ........................................................................................ 1081.1.8General....................................................................................................................... 108Sec.2Intermediate Survey....................................................................................................... 1082.1 Structure and equipment ........................................................................................................ 108

2.1.1Legs............................................................................................................................ 1082.2 Machinery and systems .......................................................................................................... 108

2.2.1Fire protection/ extinguishing/ prevention................................................................... 108Sec.3Renewal Survey ............................................................................................................. 1083.1 Extent ..................................................................................................................................... 108

3.2 Structure and equipment ........................................................................................................ 108

3.2.1Legs............................................................................................................................ 1083.2.2Acceptance criteria corrosion limits ............................................................................ 1093.2.3Tanks ......................................................................................................................... 1093.3 Weight/ displacement survey.................................................................................................. 110

3.3.1Towing equipment ..................................................................................................... 1103.4 Machinery and systems .......................................................................................................... 110

3.4.1General....................................................................................................................... 1103.4.2Jacking system ........................................................................................................... 1113.4.3Raw water pumps....................................................................................................... 1113.4.4Hazardous area .......................................................................................................... 1113.4.5Fire protection/ extinguishing/ prevention................................................................... 1113.4.6Instrumentation and automation ................................................................................. 1123.5 General ................................................................................................................................... 112

CHAPTER 5 OTHER SURVEYS ..................................................................................... 113

Sec.1Record Keeping ............................................................................................................ 113Sec.2Bottom Survey ............................................................................................................... 113Sec.3Spudcan & Leg Survey.................................................................................................. 1133.1 General ................................................................................................................................... 113

3.2 Scope ..................................................................................................................................... 113

3.3 Inspection ............................................................................................................................... 113

Sec.4Survey after Ocean Transit ........................................................................................... 113CHAPTER 6 PERMANENTLY INSTALLED SELF-ELEVATING UNITS ......................... 115

Sec.1Introduction .................................................................................................................... 115Sec.2Fatigue ............................................................................................................................ 115Sec.3Inspection and Maintenance ......................................................................................... 1153.1 Facilities for survey ................................................................................................................. 115

Sec.4Jacking System .............................................................................................................. 115PART 1 GENERAL REGULATIONS AND CONDITIONSDET NORSKE VERITAS ASCHAPTER 1 CLASSIFICATION PRINCIPLESSection 1. GeneralGeneral regulations and procedures are described in DNV Offshore Service Specifications-101, Chapter 1. Specific requirements and relevant instructions for classing conventional self-elevating units are contained in

this Rule chapter.

Deviation from the requirements may be substituted where shown to provide and equivalent or higher level of integrity or safety. Any deviation from the requirements shall be documented and agreed between all contracting parties.

The table below lists references required for a complete understanding of this chapter.

Table 1-1 Overview of references

ReferenceTitle

DNV-OSS-101Rules for Classification of Offshore Drilling and Support Units

Section 2. ApplicationThese rules are intended for Self-elevating units of conventional design, that is:

Separated legs

Not designed for field- or ocean transits under own power

Diesel driven generators

Rack and pinion type jacking system

For other types of offshore units and self-elevating units with design alternatives or technical solutions not covered in these rules is referred to DNV-OSS-101.

Unless stated otherwise, the coming into force date for these rules and the documents referenced by this OSS

as technical basis for classification shall be six (6) months after the date of publication.

Section 3. NotationsVessels build under compliance of the requirements and procedures of these rules shall be given the class notation +1A1 Self-elevating Drilling Unit NON-SELF-PROPELLED.

Table 3-1 lists most relevant additional class notation for non-self-propelled, Self-elevating units. A complete list of additional Class notations can be found in OSS-101, Ch.1, Sec.3, B600 and in Rules for Classification of Ships Pt.1 Ch.2.

Table 3-1

Class notationDescriptionQualifierDescriptionDesign requirements

CRANEOnboard craneRules for Classification of

Ships, Pt.6 Ch.1 Sec.3

DRILLDrilling plantDNV-OS-E101

E0Periodically unattended machinery spaceRules for Classification of

Ships, Pt.6 Ch.3

ECOMachinery centralized operatedRules for Classification of

Ships, Pt.6 Ch.3

ESEnhanced systemsCover fire, communication and control systemsAs marked inside these rules

HELDKHelicopter deckStructureDNV-OS-E401, Ch.2

SVessel safety

HHelicopter safety

ISDSIntegrated Software

Dependent Systems(...)See DNV-OS D203 for qualifier definitionsDNV-OS D203

Table 3-1 (Continued)

Class notationDescriptionQualifierDescriptionDesign requirements

RecyclableInventory of Hazardous

Materials Part 1Rules for Classification of

Ships, Pt.6 Ch.27

WELLWell intervention system1Vessel mounted system excluding subsea equipment.DNV-OS-E101

2Vessel mounted system including subsea equipment.

WELLTESTWell test systemDNV-OS-E101, Ch.3

CHAPTER 2 PROCEDURESSection 1. Plan Approval1.1 FormatThe documentation for plan approval may be submitted on paper or as an electronic file. Any documents submitted for re-approval or re-examination shall be especially marked to identify the revised parts. Symbols used shall be explained, or reference to a standard code shall be given. Each drawing shall include a title field stating:

name of vessel (when known)

name of document issuing company

name and signature of originator and verifier

document no.

document title

revision no.

issue date

scale

set of measurement units used in the document, e.g. System International.

The document title should not include the name of the vessel. The document title should include the function or component covered by the document.

Unique revision numbers shall be allocated to all issues of a document, including the first issue. For documents with multiple sheets, the revision number should be the same for all sheets.

1.2 SubcontractorsWhere subcontractors and suppliers are involved, the customer shall co-ordinate the submission of required plans and documents, as well as co-ordinate any approval comments given by the Society. This does not apply for materials, components and systems requiring certification as is discussed in more detail in Part 5.

1.3 Plans and data to be submittedGeneral list of plans and data to be submitted are included in the applicable technical chapters of Parts 2 to 4. A detailed and project specific list shall be supplied by the DNV responsible directly after the class agreement has been signed. Project specific implies that only those documentation is required as is relevant for the design and within the scope of the contractual agreement between yard and DNV.

Section 2. CertificationThe scope of classification requires that specified materials, components and systems intended for the vessel are certified according to the rules. The objective of certification shall ensure that materials, components and systems used in vessels to be classed by the Society comply with the rule requirements.

Certification normally includes both plan approval and survey during production and/or of the final product. A detailed description of the certification process and the specific requirements and lists of the specified

materials, components and systems is given in Part 5.

Section 3. Testing and SurveysDuring the building period DNV carries out surveys at the building yard and its suppliers. The purpose of these is to verify that the construction, components and equipment satisfy the rule requirements and are in accordance with the approved plans, that required materials are used, and that functional tests are carried out as prescribed by the rules. A complete description of these test and surveys is given in Part 6.

CHAPTER 3 PRINCIPLES AND CONDITIONSSection 1. GeneralThe table below lists references required for a complete understanding of this chapter.


ReferenceTitle

DNV-OS-D101Marine and Machinery Systems and Equipment

DNV-OS-D201Electrical Installations

DNV-OS-D202Automation, Safety, and Telecommunication Systems

Section 2. Principles2.1 Classification scopeThese rules with the referred standards give requirements in the following areas:

1) Hull and main structure

strength

materials and welding

corrosion protection

passive fire protection

weathertight and watertight integrity

stability and floatability.

2) Marine and machinery installations and equipment

Machinery installations and equipment, including their related auxiliary systems, to the following main

functions:

jacking gear

fire extinguishing

drainage and bilge pumping

ballasting

emergency shutdown systems.

3) Systems and equipment provided to prevent, detect/ warn of an accidental event and/or prevent or mitigate its effects

4) Secure integrity of shelter areas and usability of escape ways and means of evacuation

2.2 Safety and important systemsTo further frame the content of the rules, the above listed areas and systems are split into safety (or essential)

and important systems.

Safety systems are systems needed to be continuous available or available on demand to prevent, to detect, to control or to mitigate the effects of an undesirable event, and to safeguard the personnel, environment and the installation. Examples of safety systems covered by main class:

fire pumps

emergency shut down (ESD) system

fire and gas detection and alarm system

systems required to be supplied from batteries or emergency generator, e.g. public address, emergency lighting

electric generators and associated power sources supplying the above equipment.

control, monitoring and safety devices or systems for safety systems.

Important services ensure reliable operation and maintain the units operation within operational limitations. Examples of equipment or systems for important services covered by main class:

fuel oil transfer pumps and fuel oil treatment equipment

seawater pumps (note)

starting air and control air compressors

bilge- and ballast/preload pumps

ventilating fans for engine rooms

ventilating fans for gas dangerous spaces

main lighting system

watertight closing appliances

jacking system

bilge alarm system

electric generators and associated power sources supplying the above equipment.

control, monitoring and safety devices or systems for the above equipment

Seawater pumps (if used as part of a fire water supply system).

2.3 RedundancySafety systems are always to be available. To secure that safety systems always are available, the general principle is that components and systems shall be arranged with redundancy so that a single failure of any active component or system does not cause loss of any main function. Availability is as such, further indirect defined in the requirement to a system i.e where this general principle may be waived and/ or where duplication of components is required.

Redundancy can either be arranged by installing more than one unit (component redundancy) or by having two or more systems capable of performing the same functions (system redundancy).

For redundancy on a component level a single failure of an active component shall not lead to a reduction of the output power for the main function served.

When two or more components are performing the same function, these shall be mutually independent and at least one shall be independently driven. Components arranged as part of the designed redundancy, yet only performing important functions to a main unit, can be directly powered by the main unit through separate power transmissions, on the condition that these components are not necessary for the starting of the main unit.

When traditional mechanical components are replaced by electronic components, these components shall have the same reliability as the mechanical component being replaced.

Machinery or equipment having remote or automatic control, shall have additional alternative provisions for attendance and operation.

2.4 Failure effectsIn the event of failure, components and systems shall enter the least hazardous of the possible failure states with regard to machinery, personnel and environment.

Failure of one component in a system arranged as part of the designed redundancy shall not lead to failure or damage to backup or parallel components or systems.

For failure detection see Pt.4, Ch.4, Sec.2.1.

Section 3. Environmental ConditionsAll components and systems covered by this standard shall be designed to operate under the following environmental conditions unless otherwise specified in the detailed requirements for the component or system.

3.1 Design temperatureThe units design temperature is a minimum temperature used as a criterion for the selection of steel grades. The design temperature shall be specified by the customer and is to be taken as the lower or equal to the lowest mean daily temperature in air for the relevant areas. For seasonal restricted operations the lowest mean daily temperature in air for the season may be applied.

Guidance note:It is underlined that design temperatures below 0 degrees are only relevant for waters in the higher latitudes (e.g. northern part of North Sea, Canadian waters etc). For these waters and their harsh conditions, relevant considerations should be taken (e.g. OS-C201, Sec.2 B304 on water trapped in local structures, OS-D101, Ch.2 Sec.3 F108 on freezing of vents, OS-D301 in protecting the fire equipment against freezing etc) In addition, class notations related to cold climate operations as listed in OSS-101, Ch.1 Sec.3, B 700 can be relevant as well.

---e-n-d---of---G-u-i-d-a-n-c-e---n-o-t-e---

The design temperature shall be listed in the appendix to Class Certificate (see also Pt.6, Ch.5, Sec.3).

Guidance note:In the different offshore standards is in addition to a design temperature a service temperature defined. For self- elevating units, the two temperatures are equal.


3.2 Temperature for machinery systems and equipmentMachinery systems and equipment shall be constructed for continuous operation in the range of ambient

temperatures as specified in the table below.

Table 3-1

LocationMinimum ambient air temperature range for continuous operation (C)

FromTo

1Engine rooms, boiler rooms, galleys and similar spaces, accommodation spaces.0+451

2Open deck, deckhouses and similar spaces which are not provided with space heating.-25+45

1 Where equipment is installed within environmentally controlled spaces the ambient temperature for which the equipment shall be suitable may be reduced from 45C and maintained at a value not less than 35C provided:

the equipment is not for use for emergency services, and shall not be in operation after ESD has been activated

temperature control is achieved by at least two cooling units so arranged that in the event of loss of one cooling unit,

for any reason, the remaining unit(s) is capable of satisfactorily maintaining the design temperature

the equipment can be started in a 45C ambient temperature and kept in operation until the lesser ambient

temperature may be achieved

the cooling equipment shall be rated for a 45C ambient temperature

malfunction of, or loss of a cooling unit shall be alarmed at a manned control station.

In accepting a lesser ambient temperature than 45C, it shall be ensured that electrical cables for their entire length are adequately rated for the maximum ambient temperature to which they are exposed along their length.

(ref IACS UR E19)

For the different environmental classes and the specified temperature ranges as applicable for control- and communication equipment see DNV-OS-D202, Ch.2, Sec.4 B.

3.3 Cooling water temperaturesElectrical equipment shall be constructed for continuous operation under full rated load, at a seawater temperature range from 0 to +32C.

3.4 HumidityAll equipment shall be constructed to withstand, and function safely in relative humidity up to 95%.

3.5 PerformanceFor performance requirements of machine systems, the conditions of Table 3-2 can be applied (ref IACS UR M28):

Table 3-2

ParameterValue

Total barometric pressure1 bar

Ambient air temperature45C

Relative humidity of air60%

Sea water temperature32C

3.6 InclinationsAll machinery, components and systems essential for safe operation are to be designed for operation under the following inclination values:

inclination 10 from normal level in any direction under normal static conditions

inclination 15 from normal level in any direction under normal dynamic conditions

Guidance note:Other values may be accepted if justified by calculations for the particular offshore unit. National authorities may require larger inclinations.

---e-n-d---of---G-u-i-d-a-n-c-e---n-o-t-e---3.7 VibrationsElectrical equipment and components shall be constructed to withstand, without malfunctioning, or electrical connections loosening, at least a vibration frequency range 5 to 50 Hz with vibration velocity amplitude 20 mm/s.

For flexible mounted equipment, special considerations shall be given to the construction of the equipment since larger vibrations may occur.

For control- and communication equipment vibration requirements see DNV-OS-D202, Ch.2, Sec.4 B.

PART 2 MATERIALS AND WELDINGDET NORSKE VERITAS ASCHAPTER 1 METALLIC MATERIALSSection 1. GeneralThe table below lists references required for a complete understanding of this chapter.


ReferenceTitle

DNV-OS-C101Design of Offshore Steel Structures, General

DNV-OS-C201Structural Design of Offshore Units (WSD method)

DNV-OS-C301Stability and Watertight Integrity


DNV-OS-E301Position Mooring

Section 2. PrinciplesPrinciples for certification of steels for structural application are given by standard DNV-OS-B101. Requirements for the specific materials selections are given in the technical chapters of Part 3 and 4 of this book:

Table 2-1

TopicRule book referenceOffshore standard

Structural steelPt.3, Ch.1, Sec.6.2C201, Ch.2, Sec.4 D C201, Ch.2, Sec.12, B300

Watertight Integrity, Freeboard and Weathertight

Closing AppliancesC301, Ch.2, Sec.2 B

Towline fastening devices and their supporting structuresPt.3, Ch.3, Sec.2.2C101, Ch.1 Sec.4

AnchorsE301, Ch.2 Sec.4 B

Windlasses, winches and chain stoppersE301, Ch.2, Sec.2, K400

Materials for pipingPt.4, Ch.1, Sec.4.1D101, Ch.2, Sec.2 B

Jacking gearPt.4, Ch.1, Sec.6.3

When material other than steel and aluminum alloys (evidenced by previous service experience) is used in structural fabrication and for equipment relating to Main Class, documentation of the materials applicability for intended purpose shall be documented with due regard to the materials mechanical properties and its responding service performances.

Materials with low heat resistance shall not be used in components where fire may cause outflow of flammable or toxic fluids, flooding of any watertight compartment or destruction of watertight integrity.

Guidance note:Materials with high heat resistance are materials having a melting point greater than 925C. Materials with low heat resistance are all other materials. Deviations from the above requirement will be subject to special considerations.


CHAPTER 2 STRUCTURAL FABRICATIONSection 1. GeneralPrinciples and requirements for structural fabrication are given by standard DNV-OS-C401 as discussed in detail in Pt.6, Ch.3

PART 3 HULL AND EQUIPMENTDET NORSKE VERITAS ASCHAPTER 1 STRUCTURAL DESIGNSection 1. General1.1 IntroductionThe table below lists references required for a complete understanding of this chapter.


ReferenceTitle

DNV-OS-A101Safety Principles and Arrangement

DNV-OS-C104Structural Design of Self Elevating Units (LRFD method)

DNV-OS-C201Structural Design of Offshore Units (WSD method)

DNV-OS-C401Fabrication and Testing of Offshore Structures


DNV-RP-C104(recommendations for the strength analyses of main structures of) Self-elevating units.

DNV-RP-C204Design Agains

oss-104_2012-04

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