helsinki commission meeting of experts on maritime safety ... documents/safe nav 1-2011_5-2... ·...

HELSINKI COMMISSION

Meeting of Experts on Maritime Safety Malmö, Sweden, 22 February 2011

Part-financed by the European Union (European Regional Development Fund)

Note by Secretariat: FOR REASONS OF ECONOMY, THE DELEGATES ARE KINDLY REQUESTED TO BRING THEIR OWN COPIES OF THE DOCUMENTS TO THE MEETING of 14

Agenda Item 5 Risk assessments/formal safety assessments

Document code: 5/2

Date: 17.2.2011

Submitted by: Denmark

MODELLING OF RISK OF ACCIDENTS AND SPILLS IN THE BALTIC SEA WITHIN THE BRISK/BRISK-RU PROJECTS

This document presents the first outcomes of the risk assessment within the Project “Sub-regional risk of spill of oil and hazardous substances in the Baltic Sea” (BRISK in short) as well as BRISK-RU project (www.brisk.helcom.fi). All HELCOM countries participate in the risk assessment, eight EU members through EU co-financing (2.5 mln from the European Regional Development Fund within the Baltic Sea Region Programme 2007-2013) and Russia through the funding by the Nordic Council of Ministers. The project is led by the Admiral Danish Fleet.

The project is being conducted within the framework of the HELCOM Response Group to implement the national commitments under the HELCOM Baltic Sea Action Plan, and is also a flag ship project under the EU Strategy for the Baltic Sea Region.

The project is carrying out an overall risk assessment of pollution by ships covering the whole Baltic Sea area. The aim is to check whether the existing emergency and response capacities are sufficient to tackle medium-size and the largest spills of oil or hazardous substances.

Based on the identified gaps, HELCOM countries can jointly plan their investments in the response equipment so as to make sure that each sub-region of the Baltic is capable of efficiently responding to the spills.

The risk assessment modelling is based on the model developed by COWI for Denmark, which has been further developed by COWI to cater for the sub-regional differences.

So far, the ship traffic mapping, modelling of risk for en-route collisions, cross collisions and groundings as well as for spills have been done (a more detailed description in Attachment). The risk analysis model takes a variety of measures, such as VTS and response capacities in the Baltic Sea countries, into account, and it could include also further, more or less specific measures affecting the risk.

The modelling of drift and recovery of spilled oil as well as the mapping of sensitivity towards oil spill is being finalized. The risk assessment is expected to be completed in April 2011 and its results presented in the seminar in May 2011.

The Meeting is invited to take note on the information and discuss how the risk assessment could be used to strengthen the cooperation on maritime safety in the Baltic Sea region.

http://www.brisk.helcom.fi/

Document 5/2

of 14

Attachment

1. INTRODUCTION

This paper informs about the current modelling status concerning risk of accidents and spills in the BRISK/BRISK-RU projects. It contains three parts:

• Model results concerning the risk of accidents at sea (Section 2)

• Model results concerning the risk of spills (Section 0)

• An overview of local and global model parameters (Section 0)

2. RISK OF ACCIDENTS AT SEA

The ship traffic analysis is based on AIS data recorded during 12 months, 1 July 2008 to 30 June 2009. During this period average winter conditions prevailed. Thus, the assessment is based on ship traffic in ice conditions during such an average winter. Based on the AIS data, a route net was established. This route net serves as a basis for the accident and spill risk modelling.

The risk of accidents at sea refers to the yearly number of accidents with ships and offshore accidents.

The risk of accidents is not equivalent with the risk of spills because

• only a small percentage of all accidents results in spills

• the risk of spill varies greatly depending on the ship size and ship type, i.e. not every accident results in the same kind of spill

Hence, the risk of accident is only displayed for general informative purposes. The main issue, i.e. the risk of spill is treated in Section 0.

Accidents type

Ship-ship collisions and groundings are by far the most frequent type of accidents at open sea. Figure 1 illustrates the risk of these two types of accident. The size of the bubbles in the figure corresponds to the accident risk, i.e. the expected number of accidents per year. The total number of accidents (i.e. all bubbles taken together) corresponds to approximately 44 groundings and 4 collisions with ships of 300 gross tonnage and above per year.

In addition, a number of fires and explosions (7 events per year) are expected. These events are distributed in the same way as the general traffic described by AIS traffic plots and are therefore not shown in the figure.

Collisions with fixed objects (wind farms, large buoys, offshore installations) are another source of accident and are part of the model. The overall risk of such events at open sea (i.e. not in ports) is low in total numbers compared with other accident types. The local risk of a collision with a fixed object is typically smaller than the risk of collision in the same area and much smaller than the risk of groundings.

The same can be said about releases from offshore structures that are not due to ship collisions (i.e. spills from platforms and spills during hose transfer at sea).

The risk of foundering and hard weather damage events in the Baltic Sea is too low in order to give a relevant risk contribution.

Discussion

Apparently, the expected number of grounding accidents is about ten times higher than the number of ship-ship collisions. However, it needs to be born in mind that a collision is about on average roughly 100 times as dangerous in terms of spill risk as a grounding. For this reason and in order to show collisions at a larger, more easily viewable scale, collisions are illustrated separately in Figure 2 in addition to the overall illustration in Figure 1.

Document 5/2

of 14

Figure 1. Risk of accidents in the Baltic Sea area: Collisions on route (red) and in intersections (blue) and groundings (yellow).

Document 5/2

of 14

Figure 2. Risk of accidents in the Baltic Sea area (without groundings, larger scale): Collisions on route (red) and in intersections (blue).

Document 5/2

of 14

3. RISK OF SPILLS

The risk of spills at sea originates essentially from two types of events:

• Accidents at sea (described above)

• Deliberate and inadvertent action (also referred to as illegal spills)

Spills following accidents at sea

Figure 3 illustrates the risk of spill due to ship-ship collisions and groundings, which are by far the two most important spill sources. Other contributions from accidents (fire, collisions with fixes objects, spill from offshore installations) are not able to alter the overall picture, not even on a local scale.

All in all, the spill model predicts an average yearly spill of roughly 1,200 tonnes of oil (85 percent) and hazardous substances (15 percent). Note that this number is only an average indication. In reality, most of the spill tonnage is due to large spill events that only occur every few years.

Spill events with less than 10 tonnes contribute only 0.14 percent of the overall spill tonnage caused by accidents.

Deliberate and inadvertent spills

Deliberate and inadvertent action is expected to result in a spill of approximately 500 tonnes of oil per year. However, 92 percent of the overall spill tonnage is due to spill events that are smaller than one tonne. Only 1.3 percent of the overall spill is caused by events that are larger than 10 tonnes.

In this way, deliberate and inadvertent spills have almost no importance for the planning and deployment of emergency response capacities. Besides, almost 90 percent most of the spilt oil is volatile and will typically disappear before it can be contained.

Document 5/2

of 14

Figure 3. Risk of spills in the Baltic Sea area: Spills due to collisions on route (red) and in intersections (blue) and due to groundings (yellow).

Document 5/2

of 14

4. REGIONAL AND GLOBAL MODEL PARAMETERS

The following regional and global measures affect the spill risk model:

Section Modelled measures (implemented in 2009 and/or decided for 2020)

2 Error! Reference source not found.

3 4.3 Systematic calls to vessels falling under the pilotage

recommendation

4 4.4 VTS centres

5 Surveillance of potentially hazardous ships

6 4.6 Traffic separation schemes (TSS)

7 4.7 Electronic Chart Display and Information System (ECDIS)

8 4.8 Bridge Navigational Watch Alarm System (BNWAS)

9 4.9 Alcohol limits

10 4.10 Double hull at the cargo tank

11 4.11 Double hull at the bunker

12 4.12 International reporting systems

13 4.13 Ice training for navigators

14 4.14 Escort towing in narrow shipping lanes

15 Emergency towing of damaged ships

16 4.16 Regular emergency response exercises

17 4.17 Icebreaker convoys

4.1 Data

Data from the project partners

The information on measures implemented in 2009 and measures decided for 2020 have primarily been provided from project partners as specified in the project Data Collection Note.

Additional data

In addition, information has been obtained from the literature, from earlier projects performed by COWI.

Lack of data

In cases where no reliable data or no data at all is has been available, it has been necessary to make assumptions based general considerations and engineering judgment.

4.2 Pilotage

The fraction of ships using a pilot depends on the area they are sailing in, the sailing direction, the load state, the ship type and the ship size.

Fraction of affected ships in 2008/2009

The fraction of piloted ships has been modelled in two ways, depending on the sea area:

Document 5/2

of 14

• Areas with recommended pilotage for certain ships: This applies mainly to the open sea (outside the 12 mile zone) as well as to Route T and the Sound. Here, pilotage statistics have been used in order to determine the actual fraction of piloted ships.

• Areas with mandatory pilotage for certain ships: This applies essentially to the territorial waters of the respective HELCOM member countries. In addition, Sweden makes pilotage mandatory for certain Swedish-owned or -chartered tankers sailing in the open sea. In general, it was assumed that ships comply with mandatory pilotage rules.

Information on whether pilotage is recommended or compulsory for a given ship in a given area has been obtained from

• The data collected during the data collection phase

• The Admiralty Sailing Directions, Baltic Pilot Vol. I to III.

Fraction of affected ships in 2020

In the case of Route T and the Sound, estimates about the future compliance with pilotage recommendations were taken from /Oil spill DK, 2007/. In the case of other areas with pilotage recommendation it was assumed that the pilotage will be the same as today.

No information on possible changes with respect to mandatory pilotage has been received during the data collection phase. Hence, these areas are assumed to have the same number of piloted ships in 2020 as today.

4.3 Systematic calls to vessels falling under the pilotage recommendation

In some areas, pilotage is recommended, but not obligatory. Here, authorities have the option of calling every single ship that is potentially affected by the recommendation in order to convince the crew of using a pilot. This effect is modelled as part of the pilotage model (Section Error! Reference source not found.).

4.4 VTS centres

Vessel traffic service (VTS) centres are on-shore traffic surveillance centres enhancing navigational safety in critical areas. Their main interventional tools are warnings and advice to passing vessels.

Locations 2008/2009

There is VTS coverage in the following major areas:

• Great Belt (Denmark)

• The Sound (Denmark and Sweden)

• Gulf of Finland (GOFREP and national coastal VTS areas – Estonia, Finland and Russia)

• Archipelago Sea (Finland)

• Finnish west coast (i.e. the eastern shore of the Gulf of Bothnia)

• Apart from the Sound (together with Demark), Sweden operates nine local VTS centres, typically covering the coastal zones close to the major ports

• Germany operates two VTS centres in the Baltic Sea covering the coastal zones close to its main ports.

• Latvia operates three VTS centres covering the coastal area close to the ports of Riga, Ventspils and Liepaja.

• Poland operates two VTS centres covering the Gdansk Bay and the Pomeranian Bay.

Locations 2020

Document 5/2

of 14

In 2020, the VTS centres are expected to be operational in the following areas in addition to the present coverage:

• Fehmarn Belt (Denmark and Germany)

• Estonian coast to the Gulf of Finland between Paldiski and Sillamäe

4.5 Surveillance of potentially hazardous ships

General

AIS and coast radar can serve as an operational tool for identifying and surveilling potentially hazardous ships. This measure can amongst others apply to

• ships that are violating the MARPOL convention, that have earlier violated it or that are suspected of doing so

• ships that attract or have attracted attention due to unusual navigation and behaviour

• ships that have earlier been involved in accidents

• ships with a large draught

• ships that are carrying oil and hazardous substances

Location

It is assumed that systematic surveillance of potentially hazardous ships can make a difference in areas without VTS coverage or similar systems such as GOFREP. The following countries are operating a surveillance scheme outside their VTS areas:

• Denmark

• Latvia

• Lithuania

4.6 Traffic separation schemes (TSS)

All currently existing traffic separation schemes are included in the analysis. Sea areas that are located between two TSS are equally modelled as TSS, if the traffic pattern observed via AIS resembles the traffic in a TSS.

On 1 January 2010, a new TSS has been introduced in the Sea of Åland. This TSS is not part of the 2008/2009 scenario, but is included in the 2020 scenario.

4.7 Electronic Chart Display and Information System (ECDIS)


In 2008 and 2009, ECDIS was not covered by IMO’s rules yet. As a consequence, it is difficult to estimate the number of ships equipped with ECDIS. It is assumed that 30 percent of those ships that will fall under the future IMO rules on ECDIS (see next paragraph) were equipped with ECDIS in 2008 and 2009. This assumption is based on estimates given by the Danish Maritime Authority with regard to an earlier Danish spill risk analysis /Oil spill DK, 2007/.


In the years between 2012 and 2018, a set of IMO rules concerning ECDIS usage will gradually come into force /IMO, 2009/. By 1 July 2018, ECDIS will be obligatory

• for all passenger ships of 500 GT and upwards

• for all tankers of 3,000 GT and upwards

• for all cargo ships other than tankers of 10,000 GT and upwards

These rules are implemented in the 2020 scenario of the spill risk model.

Document 5/2

of 14

It can be expected that some of the smaller vessels that are not affected by the new IMO rules will be equipped with ECDIS on a voluntary basis. This possibility is disregarded, which is conservative simplification.

4.8 Bridge Navigational Watch Alarm System (BNWAS)

BNWAS is a system that strikes alarm, if no signs of human activity are registered on the bridge of a ship.


In 2008 and 2009, BNWAS was not covered by IMO’s rules yet. As a consequence, it is difficult to estimate the number of ships equipped with BNWAS. It is assumed that 20 percent of those ships that will fall under the future IMO rules on BNWAS (see next paragraph) were equipped with BNWAS in 2008 and 2009. This assumption is based on estimates given by the Danish Maritime Authority with regard to an earlier Danish spill risk analysis /Oil spill DK, 2007/.


In the years between 2011 and 2014, a set of IMO rules concerning BNWAS usage will gradually come into force /IMO, 2009/. By 1 July 2014, BNWAS will be obligatory

• for all passenger ships irrespective of size

• for all cargo ships of 150 GT and upwards

Considering that the model only regards ships of 300 GT and upwards this means that all ships within the scope of the analysis will be affected by the new IMO rules.

The rules are implemented in the 2020 scenario of the spill risk model.

4.9 Alcohol limits

Situation in 2008/ 2009

There are national alcohol limits for bridge personnel in the territorial waters of Denmark, Estonia, Germany, Latvia, Poland and Sweden, typically with limit values of 0.5 or 0.8 per mille. The alcohol ban status for the other three Baltic Sea countries is unknown, but it is assumed that the situation is similar there. There are no international regulations in power.

Expected situation in 2020

The Conference of Parties to the International Convention on Standards of Training, Certification and Watchkeeping for Seafarers has very recently decided to limit the blood alcohol content of bridge personnel to 0.5 per mille. The new regulation will enter into force in 2012 /SCTW, 2010/.

4.10 Double hull at the cargo tank

A double hull at the cargo tank reduces the risk of spill in case of grounding or collision.


During 2008/2009, only a very small number of medium-sized and large oil tankers in the Baltic Sea area were single hulled. In the case of smaller tankers below 5000 deadweight tonnes, the situation was less clear. Although only around 3 percent of all smaller tankers are known to have been single-hulled, there is uncertainty about the hull status of around 23 % of the ships (see Table 1).

In the spill risk model, it is assumed that all tankers with unknown hull status are single-hulled.

Document 5/2

of 14

Table 1 Oil and chemical tankers present in the Baltic Sea area, 2008/2009

Tanker size (DWT)

Hull type Number Percent

Double 1372 99.4 %

≥ 5000 tonnes Single 5 0.4 %

Unknown 3 0.2 %

Double 179 74.0 %

< 5000 tonnes Single 7 2.9 %

Unknown 56 23.1 %


According to the revised regulation 13G (regulation 20 in the revised Annex I which entered into force on 1 January 2007) of Annex I of MARPOL /IMO, 1987/, single-hull tankers of 5000 DWT and upwards are to be phased out between 2005 and 2010, all depending on their delivery date. Thus, no medium-sized and large single-hulled tankers will be in duty by 2020.

It is assumed that 20 % of all small tankers (<5,000 DWT) will be single hulled in 2020, as opposed to 26 % of all small tankers today (including tankers with unknown hull status, compare Table 1).

4.11 Double hull at the bunker


Regulation 12A, which is an amendment to Annex I of MARPOL /IMO, 1987/ requires that all vessels with a bunker tank volume of 600 m3 or more must be double-hulled at the bunker compartments

• if the building contract was placed on or after 1 August 2007

• or if the keel was laid on or after 1 February 2008

• or if the vessel was delivered on or after 1 August 2010

Danish Maritime Administration estimated the fraction of ships to be double-hulled at the bunker to be 10 percent by 2010 /Oil spill DK, 2007/. This number is also used for the 2008/2009 scenario.


Danish Maritime Administration estimated the fraction of ships to be double-hulled at the bunker to be 50 percent by 2020 /Oil spill DK, 2007/

4.12 International reporting systems

International reporting systems make it easier to plan and enforce port state controls. In this way, it becomes easier to enforce compliance with safety-relevant regulations.

This section applies essentially to SafeSeaNet. Other reporting systems, especially those related to VTS centres (BELTREP, SOUNDREP, GOFREP etc.) are not modelled here, but in Section 0.


Although SafeSeaNet already exists, it is not fully implemented yet as a means of enforcing compliance with safety rules. Therefore, the fraction of affected ships is modelled as zero percent for 2008/2009.

Document 5/2

of 14


On 1 January 2011, a new inspection regime based on SafeSeaNet comes into force for all ships entering or leaving ports or anchorages in the Paris MoU region (Paris Memorandum of Understanding on Port State Control) /Paris MoU, 2010/. All HELCOM member states are also members of the Paris MoU. The new inspection regime is a means of enforcing compliance with safety rules.

4.13 Ice training for navigators

The project partners have agreed to include ice training for navigators as a model parameter in the analysis. However, none of the countries has been able to provide data or even estimates on the fraction of ships sailing with specifically trained navigators. One of the reasons, why data are so difficult to get is that ice training is that the Conference of Parties to the International Convention on Standards of Training, Certification and Watchkeeping for Seafarers (STCW) does not have any requirements for inspecting ship crew certificates. Therefore, it is chosen not to model ice training at present.

Ice training can be included in the analysis at a later point, if data or estimates become available.

4.14 Escort towing in narrow shipping lanes

During escort towing, a tug boat is permanently connected to a tanker on its journey between the open sea and the port. Escort towing is especially relevant in very narrow shipping lanes.


Escort towing is presently common, recommended or obligatory in the following HELCOM countries:

• Finland: Escort towing is neither officially recommended nor obligatory, but is part of the policy of the largest Finnish oil company as far as loaded tankers are concerned /Neste Oil, 2006/. It is also known that there are too few tugs for servicing all tankers approaching or leaving the Finnish coast /VTT, 2002/. On this basis, it is conservatively estimated that 20 % of all tankers of 20,000 DWT and upwards are using escort towing between the Finnish coast and the open sea.

• Poland: Escort towing is obligatory at all ports and roadsteads, if certain wind conditions are present. In practice, this means that 10 % of all ships falling under the MARPOL Convention are using escort towing. Since these operations mainly occur inside ports, they are not part of the project scope.

• Sweden: The authorities have issued a number of recommendations about the usage of escort towing. The recommendations apply

- in the Brofjorden: To all loaded and unloaded oil tankers (loaded/unloaded) of 20,000 DWT and upwards

- in the Stenungsund: To all loaded and unloaded oil and gas tankers (loaded/unloaded) of 20,000 DWT and upwards as well as all ammonia tankers

- in Göteborg: To all loaded and unloaded oil tankers (loaded/unloaded) of 30,000 DWT and upwards

Since there are no statistics on the usage of escort towing, it is assumed that 50 % of all affected ships comply with the recommendations.


In Sweden, it is being considered to make escort towing mandatory in some areas in the future.

Document 5/2

of 14

At present, the situation in 2020 is modelled in the same way as that in 2008/2009. However, it is possible to consider other scenarios in the model, too.

4.15 Emergency towing of damaged ships

Emergency towing is an effective means of reducing the risk of spills. Leaking ships can be

towed into a port before all the potential spill volume has been leaked. Unmanoeuvrable

and/or damaged ships can be towed away before they start leaking, e.g. due to wave action

or grounding.


At present, there are no dedicated emergency towing capacities in the Baltic Sea.


By 2020, several dedicated emergency towing vessels will be in operation.

4.16 Regular emergency response exercises

Regular emergency response exercises with different types of vessels can be implemented as part of the emergency response model.

4.17 Icebreaker convoys

Icebreaker convoys involve a number of ships sailing after each other at a close distance. This involves a heightened risk for collisions between the ships of one convoy.


Icebreaker usage is very common in most Baltic Sea countries stretching north of the 59° parallel (Estonia, Finland, Russia and Sweden). However, actual ice-breaker convoys consisting of 10-20 ships are only common for ships bound to and from Russian ports in the Gulf of Finland (GoF). In practice, this means that such convoys can mainly be expected in the Eastern GoF (Russian EEZ) and on the main sailing route running on the Finnish-Estonian EEZ boarder in the Western GoF.

It is difficult to estimate the number of affected ships, since no statistics are available. It is assumed that all vessels bound to and from Russian ports that do not have ice-breaking capabilities of their own (like some oil tankers that act as icebreakers in reverse mode) are making use of icebreaker service. Some of them are sailing as single ships behind an icebreaker, while other are sailing in larger convoys. It is estimated that 75 % of all ship movements in the Eastern GoF occur within larger convoys under ice conditions. As far as the main sailing route in the middle of the Western GoF is concerned, the number is estimated to 25 %.

Fraction of affected ships 2020

There is no information about future plans available. Therefore the same assumptions as for 2008/2009 are used.

Document 5/2

of 14

5 REFERENCES

/IMO, 1987/ International Maritime Organization IMO), Annex I, Regulations for the Prevention of Pollution by Oil, to International Convention for the Prevention of Pollution from Ships, 1973, as modified by the Protocol of 1978 relating hereto (MARPOL 73/78)

/IMO, 2009/ International Maritime Organization, Report of the Maritime Safety Committee on it eighty-sixth session. MSC 86/26/Add. 1, 25 June 2009

/Oil spill DK, 2007/ Risikoanalyse: Olie- og kemikalieforurening i danske farvande (Risk analysis: Oil and chemicals pollution in Danish waters), prepared for Danish Ministry of Defence by COWI, COWI report 63743-1-01, October 2007

/Paris MoU, 2010/ Paris Memorandum of Understanding on Port State Control, adopted on 11 May 2010, http://www.parismou.org/upload/pdf/amended%20MoU%20clean%20accepted%201%20November%202010.pdf

/SCTW, 2010/ Conference of Parties to the International Convention on Standards of Training, Certification and Watchkeeping for Seafarers, 1978, Manila, the Philippines, 21-25 June 2010. Information obtained from IMO's website (http://www.imo.org/MediaCentre/PressBriefings/Pages/STCW-revised-adopted.aspx) and DMA's website (http://www.sofartsstyrelsen.dk/Nyheder/Sider/Nyeinternationalereglerstrammeroppåalkohologhviletidtilsøs.aspx), both viewed on 17 December 2010

/VTT, 2002/ VTT, The implementation of the VTMIS system for the Gulf of Finland, prepared for the Finnish Ministry of Transport and Communications and Finnish Maritime Administration, VTT research report NO VAL34-013153, 2002, http://www.vtt.fi/files/projects/bassy/goffsa.pdf

http://www.parismou.org/upload/pdf/amended%20MoU%20clean%20accepted%201%20November%202010.pdf

http://www.parismou.org/upload/pdf/amended%20MoU%20clean%20accepted%201%20November%202010.pdf

http://www.imo.org/MediaCentre/PressBriefings/Pages/STCW-revised-adopted.aspx

http://www.sofartsstyrelsen.dk/Nyheder/Sider/Nyeinternationalereglerstrammeroppåalkohologhviletidtilsøs.aspx

http://www.sofartsstyrelsen.dk/Nyheder/Sider/Nyeinternationalereglerstrammeroppåalkohologhviletidtilsøs.aspx

http://www.vtt.fi/files/projects/bassy/goffsa.pdf

helsinki commission meeting of experts on maritime safety ... documents/safe nav 1-2011_5-2... ·...

Documents