ANNEX II FSA STEP 2: RISK ASSESSMENT II.1 …research.dnv.com/skj/FsaLsaBc/ANNEX-II.pdfANNEX II: FSA/LSA/BC: RISK ASSESSMENT ... 9 19940313 SHIPBROKER 1980 Collision ... 27 19930810

ANNEX II: FSA/LSA/BC: RISK ASSESSMENT

16/02/2001 Annex II, page 1

ANNEX IIFSA STEP 2: RISK ASSESSMENT

II.1 INTRODUCTION

In this annex the model of fatality risks in evacuations from bulk carriers is presented. The level of detail inthe risk model enables evaluation of different Risk Control Options (RCOs) associated with emergencyevacuations.

II.2 EVACUATION EXPERIENCE

II.2.1 DATA SOURCES

The definition of bulk carrier utilised in this assessment consists of bulk carriers (including all bulk dry) andore carriers. The analysis is based on LMIS (Lloyd's Maritime Information Services) incident data for 1991 -98, with supplementary information from LCRs (Lloyd's Casualty Reports).

None of the fields in the LMIS database identify whether or not an evacuation has taken place and, to ourknowledge, no other comprehensive list of evacuation is available. Therefore, cases in which evacuation hasor should have taken place is identified as follows:• Any incidents where the LMIS complementary text mentions "crew rescued/abandoned ship"• Incidents where the LMIS complementary text mentions "crew missing/dead" and evacuation confirmed

by LCR.• Incidents where the LMIS severity is categorised as total lossI and evacuation confirmed by LCR.• Incidents where the LMIS basic retrieval group is founderedII and evacuation is confirmed by LCR.• All total loss and foundering events in which it seems that the entire crew is either reported as killed or

missing.

This procedure may result in some events being omitted for cases in which reporting is incomplete; however,the procedure appears to be reasonably comprehensive.

I Total loss refers to a ship which has ceased to exist, either by virtue of the fact that the ship was irrecoverable or wasbroken up as a consequence of that casualty.II Foundered includes ships which sank as a result of heavy weather, springing leak, breaking in two, etc.



II.2.2 BULK CARRIER EVACUATIONS

Table 1 gives the full list of bulk carrier evacuations identified during 1991-98, in total 117 events. The tableincludes ship name and built year, the date and type of event, as well as whether the ship was declared a totalloss.

Table 1 Bulk Carrier Evacuations 1991-98Event No. DATE SHIPNAME BUILT YEAR EVENT TYPE TOTAL LOSS

1 19910210 C. EREGLI 1974 Collision X2 19910717 NISSHIN MARU 1974 Collision X3 19910720 AIKO MARU 1990 Collision X4 19910927 OSHIMA MARU 1972 Collision X5 19920605 JEH HUN 1971 Collision X6 19930223 RYONAN MARU 1972 Collision X7 19930707 TEAM STAR 1974 Collision X8 19930826 NISSEI MARU 1974 Collision X9 19940313 SHIPBROKER 1980 Collision

10 19940525 WEI HAI 1964 Collision X11 19950526 TAMAYOSHI MARU No. 12 1989 Collision X12 19950622 MINERAL DAMPIER 1986 Collision X13 19960615 ANNA SPIRATOU 1978 Collision X14 19970926 ICL VIKRAMAN 1979 Collision X15 19980113 ALTNES 1978 Collision X16 19910227 FAIRWIND 1967 Contact X17 19911122 HANJIN KARACHI 1973 Contact X18 19920219 VIHREN 1981 Contact X19 19950104 PARIS 1972 Contact X20 19950104 YOU XIU 1992 Contact X21 19910106 DEMETRA BEAUTY 1974 Fire/explosion X22 19910605 FREE POWER 1968 Fire/explosion X23 19910721 SWAN POINT 1973 Fire/explosion24 19910823 JAY BOLA 1970 Fire/explosion X25 19930417 ATLAS 1977 Fire/explosion X26 19930513 SAMICK NORDIC 1975 Fire/explosion X27 19930810 SKS HORIZON 1992 Fire/explosion28 19940225 AEGEAN TRADER 1970 Fire/explosion X29 19940701 FORUM CHEMIST 1981 Fire/explosion30 19941120 POLYDOROS 1974 Fire/explosion X31 19950403 MILENAKI 1970 Fire/explosion32 19961017 AG. APOSTOLOS 1973 Fire/explosion X33 19970807 MING MERCY 1984 Fire/explosion34 19970817 GOODEAST 1975 Fire/explosion35 19980803 SEA DREAM 1974 Fire/explosion X36 19981230 KAAN 1965 Fire/explosion37 19910111 PROTEKTOR 1967 Foundered X38 19910121 CONTINENTAL LOTUS 1967 Foundered X39 19910209 SALVIA 1970 Foundered X40 19910404 VASSO 1967 Foundered X41 19910707 MANILA TRANSPORTER 1976 Foundered X42 19910730 SUNSET 1970 Foundered X43 19910818 PETCHOMPHOO 1969 Foundered X44 19910824 MELETE 1975 Foundered X



45 19911021 ERATO 1968 Foundered X46 19911113 SONATA 1969 Foundered X47 19911127 ENTRUST FAITH 1973 Foundered X48 19920330 KARADENIZ S 1969 Foundered X49 19920530 GREAT EAGLE 1968 Foundered X50 19920613 YUKATU 1970 Foundered X51 19920910 KINSEI MARU No. 5 1986 Foundered X52 19921022 DAEYANG HONEY 1970 Foundered X53 19921223 NAKAFUKU MARU 1969 Foundered X54 19930106 COTY I 1962 Foundered X55 19930305 GEORGIOS XII 1977 Foundered56 19930315 GOLD BOND CONVEYOR 1974 Foundered X57 19930526 NAGOS 1969 Foundered X58 19930917 ANDERSON 1975 Foundered X59 19940101 MARIKA 1973 Foundered X60 19940203 CHRISTINAKI 1973 Foundered X61 19940225 KAMARI 1973 Foundered X62 19940305 LEADER FORTUNE 1977 Foundered X63 19940528 JAG SHANTI 1972 Foundered X64 19940620 APOLLO SEA 1973 Foundered X65 19940903 IRON ANTONIS 1968 Foundered X66 19941115 GOLDEN CHARIOT 1972 Foundered X67 19950624 NIVIA 1968 Foundered X68 19951101 EBISU MARU No. 15 1971 Foundered X69 19951101 SUMISE MARU No. 35 1980 Foundered X70 19951222 MEMED ABASHIDZE 1978 Foundered X71 19960209 INNOVATOR 1973 Foundered X72 19960217 SEAFAITH 1973 Foundered X73 19960322 SUPER ORIENT 1974 Foundered X74 19960628 WILLIAM SHAKESPEARE 1978 Foundered X75 19960816 AL HADI 1968 Foundered X76 19960914 IOLCOS VICTORY 1980 Foundered X77 19961228 DYSTOS 1972 Foundered X78 19970208 LEROS STRENGTH 1976 Foundered X79 19970218 ALBION TWO 1976 Foundered X80 19980116 FLARE 1972 Foundered X81 19980207 FEI CUI HAI 1973 Foundered X82 19980410 CHIAN MARINER 1974 Foundered X83 19980608 GOLDEN HARVEST 1975 Foundered X84 19980721 OSOOL 1974 Foundered X85 19980802 ASEAN CARRIER 1969 Foundered X86 19980826 SEA PROSPECT 1996 Foundered X87 19981118 MIYAHATA 1976 Foundered X88 19931226 ALPHA STAR 1972 Hull/machinery X89 19940606 SHIN-KAKOGAWA MARU 1981 Hull/machinery90 19951201 MOUNT OLYMPUS 1978 Hull/machinery91 19960110 AMPHION 1978 Hull/machinery92 19960720 IMAN 1972 Hull/machinery X93 19980928 GRIGOROUSSA 1972 Hull/machinery X94 19910417 MINERAL DIAMOND 1982 Missing X95 19910213 SANKO HARVEST 1985 Wrecked/stranded X96 19910228 ANJA 1972 Wrecked/stranded X



97 19911206 MARMARA S 1970 Wrecked/stranded X98 19920111 ARISAN 1974 Wrecked/stranded X99 19920523 DIMI 1970 Wrecked/stranded X100 19920606 FLYING FALCON 1970 Wrecked/stranded X101 19920616 HAR RAI 1977 Wrecked/stranded X102 19920717 AL MUJEEB 1985 Wrecked/stranded103 19920721 TANTA 1972 Wrecked/stranded X104 19921203 AEGEAN SEA 1973 Wrecked/stranded X105 19931016 RONJAY TIHI 1970 Wrecked/stranded X106 19940605 SEA TRANSPORTER 1973 Wrecked/stranded X107 19940805 WELLBORN 1971 Wrecked/stranded X108 19941025 OCEAN LUCKY 1971 Wrecked/stranded X109 19950111 SEAPRINCE 1965 Wrecked/stranded X110 19950710 IRON BARON 1985 Wrecked/stranded X111 19960118 PLOUGASNOU 1939 Wrecked/stranded x112 19960620 MILLION HOPE 1972 Wrecked/stranded X113 19961102 NING HAI 1981 Wrecked/stranded X114 19961129 FU KUO HSIN No. 2 1975 Wrecked/stranded X115 19970802 GOLDEN TIGER 1982 Wrecked/stranded X116 19970924 CORRIENTE 1989 Wrecked/stranded X117 19980410 SIR MICHAEL 1973 Wrecked/stranded X

Table 2, on the next page, includes the type of accidental event, number of persons on board the ship,number of fatalities, whether or not the environmental conditions were unfavourable, as well as a summaryof the description of the evacuation as presented in the LCRs. Particularly, the term "possibly no time fororderly evacuation", which really means that the situation is misjudged, is an interpretation in cases forwhich it seems as no evacuation has taken place when a correct evaluation of the situation would haveresulted in an evacuation.

The types of accidental events are categorised according to the following definitions, based on LMIS:• Collision: Striking or being struck by another ship, regardless of whether under way, anchored or

moored.• Contact: Striking or being struck by an external object, excluding other ships or the sea bottom. (The

category includes striking drilling rigs/platforms, regardless of whether in fixed position or in tow.)• Fire/Explosion: Includes events involving fire and/or explosion.• Foundered: Includes ships, which sank as a result of heavy weather, springing leak, breaking in two,

etc.• Hull/Machinery: Includes ships lost or damaged as a result of hull or machinery damage or failure.• Missing: Includes vessels for which no news has been received after a reasonable period of time.• Wrecked/Stranded: Includes grounding, stranding and entanglement on underwater wrecks.

For the event type Hull/Machinery, the cases have been split into subgroups of Hull and MachineryIII. Thereis one event of the Missing category; however, this event is included in the Foundered events in the analysis,as this is the most likely explanation for the vessel missing. The number of fatalities includes fatalitiesoccurring in the incident requiring evacuation, as well as those in the evacuation itself, as these areimpossible to separate in many cases.

As seen from the descriptions, there are only 46 cases for which the exact method of evacuation is known.These cases are summarised in Table 3.

III This is based on the component group, i.e. EV1C, with which the events are categorised



Table 2 Selected Bulk Carrier Evacuations 1991-98No. DATE SHIPNAME EVENT NO. ON

BOARDFATALITIES DESCRIPTION

1 19910210 C. EREGLI Collision 26 1 Rescued by vessel2 19910717 NISSHIN MARU Collision 5 Rescued by vessel3 19910720 AIKO MARU Collision 14 Rescued by vessel4 19920605 JEH HUN Collision 18 Rescued by vessel5 19930223 RYONAN MARU Collision 13 5 Method of evacuation not mentioned6 19930707 TEAM STAR Collision 13 Rescued by vessel7 19930826 NISSEI MARU Collision 10 Rescued by vessel8 19940313 SHIPBROKER Collision 29 25 Possibly no time for orderly evacuation?9 19940525 WEI HAI Collision 37 Rescued10 19950526 TAMAYOSHI MARU No. 12 Collision 3 Rescued by vessel11 19950622 MINERAL DAMPIER Collision 27 27 Possibly no time for orderly evacuation?12 19960615 ANNA SPIRATOU Collision 26 26 Probably used lifeboats.13 19970926 ICL VIKRAMAN Collision 34 29 No time for orderly evacuation. Vessel sank within a minute as it was cut in two in the collision.14 19980113 ALTNES Collision 17 Evacuated using lifeboat and liferaft, picked up by vessel

1 19910227 FAIRWIND Contact 24 Rescued by vessel2 19911122 HANJIN KARACHI Contact 22 Rescued by vessel3 19920219 VIHREN Contact Taken off by helicopter4 19950104 PARIS Contact 27 27 Possibly no time for orderly evacuation?5 19950104 YOU XIU Contact 27 27 Possibly no time for orderly evacuation?

1 19910106 DEMETRA BEAUTY Fire/explosion 23 Lifted off by coast guard vessel2 19910605 FREE POWER Fire/explosion 24 1 Rescued by vessel3 19910721 SWAN POINT Fire/explosion 1 Rescued by vessel (1 crew member reported as missing)4 19910823 JAY BOLA Fire/explosion Abandoned using lifeboats and liferaft, rescued by vessel5 19930417 ATLAS Fire/explosion 21 Abandoned ship and rescued by vessel6 19930513 SAMICK NORDIC Fire/explosion Abandoned ship7 19930810 SKS HORIZON Fire/explosion 1 Transferred to other vessel (1 crew member reported as missing)8 19940225 AEGEAN TRADER Fire/explosion Taken off by vessel9 19940701 FORUM CHEMIST Fire/explosion 27 Abandoned ship using lifeboats, rescued by vessel10 19941120 POLYDOROS Fire/explosion 29 1 25 lifted off by helicopter, 4 evacuated by lifeboat. (1 died in helicopter, probably because of burns)11 19950403 MILENAKI Fire/explosion 21 1 Evacuated using lifeboat and liferaft, rescued by vessel (1 killed in fire incident)12 19961017 AG. APOSTOLOS Fire/explosion Rescued by vessel13 19970807 MING MERCY Fire/explosion Removal of crew (1 person airlifted to hospital with minor injuries. Assume rest of crew transferred to

other vessel)



14 19970817 GOODEAST Fire/explosion 24 13 picked up by helicopter, 11 abandoned later and picked up by passing vessel.15 19980803 SEA DREAM Fire/explosion 24 Transferred to other vessel16 19981230 KAAN Fire/explosion 1 Helicopter and lifeboats used to transfer crew to safety. (6 injured, 1 of them died due to burns from fire.)

1 19910111 PROTEKTOR Foundered 33 33 Evacuated using lifeboat2 19910121 CONTINENTAL LOTUS Foundered 42 38 Rescued by vessel3 19910209 SALVIA Foundered 28 Evacuated using lifeboats and liferaft, rescued by vessel4 19910404 VASSO Foundered 27 Crew abandoned ship using 2 lifeboats, taken on board 2 passing vessels.5 19910707 MANILA TRANSPORTER Foundered 24 Evacuated using lifeboats and liferafts, rescued by vessel6 19910730 SUNSET Foundered 24 Evacuated using lifeboat and liferafts, rescued by vessel7 19910818 PETCHOMPHOO Foundered 24 24 Possibly no time for orderly evacuation?8 19910824 MELETE Foundered 27 25 Sank within 10 min, preventing lifeboat use. Survivors rescued by vessel.9 19911021 ERATO Foundered 25 6 Survivors jumped into sea, rescued by vessels10 19911113 SONATA Foundered 24 Taken off by helicopter11 19911127 ENTRUST FAITH Foundered Abandoned ship12 19920330 KARADENIZ S Foundered Abandoned ship, rescued by vessel13 19920530 GREAT EAGLE Foundered 19 Evacuated using lifeboats and liferaft, rescued by vessel14 19920613 YUKATU Foundered Possibly no time for orderly evacuation?15 19920910 KINSEI MARU No. 5 Foundered 4 3 Method of evacuation not mentioned16 19921022 DAEYANG HONEY Foundered 28 28 Possibly no time for orderly evacuation?17 19921223 NAKAFUKU MARU Foundered 4 2 Fell into sea, rescued by vessel18 19930106 COTY I Foundered 17 17 Abandoned ship19 19930305 GEORGIOS XII Foundered 10 7 taken off by helicopter, while 3 remained on board while being towed20 19930315 GOLD BOND CONVEYOR Foundered 33 33 Abandoned ship21 19930526 NAGOS Foundered 33 17 Taken off by helicopter22 19930917 ANDERSON Foundered 25 24 Evacuated using lifeboat, spent hours in raging swells, rescued by vessel.23 19940101 MARIKA Foundered 36 36 Deficient liferafts, buoys lifejackets when inspected, but said to have been fixed. Jumped into sea (lights

in the water)24 19940203 CHRISTINAKI Foundered 27 27 Evacuated using lifeboats and liferaft25 19940225 KAMARI Foundered Abandoned ship/Crew brought ashore26 19940305 LEADER FORTUNE Foundered 15 14 Method of evacuation not mentioned27 19940528 JAG SHANTI Foundered 45 Abandoned ship, crew picked up by vessel.28 19940620 APOLLO SEA Foundered 36 36 Possibly use of lifeboats?29 19940903 IRON ANTONIS Foundered 24 24 Evacuation by lifeboats and liferaft30 19941115 GOLDEN CHARIOT Foundered 25 Evacuation by liferafts, rescued by vessel31 19950624 NIVIA Foundered 6 Rescued by helicopter and vessel32 19951101 EBISU MARU No. 15 Foundered Unknown Possibly no time for evacuation?



33 19951101 SUMISE MARU No. 35 Foundered Unknown Possibly no time for evacuation?34 19951222 MEMED ABASHIDZE Foundered 31 3 Evacuation by lifeboat and liferaft, rescued by vessel35 19960209 INNOVATOR Foundered 24 Rescued36 19960217 SEAFAITH Foundered 30 19 Rescued by vessel37 19960322 SUPER ORIENT Foundered 8 5 Rescued by vessel38 19960628 WILLIAM SHAKESPEARE Foundered 17 Abandoned ship39 19960816 AL HADI Foundered 23 Rescued40 19960914 IOLCOS VICTORY Foundered 25 5 Evacuated using lifeboats and liferaft, rescued by helicopter and vessel41 19961228 DYSTOS Foundered 21 20 1 jumped into sea, rescued. Others: No time for orderly evacuation.42 19970208 LEROS STRENGTH Foundered 20 20 Sank while master was calling rescue service, no time for evacuation.43 19970218 ALBION TWO Foundered 25 25 Possibly no time for orderly evacuation?44 19980116 FLARE Foundered 25 21 Ship snapped in two. Evacuation by lifeboats and liferaft. Possibly rusted lifeboat davits, making lowering

difficult. Rescued by helicopter.45 19980207 FEI CUI HAI Foundered 34 30 Jumped into sea with lifejackets, rescued by vessels46 19980410 CHIAN MARINER Foundered 25 Abandoned, rescued by vessel47 19980608 GOLDEN HARVEST Foundered 24 24 Possibly no time for orderly evacuation?48 19980721 OSOOL Foundered 20 Evacuation by lifeboat and liferaft, rescued by vessel49 19980802 ASEAN CARRIER Foundered 22 Evacuation by liferafts, rescued by vessel50 19980826 SEA PROSPECT Foundered 21 10 Evacuation by liferaft, rescued by vessel51 19981118 MIYAHATA Foundered 17 10 Rescued by vessel

1 19931226 ALPHA STAR Hull 42 Taken off by helicopter2 19940606 SHIN-KAKOGAWA MARU Hull 27 Lifted off by helicopter3 19951201 MOUNT OLYMPUS Hull 30 Transferred to other vessel4 19960110 AMPHION Hull 24 Small rigid-hull inflatable rescue boat tied alongside Amphion to take crew off (5 at the time) and transfer

to vessel5 19960720 IMAN Hull Abandoned ship, rescued by vessel6 19980928 GRIGOROUSSA Machinery 16 Rescued by vessel

1 19910417 MINERAL DIAMOND Missing 27 27 Possibly no time for orderly evacuation?

1 19910213 SANKO HARVEST Wrecked/stranded 20 Brought ashore2 19910228 ANJA Wrecked/stranded 16 Lifted off by helicopter3 19911206 MARMARA S Wrecked/stranded 33 While laid-up. Crew abandoned ship, rescued by vessel4 19920111 ARISAN Wrecked/stranded 23 Taken off by helicopter5 19920523 DIMI Wrecked/stranded Abandoned ship6 19920606 FLYING FALCON Wrecked/stranded Taken off by vessel7 19920616 HAR RAI Wrecked/stranded All crewmembers probably safe, but little info8 19920717 AL MUJEEB Wrecked/stranded Rescued by marine police9 19920721 TANTA Wrecked/stranded Picked up by vessel



10 19921203 AEGEAN SEA Wrecked/stranded 29 Taken off by helicopter11 19931016 RONJAY TIHI Wrecked/stranded 23 Brought ashore12 19940605 SEA TRANSPORTER Wrecked/stranded 31 Evacuated, rescued by helicopter13 19940805 WELLBORN Wrecked/stranded Taken off14 19941025 OCEAN LUCKY Wrecked/stranded 25 9 lifted off by helicopter, 16 who had fallen into sea were rescued by 3 fishing vessels15 19950111 SEAPRINCE Wrecked/stranded 17 Rescued16 19950710 IRON BARON Wrecked/stranded 18 Evacuated17 19960118 PLOUGASNOU Wrecked/stranded Crew rescued18 19960620 MILLION HOPE Wrecked/stranded 25 Crew first refused to abandoned ship before understood that sank. Transferred to other vessel.19 19961102 NING HAI Wrecked/stranded Picked up by vessel20 19961129 FU KUO HSIN No. 2 Wrecked/stranded Crew rescued21 19970802 GOLDEN TIGER Wrecked/stranded 17 Brought ashore22 19970924 CORRIENTE Wrecked/stranded Method of evacuation not mentioned23 19980410 SIR MICHAEL Wrecked/stranded Abandoned


16/02/2001 Annex II,page

9

Table 3 Effect of Evacuation Method in Bulk Carrier Evacuations, 1991-98EVACUATION METHOD NO. OF

EVENTSFATALITIES NUMBER

EVACUATEDPROB. OFFATALITY

TRANSFERRED TO HELICOPTER 8 17 219 0.078TRANSFERRED TO VESSEL 8 1 201 0.005LIFEBOAT ONLY 4 57 112 0.509 Lifeboat - Then picked up by helicopter 0 Lifeboat - Then picked up by vessel 3 24 79 0.304 Lifeboat - Unknown whether picked up by helicopter or vessel 1 33 33 1.000LIFERAFT ONLY 3 10 68 0.147 Liferaft - Then picked up by helicopter 0 - - - Liferaft - Then picked up by vessel 3 10 68 0.147UTILISING BOTH LIFEBOAT AND LIFERAFT 13 81 310 0.261 Lifeboat and liferaft - Then picked up by helicopter 1 21 25 0.840 Lifeboat and liferaft - Then picked up by vessel 9 4 209 0.019 Lifeboat and liferaft - Then picked up by helicopter and vessel 1 5 25 0.200 Lifeboat and liferaft - Unknown whether picked up by helicopter or vessel 2 51 51 1.000DIRECT TO SEA 6 99 127 0.780 Direct to sea - Then picked up by helicopter 0 - - - Direct to sea - Then picked up by vessel 4 63 90 0.700 Direct to sea - Unknown whether picked up by helicopter or vessel 2 36 37 0.973TRANSFERRED TO HELICOPTER and EVACUATION BY SURVIVAL CRAFT 3 1 78 0.013TRANSFERRED TO HELICOPTER and JUMPING/Then picked up by vessel 1 0 25 0.000

TOTAL 46 266 1140 0.233

II.2.3 EVACUATION FREQUENCIES

Table 1 and Table 2 list 117 evacuations of bulk carriers during 1991-98. The population exposure duringthis time is estimated as 44,732 ship years (Lloyd's Register's World Fleet Statistics). This gives a totalevacuation frequency of 2.6⋅10-3 per ship year.

The evacuation frequency above may include cases where non-essential personnel were evacuated, whileothers remained on board. These events are precautionary evacuations, as the evacuation ultimately provedunnecessary, contrasted with emergency evacuations where all personnel had to leave the ship. Based on thedescriptions in Table 2, one of the foundering events was clearly a precautionary evacuation, i.e.approximately 1%. In Spouge(2000), presenting an evacuation analysis for oil tankers, it was found thatprecautionary evacuations represented 8% of the incidents. However, as it is likely that precautionaryevacuation is performed more frequently for oil tankers (due to the increased risk related to fire/explosion), avalue of 1% is utilised for bulk carriers.

For comparison, the frequency of evacuation from merchant ships in general has previously been estimatedas 2.6⋅10-3 per ship year (COMSAR 3/2).

Distributed with respect to type of accidental event, the resulting evacuation frequencies are listed in Table4. The number of crewmembers onboard is obtained by multiplying the number of events with the averagecrew size, i.e. 23.7, based on events for which crew size is identified.

As seen from Table 4, the accidental event of foundering is clearly the event that most often is the cause ofevacuation.



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Table 4 Evacuation frequencies for different types of events 1991-98Type of Event No. of

EventsEvacuationFrequency

[per ship year]

Fatalities No. onboard

Probability offatality [%]

Collision 14 3.1⋅10-4 116 332 35Contact 5 1.1⋅10-4 54 119 45Fire/Explosion 16 3.6⋅10-4 6 379 2Foundered 51 1.1⋅10-3 618 1209 51Hull failure 5 1.1⋅10-4 0 119 0Machinery failure 1 2.2⋅10-5 0 24 0Wrecked/Stranded 23 5.1⋅10-4 0 545 0

II.2.4 EFFECT OF WEATHER

The type of weather will influence the probability of a successful evacuation. The weather categoriesadopted are presented in Table 5.

Table 5 Weather CategoriesWeather category Beaufort Force Wind-speed [m/s]Calm 0 - 3 0 - 5.4Moderate 4 – 7 5.4 - 17.3Severe > 8 > 17.3

In Figure 1, the locations of lost bulk carriers due to structural failure are indicated, for cases that wasreported in the period from 1980 to 1996 (Eknes et al, 1996). In 38 out of 43 events in which total lossoccurred, heavy weather was reported. However, for the remaining events, the type of weather was notreported, i.e. unknown. In Figure 2, areas with extreme significant wave heights of more than 14 and 15 mare shown (Bitner-Gregersen et al, 1995). It appears that the majority of the losses due to foundering haveoccurred in the areas where the trade routes cross areas with extreme significant wave heights.

Based on these figures, it is assessed that foundering always occur in severe weather. Regarding the othertypes of accidental events, these are assessed to be fairly independent of weather. Worldwide weatherprobabilities utilised in the model are presented in Table 6.

Table 6 World-Wide Weather ProbabilitiesWeather category Approximate

Significant Wave HeightProbability

(World-wide statistics)Calm 0-0.85 meter 0.086Moderate 0.85-6.75 meter 0.899Severe >6.75 meter 0.015Total 1.000



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80

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430

500

620

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770

790

890

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920

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1010

1020

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1060

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1130

1180

1190

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1250

1280

1330

1370

1420

14301450

1460 15001510

1530

1550

1570

Figure 1 Locations of Bulk Carriers Lost

larger than 15 msignificant wave heightlarger than 14 msignificant wave height

(20-years extreme)

Figure 2 Zones with 20-Year Extreme Significant Wave Height Larger than 14 and 15 m



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II.3 EVACUATION MODEL

II.3.1 APPROACH

In order to model the evacuation process, the following preference of the crew is assumed:1. Gangway to shore2. Direct transfer to other vessel3. Helicopter4. Lifeboat5. Liferaft6. Direct to sea

In general, the most preferred option will be used assuming that it is available, has sufficient capacity andcan be used in the time available. Regarding gangway to shore, this is not considered relevant in bulk carrierevacuation.

The evacuation model is illustrated by a number of generic event trees, which are independent of type ofaccident, e.g. foundering, fire/explosion, etc. The event trees develop in time sequence from left to right. Foreach header there are two branches. The branch with a “yes” outcome points up, the branch with a “no”outcome points down, when the header is formulated as a question. The probability values associated withthe different branches in the event trees are varying dependent on the accident type. The values are discussedin the following sections and summarised in tables were appropriate.

The sequence of events following an initiating event until selection of evacuation method is discussed inSection II.3.2 and illustrated by the event tree in Figure 3. The process of selecting evacuation method andabandoning is discussed in Section II.3.3 and illustrated by the event tree in Figure 5. Lifeboat evacuation isdiscussed in further detail in Section II.3.3.1 and illustrated by the event tree in Figure 7, while davit/cranelaunched liferaft and throw overboard liferaft evacuations, respectively, are discussed in Section II.3.3.2 andSection II.3.3.3 and illustrated by event trees in Figure 8 and Figure 9. The resulting probabilities of fatality,associated with the different types of accidental events, are presented and discussed in Section II.3.4.

To illustrate typical sequences of events associated with evacuation, the sequences of events associated withevacuation utilising conventional lifeboat, davit/crane launched liferaft and throw overboard liferaft arelisted in Table 7.

Table 7 Sequences of EventsConventional lifeboat Liferafts –

throw over boardLiferafts –davit/crane launched

1. Initiating event2. Evaluation of situation3. Decision to muster4. Mustering alarm5. Escape to mustering station6. Mustering7. Search for missing persons8. Selection of life saving appliances Same Same9. Preparation of equipment10. Decision to abandon ship11. Boarding12. Lowering13. Release14. Clear ship15. Survival at sea16. Rescue

9. Preparation of equipment10. Decision to abandon ship11. Launching12. Boarding13. Clear ship14. Survival at sea15. Rescue

9. Preparation of equipment10. Decision to abandon ship11. Boarding12. Launching13. Release14. Clear ship15. Survival at sea16. Rescue



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The model is developed by following an individual crewmember. In some nodes of the event tree theprobability of a situation is modelled, while in some nodes the fatality probability is modelled, as indicatedby the relevant header in the event tree.

II.3.2 MUSTERING

In the following section, the following events are discussed, i.e. the events following an initiating event untilpreparation of the LSA:

1. Initiating event2. Evaluation of situation3. Decision to muster4. Mustering alarm5. Escape to mustering station6. Mustering7. Search for missing persons8. Selection of life saving appliances

The modelling of the sequence is illustrated by the event tree in Figure 3. (Note that one "sub-tree" isrepeated four times. That is, the scenario of jumping to sea, awaiting and being rescued may occur in thecase that there is a faulty evaluation of the situation, untimely decision to muster, unable to reach musteringstation and not terminating search in time.) The values associated with the different branches of the eventtree differ with respect to type of initiating event, as discussed in the following sections. The values aresummarised in Table 8.

Table 8 Branch Probabilities for MusteringBranch probabilities

Collision

Contact

Fire/E

xplosion

Foundered

Hull/

Machinery

Wrecked/

Stranded

Fatality as result of initiating event 0.0001 - 0.007 - - -Faulty evaluation of situation 0.31 0.31 - 0.37 - -Fatality as a result of not jumping to sea- given faulty evaluation of situation

1 1 - 1 - -

Untimely decision to muster 0.03 0.03 0.015 0.03 0.03 0.03Fatality as a result of not jumping to sea- given untimely decision to muster

0.90 0.90 0.90 0.95 0.95 0.95

Unable to reach mustering station 0.06 0.06 0.03 0.07 0.02 0.06Fatality as a result of not jumping to sea- given unable to reach mustering station

0.95 0.95 0.95 1 0.95 0.95

Not terminating search in time 0.04 0.04 0.04 0.04 0.04 0.04Fatality as a result of not jumping to sea- given not terminating search in time

0.625 0.625 0.625 0.625 0.625 0.625

Fatality associated with jumping and awaiting rescue 0.358 0.323 0.420 0.970 0.420 0.323Fatality as a result of not successfully rescued from the sea 0.016 0.016 0.021 0.050 0.021 0.016


16/02/2001 Annex II, page 14

Initiating event Fatality as result Faulty evaluation Untimely decision Unable to reach Not terminating search Fatality as a result Fatality associated Fatality as a result of notrequiring evacuation of initiating event of situation to muster mustering station in time of not jumping to sea With jumping to sea successfully rescued

Event Tree -

Abandoning

Figure 3 Event Tree - Mustering



15

Initiating event requiring evacuation

The evacuation frequencies per ship year for the different types of accidents utilised in the model are listedin Table 4. Data are based on world statistics for the period 1991-98.

Fatality as a result of initiating event

The probability of fatality in the initial incident, prior to the evacuation starting, depends on the type ofincident. In general, most such fatalities occur in fires/explosions or collisions resulting in fires/explosions.Based on the LCR descriptions, it is assessed that there were 3 fire/explosion incidents for which 1 fatalityoccurred due to the initiating event. In addition, there are 2 cases in which 1 crewmember is reported asmissing. There is a possibility that the person has escaped to sea by himself; however, it is less likely forfires/explosions than some of the other events. It is therefore assumed that the person is killed in thefire/explosion. It is thus assumed that for fire/explosions, the record of missing is based on poor reporting,i.e. not updated since first reports of incidents. Based on this, it is estimated that there have been 5 fatalitieson board out of 379 people on board in evacuations associated with fire/explosion events, i.e. a probabilityof approximately 0.013. However, the value most likely includes people trapped on board and unable toescape. In the absence of any data with respect to this, it is assumed that 50% of these cases involve peoplebeing killed in the initial incident, while 50% of the cases involve people being trapped. That is, theprobability of being killed in the initiating incident is approximately 0.0065, while the probability of beingtrapped, which will be discussed later, is also approximately 0.0065.

For collisions, only 1 of the incidents involved fire/explosion resulting in a large number of fatalities,namely the accident involving Shipbroker, 13 March 1994. That is, 1 incident out of a total of 14 collisionincidents. In the collision accident resulting in fire/explosion, it is assessed that 20 fatalities were a result ofthe fire/explosion. (This is based on the fact that 18 bodies were recovered from the vessel and 2 burnedbodies were found in the sea nearby; the 9 remaining crewmembers are reported missing.) Based on this,there have been 20 fatalities out of 116 on board, i.e. 17.2%. This value does not seem reasonable, as it ishigher than the value for fire/explosion events. As this value is determined by only one accident, it is judgedless reliable. Therefore, it is assumed that the probability of fatalities associated with collisions resulting infire/explosion is the same as for the fire/explosion events. The resulting probability value is 0.0026, i.e.0.20⋅0.013 = 0.0026. (Note that approximately 20% of the collision incidents result in fire/explosion.) Thelikelihood of being killed in the initiating incident versus being trapped is assessed in the same manner as forfire/explosion events. That is, it is assumed that 50% of these cases involve people being killed in the initialincident, while 50% of the cases involve people being trapped. Therefore, the probability of being killed onboard in collision events is estimated to be 0.0013, while the probability for being trapped (discussed later)is also estimated to be 0.0013.

For all other event types, it is assumed that the probability of fatality as a result of the initial incident isnegligible.

The total value for all types of accidental events is approximately 0.008, i.e. 0.0065+0.0013=0.0078≈0.008.For comparison, a total value of 0.02 was estimated for oil tankers (Spouge,2000).

Faulty evaluation of situation

• Probability of faulty evaluation of situation

Faulty evaluation of the situation may be a result of a human error; however, it may also be a result of themaster not being provided with sufficient warning signs to be able to perform an evaluation. That is, theability of the master to understand the nature of the incident is dependent on the number and type of warningsignals perceived by him/her or the crew. Most people need several signs before understanding anemergency situation and reacting. For bulk carriers, this is most likely a great problem with respect to theevent of foundering. There are a number of incidents for which it seems that the vessel has sunk before the



16

crew realised the seriousness of the situation. For example, in the LCR for one of the foundering incidents,the vessel is described as having sunk while the master was talking to the rescue service.

It is assessed that events in which the descriptions indicate that there have been no time to evacuate, therehas been a faulty evaluation of the situation. This is only an approximation, as some of the events may bedue to an untimely decision to muster, crew being unable to reach the mustering station or not terminatingsearch in time. However, as it is impossible to distinguish between these types of causes, it is assumed that afaulty evaluation is the main cause for these events.

Based on the descriptions in Table 2, it is found that for collisions there have been 3 cases out of 14 in whichthere were no time for orderly evacuation, i.e. 21%. For contact, it is found that there have been 2 cases outof 5 with no time for orderly evacuation, i.e. 40%. However, it is difficult to find any good reason for whythese values are that different, and the probability value for faulty evaluation. associated with both collisionand contact, is therefore assumed to be the average of these two values, i.e. 31%.

For foundering, there have been 10 cases out of 51 with no time for orderly evacuation, i.e. 19%. However,by considering the events in which 50% or more of the crew is lost, a probability of 55% results, i.e. 28events. It is assessed that these probability rates represent the upper and lower bound, and the probability ofa faulty evaluation for foundering is assessed to be in between these two values, i.e. 37%.

For the other types of accidents, there are no cases for which the descriptions indicate that there has been notime for orderly evacuation. That is, the risk is found to be negligible for the other types of accidental events.

• Fatality as a result of not jumping to sea- given faulty evaluation of situation

In the case that the crew is unable to perform a non-orderly evacuation in time, i.e. jumping to sea, fatalitieswill result. This factor is dependent on the individual crewmember's ability to perceive the situation andjumping into the sea before it is too late.

Based on the descriptions in Table 2, the probability of fatality associated with faulty evaluation of thesituation for collision, contact and foundering are assessed to be approximately 1. That is, the entire crewwill be lost in these cases. For the other types of events, the risk related to faulty evaluation of the situationis negligible.

Untimely decision to muster

• Probability of untimely decision to muster

The master may hesitate to make the decision to muster, even though the emergency situation is understood.That is, a decision is not made with respect to start mustering in time. The task associated with deciding tomuster may be categorised as a task in which the master has perceived/understood the situation, but thewrong action pathway is selected. A human error probability of 0.03 is selected for all types of events,except fire/explosion, based on Table 5-36 in Human Reliability and Safety Analysis Data Handbook(Gertman and Blackman, 1994). For fire/explosion, it is assessed that the seriousness of the situation is moreapparent and therefore the human error probability is reduced by 50%, i.e. 0.015.

• Fatality as a result of not jumping to sea- given untimely decision to muster

Fatalities will result in the case that the crewmembers are not able to perform a non-orderly evacuation, inthe manner of jumping to sea, in time. The factor is dependent on the individual crewmember's ability toperceive the situation and jump into the sea before it is too late. In the case that the crewmembers do notjump to the sea, fatality is assessed to be certain. It is assessed that in collision, contact and fire/explosionevents, the crewmembers will be able to perceive some warning signs, while in all other types of events,



17

there are no warning signs. In the absence of data, the probability of fatality is assumed to 0.90 for collision,contact and fire/explosion events, while it is assumed to 0.95 for the other types of accidents.

Unable to reach mustering station

• Probability of unable to reach mustering station

Even though the decision to muster is taken in due time, the crew may be unable to reach the musteringstation. There are basically two reasons for this; the mustering alarm is not taken seriously (i.e. seriousnessof the situation is not realised) or the person is being trapped. In addition, the person is not retrieved by therest of the crew.

The probability values for being unable to reach the mustering station, illustrated in Figure 4 andsummarised in Table 9, are calculated by the following equation:

P Unable to reach mustering station = [[PHuman error related to sounding alarm + PAlarm - Technical failure + PNot hearing alarm due to location

+ PBelieve it is false alarm + PToo busy - does not perceive alarm] ⋅ PDo not discover other warning signals + [PInitial event blocking escape way + PExcessive heel/trim/acceleration + PExtreme weather]] ⋅ PNot being retrieved

The values for the different basic factors in the fault tree in Figure 4 are assessed as follows:• Human error related to sounding alarm: A human error probability of 0.001 is selected based on

Table 20-13 in the Handbook of Human Reliability Analysis with Emphasis on Nuclear Power PlantApplications (Swain and Guttmann, 1983). That is, the task is assessed to have similar human errorprobability as selecting locally operated valves that are clearly and unambiguously labelled and setapart from valves that are similar in size and shape.

• Technical failure of alarm: In the absence of any data, a failure probability of 0.01 is assumed.• Not hearing alarm due to location: The alarm should be designed in such a manner that it is heard or

perceived regardless of location and work task. Therefore, the probability value is assumed to benegligible compared to the other factors.

• Believing it is false alarm: This factor is influenced by the number of times that a false alarm hasbeen experienced. It is assessed that the failure is due to symptoms being noticed but with anincorrect interpretation, Table 5-36 in Human Reliability and Safety Analysis Data Handbook(Gertman and Blackman, 1994). A probability value related to the alarm being perceived as false of0.02 is assumed.

• Too busy - does not perceive alarm: The probability associated with not perceiving the alarm isassumed negligible compared to other factors.

• Do not discover other warning signals: This greatly depends on the location of the crew and the typeof event. For collision, contact and wrecked/stranded it is assumed a value of 0.80, for fire/explosiona value of 0.85, for foundering a value of 0.90, and for hull/machinery a value of 0.95.

• Initial event blocking escape way: As previously discussed, the probability that the initial event isblocking the escape way, i.e. probability of being trapped, is 0.0065 for fire/explosion events and to0.0013 for collisions. For all other events it is assumed to be negligible.

• Excessive heel/trim/acceleration: Regarding excessive heel/trim/acceleration preventing escape tothe mustering station, it is assumed that the probability is 0.05 for collision, contact, foundering andwrecked/stranded, while it is negligible for the other events.

• Extreme weather: The probability of being trapped because of extreme weather is assumed to be0.01 for foundering and 0.001 for all other types of events. (That is, it is assessed that the probabilityof being trapped related to extreme weather is approximately a factor of 10 higher for founderingthan the other types of events.)

• Not being retrieved: In the absence of any data, it is assumed that the probability that missingcrewmembers are not rescued is 0.80 for all accidental events except foundering. For foundering, aprobability value of 0.85 is assumed due to severe weather.



18

Table 9 Unable to Reach Mustering Station

Col

lisio

n

Con

tact

Fire

/Ex

plos

ion

Foun

dere

d

Hul

l/M

achi

nery

Wre

cked

/St

rand

ed

PHuman error related to sounding alarm 0.001 0.001 0.001 0.001 0.001 0.001PAlarm - Technical failure 0.01 0.01 0.01 0.01 0.01 0.01PNot hearing alarm due to location - - - - - -PBelieve it is false alarm 0.02 0.02 0.02 0.02 0.02 0.02PToo busy - does not perceive alarm - - - - - -PDo not discover other warning signals 0.80 0.80 0.85 0.90 0.95 0.80PInitial event blocking escape way 0.0001 - 0.007 - - -PExcessive heel/trim/acceleration 0.05 0.05 - 0.05 - 0.05PExtreme weather 0.001 0.001 0.001 0.01 0.001 0.001PNot being retrieved 0.80 0.80 0.80 0.85 0.80 0.80

P Unable to reach mustering station 0.06 0.06 0.03 0.07 0.02 0.06



19

Figure 4 Fault Tree - Unable to Reach Mustering Station

Not reachingmustering station

And

Not reachingmustering station byown power

Or 7

Not understandingsituation

And 1

Do not perceive alarm

Or 3

No alarm

Or 4

Human error relatedto sounding alarm

Basic 4

Alarm - Technicalfailure

Basic 5

Alarm not followed

Or 5

Not hearing alarm dueto location

Basic 7

Believe it is falsealarm

Basic 8

Too busy - do notperceive alarm

Basic 10

Do not discover otherwarning signals

Basic 1

Trapped/Not able toescape

Or 2

Initial event blockingescape way

Basic 11

Excessiveheel/trim/acceleration

Basic 12

Extreme weather

Basic 13

Not being retrieved

Basic 16



20

• Fatality as a result of not jumping to sea- given not reaching mustering station

Fatalities will result in the case that the crewmembers are not able to perform a non-orderly evacuation, inthe manner of jumping to sea, in time. As previously discussed, the factor is dependent on the individualcrewmember's ability to perceive the situation and jump into the sea before it is too late. In the case thatjumping to the sea is not performed, fatalities are certain. In the absence of data, the probability of fatality isassumed to be 0.95 for all types of accidental events, with the exception of foundering for which a value of 1is assumed.

Not terminating search in time

• Probability of not terminating search in time

The decision to terminate the search for missing persons onboard is extremely difficult. However, ifnot terminated when needed, the whole crew may lose their lives. The need for searching forpersonnel is determined by the fault tree in Figure 4, discussed in the above section covering unable toreach mustering station, with the exception of the factor related to being retrieved. That is, the probabilitythat a search operation is necessary is approximately 0.075 for collision, contact and wrecked/strandedevents, 0.034 for fire/explosion, 0.088 for foundering and 0.030 for hull/machinery events.

The situation in which search for missing persons is not terminated in time is a result of competing goalsleading to the wrong conclusion, and the human error probability of 0.04 is selected, based on Table 5-36 inHuman Reliability and Safety Analysis Data Handbook (Gertman and Blackman, 1994).

Combining the probability of a search operation being necessary and the probability of not terminating theoperation in time (by multiplying the values), the resulting probabilities are approximately 0.003 forcollision, contact and wrecked/stranded events, 0.001 for fire/explosion, 0.004 for foundering and 0.001 forhull/machinery events.

• Fatality as a result of not jumping to sea- given not terminating search in time

In this case, some of the crewmembers will be at the mustering stations while some will be involved in thesearch for missing persons. It is assumed that approximately 50% of the crew is involved in the search, andtherefore will not be able to jump into sea. It is assumed that of the other 50%, located at the musteringstation, 75% will be able to jump into the sea. That is, 62.5% of the crewmembers are unable to jump to sea,and are therefore assumed to lose their lives.

Fatality associated with jumping to sea and awaiting rescue

Fatalities associated with jumping to sea and awaiting rescue is calculated by the following equation:PFatality associated with jumping to sea = PFatality due to entering sea + PFatality due to fire at sea + PFatality related to awaiting rescue

The values for the factors in the above equation are determined in the following manner :• Fatality probability as a result of entering the sea, which is assumed to be 0.02. Jumping from the

deck involves a risk of injury, which may lead to drowning. Especially, entering cold water involvesa risk of heart failure due to shock of immersion. Being in the water in the vicinity of the vesselinvolves a risk of being trapped by debris or swamped by turbulence. It has previously beenestimated that 6% of ferry passengers may die from entering the sea (DNV, 1989). However, mostof these would be elderly compared to a bulk carrier crew, and therefore the value of 2% is selected.

• Fatality probability due to being engulfed in fire on the sea is assessed to be only a problem relatedto collisions with oil tankers requiring evacuation. Based on the selected accidents listed in Table 2,



21

only 1 of the 14 collision events involved a scenario with a large oil spill and fire on the water,namely the Shipbroker accident. It is further assumed that the probability of being engulfed in thecase that there is a fire on the sea is 50%. Based on these considerations, the fatality probability dueto being engulfed in fire on the sea is 0.035 for collisions, while it is negligible for the other types ofevents.

• Fatality probability associated with awaiting rescue from the sea. Death from hypothermia ordrowning is likely if people are not rescued quickly. The time awaiting rescue depends on theavailability of passing vessels or rescue boats/helicopters, their effectiveness of finding and pickingpeople out of the water, and the weather conditions.World-wide offshore experience with rescue from the sea give probabilities of fatality of 6% incalm, 22% in moderate and 92% in severe weather (DNV, 2000). However, rescue services areexpected to be more available and of better quality for offshore installations than for bulk carriers ininternational trade. Therefore, values for bulk carriers are obtained by multiplying the probabilitiesof fatality with a factor of 1.5 for collision, contact and wrecked/stranded events, as these are likelyto occur in coastal areas close to shore or with other vessels nearby. Values for foundering,fire/explosion and hull/machinery events are obtained by multiplying the probabilities of fatalitywith a factor of 2, as these are less likely to occur close to shore. That is, the probabilities of fatalityfor bulk carriers are assessed to be 9% in calm, 33% in moderate and 100% in severe weather forcollision, contact and wrecked/stranded events. For fire/explosion, foundering and hull/machineryevents, the probabilities of fatality are assessed to be 12% in calm, 44% in moderate and 100% insevere weather.Based on the weather distribution discussed in Section II.2.4, the probability of fatality forfoundering is assessed to 1.00, while it is assessed to be 0.421 for fire/explosion and hull/machineryevents and 0.319 for all other types of accidents:

Collision: 0.09⋅0.086+0.33⋅0.899+1.00⋅0.015 = 0.319Contact: 0.09⋅0.086+0.33⋅0.899+1.00⋅0.015 = 0.319Fire/Explosion: 0.12⋅0.086+0.44⋅0.899+1.00⋅0.015 = 0.421Foundering: 1.00 ⋅1.000 =1.000Hull/Machinery: 0.12⋅0.086+0.44⋅0.899+1.00⋅0.015 = 0.421Wrecked/Stranded: 0.09⋅0.086+0.33⋅0.899+1.00⋅0.015 = 0.319

However, the values include both the risk related to awaiting rescue and the risk related to the actualrescue operation (discussed later). In the absence of data, it is assumed that 95% of the risk is relatedto awaiting rescue, while 5% is related to the actual rescue operation. That is, the probabilities offatality associated with awaiting rescue from sea are 95% of the above probability of fatality values,as given in the table below for the different accidental events.

In Table 10, the above discussed probabilities of fatality are listed for the different types of accidentalevents, which combined give the probabilities of fatality associated with jumping to sea and awaiting rescue.

Table 10 Estimated Probabilities in Jumping to Sea and Awaiting RescueEvent PFatality due to entering sea PFatality due to fire at sea PFatality related to awaiting rescue OverallCollision 0.02 0.035 0.303 0.358Contact 0.02 - 0.303 0.323Fire/Explosion 0.02 - 0.400 0.420Foundered 0.02 - 0.950 0.970Hull/Machinery failure 0.02 - 0.400 0.420Wrecked/Stranded 0.02 - 0.303 0.323

Fatality as a result of not successfully rescued from sea

This is the probability of fatality associated with the actual rescue operation, i.e. being picked up from thesea. The fatality probability depends on the passing/rescue vessels' or helicopters' effectiveness of pickingpeople out of the water, the distance from shore and the weather conditions. Based on the discussion above



22

(related to probability of fatality associated with awaiting rescue from the sea), the probabilities of fatalityare 0.016 for collision, contact and wrecked/stranded, 0.021 for fire/explosion and hull/machinery, and 0.05for foundering events.

II.3.3 ABANDONING

Following search for onboard missing persons, a decision has to be made with respect to selecting andpossibly preparing the LSAs. Based on the list of preferred types of evacuation options, direct transfer toanother vessel is the most preferred option. The model for the various LSAs is illustrated by the event tree inFigure 5, while the associated factors are discussed in the sections below and summarised in Table 11.

Table 11 Probability Values for AbandoningProbability value

Col

lisio

n

Con

tact

Fire

/E

xplo

sion

Foun

dere

d

Hul

l/Mac

hine

ry

Wre

cked

/St

rand

ed

Other vessel available 0.17 0.17 0.17 0.17 0.17 0.17Fatality in evacuation- given vessel evacuation

0.02 0.02 0.02 0.02 0.02 0.02

Helicopter available 0.11 0.11 0.11 0.02 0.11 0.11Fatality in evacuation- given helicopter evacuation

0.04 0.04 0.04 0.04 0.04 0.04

Lifeboat available 0.845 0.925 0.525 0.925 0.925 0.875Rescue boat sufficient and available 0.02 0.03 0.03 0.03 0.06 0.03Fatality in evacuation-given rescue boat

0.06 0.06 0.06 0.06 0.06 0.06

Liferaft available - Davit/Crane launched 0.39 0.44 0.19 0.44 0.44 0.44Liferaft available - Throw overboard 0.44 0.49 0.24 0.49 0.49 0.49Fatality as a result of not jumping to sea 0.25 0.25 0.25 0.25 0.25 0.25


16/02/2001 Annex II, page 23

Terminating search Other vessel Helicopter Lifeboat Rescue boat Liferaft Fatality in Fatality as a result Fatality associated Fatality as a result of not

and rescue in time available available available sufficient available evacuation of not jumping to sea with jumping to sea successfully rescued

and available

Event Tree -

Lifeboat

Event Tree -

Liferaft

Figure 5 Event Tree - Abandoning



24

Other vessel available

• Probability that other vessel is available

Direct transfer to another vessel may be performed by utilising an accommodation ladder, pilot ladder,berthing opening through which personnel can transfer to vessels such as pilot boats, tugs or other harbourcrafts, and in some cases, passing ships may use their lifeboats or rescue boats to transfer personnel.

Availability of other vessels for direct transfer requires the following:• Suitable vessels are available nearby or are able to reach the vessel before it is too late.• Weather is suitable for direct transfer, which is mostly in calm or moderate conditions.• Access to the other vessel is not impaired, e.g. flames, heat or smoke.

In the 46 cases in which the method of evacuation is known, during 1991-98, there were 8 cases where othervessels were used for direct transfer, i.e. probability of 0.17. For comparison, for oil tankers the value wasfound to be 0.12 (Spouge, 2000). The value of 0.17 is utilised for all the different types of accident types.

• Fatality risk in evacuation- given vessel evacuation

In evacuations of bulk carriers in the period 1991-98, 1 persons died out of 201, i.e. approximately 0.5%,during direct transfer to other vessels. In comparison, for oil tankers, a probability of fatality of 2% wasfound for direct transfer to vessels (Spouge, 2000). In order to be somewhat conservative, the probability offatality of 2% is selected for all types of accidents.

Helicopter available

• Probability that helicopter is available

Availability of helicopters for evacuation requires that:• Suitable helicopters are available within the vessel in distress. This is likely to be the case in many

coastal areas. It has previously been estimated that helicopters might be within range of 30% ofmerchant ship evacuations, COMSAR 3/2.

• Helicopters are able to reach the vessel before evacuation becomes essential by other methods. It haspreviously been estimated in COMSAR 3/2 that helicopters might be able to reach 56% ofmerchant ship evacuations before they were complete, given that they were within range.

• Weather is suitable for helicopter evacuation. Helicopters achieve very high operability, typically in97% of weather conditions, COMSAR 3/2.

• Suitable helicopter pick-up area is available and not impaired, e.g. by fire and smoke. There is nohelicopter landing area on bulk carriers; however, a suitable pick-up area may in some cases beidentified dependent on the type of accidental event. Another possibility is to pick up people fromthe sea, one by one. In the absence of data related to helicopter pick-up area impairment, anavailability value of 70% is assumed.

The above theoretical considerations suggests that the overall proportion of evacuations where helicoptersare able to assist is:

P Helicopter available = 0.3 ⋅0.56 ⋅0.97 ⋅0.7= 0.11

In the 46 bulk carrier evacuations for which the method of evacuation is known, there were 8 cases whereonly helicopters were used for direct evacuation, i.e. 17%. Including the cases in which direct transfer tohelicopter were used for some persons, while others evacuated by some other mean, the probability is 28%(i.e. an additional 5 cases). These relatively high values may result because evacuation by helicopter is morelikely to be reported than evacuation by other means, as it involves more radio transmissions that are



25

commonly reported to LMIS by Coastguards. In order to be somewhat conservative, the theoretical value of0.11 is adopted for all types of accidents, with the exception of foundering. Based on Figure 1, availabilityof helicopters in events of foundering is assessed to be much smaller. Of the 51 cases of foundering shownin Table 2, only 1 case involved evacuation by helicopter. Based on this, a probability value of 0.02 isselected for foundering.

• Fatality risk in evacuation- given helicopter evacuation

In the bulk carrier evacuations during 1991-98, 17 people died out of 219 directly transferred to helicopter(including only the cases in which only helicopter was used), i.e. a probability of fatality of approximately8%. The 17 fatalities were a result of insufficient time available for rescue operations, i.e. the 17 peoplewent down with the vessel while awaiting rescue by helicopter (16 had been hoisted to safety at that time).As the above probability of fatality include fatalities due to unavailability, it is reduced by 50%, resulting ina probability of fatality of approximately 4%.

Lifeboat available

The availability of lifeboats is obtained by considering the unavailability, as illustrated by the fault tree in Figure 6. As is seen, unavailability of lifeboats for evacuation may be due to:

• Lifeboats are not operable when required: Despite extensive testing, lifeboats have poor reliabilityand may be undergoing maintenance when needed. If the engine fails to start or the craft fails tolower properly, the lifeboat is in effect unavailable since any occupants may transfer to othermethods. Offshore experience indicates a probability of 2% of this type of failure for any onelifeboat (DNV, 2000). As the inspection and maintenance program on offshore installations aresomewhat more extensive compared to on bulk carriers; it is assumed that the probability is a factorof 2 higher for bulk carriers, i.e. 4%.It is further assumed that in 50% of the cases the failure is discovered before lowering the lifeboat,in the remaining 50% of the cases it is discovered while in the water (discussed later). That is, theprobability that the lifeboat is found not to be operable when required is 0.02.

• Access to the lifeboats impaired: The following causes are considered:• Fire and smoke: It is assumed that 50% of the fire/explosion evacuation events impair at least

one lifeboat and 40% impair all lifeboats. That is, the probabilities of one or both lifeboats,respectively, being unavailable due to fire and smoke are 0.50 and 0.40 for fire/explosionevents, 0.10 and 0.08 for collisions, and negligible for all other events. (Note that 20% ofcollisions result in fire/explosions, as discussed previously.)

• Heel: For collision, contact, foundering and wrecked/stranded events, it is assumed that theprobability of one lifeboat being impaired is 0.5. For the other types of events, the probability ofimpairment due to heel is assumed to be negligible.

• Impact: For collisions, it is assumed that the probability of damaging any one lifeboat is 0.05.The probability for access being impaired for lifeboats is calculated based on the followingequation:

PAccess Impaired = PImpaired due to fire/smoke + PImpaired due to heel + P Impaired due to impact

The resulting probabilities of access being impaired for one or both lifeboats, respectively, are asfollows:

1 lifeboat Both lifeboatsCollision: 0.65 0.08Contact: 0.50 NegligibleFire/Explosion: 0.50 0.4Foundered: 0.50 NegligibleWrecked/Stranded: 0.50 NegligibleHull/Machinery: Negligible Negligible



26

• Launching equipment (davit) is impaired: This type of failure includes mechanical failures of thedavits, hook release, etc. It also includes the probability that the failure is being discovered beforestarting to lower, which is assumed to be 0.5. Several accidents that have occurred during drills andmaintenance demonstrate the potential for this type of failure, but no suitable statistical data isavailable to indicate the likelihood. Reliability analyses for offshore evacuation indicate failureprobabilities in the region of 2% for this type of event, depending on the release system (DNV,2000). Many of these failures result from human error during operation, attributable to poor designand inadequate training, but they may also result from poor maintenance in service. In the absenceof better data, it is assumed that 50% is due to failure in the equipment, while 50% occur due tofaulty operation (discussed later).Based on the above, including the probability of the failure being detected, the probability that afailure in the launching equipment exists is 0.005.

• Obstruction: For wrecked/stranded events, it is assumed that in 50% of the events the vesselremained hard aground and a conditional probability of the lifeboat being obstructed by rocks of10%. Based on this, the overall probability of obstruction is 0.05.

• Lifeboat launched before all personnel are onboard: There is a possibility that the lifeboats arelaunched early, in effect preventing some crew from using lifeboat evacuation. Offshore experienceindicates a probability of 5% of being left behind in this way (DNV, 2000). This is for multiplelifeboat installations, and it may be different for bulk carriers. However, in the absence of data, theprobability of 0.05 is utilised.

If one lifeboat is impaired, the crew will in general be able to use the other one. Therefore, only theprobability of both lifeboats being unavailable is of interest. The overall probability that a lifeboat isunavailable is calculated by the following equation:

PBoth lifeboats unavailable = PLifeboats not operable when required + PAccess to lifeboats impaired + PLaunching equipment impaired + PObstruction + PLifeboats launched before all personnel onboard

The probabilities that both lifeboats are unavailable are summarised in Table 12 for all the different events.The probabilities that a lifeboat is available is obtained by the following equation:

PLifeboat available = 1 - PBoth lifeboats unavailable

Table 12 Both Lifeboats Unavailable

Col

lisio

n

Con

tact

Fire

/Ex

plos

ion

Foun

dere

d

Hul

l/M

achi

nery

Wre

cked

/St

rand

ed

PLifeboats not operable when required 0.02 0.02 0.02 0.02 0.02 0.02PAccess to lifeboats impaired 0.08 - 0.40 - - -PLaunching equipment impaired 0.005 0.005 0.005 0.005 0.005 0.005PObstruction - - - - - 0.05PLifeboat launched before all personnel onboard 0.05 0.05 0.05 0.05 0.05 0.05PBoth lifeboats unavailable 0.155 0.075 0.475 0.075 0.075 0.125



27

Figure 6 Fault Tree - Lifeboat Unavailable

Lifeboat unavailable

Or 1

Lifeboat not operablewhen required

Basic 2

Access isimpaired/Launchingzone is restricted

Basic 3

Launching equipment(davit) is impaired

Basic 4

Lifeboat launchedbefore all personnel onboard

Basic 5

Obstruction

Basic 6


16/02/2001 Annex II, page 28

Lifeboat Unsuccessful Untimely Fatality due to Unsuccessful Unsuccessfully Fatality as a Fatality Fatality Fatality as a resultavailable preparation of decision unsuccessful lowering clearing ship result of not associated associated with of not successfully

equipment to abandon boarding jumping to sea with jumping to sea being at sea rescued

Figure 7 Event Tree - Lifeboat Evacuation



29

II.3.3.1 LIFEBOAT

Evacuation by lifeboat is further discussed below, as well as illustrated in the event tree in Figure 7. Thesequence of events following the decision to utilise conventional lifeboats is:

9. Preparation of equipment10. Decision to abandon ship11. Boarding12. Lowering13. Release14. Clear ship15. Survival at sea16. Rescue

The different factors shown in the event tree are discussed in the sections below, and the probability valuesare summarised in Table 13.

Table 13 Probability Values for Lifeboat EvacuationProbability value

Col

lisio

n

Con

tact

Fire

/E

xplo

sion

Foun

dere

d

Hul

l/Mac

hine

ry

Wre

cked

/St

rand

ed

Unsuccessful preparation of equipment 0.013 0.013 0.013 0.013 0.013 0.013Fatality as a result of not jumping to sea- given unsuccessful preparation of equipment

0.25 0.25 0.25 0.25 0.25 0.25

Untimely decision to abandon 0.04 0.04 0.04 0.04 0.04 0.04Fatality as a result of not jumping to sea- given untimely decision to abandon

0.25 0.25 0.25 0.25 0.25 0.25

Fatality due to unsuccessful boarding 0.01 0.01 0.01 0.05 0.01 0.01Unsuccessful lowering 0.043 0.043 0.043 0.046 0.043 0.043Fatality as a result of not jumping to sea- given unsuccessful lowering

0.5 0.5 0.5 0.5 0.5 0.5

Unsuccessfully clearing ship 0.0225 0.0225 0.0225 0.0225 0.0225 0.0225Fatality as a result of not jumping to sea- given unsuccessfully clearing ship

0.5 0.5 0.5 0.5 0.5 0.5

Fatality associated with being at sea 0.05 0.05 0.05 0.05 0.05 0.05Fatality as a result of not successfully rescued 0.0005 0.0005 0.0005 0.03 0.0005 0.0005

Unsuccessful preparation of equipment

• Probability of unsuccessful preparation of equipment

Preparation of the lifeboat and the launching equipment include the need for removing the lifeboat cover (ifapplicable), fitting bottom plug (if applicable), release the lashing, swing out of davit, lowering toembarkation deck, bowsing (pre 1986). (Possibly need for releasing lashing and connecting painter (post1986)). Even though the failure rate associated with preparing the equipment may be fairly high, consideringthe highly stressful situation, it is very likely that the error is discovered and therefore does not represent acritical failure. A general probability for error of omission of 0.01 is selected (Kirwan, 1994), and withapproximately 5 subtasks a human error probability of 0.05 is obtained. Given the extremely high stresslevel and a step-by-step task, the estimated error probability is modified by multiplying it by a factor of 5, as



30

described in Table 20-16 in Handbook of Human Reliability Analysis with Emphasis on Nuclear PowerPlant Applications (Swain and Guttmann, 1983). The probability that the error is not detected by others isestimated to 0.05, as it is a special short-term, one-of-a-kind checking with alerting factors, Table 20-22(Swain and Guttmann, 1983). The resulting probability value is 0.013.

• Fatality as a result of not jumping to sea- given unsuccessful preparation of equipment

In this case, all the crewmembers will be at the mustering stations. It is assumed that 75% will be able tojump into the sea at the time it becomes necessary, while 25% will remain onboard. That is, 25% of thecrewmembers are unable to jump to sea, and are therefore assumed to lose their lives.

Untimely decision to abandon

• Probability of untimely decision to abandon

A faulty decision with respect to abandoning the vessel, which is very difficult, includes both a decision toabandon too early/unnecessary and a decision to abandon the ship too late. A faulty decision to abandon theship too early may be due to lack of competence, lack of knowledge related to the specific situation, panic,wrong assessment of situation and a realisation of the time factor (i.e. the fact that evacuations are timeconsuming). A faulty decision resulting in abandoning the ship too late may be due to commercial pressure,conflicts of interests (e.g. safety versus business interruption), lack of competence or knowledge of thespecific situation, apathy, reluctance to make decisions, wrong assessment of the situation, lack ofconfidence in the survival craft and a traditional view that the "ship is the best survival craft". Also, lifeboatsare difficult to launch in severe weather, and experience from accidents suggests that in severe weather thecrew may prefer to remain on board until the vessel sinks, and then jump into the sea or liferafts.

The decision may to a certain extent depend on whether or not the lifeboat is enclosed or open. In the casethat the lifeboat is enclosed, it may be easier to make a decision to evacuate, as the probability of survivingat sea in an enclosed lifeboat is larger than for an open lifeboat. However, on the other hand, the decision isharder to make due to resistance to enter an enclosed lifeboat, i.e. people will feel less in control whencontained inside an enclosed lifeboat. Therefore, no distinction is made between enclosed and open lifeboatswith respect to untimely decision to abandon the ship.

For simplicity in the model, it is assumed that the risk related to abandoning too early/unnecessary isnegligible compared to abandoning the ship too late. Similar to the decision to terminate the searchoperation, a faulty decision with respect to abandoning the vessel may result in the whole crew losing theirlives. The error may result from competing goals leading to the wrong conclusion, and the human errorprobability of 0.04 is selected, based on Table 5-36 in Human Reliability and Safety Analysis DataHandbook (Gertman and Blackman, 1994).

• Fatality as a result of not jumping to sea- given untimely decision to abandon

All the crewmembers are on the deck also in this case. It is therefore assumed that 75% will be able to jumpinto the sea at the time it becomes necessary, while 25% will remain onboard. That is, 25% of thecrewmembers are unable to jump to sea, and are therefore assumed to lose their lives.

Fatality due to unsuccessful boarding

Boarding may be made difficult due to a crowded lifeboat (e.g. due to stretchers, injured personnel,oversized personnel, etc.). Also, boarding may represent a greater risk for one of the crewmembers in thecase there is a need for the winch operator to be left onboard (pre 1986). However, for simplicity, the riskrelated to one person jumping into the sea after lowering the lifeboat is not included in the model. In themodel, fatality due to unsuccessful boarding refers to fatalities associated with actual boarding of the



31

lifeboat, which is mostly a problem in severe weather. In the absence of any data, a probability of fatality of0.01 in moderate weather and 0.05 in severe weather is assumed. Based on the weather distributionsdiscussed in Section II.2.4, the resulting probabilities of fatality are 0.05 for foundering and 0.01, i.e.0⋅0.086+0.01⋅0.899+0.05⋅0.015 = 0.010, for all other types of accidental events.

Unsuccessful lowering

• Probability of unsuccessful lowering

Unsuccessful lowering may be due to the following:• Lifeboat being stuck: This failure may be due to malfunction of the winch system or due to obstacles

during lowering. Based on the discussion related to launching equipment (davit) being impaired, theprobability of launching equipment failure, which is not discovered before attempting lowering, is0.005. This value include mechanical failures of the davits, hook release, etc. It is assumed that 50%of the failures are related to the lowering function, while 50% are related to the release of the hook(discussed later). Therefore, the probability of the lifeboat being stuck is assessed to 0.0025.

• Lifeboat being lowered uncontrollably: This may be due to malfunction of the winch and brakerelease system. As previously discussed in relation to launching equipment (davit) being impaired,failures may result from human error during operation, attributable to poor design and inadequatetraining. It was found that a probability value of 0.01 may be assumed.

• Collisions with the vessel: Theoretical models for offshore evacuation demonstrates the importanceof clearance from the structure in achieving successful evacuation for davit-launched lifeboats.Impacts on the hull may result from pendulum motions on the falls and wave-induced motions in thewater. Failure probabilities in launch have been obtained in the range 3% (DNV, 1999) to 27%(DNV, 1998). In the absence of other data, a probability value of 0.03 is adopted (DNV,1999)represents the most recent study) for all event types, with the exception of foundering for which avalue of 0.06 is assumed due to heavy weather.

The resulting probabilities of unsuccessful lowering are 0.046 for foundering and 0.043 for all other types ofaccidental events, calculated by the following equation:

PUnsuccessful lowering = PLifeboat being stuck + P Lifeboat being lowered uncontrollably + PCollision with the vessel

• Fatality as a result of not jumping to sea- given unsuccessful lowering

The ability of the crewmembers in the lifeboat to jump overboard is somewhat dependent on the type oflifeboat. Jumping overboard will take more time from an enclosed lifeboat compared to an open lifeboat.However, it is assumed that on average 50% will be able to jump into the sea in time. That is, 50% of thecrewmembers are unable to escape by jumping to sea, and are therefore assumed to lose their lives.

Unsuccessfully clearing ship

• Probability of unsuccessfully clearing ship

In the model, the risk related to clearing the ship also includes the risk of not being able to perform release,which is due to unsuccessful release of the hooks (off-load hooks for pre 1986 ships and on-load release ofhooks with hydrostatic sensors for post 1986 ships). It may also be due to unsuccessfully or forgetting torelease painter (post 1986). Based on the discussion above, related to the lifeboat being stuck duringlowering, the probability related to the release of the hook is assessed to 0.0025. Machinery, rudder andpropeller failure may also prevent the lifeboat from clearing the ship. As previously discussed for lifeboatsbeing operable when required, it is assumed that the probability that a failure (resulting in the lifeboat notbeing operable) is not discovered before in the water is 0.02. Based on the two factors discussed, a resultingprobability of unsuccessfully clearing the vessel of 0.0225 is obtained.



32

• Fatality as a result of not jumping to sea- given unsuccessfully clearing ship

As previously discussed, jumping overboard will take a little more time from an enclosed lifeboat comparedto an open lifeboat. However, it is assumed that on average 50% will be able to jump into the sea in time.That is, 50% of the crewmembers are unable to escape by jumping to sea, and are therefore assumed to losetheir lives.

Fatality associated with being at sea

Fatality while awaiting recovery may be due to bad or extreme weather conditions (especially for pre 1986),stranding of the lifeboat, insufficient supply of water, food, medical supplies and fuel, exposure to heat/coldweather and water, as well as flooding. However, modern distress signals and lifeboat designs reduce therisks of such failures compared to earlier times. According to DNV(2000) there are no known cases inemergency evacuations in which the lifeboat has capsized or sunk while awaiting recovery. In the absence ofany data, probabilities of fatality of 4% and 6% are assumed for enclosed and open lifeboats, respectively.As it is assumed that 50% of the vessels are fitted with enclosed lifeboats and 50% of the vessels are fittedwith open lifeboats; the resulting average probability of fatality is 5%.

In the case of a fire on the sea, a lifeboat can be steered away (even though some difficulties may arise dueto visibility and manoeuvrability being insufficient). A totally enclosed lifeboat, which is required for bulkcarriers with keel laid on or after 1. July 1986, should withstand being engulfed in a fire on the sea. Inpractice, some smoke may enter through improperly sealed hatches or the water spray system may fail.However, in the model, this is assumed to represent a negligible risk.

Fatality associated with being rescued

In severe weather, it is very difficult to recover personnel from lifeboats to larger vessels. Risks to thepersons inside the lifeboat during the rescue operation may be due to bad weather (in combination withinsufficient communication equipment, manoeuvrability, training and transfer system), poor design of thelifeboat, lack of personnel pick-up and transfer facilities on the assisting vessel, seasickness andincapacitated persons, and collisions with the assisting vessel. In the offshore industry, major loss of life hasbeen contributed to this factor. Worldwide offshore experience with rescue from liferafts indicate 6%fatalities in severe weather (DNV, 2000). Rescue from a lifeboat will be different for a lifeboat compared toa liferaft. In the absence of other data, it is assumed that this probability of fatality is reduced by 50% forlifeboats, i.e. 3%. Based on the weather distributions discussed in Section II.2.4, the resulting probabilitiesof fatality are 0.03 for foundering events and 0.0005, i.e. 0.03⋅0.015 = 0.0005, for all other events.

Rescue boat sufficient and available

• Probability that rescue boat is sufficient and available

Availability of rescue boats for evacuation requires that:• Rescue boat is fitted on the ship: Bulk carriers with keel laid on or after 1. July 1986 are required to

be equipped with a rescue boat, or one of the lifeboats are accepted as rescue boat. It is assumed thatthat 30% of the bulk carriers have separate rescue boats.

• Rescue boat is operable when required: Experience with fast rescue boats in man overboardincidents in the offshore industry indicates a probability of engine failure of 0.17 (DNV, 2000). Asthe inspection and maintenance programs on offshore installations are a bit more extensivecompared to bulk carriers, it is assumed that the probability is a factor of 2 higher for bulk carriers,i.e. 0.34. That is, the probability that the rescue boat is operable when required is 0.66.



33

• Rescue boat has sufficient capacity for the people needing to use it: The capacity of a rescue boatshould be capable of carrying at least 5 people and one person lying down. The normal maximumcapacity is assumed to be 6 including the coxswain. Compared to the assumed average crew, this isonly 26%.

• Access to the rescue boat is not impaired by the initial incident: The probabilities that access is bothimpaired and available, respectively, for the different types of accidental events are (based on accessto 1 lifeboat being impaired, see section covering lifeboat availability):

Impaired AvailableCollision: 0.65 0.35Contact: 0.50 0.50Fire/Explosion: 0.50 0.50Foundered: 0.50 0.50Hull/Machinery: Negligible 1Wrecked/Stranded: 0.50 0.50

• Weather is suitable for rescue boat evacuation: Rescue boats are slightly easier to deploy in roughweather compared to lifeboats, and an impairment probability of 0.1 is assumed for founderingevents, while a value of 0.05 is assumed for all other types of events. That is, the probability that theweather is suitable is 0.90 for foundering and 0.95 for all other accidental events.

These theoretical considerations result in overall availability of the rescue boat in evacuations for thedifferent types of accidental events as listed in Table 14, calculated by the following equation:

PRescue boat available = PRescue boat fitted on the ship ⋅ POperable when required ⋅ PSufficient capacity ⋅ PAccess not impaired ⋅ PWeather is suitable

Table 14 Rescue Boat Available

Col

lisio

n

Con

tact

Fire

/Ex

plos

ion

Foun

dere

d

Hul

l/M

achi

nery

Wre

cked

/St

rand

ed

PRescue boat fitted on the ship 0.3 0.3 0.3 0.3 0.3 0.3POperable when required 0.66 0.66 0.66 0.66 0.66 0.66PSufficient capacity 0.34 0.34 0.34 0.34 0.34 0.34PAccess not impaired 0.35 0.50 0.50 0.50 1 0.50PWeather is suitable 0.95 0.95 0.95 0.9 0.95 0.95PRescue boat available 0.02 0.03 0.03 0.03 0.06 0.03

• Fatality risk in evacuation- given rescue boat evacuation

Fatalities during evacuation using rescue boats may be slightly less likely than for lifeboats. In the absenceof data, the probability of fatality is assumed to be 5%. (For comparison, the probability of fatality assumedfor rescue boat evacuations associated with oil tankers is 6% (Spouge, 2000).)



34

Liferaft available

Liferafts may be either of the davit/crane launched type or the throw overboard type. It is assumed that 50%of the liferafts are davit launched, while 50% are throw overboard.

The availability values for davit/crane launched liferafts are obtained by considering the unavailability ofsuch liferafts, which are dependent on the following factors:

• Liferaft is not operable when required: The operability values for liferafts are dependent onother factors than those for lifeboats. However, it is assumed that the probabilities are ofapproximately the same magnitude, and in the absence of data the same value is used, i.e.2%.

• Access to the liferaft impaired: Access to the liferaft may be impaired due to fire and smoke. It isassumed that the impairment values are the same as for 1 lifeboat. That is, the probabilities of theliferaft being unavailable due to fire and smoke are 0.50 for fire/explosion events, 0.10 forcollisions, and negligible for all other events. (Note that 20% of collisions result in fire/explosions,as discussed previously.)

• Launching equipment (davit) is impaired: As discussed in the section covering lifeboats, this type offailure includes mechanical failures of the davits, hook release, etc. It also includes the probabilitythat the failure is being discovered before starting to lower. Many of these failures result fromhuman error during operation, attributable to poor design and inadequate training, but they may alsoresult from poor maintenance in service. In the absence of better data, it is assumed that 50% is dueto failure in the equipment, while 50% occur due to faulty operation (discussed later).Based on the above, including the probability of the failure being detected, the probability that afailure in the launching equipment exists is assumed similar to that for lifeboats, namely 0.005.

• Liferaft launched before all personnel are onboard: Similar to evacuation by lifeboats, there is apossibility that the liferafts are launched early, in effect preventing some crew from using liferaftevacuation, and in the absence of data, the probability of 0.05 is utilised.

The overall probability that a liferaft is unavailable is calculated by the following equation:PLiferaft unavailable = PLiferaft not operable when required + PAccess to liferaft impaired

+ PLaunching equipment impaired + PLiferaft launched before all personnel onboard

The probabilities that the liferaft is unavailable are summarised in Table 15 for all the different events. Theprobabilities that the liferaft is available is obtained by the following equation:

PLiferaft available = 1 - PLiferaft unavailable

Table 15 Davit/Crane Launched Liferaft Unavailable

Col

lisio

n

Con

tact

Fire

/Ex

plos

ion

Foun

dere

d

Hul

l/M

achi

nery

Wre

cked

/St

rand

ed

PLiferaft not operable when required 0.02 0.02 0.02 0.02 0.02 0.02PAccess to liferaft impaired 0.10 - 0.50 - - -PLaunching equipment impaired 0.005 0.005 0.005 0.005 0.005 0.005PLiferaft launched before all personnel onboard 0.05 0.05 0.05 0.05 0.05 0.05PLiferaft unavailable 0.18 0.08 0.58 0.08 0.08 0.08

The availability values for throw overboard liferafts are obtained by considering the unavailability of suchliferafts, which are dependent on the following factors:



35

• Liferaft is not operable when required: The operability value is assumed similar to that fordavit/crane launched liferaft, i.e. 2%.

• Access to the liferaft impaired: Access to the liferaft may be impaired due to fire and smoke. It isassumed that the impairment values are the same as for 1 lifeboat. That is, the probabilities of theliferaft being unavailable due to fire and smoke are 0.50 for fire/explosion events, 0.10 forcollisions, and negligible for all other events. (Note that 20% of collisions result in fire/explosions,as discussed previously.)

• Liferaft launched before all personnel are onboard: The risk related to this factor is assessed to benegligible, as the crewmembers have to jump into the water to enter the liferaft that is thrownoverboard. (Even though there is a slight chance that it is thrown overboard a long time before allcrewmembers are ready to jump.)

The overall probability that a liferaft is unavailable is calculated by the following equation:PLiferaft unavailable = PLiferaft not operable when required + PAccess to liferaft impaired

+ PLiferaft launched before all personnel onboard

The probabilities that the liferaft is unavailable are summarised in Table 16 for all the different events. Theprobabilities that the liferaft is available is obtained by the following equation:

PLiferaft available = 1 - PLiferaft unavailable

Table 16 Throw Overboard Liferaft Unavailable

Col

lisio

n

Con

tact

Fire

/Ex

plos

ion

Foun

dere

d

Hul

l/M

achi

nery

Wre

cked

/St

rand

ed

PLiferaft not operable when required 0.02 0.02 0.02 0.02 0.02 0.02PAccess to liferaft impaired 0.10 - 0.50 - - -PLiferaft launched before all personnel onboard - - - - - -PLiferaft unavailable 0.12 0.02 0.52 0.02 0.02 0.02

Evacuation by davit/crane launched liferafts and throw overboard liferafts are further discussed in SectionII.3.3.2 and Section II.3.3.3, as well as illustrated by the event trees in Figure 8 and Figure 9, respectively.

II.3.3.2 Davit/Crane launched liferaft

For davit/crane launched liferafts, the sequence of events following the decision to utilise liferafts is asfollows:

9. Preparation of equipment10. Decision to abandon ship11. Boarding12. Launching13. Release14. Clear ship15. Survival at sea16. Rescue

The model for davit/crane launched liferaft is illustrated by the event tree in Figure 8, discussed in thefollowing sections, and summarised in Table 17.



36

Table 17 Probability Values for Davit/Crane Launched Liferaft EvacuationProbability value

Col

lisio

n

Con

tact

Fire

/E

xplo

sion

Foun

dere

d

Hul

l/Mac

hine

ry

Wre

cked

/St

rand

ed


0.25 0.25 0.25 0.25 0.25 0.25


0.25 0.25 0.25 0.25 0.25 0.25

Fatality due to unsuccessful boarding 0.01 0.01 0.01 0.05 0.01 0.01Unsuccessful lowering 0.043 0.043 0.043 0.043 0.043 0.043Fatality as a result of not jumping to sea- given unsuccessful lowering

0.75 0.75 0.75 0.75 0.75 0.75


0.75 0.75 0.75 0.75 0.75 0.75




Preparation of the liferaft and the launching equipment include the need for releasing lashing, hook on,swing out of davit, lowering to embarkation deck, inflation and bowsing. One specific cause forunsuccessful preparation may be no or insufficient inflation. Even though the failure rate associated withpreparing the equipment may be fairly high, considering the highly stressful situation, it is very likely thatthe error is discovered and therefore does not represent a critical failure. Similar to that for lifeboats, ageneral probability for error of omission of 0.01 is selected (Kirwan, 1994), and with 6 subtasks a humanerror probability of 0.06 is obtained. Given the extremely high stress level and a step-by-step task, theestimated error probability is modified by multiplying it by a factor of 5, as described in Table 20-16 inHandbook of Human Reliability Analysis with Emphasis on Nuclear Power Plant Applications (Swain andGuttmann, 1983). The probability that the error is not detected by others is estimated to 0.05, as it is aspecial short-term, one-of-a-kind checking with alerting factors, Table 20-22 (Swain and Guttmann, 1983).The resulting probability value is approximately 0.015.

• Fatality as a result of not jumping to sea- given unsuccessful preparation of equipment




37



Similar to that for lifeboats, a faulty decision with respect to abandoning the vessel, which is very difficult,includes both a decision to abandon too early/unnecessary and a decision to abandon the ship too late. Also,liferafts are difficult to launch in severe weather. For simplicity in the model, it is assumed that the riskrelated to abandoning too early/unnecessary is negligible compared to abandon the ship too late. Similar tothat for lifeboats, the error may result from competing goals leading to the wrong conclusion, and the humanerror probability of 0.04 is selected, based on Table 5-36 in Human Reliability and Safety Analysis DataHandbook (Gertman and Blackman, 1994).



Fatality due to unsuccessful boarding

Boarding may be made difficult due to a crowded liferaft (e.g. due to stretchers, injured personnel, oversizedpersonnel, etc.). Similar to that for lifeboats, the probabilities of fatality are assessed to 0.05 for founderingand 0.01 for all other types of accidental events.

Unsuccessful lowering

• Probability of unsuccessful lowering

Similar to that for lifeboats, unsuccessful lowering may be due to the following:• Liferaft being stuck: This failure may be due to malfunction of the winch system or due to obstacles

during lowering. The probability of the liferaft being stuck is assessed to 0.0025, see discussionrelated to lifeboats.

• Liferaft being lowered uncontrollably: This may be due to malfunction of the winch and brakerelease system. A probability value of 0.01 is assumed in the same manner as for lifeboats.

• Collisions with the vessel: The probability is assumed to be similar that for lifeboats, i.e. 0.03.The resulting probability of unsuccessful lowering is 0.043 for all the types of accidental events, calculatedby the following equation:

PUnsuccessful lowering = PLiferaft being stuck + P Liferaft being lowered uncontrollably + PCollision with the vessel = 0.0025 + 0.01 + 0.03 = 0.043

• Fatality as a result of not jumping to sea- given unsuccessful lowering

It is most likely more difficult to jump overboard from a liferaft compared to a lifeboat. In the absence ofdata, it is assumed that on average 25% will be able to jump into the sea in time. That is, 75% of thecrewmembers are unable to escape by jumping to sea, and are therefore assumed to lose their lives.



38



In the model, the risk related to clearing the ship also includes the risk of not being able to perform release,which is due to unsuccessful release of the hooks (off-load hooks for pre 1998 ships and on-load release ofhooks with hydrostatic sensors for post 1998 ships). The probability related to the release of the hook isassessed to 0.0025. Liferafts are only able to drift downwind, and therefore a probability of not clearing thevessel due to this factor is assumed to be 0.1. The total resulting probability that the liferaft does not clearthe vessel in time is 0.1025.


As previously discussed, it is assumed that approximately 25% will be able to jump into the sea in time. Thatis, 75% of the crewmembers are unable to escape by jumping to sea, and are therefore assumed to lose theirlives.


Fatality while awaiting recovery may be due to bad or extreme weather conditions, stranding and capsizingof the liferaft, insufficient supply of water, food and medical supplies, exposure to heat/cold weather andwater, as well as flooding. In the absence of any data, a probability of fatality of 30% is assumed.

In the case of a fire on the sea, a liferaft cannot be steered unless controlled by rescue boats. That is, it isonly able to drift downwind. A fire at sea is mainly a problem for collisions involving oil tankers. Based onthe discussion related to fatality associated with jumping to sea, it is assessed that the fatality probabilityrelated to being engulfed in a fire at sea is 0.035. That is, the fatality rate is assessed to be similar regardlessof whether the persons are inside a liferaft or not.

Combining the two above discussed factors, the probabilities of fatality are 0.335 in collision accidents and0.30 for all other types of accidental events.


In severe weather, it is very difficult to recover personnel from a liferaft to larger vessels. Risks to thepersons inside the liferaft during the rescue operation may be due bad weather (in combination withinsufficient communication equipment, manoeuvrability, training and transfer system), poor design of theliferaft, lack of personnel pick-up and transfer facilities on the assisting vessel, seasickness and incapacitatedpersons, collisions with the assisting vessel resulting in rupture of the raft, and difficulties with respect totowing the liferaft. The raft may be blown away from rescue vessels. (In addition, there is a risk of capsizingdue to down-wind from helicopter.) World-wide offshore experience with rescue from liferafts indicated 6%fatalities in severe weather (DNV, 2000). Based on the weather distribution discussed in Section II.2.4, theresulting probabilities of fatality are 0.06 for foundering events and 0.0009, i.e. 0.06⋅0.015 = 0.0009, for allother events.


16/02/2001 Annex II, page 39

Liferaft Unsuccessful Untimely Fatality due to Unsuccessful Unsuccessfully Fatality as a Fatality Fatality Fatality as a resultavailable preparation of decision unsuccessful lowering clearing ship result of not associated associated with of not successfully

equipment to abandon boarding jumping to sea with jumping being at sea rescued

Figure 8 Event Tree - Davit/Crane Launched Liferaft Evacuation


16/02/2001 Annex II, page 40

Liferaft Unsuccessful Untimely Unsuccessful Fatality due Unsuccessful Unsuccessfully Fatality as a Fatality Fatality Fatality as a resultavailable preparation of decision launching to jumping boarding clearing ship result of not associated associated with of not successfully

equipment to abandon to board jumping to sea with jumping being at sea rescued

Figure 9 Event Tree - Throw Overboard Liferaft Evacuation



41

II.3.3.3 Throw overboard liferaft

For throw overboard liferafts, the sequence of events following the decision to utilise the liferaft is asfollows:

9. Preparation of equipment10. Decision to abandon ship11. Launching12. Boarding13. Clear ship14. Survival at sea15. Rescue

The model for throw overboard liferaft is illustrated by the event tree in Figure 9, discussed in the followingsections and summarised in Table 18.

Table 18 Probability Values for Throw Overboard Liferaft EvacuationProbability value

Col

lisio

n

Con

tact

Fire

/E

xplo

sion

Foun

dere

d

Hul

l/Mac

hine

ry

Wre

cked

/St

rand

ed


0.25 0.25 0.25 0.25 0.25 0.25


0.25 0.25 0.25 0.25 0.25 0.25

Unsuccessful launching 0.03 0.03 0.03 0.03 0.03 0.03Fatality as a result of not jumping to sea- given unsuccessful launching

0.25 0.25 0.25 0.25 0.25 0.25

Fatality due to jumping to board 0.02 0.02 0.02 0.02 0.02 0.02Unsuccessful boarding 0.3 0.3 0.3 0.3 0.3 0.3Fatality associated with being at sea- given unsuccessful boarding

1 1 1 1 1 1


0.75 0.75 0.75 0.75 0.75 0.75




Preparation of the liferaft includes the need for releasing lashing and securing painter. A general probabilityfor error of omission of 0.01 is selected (Kirwan, 1994), and with 2 subtasks a human error probability of0.02 is obtained. Given the extremely high stress level and a step-by-step task, the estimated errorprobability is modified by multiplying it by a factor of 5, as described in Table 20-16 in Handbook ofHuman Reliability Analysis with Emphasis on Nuclear Power Plant Applications (Swain and Guttmann,1983). The probability that the error is not detected by others is estimated to 0.05, as it is a special short-term, one-of-a-kind checking with alerting factors, Table 20-22 (Swain and Guttmann, 1983). The resultingprobability value is approximately 0.005.



42

• Fatality as a result of not jumping to sea - given unsuccessful preparation of equipment




Similar to that for davit/crane launched liferaft, a faulty decision with respect to abandoning the vessel,which is very difficult, includes both a decision to abandon too early/unnecessary and a decision to abandonthe ship too late. Also, liferafts are difficult to launch in severe weather. For simplicity in the model, it isassumed that the risk related to abandoning too early/unnecessary is negligible compared to abandon theship too late. Similar to that for davit/crane launched liferafts, the error may result from competing goalsleading to the wrong conclusion, and the human error probability of 0.04 is selected, based on Table 5-36 inHuman Reliability and Safety Analysis Data Handbook (Gertman and Blackman, 1994).



Unsuccessful launching

• Probability of unsuccessful launching

Launching of a throw overboard liferaft includes throw over board, inflate, bowse and secure raft. Onespecific cause of unsuccessful launching may be that the raft does not inflate properly or it inflates upsidedown. In the absence of any data, a failure probability related to insufficient inflation of 0.02 is assumed,while a general probability for human error of omission of 0.01 is selected (Kirwan, 1994). The resultingfailure probability is 0.03.

• Fatality as a result of not jumping to sea- given unsuccessful launching


Fatality due to jumping to board

In order to board throw overboard liferafts, personnel must enter the sea, and then climb onto the raft.Entering cold water involves a risk of heart failure due to the shock of immersion. It has been estimated byDNV that 6% of ferry passengers may die from this (DNV, 1989). Most of these would be elderly, and asthe average age of the bulk carrier crew is lower, a value of 2% is assumed.



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Unsuccessful boarding

• Probability of unsuccessful boarding

Unsuccessful boarding means a failure to enter the liferaft. Climbing on board is the most difficult part ofthrow overboard liferaft evacuation. In the absence of any data, it is assumed that 30% of the personnel areunable to board the throw overboard liferaft. There is an increased risk related to injured, incapacitated andoversized people entering the sea and boarding the liferaft; however, this is not quantitatively modelled.

• Fatality associated with being at sea- given unsuccessful boarding

The probability of fatality associated with being at sea, following an unsuccessful boarding of a throwoverboard liferaft, is assessed to be 1. That is, given that a person has been struggling to board the liferaftwithout being successful, the person is likely to be worn out and therefore unlikely to survive for longerperiods of time.



Liferafts are only able to drift downwind, and therefore a probability of not clearing the vessel due to thisfactor is assumed to be 0.1. In addition, there is a risk for unsuccessful (including forgetting) release ofpainter. A general error of omission probability of 0.01 is selected (Kirwan, 1994). The resulting failureprobability is 0.11.


Similar to that for davit/crane launched liferafts, it is assumed that approximately 25% will be able to jumpinto the sea in time. That is, 75% of the crewmembers are unable to escape by jumping to sea, and aretherefore assumed to lose their lives.


Fatality while awaiting recovery may be due to bad or extreme weather conditions, stranding and capsizingof the liferaft, insufficient supply of water, food, medical supplies and fuel, exposure to heat/cold weatherand water, as well as flooding. Similar to that for davit/crane launched liferafts, a probability of fatality of30% is assumed.

In the case of a fire on the sea, a liferaft cannot be steered unless controlled by rescue boats. That is, it isonly able to drift downwind. A fire at sea is mainly a problem for collisions involving oil tankers. Based onthe discussion related to fatality associated with jumping to sea, it is assessed that the fatality probabilityrelated to being engulfed in a fire at sea is 0.035. That is, the fatality rate is assessed to be similar regardlessof whether the persons are inside a liferaft or not.

Combining the two above discussed factors, the probabilities of fatality are 0.335 in collision accidents and0.30 for all other types of accidental events.



44


In severe weather, it is very difficult to recover personnel from liferaft to larger vessels. Similar to that fordavit/crane launched liferafts, a probability of fatality of 6% in severe weather is selected. Based on theweather distribution discussed in Section II.2.4, the resulting probabilities of fatality are 0.06 for founderingevents and 0.0009, i.e. 0.06⋅0.015 = 0.0009, for all other events.

Fatality as a result of not jumping to sea

In the case that no survival craft is available, it is assumed that the probability that a crewmember is unableto jump to the sea is 0.25.

II.4 Results

The resulting probabilities of fatality and PLL (Potential Loss of Life) are summarised in Table 19 for thedifferent types of accidental events considered.

Table 19 Probabilities of Fatality Associated with EvacuationBased on model Based on statisticsType of Event

Probability of fatality[%]

PLL[per ship year]

Probability of fatality[%]

PLL[per ship year]

Collision 45.7 3.36⋅10-3 35 2.6⋅10-3

Contact 44.1 1.15⋅10-3 45 1.2⋅10-3

Fire/Explosion 27.7 2.36⋅10-3 2 1.7⋅10-4

Foundered 55.4 1.44⋅10-2 51 1.3⋅10-2

Hull/Machinery failure 16.2 5.12⋅10-4 0 0Wrecked/Stranded 20.2 2.45⋅10-3 0 0

II.5 DISCUSSION

The model reflects data quite well. This is mainly due to the method used, where actual data are used asbasic input and broken down to branch probabilities in the event trees. Still many of the branch probabilitieshad to be assessed based on comparison with other ship types and other industries, like e.g. offshore. Alsosome probabilities are assessed by using generic human reliability data from the literature. This result of thelack of good data from shipping.

The need to make a detailed model is defined by a need for a model that may be used to quantify the effectof the RCOs (Risk Control Options). The HAZID report is therefore used as input in evaluating which levelof detail is necessary.

Regarding fire/explosion, hull/machinery and wrecked/stranded events, the probabilities of fatality resultingfrom the model may be somewhat conservative. This may be due to not sufficiently accounting for the timefactor in the model, i.e. in some cases the crew have more time available than in other cases. However, asthe probabilities of fatality resulting from statistics are based on a fairly limited number of events, thesevalues are associated with some uncertainty, which also may explain the differences between the resultsassociated with the model and the statistics.



45

LIST OF REFERENCES

Bitner-Gregersen, E.M., Cramer, E.H., Løseth, R., Uncertainties of Load Characteristics andFatigue Damage of Ship Structures, Marine Structures, Vol. 8, 1995.

COMSAR 3/2 “Formal Safety Assessment of Helicopter Landing Area as a Safety Measure”, submitted byNorway and ICCL.

DNV, Report C1669, 1989. (Internal)



DNV, ARF, Vol IV Appendix VI, July 2000. (Internal)

Eknes, M. L., Astrup, O.C., Ronold, K., Gran, S., “Statistical Data for Bulk Carrier Casualties whereStructural Failure may have been a Factor”, DNV Research Report No. 96.2042, Rev. 0, December 1997.

Eknes M, Kvien M.H, "Historical Risk Levels in the Maritime Industry", DNV Report No. 99-2028, rev. 01,13 October 1999.

Gertman D.I., Blackman H.S., Human Reliability & Safety Analysis Data Handbook, John Wiley & Sons,Inc. New York, 1994.

IMO (1997) “Interim Guidelines for the application of Formal Safety Assessment (FSA) to the IMO Rule-Making Process”. MSC Circ.829/MEPC/Circ.335.

IMO, Bulk Carrier Safety - Hazard Identification of Life Saving Appliances for Bulk Carriers, MSC, 73rdSession, Agenda Item 4, Submitted by Norway and ICFTU, 5 September 2000.

Kirwan B., A Guide to Practical Human Reliability Assessment, Taylor & Francis, 1994.

LCR, Lloyd's Casualty Reports, Bulk and Ore Carriers 1991-98, Lloyd's Maritime Information Systems.

LMIS, Casualty Database, Bulk and Ore Carriers 1991-98, Lloyd's Maritime Information Systems.

Spouge J., DNV Report, Appendix IX.i, Rev. 1, July 2000 (Internal)

Swain A.D., Guttmann H.E., Handbook of Human Reliability Analysis with Emphasis on NuclearPower Plant Applications, NUREG/CR-1278, U.S. Nuclear Regulatory Commission, Washington,D.C., 1983.

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ANNEX II FSA STEP 2: RISK ASSESSMENT II.1 …research.dnv.com/skj/FsaLsaBc/ANNEX-II.pdfANNEX II: FSA/LSA/BC: RISK ASSESSMENT ... 9 19940313 SHIPBROKER 1980 Collision ... 27 19930810