MAIB Report No 32/2014 - Wacker Quacker 1 - Very Serious Marine Casualty · SECTION 2 – FACTUAL...
Transcript of MAIB Report No 32/2014 - Wacker Quacker 1 - Very Serious Marine Casualty · SECTION 2 – FACTUAL...
MA
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VERY SERIOUS MARINE CASUALTY REPORT NO 32/2014 DECEMBER 2014
Combined report on the investigations of the
sinking and abandonment of the DUKW amphibious passenger
vehicle
Wacker Quacker 1in Salthouse Dock, Liverpool
on 15 June 2013
and the
fire and abandonment of the DUKW amphibious passenger
vehicle
Cleopatraon the River Thames, London
on 29 September 2013
Extract from
The United Kingdom Merchant Shipping
(Accident Reporting and Investigation)
Regulations 2012 – Regulation 5:
“The sole objective of the investigation of an accident under the Merchant Shipping (Accident
Reporting and Investigation) Regulations 2012 shall be the prevention of future accidents
through the ascertainment of its causes and circumstances. It shall not be the purpose of an
investigation to determine liability nor, except so far as is necessary to achieve its objective,
to apportion blame.”
NOTE
This report is not written with litigation in mind and, pursuant to Regulation 14(14) of the
Merchant Shipping (Accident Reporting and Investigation) Regulations 2012, shall be
inadmissible in any judicial proceedings whose purpose, or one of whose purposes is to
attribute or apportion liability or blame.
© Crown copyright, 2014You may re-use this document/publication (not including departmental or agency logos) free of charge in any format or medium. You must re-use it accurately and not in a misleading context. The material must be acknowledged as Crown copyright and you must give the title of the source publication. Where we have identified any third party copyright material you will need to obtain permission from the copyright holders concerned.
All MAIB publications can be found on our website: www.maib.gov.uk
For all enquiries:Marine Accident Investigation BranchMountbatten HouseGrosvenor SquareSouthampton Email: [email protected] Kingdom Telephone: +44 (0) 23 8039 5500SO15 2JU Fax: +44 (0) 23 8023 2459
CONTENTS
GLOSSARY OF ABBREVIATIONS AND ACRONYMS
SYNOPSIS 1
SECTION 1 - FACTUAL INFORMATION WACKER QUACKER 1 3
1.1 Particulars of Wacker Quacker 1 and accident 31.2 Background 41.3 Narrative 41.4 Environmental conditions 131.5 The Yellow Duckmarine 13
1.5.1 Company history and structure 131.5.2 Thefleet 16
1.6 Thecrew 181.6.1 Master 181.6.2 Driver 18
1.7 Thevehicle 181.7.1 TheDUKW 181.7.2 Wacker Quacker 1 21
1.8 Regulatoryrequirements 231.8.1 General 231.8.2 Stabilityandsurvivabilityrequirements 26
1.9 Buoyancy foam 271.10 Post-accidentinspections,testsandtrials 28
1.10.1 MAIBandMaritimeandCoastguardAgencyinspections 281.10.2 Metallurgicalanalysisofhullplating 321.10.3 Stabilitytestsandfloodingtrials 34
1.11 The Yellow Duckmarine safety management system 391.11.1 SafetyPolicyandGeneralSafeOperationalProceduresmanual 391.11.2 Emergency preparedness 411.11.3 Passenger safety announcements 411.11.4 Pre-splashdown safety checks 421.11.5 Life saving appliances 421.11.6 Personalflotationdevices 42
1.12 The Yellow Duckmarine maintenance management system 441.12.1 Planned maintenance routines 441.12.2 Unplannedbreakdownrepairs 44
1.13 Vehicle surveys and inspections 451.13.1 MaritimeandCoastguardAgency 451.13.2 VehicleandOperatorServicesAgency 45
1.14 Industryguidanceandinstructionsforsurveyors 461.15 Passengerquestionnairesandfeedback 461.16 Similarincidentsandaccidents 46
1.16.1 TheYellowDuckmarine 461.16.2 Beatrice 501.16.3 Miss Majestic 501.16.4 DUKW 34 531.16.5 LessonslearnedduringWorldWar2operations 54
SECTION 2 – FACTUAL INFORMATION CLEOPATRA 55
2.1 Particulars of Cleopatra and accident 552.2 Background 562.3 Narrative 562.4 Environmentalconditions 622.5 LondonDuckTours 622.6 Thecrew 62
2.6.1 Master 622.6.2 Tourguide 63
2.7 Cleopatra 632.7.1 Generaldescription 632.7.2 Hull 632.7.3 Propulsiondrivetrain 642.7.4 Ruddercontrol 642.7.5 Brakesystem 642.7.6 Enginecompartment 642.7.7 Engine compartment extraction fan controls 712.7.8 Passengercompartment 712.7.9 Engine fuel oil system 712.7.10 Electricaldistributionsystem 74
2.8 Fire-fightingarrangements 752.8.1 Fire-fightingappliances 752.8.2 Enginecompartmentshut-down 75
2.9 Lifesavingappliances 782.10 Vesselsurvivability 78
2.10.1 Buoyancyfoam 782.10.2 AdditionofbuoyantfoamfollowingthesinkingofWacker Quacker 1 802.10.3 Typesofbuoyancyfoam 80
2.11 Fireinvestigation 822.11.1 Overview 822.11.2 Theexternalhull 832.11.3 Crewcabareaandpassengercompartment 832.11.4 Enginecompartment 832.11.5 Enginecompartmentcoolingairventilationvoidspaces 852.11.6 Centralvoidspace 862.11.7 Hydraulicsteeringsystem 862.11.8 Enginefueloilsystem 862.11.9 Electricaldistributionsystem 892.11.10 Hand-operatedbandbrake 892.11.11 Brakesystemairreservoirs 89
2.12 Externalfireinvestigationsupport 892.12.1 BureauVeritasFireScienceDepartmentfireinvestigationreport 892.12.2 MetallurgicalanalysisofCleopatra’s drive shaft and UJs 91
2.13 Safetymanagementsystem 912.14 Vehicle maintenance 93
2.14.1 Maintenancemanagementsystem 932.14.2 Planned maintenance 932.14.3 Unplannedbreakdownrepairs 95
2.15 Surveysandinspections 952.16 Emergencyresponse 95
2.16.1 ThamesRIBExperience 952.16.2 RoyalNationallifeboatInstitution 95
2.16.3 Police 962.16.4 LondonFireBrigade 96
2.17 Passengerfeedback 962.18 Similaraccidents 97
2.18.1 MAIBdatabase 972.18.2 Elizabeth 972.18.3 Mistress Quickly 972.18.4 WorldWar2 98
SECTION 3 - ANALYSIS 99
3.1 Aim 993.2 Overview 993.3 The sinking of Wacker Quacker 1 99
3.3.1 Overview 993.3.2 The hull failure 993.3.3 The fouling of the propeller 1013.3.4 MaterialconditionofWacker Quacker 1andTheYellowDuckmarinefleet1013.3.5 Maintenancemanagement 102
3.4 ThefireonboardCleopatra 1023.4.1 Overview 1023.4.2 Seatofthefire 1023.4.3 Firedevelopment 1023.4.4 Sourceofignition 1033.4.5 Failureoftheuniversaljoint 1053.4.6 MaterialconditionofCleopatraandLondonDuckToursfleet 106
3.5 Vesselsurvivability 1063.5.1 Regulatorycompliance 1063.5.2 Theuseofbuoyancyfoam 1063.5.3 Buoyancy foam calculations 107
3.6 Passengerandcrewsurvivability 1083.6.1 Riskofentrapment 1083.6.2 Theriskofdrowning 1083.6.3 TheIrishmodel 110
3.7 Roleoftheregulators 1113.7.1 Effectiveness of survey and inspection regimes and unscheduled interventions 1113.7.2 Instructions,guidanceandtraining 1123.7.3 Sharingofinformation 112
3.8 Roleoftheoperator 1133.9 Emergency preparedness 113
3.9.1 General 1133.9.2 Emergency preparedness – Wacker Quacker 1 1143.9.3 Emergency preparedness – Cleopatra 115
3.10 Emergency response – Wacker Quacker 1 1153.10.1 Raisingthealarm 1153.10.2 Theabandonment 1153.10.3 Shorebasedemergencyresponse 116
3.11 Emergency response – Cleopatra 1163.11.1 Raisingthealarm 1163.11.2 Firecontainmentandfire-fighting 1173.11.3 Theabandonment 1183.11.4 Shorebasedemergencyresponse 118
SECTION 4 - CONCLUSIONS 119
4.1 The sinking of Wacker Quacker 1 1194.2 ThefireonboardCleopatra 1194.3 Common safety issues 120
SECTION 5 - ACTION TAKEN 122
5.1 MAIBactions 1225.2 Actionstakenbyotherorganisations 122
SECTION 6 - RECOMMENDATIONS 124
FIGURES
Figure 1 - FirstDUKWamphibiousvehiclesusedtocarrypassengersintheWisconsinDells,USA
Figure 2 - Wacker Quacker 4sinkinginSalthouseDock,Liverpool,on30March2013
Figure 3 - AmphibiouspassengervehicleWacker Quacker 1
Figure 4 - TheYellowDuckmarineamphibiouspassengervehiclesightseeingtour route
Figure 5 - Crew positions during sightseeing tour
Figure 6 - Wacker Quacker 1’sfailedattempttoexitSalthouseDockat1205on15 June 2013
Figure 7 - Wacker Quacker 1’s passenger and crew seating arrangements
Figure 8 - SplashdownintoSalthouseDock
Figure 9 - Abandonshipandrescuesequence
Figure 10 - Police divers’ underwater survey
Figure 11 - PhotographstakenbypoliceaftertherecoveryofWacker Quacker 1
Figure 12 - Wacker Quacker 4 and Wacker Quacker 8beforeandaftertheirconversion to carry 30 passengers
Figure 13 - Propeller shaft v-strut support
Figure 14 - OriginalDUKWhulldesignandcompartmentlayout
Figure 15 - Liverpool DUKW side curtains
Figure 16 - Wacker Quacker 1bilgepumpcontrols
Figure 17 - Wacker Quacker 1 hull drain plugs
Figure 18 - Roadtilttest
Figure 19 - FoamremovedfromWacker Quacker 1, Wacker Quacker 2 and Wacker Quacker 8
Figure 20 - Wacker Quacker 8driver’scabinstrumentationandelectricalwiring
Figure 21 - External patch repairs to the hull of Wacker Quacker 1
Figure 22 - V-strut suspended from Wacker Quacker 1’s propeller shaft
Figure 23 - Sectionsofpropellershafttunnelandafttransversebulkheadcutaway and despatched for metallurgical analysis
Figure 24 - Analysisofpropellertunnelplatingandweldedrepairs
Figure 25 - MAIBfoaminsertiontrialsandfloodingreconstruction
Figure 26 - Hull preparations and foam insertion process
Figure 27 - Wacker Quacker 1floodingreconstruction
Figure 28 - TheYellowDuckmarinelifejacketsandbuoyancyaids
Figure 29 - SimilarhullfailurediscoveredonboardWacker Quacker 2 two weeks earlier
Figure 30 - Hullrepairscarriedoutbygaragestaff
Figure 31 - SinkingofDUKWMiss Majesticon1May1999
Figure 32 - Collisionbetweentugboat/bargeCaribbean Sea/The Resource and DUKW 34 on 7 July 2010
Figure 33 - World War 2 operations manual
Figure 34 - LondonDuckToursamphibiouspassengervehicleCleopatra
Figure 35 - ThewaterbornesectionoftheLondonDuckTourssightseeingroutes
Figure 36 - Engine compartment cooling air vents on a similar London Duck Tours vehicle
Figure 37 - Abandonshipandrescuesequence
Figure 38 - SimplifiedillustrationofCleopatra’s drivetrain
Figure 39 - Typicalslidingsplineddriveshaftanduniversaljointarrangement
Figure 40 - Braking system air reservoirs
Figure 41 - OriginalDUKWenginecompartmentcoolingairsystem
Figure 42 - Modifiedenginecoolingairflowandenginecompartmenthotairextraction
Figure 43 - Cleopatra’s engine exhaust pipe
Figure 44 - Typical London Duck Tours DUKW passenger compartment and crew cablayout
Figure 45 - Boarding platform and ladders
Figure 46 - SimplifiedillustrationofCleopatra’s fuel supply system
Figure 47 - TypicalLondonDuckToursDUKWenginecompartmentfixedfire-fightingsystem
Figure 48 - Emergencyfuelshut-offvalvesandfiredamperreleasehandlesinasimilar vehicle
Figure 49 - BCTQLtd’s2008buoyancyfoamcalculations
Figure 50 - Buoyancy foam packed around the drivetrain in the centre void space of a London Duck Tours DUKW
Figure 51 - Buoyancy foam packed into the engine compartment ventilation void spaces
Figure 52 - Firedamagedpassengercompartmentandcrewcab
Figure 53 - Firedamagewithintheenginecompartmentandstarboardventilationvoid space
Figure 54 - Firedamageunderthecrewcab
Figure 55 - Areaofdeepestburnwithincentralvoidspaceaftoftheautomaticgearbox
Figure 56 - Burntthroughsectionofflexiblehose
Figure 57 - Greasecontaminatedfoamremovedfromaroundthebandbrake
Figure 58 - Laboratoryanalysisoftheforwarddriveshaftuniversaljoint
Figure 59 - Tightly packed foam in central void space
Figure 60 - Hull corrosion within Wacker Quacker 1’s aft void space
Figure 61 - Firedevelopment
Figure 62 - The last of the passengers to escape from Wacker Quacker 1’s passenger compartment
Figure 63 - DublinDUKWsoperatingwithexternalbuoyancytubesandopencanopy
Figure 64 - MemberofthepublicjumpingfromPredator 3 to help passengers in the water
TABLES
Table 1 - SpacesidentifiedbyBCTQaslocationstofitbuoyantmaterial
Table 2 - VolumesandlocationsofbuoyancyfoaminsertedpriortoMAIBfloodingtrials
ANNEXES
Annex A - The Yellow Duckmarine vehicle drivers’/masters’ safety checklists
Annex B - The Yellow Duckmarine 2013 pre-departure and pre-splashdown safetybriefs
Annex C - AnexampleofanearlierversionofTheYellowDuckmarinepre-splashdownsafetybrief
Annex D - The Yellow Duckmarine maintenance and inspection record sheets
Annex E - DesignplansfortheLondonFrogCompanystrengthenedpropellershaft tunnel
Annex F - DesignmodificationscarriedoutbyLondonDuckToursLtdfollowingthe suspension of its operations after the Cleopatrafire
GLOSSARY OF ABBREVIATIONS AND ACRONYMS
A - Ampere
AIS - AutomaticIdentificationSystem
APV - Amphibiouspassengervehicle
BCTQ - Burness Corlett Three Quays Ltd
BV - Bureau Veritas
°C - Degrees Celsius
CCTV - Closed-circuit television
COIF - Certificateofinitialfitnessforroaduse
DfT - Department for Transport
DPA - DesignatedPersonAshore
DSC - Digitalselectivecalling
DSMCode - DomesticPassengerShip(SafetyManagementCode) Regulations2001
GPS - Globalpositioningsystem
kg - kilogram
kPa - kilopascal
kt - knot
kW - kilowatt
LDT - London Duck Tours Ltd
LFB - LondonFireBrigade
LSA - Lifesavingappliance
m - metre
m3 - cubicmetres
MCA - MaritimeandCoastguardAgency
MGN - MarineGuidanceNote
mm - millimetre
mph - miles per hour
MSN - MerchantShippingNotice
MTB - Marinetransferbox
MTL - MaterialsTechnologyLtd
N - Newton
NTSB - NationalTransportationSafetyBoard
NVIC - NavigationandVesselInspectionCircular
PFD - Personalflotationdevice
PLA - PortofLondonAuthority
PSV - PublicServiceVehicle
RIB - Rigid-hulledinflatableboat
RNLI - RoyalNationalLifeboatInstitution
rpm - Revolutionsperminute
t - tonne
TYD - The Yellow Duckmarine
UJ - Universaljoint
V - volts
VHF - VeryHighFrequency
VOSA - VehicleandOperatorServicesAgency
VTS - VesselTrafficServices
WQ - Wacker Quacker
WW2 - World War 2
TIMES: AlltimesinthisreportareUTCunlessotherwisestated
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SYNOPSIS
Atabout1553on15June2013,theamphibiouspassengervehicleWacker Quacker 1 sankbythebowduringasightseeingtourinSalthouseDock,Liverpool.Thevehicle’s31passengersand2crewabandonedintothewaterandeitherswamashoreorwererecoveredwithoutseriousinjurybythecrewsofthreerecreationalnarrowboats.Wacker Quacker 1hadsufferedseverefloodingthroughtwoholesthathadbeentorninitshullwhenitspropellerwasfouledbyadiscardedcartyre.
Atabout1150on29September2013,afirebrokeoutonboardtheamphibiouspassenger vehicle CleopatraduringasightseeingtourontheRiverThames,London.Its28passengersand2crewwerealsoforcedtoabandonthevehicleandwererecoveredfromthewaterwithoutseriousinjurybythecrewsandpassengersofthreecommerciallyoperatedrigid-hulledinflatableboats.
Wacker Quacker 1wasthesecondamphibiousvehicletosinkinSalthouseDockwithina3-monthperiod;onbothoccasionsthevehiclesdidnothavethequantityofbuoyancyfoamrequiredtoprovidethemandatedlevelofresidualbuoyancy.Followingthe sinking of Wacker Quacker 1,theMaritimeandCoastguardAgencydiscoveredthattheLondon-basedamphibiouspassengervehicleswerebeingoperatedwithabouttwothirdsofthebuoyancyfoamrequiredtomeettheUK’sdamagedsurvivabilitystandard.Asaresult,thevehiclesweretemporarilytakenoffthewatertoallowtheoperatortofittheadditionalfoamneededtoensureitsvehiclesremainedafloatinthefullyfloodedcondition.Inordertoachievethis,additionalunsecuredandunprotectedbuoyancyfoamwastightlypacked around the engine compartment and in the void spaces under the passenger deck. Thisincreasedtheambienttemperaturesinandaroundthevehicles’enginecompartments.
The investigation concluded that:
• Prior to the sinking of Wacker Quacker 1,theLiverpoolandLondonoperators(TheYellowDuckMarineandLondonDuckTours,respectively)hadfailedtomeettheUK’smandatedbuoyancystandard;whentheLondonDuckToursdid,itintroducedthecircumstancesthatledtothefireonboardCleopatra.
• TheLiverpoolbasedvehicleshadbeenpoorlymaintainedandtheirmaterialconditionhadbeenallowedtoprogressivelydeterioratetoanunsafeleveloveraprolongedperiodof time.
• Inbothinstances,thecrewhadlittletimetoco-ordinatetheevacuationprocessandtheconfinednatureofpassengerspacesmadeitalmostimpossibleforthemtocontrolorassist the passengers.
Factorscontributingtotheaccidentsincluded:
• Inrespecttobuoyancy,theoperatorshadnottakenappropriateactiontoaddressthelessonslearnedfromprevioushighprofileaccidentsandfromrecentsimilarhazardousincidents.
• InLiverpool,thepassengersandcrewwerenotadequatelypreparedtodealwiththeemergency situation.
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• TheMaritimeandCoastguardAgency’speriodicsurveyandinspectionregimes,andtheirunscheduledinterventionshadbeenineffective.
• TheMaritimeandCoastguardAgencysurveyorswithresponsibilityforamphibiouspassengervehicleshadnotbeenprovidedwithappropriateinstructions,guidanceortraining.
TheinvestigationalsoidentifiedthattheDepartmentforTransport’sMaritimeandCoastguardAgencyandVehicleandOperatorServicesAgencybothhadlong-standingconcernsoverthesafeoperationofthesevintageamphibiousvehicles.ButtheydidnotsharetheirconcernsorknowledgeeffectivelybeforeorfollowingthesinkingofthetwoLiverpoolvehicles.ThefireonboardCleopatra could easily have occurred on the road and thereforecomeunderthejurisdictionofthelandbasedregulator.
InresponsetoMAIBrecommendationSB3/2013,theMaritimeandCoastguardAgencytookactiontotemporarilysuspendamphibiousoperationsontheRiverThames.Ithasalsoprovidedguidancetoitssurveyorstohelpthemverifythevolumeoffoamfittedintothehullsofamphibiousvehicles,andhascarriedoutaninternalinvestigationintotheperformanceofitsLiverpoolandOrpingtonMarineOffices.LondonDuckTourshasmodifieditsvehiclestoprovideanalternativemethodofsatisfyingthedamagedsurvivabilitystandard,andhassubsequentlybeenpermittedtoresumeitswaterborneoperations.TheYellowDuckmarinehasbeenputintoadministrationandthenorth-westTrafficCommissionerhaswithdrawnitsPassengerServiceVehiclelicence.
RecommendationshavebeenmadetotheMaritimeandCoastguardAgencyandtheDriverandVehicleStandardsAgencywiththeaimofimprovingcrossagencyinformationflow,thestandardofAPVsurveysandinspectionsandimprovingtheindustry’soperationalpractices.LondonDuckToursLtdhasbeenrecommendedtocarryoutathoroughassessmentoftherisksintroducedbyanyfuturemodificationstoitsvehicles.
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SECTION 1 - FACTUAL INFORMATION WACKER QUACKER 1
1.1 PARTICULARS OF WACKER QUACKER 1 AND ACCIDENT
SHIP PARTICULARSVessel’s name Wacker Quacker 1
Flag UKCertifying authority MaritimeandCoastguardAgencyVessel type Class V passenger vesselVehiclechassisnumber 353-19572Vehicle type DUKWamphibiouspassengervehicleYearofbuild 1945(convertedtoAPVin2001)Registeredowner Pearlwild LtdTrading name The Yellow DuckmarineConstruction SteelHull length 9.45mLength overall 10.43mWidth overall 2.55mHeightofcanopy(fromtheroad) 4.1mOnroadweight 8.3tVOYAGE PARTICULARSPort of departure SalthouseDock,Liverpool,EnglandPort of arrival SalthouseDock,Liverpool,EnglandType of voyage Sightseeingtour,inlandwaterwaysManning 2MARINE CASUALTY INFORMATIONDate and time 15June2013atabout1553Type of marine casualty or incident VerySeriousMarineCasualtyLocation of incident SalthouseDock,LiverpoolPlaceonboard Propeller shaft tunnelInjuries/fatalities NilDamage/environmentalimpact NilShipoperation SightseeingtoursVoyage segment ArrivalExternal & internal environment Daylight, dry and clear, sheltered waters.Personsonboard 33(2crew+31passengers)
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1.2 BACKGROUND
Amphibiouspassengervehicles(APV)arewidelyusedthroughouttheworldbytourismandleisurecompaniestodeliverlandandwaterbornesightseeingtours.ThemodernamphibioussightseeingtourconceptoriginatedintheUSAwhen,in1946,anAmericanbusinessmanboughtasurplusUSarmyDUKW1amphibiousvehicleandmodifiedittocarrypassengers(Figure 1).Overthefollowing60years,theamphibioussightseeingtourconceptevolved,withfleetsofconvertedDUKWs,otherex-militaryvehiclesandavarietyofspecificallydesignedcommercialAPVsoperatinginmanymajorcitiesacrosstheworld.
In2000,theAmericanbusinessmodelwasreplicatedintheUKwhenthefirstAPVsightseeingtourswereintroducedontheRiverThames,London,bytheLondonFrogCompanyLtd.Ayearlater,asimilaroperationwasstartedinLiverpool.By2013, four converted DUKWs, Wacker Quacker 1(WQ1),Wacker Quacker 2 (WQ2),Wacker Quacker 4(WQ4)andWacker Quacker 8(WQ8),werebeingoperatedinLiverpool’sSouthDocks2complexbyPearlwildLtdunderthetradingnameofTheYellowDuckmarine(TYD).
On30March2013,WQ4 sank (Figure 2)whileundertowinSalthouseDock,Liverpool.Therewasnooneonboardatthetime,andthesinkingwasinvestigatedbytheMaritimeandCoastguardAgency(MCA).Duringitsinvestigation,theMCAdiscoveredthatthehullsofTYD’svehiclesdidnotcontaintheappropriatequantitiesofbuoyancyfoamrequiredtokeepthemafloatwhenflooded.TheMCAimmediatelysuspendedTYD’swaterborneoperationsandinstructedthecompanytoinsertanagreed volume of additional foam. TYD engaged the services of an independent firmofnavalarchitects,BurnessCorlettThreeQuaysLtd(BCTQ),tocalculatehowmuchfoamwasneededtomeettheMCA’srequirements.Sixweekslater,havingsatisfiedtheMCAthatithadmetitsbuoyancystandards,TYDresumeditsoperations on the water.
1.3 NARRATIVE
Atabout0900on15June2013,themasteroftheDUKWWQ1 (Figure 3), and his driver,arrivedforworkatTYD’sfleetmaintenancegarageinLiverpool,England.Thecompany’s mechanics, having carried out their daily maintenance routines the night before,presentedWQ1 for inspection. The master and driver examined WQ1 and completed the vehicle drivers’/masters’ safety checklist (Annex A). They then drove WQ1fromthegaragetoTYD’spassengerpick-uppointonGowerRoad,adjacenttoSalthouseDock(Figure 4).
WQ1 was one of three TYD vehicles operating that day and was scheduled to undertakeseventoursbetween1000and1830.At0950,themasterstartedtoboardthepassengersforhisfirsttour.Tenminuteslater,WQ1 departed with 30 passengersonboard.Theroadtriparoundthecitycentreandthewaterbornetourthroughtheinterlinkedsoutherndockscomplextookabout55minutestocomplete.During each trip, the master sat next to the driver and assumed the role of the tour guide (Figure 5).
1 ADUKW(Pronounced“duck”)isanamphibiouslandingvehiclethatwasdesignedtotransportmilitarypersonnelandsuppliesfortheUSarmyduringWorldWar2.TheacronymDUKWindicatesthatthevehiclewasdesignedin1942(D),itisanamphibian(U)andhasbothfront-wheelandrear-wheeldrivecapability(KandWrespectively).
2 Liverpool’sSouthDockscomplexismadeupofsixinterlinkeddocks(SalthouseDock,AlbertDock,WappingDock,QueensDock,CoburgDockandBrunswickDock)thathavesignificantheritagevalueandhavebeenredevelopedspecificallyforthetourismtrade.
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WQ4undertowinSalthouseDock
Figure 2: Wacker Quacker 4sinkinginSalthouseDock,Liverpool,on30March2013
ImagescourtesyofRogerODoherty
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Figure 3: AmphibiouspassengervehicleWacker Quacker 1
Figure 4: TheYellowDuckmarineamphibiouspassengervehiclesightseeingtourroute
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Atabout1204,havingcompletedthewaterbornesectionofthethirdtouroftheday, the driver attempted to drive WQ1uptheSalthouseDockslipway.Duringhis approach, the driver increased the vehicle’s propeller speed and attempted to engage six-wheel drive. When WQ1’s wheels made contact with the slipway the vehiclebegantoclimboutofthewater.Thedriveralmostimmediatelyrealisedthatthe engine was losing power (Figure 6). Concerned that the engine might stall, the driverabortedhisattempttoexitthedockandallowedWQ1torollbackintothewater.Heputthepropellerasternandmanoeuvredbackwardstomakeroomfora second attempt. The second attempt was successful and the passengers were driventoGowerStreet,wheretheyweredisembarked.
At1454,WQ1setoffonitsfifthtourofthedaywith31passengersonboard.Fourofthe passengers were children, the youngest of whom, a 2 year old girl, was sitting on hermother’slapatthebackofthevehicle(Figure 7).At1529,WQ1 arrived at the SouthDockscomplexandstoppedontheroadoppositetheSalthouseDockaccessslipway.Fifteensecondslater,thedrivermanoeuvredWQ1 to the top of the slipway, sounded the vehicle’s horn and then drove it into the water (Figure 8).
Thedriverfollowedthecompany’snormalroutethroughtheinterlinkedSalthouse,WappingandAlbertdocks(Figure 4). At1546,thedrivermanoeuvredWQ1 out of AlbertDockandbeganhisapproachtowardstheSalthouseDockslipway.At1548,WQ1’swheelsmadecontactwiththeslipwayandthevehiclebegantoclimboutofthewater.Again,thedriverlostpowerandhadtoaborthisattempttoexitthewaterand allowed WQ1torollbackintothedock.
AsthedriverattemptedtomanoeuvreWQ1 into position to make a second attempt toclimbtheslipway,athudwasheardtowardsthebackofthevehicleanditsdriveshaftsstartedtovibrate.ThedriveralertedthemastertotheproblemandtheydecidedtomaketheirwaytoCoburgDock,whichhadaslipwaywithalesssteepincline.
Figure 5: Crew positions during sightseeing tour
Master’sposition(tourguide)Driver’s position
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As WQ1driftedastern,thedriverwasunabletodisengagethewaterpropellerdriveshaft,andtheenginestalled.Themastertriedtohelpthedriverbykickingthegearlevers.Atthesametime,passengersatthebackofthevehiclesawwaterfloodinginfromundertheirseatsandbegantoshouttothecrewmenatthefront.Initially,themastercontinuedtohelpthedriverwhowasaskinghimwherethecompanymobilephonewas.Withthewaterlevelrisingrapidlythepassengersbegantoscreamandshoutevenmore.Thepassengersontheupperlevelatthebackofthevehiclegrabbedlifejacketsfromaboxunderoneoftheaftbenchseatsandbegantopassthemforward.Themasterwenttothebackofthevehicletohelpdistributethelifejacketsandgiveinstructionstothepassengers.
Within 1 minute, the water level within the passenger space had reached the top oftheforwardfacingseatsandsomeofthepassengersbegantopanic.Membersofthepubliconthedocksideandtheownersofseveralrecreationalnarrowboats,whichwereberthedinthedock,begantorealisethattherewasaseriousproblemonboardWQ1.Asthetouristsbegantogatheratthewater’sedge,severalnarrowboatslefttheirmooringsandwenttohelp.
Themastertriedtocalmhispassengersandtoldthemtoputtheirlifejacketsonandremainattheirseats.Mostofthepassengerscouldnotseeorhearthemasterand started to evacuate through the windows (Figure 9).Withwaternowbeginningto lap over the vehicle’s side coaming into the passenger space, more and more passengersleaptintothewater.A70yearoldmalepassenger,whohadclimbedoutofhiswindowandontotheroof,begantolaunchthevehicle’sbuoyantfloats.
Figure 8: SplashdownintoSalthouseDock
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Figu
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:Abandonshipandrescuesequence
Vehicleflooding
Finalattempttore-starttheengine
Pas
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Passengerlaunchingbuoyantapparatus
PassengerrecoveredonboardP
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Mem
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At1553,afterabout2minutes’flooding,thebowofWQ1sank.Asitdidsothemasterjumpedofftheboardingplatformatthebackofthevehicleandintothewaterandthedriver,whowasmomentarilysubmerged,hadtoescapethroughtheforwardport side window and swim to the surface. By now, most of the passengers were inthewaterandmostwerenotwearinglifejackets.Asthefirstofthenarrowboats,Predator 3,arrivedonthescene,oneofitsoccupantsleaptfromitsbowintothewatertohelprescuethepassengers.Membersofthepublicwhohadgatheredonthe dockside and on the access slipway, alerted the emergency services and started tothrowlifebuoysintothedock.
WQ1’sbowhadhitthedockbedbutitssternremainedafloat.Thelastpassengertoleavethevehiclewasthemotherofthe2yearoldchild.Shehadpassedherdaughterthroughtheportaftwindowtoherhusband,beforeclimbingoverthesterndoorontotheaftboardingplatform.Mostofthepassengerswererescuedfromthewater,ortransferredfromthesternofthevehicleontothecanalnarrowboatsthatcametotheirassistance.Someofthestrongerswimmersswamtotheslipwayandwalked ashore.
TYD’soperationsmanagerranfromherofficetoWQ8, which was in the process of boardingpassengers,andalerteditsmaster.TheoperationsmanagerreturnedtoherofficeandWQ8wasdrivenawayfromGowerRoad.Bynow,paramedics,policeofficers,ambulancesandfireengineswereonscene,andasearchandrescuehelicopterwasintheair.At 1556,TYD’soperationsmanagerranfromherofficetothe scene.
Initiallytherewassomeconfusionoverthenumberofpersonsthathadbeenonboard,andwhenaheadcountwascarriedoutninepassengerswereunaccountedfor.Someofthemissingpassengershadalreadybeentakentohospitalforassessment and the others had returned to their hotels to change their clothes. Confirmationthatallpassengersandcrewhadbeenrescuedandweresafewasachieved at 1745.
Later in the evening, police divers carried out an underwater inspection (Figure 10) of WQ1 and then attached recovery slings to the vehicle’s rear wheel axle. Oncerecoveredbackontotheslipway,WQ1wasinspectedandphotographedbyaMerseysidePolicesceneofcrimeofficer.Thepolicediscoveredacartyrewrappedaround the propeller and found two large holes in the vehicle’s propeller shaft tunnel shell plating (Figure 11).
1.4 ENVIRONMENTAL CONDITIONS
Itwasadryday,thewindwasslightandthewatersinthedockswereflatcalm.Theambientairtemperaturewasabout20ºCandthewatertemperaturewasabout15ºC.Liverpool’sSouthDockswasfilledwithsaltwatertakenfromthetidalRiverMersey,andthedepthofwaterwhereWQ1 sank was approximately 4.5m.
1.5 THE YELLOW DUCKMARINE
1.5.1 Company history and structure
In2001,LiverpoolDuckToursLtdlauncheditsamphibioussightseeingtoursaroundthestreetsofLiverpoolcitycentreandthroughthecity’shistoricSouthDockscomplex.In2003,PearlwildLtdpurchasedLiverpoolDuckToursLtdandstartedto
14
Starboardaftwheels
WQ1’sbowonthedockbed
Passengeraislefloorplateslifted
Figure 10: Police divers’ underwater survey
15
Car
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1:PhotographstakenbypoliceaftertherecoveryofW
acke
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tradeunderthenameTheYellowDuckmarine.Inthemonthsleadinguptotheaccident,thecompanyemployed35staffandwasoperatingupto28tourseachday.
Thecompanystructurecomprisedanoperationsdepartment,whichwasledbytheoperationsmanager,andanengineeringdepartment,whichwasledbythedirectorofengineering.Theoperationsteamwaslocatedinanofficenexttothetourcompany’sticketofficeintheAlbertDockbuildings(Figure 4). The operations team included the company’s nominated transport manager3, its sales and marketing managers, and its drivers and crew.
The engineering team worked from the company’s vehicle maintenance garage locatedabout1milefromSalthouseDock.Thedirectorofengineeringoversawtheday to day implementation of the company’s maintenance management system and was TYD’s designated person ashore4.Thegarageoperatedfrom0800-2000sevendays a week using a two shift system, 4 days on and 4 days off. Each shift was led byanengineeringmanagerandhadthreemechanics.
ThemajorityofTYDemployeeshadroadtransportbackgroundsandnoneofthemanagement team or technical staff had any commercial maritime experience prior tojoiningthecompany.
1.5.2 The fleet
TYD’sDUKWswerecertifiedbytheMCAtooperateonCategoryB5 waters as Class V6 passenger vessels. Pearlwild Ltd also held a Department for Transport (DfT)TrafficCommissioners’StandardNationalLicencethatauthorisedTYDtooperateitsDUKWsaspublicservicevehicles7 on the road. Each vehicle was certifiedtocarryupto30passengersandwasrequiredtohaveacrewoftwo.Inaccordance with local arrangements, each vehicle was also permitted to carry up to twobabesinarms8.
WQ1 and WQ2werebothconvertedtoAPVsin2001andwerealmostidentical.WQ8 and WQ4wereconvertedtoAPVsbyacompanyonthesouthcoastofEnglandin2000andwereoriginallyoperatedinGlasgow,Scotland.WhentheyfirstjoinedTYD’sfleetin2006and2009respectively,theirpassengerspaceandcanopy design were different to that of WQ1 and WQ2 and they could only carry 24 passengers.Theircanopieswereoriginallymadefromwoodandhadaretractablesun roof (Figure 12). WQ4 and WQ8 were later converted to carry 30 passengers andthewoodencanopieswerereplacedwithsteelones,similartothosefittedtoWQ1 and WQ2.
3 TheappointmentofaprofessionallycompetenttransportmanagerwasastatutoryrequirementunderthePublicPassengerVehiclesAct1981.Thenominatedtransportmanageristhepersonresponsiblefortheeffective and continuous management of the transport activities of the company.
4 Thedesignatedpersonashoreisthepersonwhoprovidesthelinkbetweenship’sstaffandshorestafftoverifythe implementation of the company’s safety management system.
5 UK Category B inland waters – wider rivers and canals where the depth of water is generally 1.5m or more and where the significant wave height could not be expected to exceed 0.6m at any time.
6 ClassVpassengervessel-shipengagedonlyonvoyagesinCategoryA,BandCwaters.7 Publicservicevehicle–avehiclewithmorethaneightpassengerseatsusedtotransportpeopleforprofit.8Babes in arms – children under the age of 1 year old.
17
Retractablesunroof
WQ8 converted to carry 30 passengers
WQ4
WQ8certifiedfor24passengers
Figure 12: Wacker Quacker 4 and Wacker Quacker 8beforeandaftertheirconversiontocarry30passengers
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1.6 THE CREW
1.6.1 Master
ThemasterwasBritishandwas60yearsofage.HehadworkedforTYDfor2yearsandheldabespoke,operation-specificBoatmasters’Licence.Hehadbeena master for a year, and prior to that he was a crewman and tour guide. He did not holdapublicservicevehicle(PSV)drivers’licenceandthereforewasnotqualifiedtodrive WQ1 on the road.
1.6.2 Driver
The driver was British and was 51 years of age. He had worked for TYD for 4 monthsandheldaPSVdrivers’licence.HehadbeenlearningtodrivetheAPVsonthe water under the supervision of a master for 3 months and was working towards gaininghisBoatmasters’Licence.PriortojoiningTYDhedrovecommercialbuses,coaches and heavy goods vehicles.
1.7 THE VEHICLE
1.7.1 The DUKW
MilitaryDUKWsweredesignedduringtheWorldWar2(WW2)forthepurposeofmakingbeachlandingsandtransportingtroopsandequipmentawayfromabeachhead.Althoughmechanicallyrugged,hullconstructionwassimplifiedforthesake of an accelerated production schedule and the anticipated short life expectancy ofthevehicles.Over21,000DUKWswerebuiltintheUSbetween1942and1945,themajorityofwhichweretransportedoverseas.
TheDUKWinitsmilitaryconfigurationwasbuiltonaGeneralMotors’2½ton6x6truckchassis(3axlesand6wheels)andhadanoverallhulllengthof9.45m.Itwasequippedwitha6-cylinderGMC270gasoline(petrol)engineandhada5-speedmanualgearbox.Thevehiclehada2-mancrewandcouldcarryapayloadofupto2.3tofstoresor25fullyequippedcombattroops.Ithadamaximumspeedofabout50mphonlandandjustover5ktsonthewater.
Thevehiclehadathreeblade,clockwiserotating,phosphor-bronzepropelleranda single spade-type rudder. The propeller shaft was supported externally in the waterpropellertunnelbyacaststeelv-strut(Figure 13). The vehicle was left-hand drive and on land its front two wheels were steered in a conventional manner. The rudderwasconnected,bywirecables,tothemainsteeringwheelandmovedasthevehicle’s two front wheels were turned.
Thebasichullwasofweldedconstructionandwasfabricatedfromacombinationof2mm,2.4mmand2.8mmthickcold-rolledcarbonsteelplates.Thevehiclecomprisedfivemaincompartments:bow(forward)compartment,enginecompartment,driver’scompartment(crewcab),cargocompartmentandstern(aft)compartment.Thedriver’scompartment,bowandsterndecks,andthesidecoamingweremanufacturedassubassembliesandwereboltedtothebasichull(Figure 14). The original design took into consideration the interaction of road stressesonatruckchassisaswellasthewaterbornestressesonthehull.Interiorbulkheadsandreinforcementribsprovidedextrarigidity(Figure 14),butthehullhad
19
Propeller tunnel
V-strut
Afttransversebulkhead Propeller tunnel
V-strut shoes
Figure 13: Propeller shaft v-strut support
Bulkhead stiffeners
Sidecoaming
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Afttransversebulkhead
Whe
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Pressedsteelrubbingrails
21
toflexwiththechassistopreventitfailingduringroaduse.Pressedsteelrubrailswereweldedforwardtoaftalongtheoutsideofthehull(sidesandbottom)toprotectthe shell plating from contact damage and to provide additional structural integrity.
The hull had three drive shaft tunnels: one for the propeller, one for the front wheel-axle; and one for the rear wheel-axles. The tunnels housed the hull penetrations for the propeller shaft and the wheel-axle drive shafts. The hull penetrationforthepropellershaftwassealedusingastandardmarinestuffingbox.The sealing of the hull penetrations for the wheel-axle drive shafts presented the designerswithamoredifficultchallengeasthedriveshaftsneededtomoveupanddown due to the action of the vehicle’s suspension system. Tosolvetheproblem,the drive shafts were encased within watertight housings. The drive shaft housings permittedthesizeofholeinthehullnecessarytoprovidetherequiredverticalmovement and elongation of the drive shaft. The drive shaft housings were sealed at bothendsusingflexiblerubberboots(Figure 14).
Thehullhadtwotransversebulkheads.Theafttransversebulkheadseparatedthe cargo compartment from the stern compartment and the forward transverse bulkheadseparatedthecrewcabfromtheenginecompartment.Theseinternalbulkheadsaddedstructuralstrengthbutwerenotwatertight.Anywaterthatenteredthehullwasfreetotravelthroughoutitslength.Inordertoremovewaterthatmightenterthehulloverthedeckcoamingsorthroughhullpenetrations(duetosealfailuresorhulldamage),thevehiclehadtwopropellershaft-drivende-watering/bilgepumpsandanemergencyhandoperatedbilgepump.Thelargercapacityshaft-driven pump, known as the Higginspump,wascapableofdischarging200gallons(1,100litres)ofwaterperminute.Thecapacitiesofthesmallershaft-drivenpump and the hand operated pump was 50 and 25 gallons per minute, respectively. Tooperatetheshaft-drivenpumps,thepropellerdriveshafthadtobeengaged;thehigher the revolutions, the greater the pumping rate.
TheDUKWwasoriginallyfittedwithsixdrainplugs:3x76mmdiameterhulldrainplugsand3x38mmdiameterdriveshafthousingdrainplugs.Theseallowedthecrew to drain water and oil from the hull after exiting the water, and also provided accessforgreasingsomeofthedriveshafts’universaljoints(UJ).Inadditiontothedrainplugs,fourhulldrainvalveswerefittedtolaterDUKWmodels.
1.7.2 Wacker Quacker 1
WQ1wasbuiltin1945andin2001wasconvertedforuseasanAPV.Itwas9.45mlong(hulllength),2.55mwide,hadaroadheightof4.1mandweighed8.35t.InitsAPVconfigurationitcouldcarryupto30seatedpassengersandwasmannedbyacrew of two.
WQ1waspoweredbya6-cylinder,4-stroke,naturallyaspirated,Bedford330dieselenginewithamanualgearbox.Thechassisandbasichullwereoriginalandits drivetrain arrangements allowed the driver to manually select four or six-wheel drive,andengagethewaterpropellerdriveshaftaheadorastern.Infour-wheeldrive, power was delivered to the rear two axles, when six-wheel drive was engaged power was also delivered to the front axle.
MuchofWQ1’s hull plate thicknesses were as original:
• 2.8mmatthebowandonthebottomatthestern;• 2.4mmonthebottominthecentre;and• 2mm on its sides.
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Thepropellerandwheel-axledriveshafttunnelswereoriginallyformedfrom2.8mmand 2.4mm steel plate respectively.
The vehicle’s original cargo compartment and stern deck was converted to provide the passenger compartment. The passenger compartment was decked with steel plates.Thedeckwasnotwatertightand,althoughbolteddown,theplatescouldbeliftedtoallowaccessformaintenance.Buoyantmaterialwasrequiredtobefittedinthevoidspacesbelowthepassengerdeckandinseveralotherlocationswithinthevehicle.
Thehullpenetrationsforthevehicle’swheel-axledriveshaftshadbeenmodifiedtoallowtheremovalofthedriveshafthousingsandrubberbootarrangements.The original side coaming around the cargo compartment was extended aft to the transomandawatertightaccessdoorandboardingplatformwasfittedatthestern.Aboardingladderwasfittedontheportsideoftheboardingplatform.
Elasticated cord
Sidecurtainsraised
Zip & velcro release
Sidecurtainslowered
Securinghooks
Figure 15: Liverpool DUKW side curtains
23
Asteelcanopy,withasolidPerspexsunroofandtransparentplasticsidecurtains,was welded to the top of the passenger space side coaming. The side curtains were designedsothattheycouldberolledupandsecuredintheopenpositionorclosedusingzips(Figure 15).ThezipswereconnectedtoindividualwindowpanelsusingVelcrosothatthewindowscouldbepushedopeninanemergency.Elasticcords,whichcouldbestretchedoverhooksontheoutsideofthesidecoaming,werefittedtothebottomofthesidecurtainstohelpholdthemdownwhileontheroad.
Thepassengercompartmenthad12forward-facing2-personbench-typepassengerseatsarrangedforwardtoaftintworowsof6alongitslowerlevel,withacentreaisle.Therewerealsotwoinwardfacing3-personbench-typepassengerseatsontheraisedplatformatthebackofthecompartment(Figure 7).
WQ1hadrecentlyhaditshighcapacityshaft-driven(Higgins)bilgepumpremoved,andwasbeingoperatedwithfourelectrically-drivenbilgepumps.Thebilgepumpoperating switches were located on the driver’s control panel (Figure 16) and couldbesettotheoff, manual or automatic position. When in automatic mode, the bilgepumpswerestartedandstoppedbytheirindividualfloatswitches.Awarningbuzzersoundedwheneverthebilgepumpsoperated.Therewasalsoanemergencyhand-poweredbilgepumppositionedonthestarboardsideofthepassengercompartmentbehindthecrewseats.Inaddition,sevenexternaldrainpipeswithscrew-threadedplugswerefittedtothebottomofthehull(Figure 17). These were usedinsteadoftheoriginalbottomplugstodrainwaterfromthehullwhenonland.
TYD’svehicleswerenotfittedwithanynavigationalaidsanddidnotcarryradioequipment.Eachmastercarriedacompanymobilephonetoallowthemtocommunicatewiththecompany’soperationsofficeandgarage.
1.8 REGULATORY REQUIREMENTS
1.8.1 General
Amphibioussightseeingtoursareconsideredtobeanicheindustrybyboththemaritimeandroadregulators.ThemodificationofaDUKWforuseasanAPVpresentsauniquechallengeasthevehiclemustmeetbothlandandmaritimeregulatoryrequirements.Anymodificationsmadefromtheoriginaldesignmusttakeintoconsiderationtheimpactonboththelandandwateraspectsoftheoperation.
TooperateontheroadasaPSV,theconvertedDUKWswereclassedashistoricalvehiclesandwererequiredtohaveaDfTCertificate of Initial Fitness for Road Use (COIF).AspartoftheCOIFprocess,theDUKWswereinspectedbytheDfT’sVehicleandOperatorServicesAgency(VOSA)9andweresubjectedtoastandardtilttest (Figure 18).
WhenTheLondonFrogCompanyfirstapproachedtheMCAin1998,theMCAtreatedtheDUKWAPVsasnewvessels.Assuch,theMCArequiredownerstocomplywiththelatestconstructionandstabilitystandardssetoutintheMerchantShipping(PassengerShipConstruction:ShipsofClassesIIItoVI(A))Regulations1998.ThestandardsrequiredbytheseregulationswereexplainedintheMCA’sMerchantShippingNotice(MSN)1699(M).
9 Atthetimeofinitialcertification,theCOIFinspectionswerecarriedoutbytheDfT’sVehicleInspectorate.InApril2014,VOSAandtheDfT’sDrivingStandardsAgency(DSA)mergedtoformtheDriverandVehicleStandardsAgency(DVSA).
24
Bilge pump control switches
Crewcabconsole
Starboardforwardbilgepumpdischarge Port aft pump
discharge
WQ1 operating with 2bilgepumpsrunning
Figure 16: Wacker Quacker 1bilgepumpcontrols
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Port aft drain plug Drain plugchains
Figure 17: Wacker Quacker 1 hull drain plugs
Figure 18: Roadtilttest
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In2005,theMCAheldameetingatitsheadquarterstoreviewitsinitialapprovalprocessfortheconvertedWW2DUKWsandotherAPVs.Atthetime,anotherDUKW(intendedforuseinPlymouth,England)hadbeensubmittedforapprovalbutthelocalMarineOfficehadconcernsoveritshullconstruction;inparticular,itshullplatethickness.AccordingtotheMCA’sInstructions for the guidance of surveyors:
Unless justified by the use of special materials with supporting information to the satisfaction of MCA HQ, hull thickness of less than 3mm will not be accepted.
TheaimofthemeetingwastoestablishwhatapprovalstandardsshouldbeappliedtofutureAPVs,andwhatactionshouldbetakenwithregardtoexistingDUKWs.ItwasestablishedatthemeetingthattherecordsheldonfileattheMCA’sMarineOfficeswerelessthansatisfactoryandcouldnotbeusedtoconfirmthattheoriginalDUKWAPVswereproperlyapprovedwhentheywerefirstallowedtooperateintheUK.Followingthemeeting,MCAheadquartersinstructeditsMarineOfficestoensurethatallfutureAPVs,andmodificationstoexistingAPVs,wereapprovedtoappropriateclassificationsocietyrules.ThismeantthatfutureconvertedDUKWswouldrequireminimumhullbottomandsideplatethicknessesof3.5mmand3.0mm respectively. Existing vessels were allowed to continue to operate on the understandingthatspecialmeasureswouldbeputinplace;suchasfrequentinspectionsbyoperators,annualhullthicknesschecksbysurveyors,andtheapplicationofepoxycoatings.AprogrammewasalreadyinplacetoincreasethehullplatethicknessoftheLondonbasedvehiclesto3mm.
When Pearlwild Ltd purchased WQ8in2005,theMCA'sstancethatallnewlyconvertedDUKWshadtocomplywithappropriateClassificationSocietyrules,ledtheLiverpoolMarineOfficetorefusetocertifythevehicle.ThecompanyappealedagainsttheMCA'sdecisiononthegroundsthattherewerenoclassrulesforAPVsanditsnewlyacquiredvehiclehadpreviouslybeenissuedaClassVpassengercertificate.In2006theregulatoroverturneditsdecisionandcertifiedWQ8.Similarlyin 2009, WQ4wascertifiedtooperateonthewaterinLiverpool'sSouthDocks.
In2010,theMCApublishedMSN1823(M),Safety Code for Passenger Ships Operating Solely in UK Categorised WatersandMSN1824(M),EU Directive 2006/87/EC (as amended) – Laying Down Technical Requirements for Inland Waterway Vessels. The mandatory safety code was developed in consultation with surveyors and the marine industry, and the technical standards superseded those setoutinMSN1699(M).Althoughmandatory,theDUKWswerenotrequiredtomeetthemorerobusttechnicalstandardssetoutinMSN1823(M)astheyonlyappliedtonewships(thosethatdidnothaveavalidpassengercertificateonthedatethecodecameintoeffect).
In2012,PearlwildLtdacquiredafifthDUKWbut,asithadnotbeenpreviouslycertifiedtooperateasaClassVpassengervessel,thevehiclewasrequiredtomeetthelatestconstructionstandardssetoutinMSN1823(M).Unabletomeetthe new standard, the company did not convert the DUKW to carry passengers and continued to operate with four vehicles.
1.8.2 Stability and survivability requirements
MSN1699(M)setoutthestabilityrequirementsforundamagedvessels(intactstability)andthestandardsofsurvivabilityrequiredforthedamagedcondition.
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AstheconvertedDUKWshadnointernalwatertightsubdivisionandtheirdeckswerenotwatertight,theywereconsideredtobeopenships.TosatisfythestandardsofsurvivabilityprescribedinMSN1699(M)foraClassVpassengervesseloperating in Category B waters and carrying no more than 50 passengers the DUKWAPVshadtoachievetheheelingteststandarddescribedinSchedule2,Section3,andthebuoyancyteststandarddescribedinSchedule2,Section4.
TomeetthebuoyancytestsurvivabilitystandardtheDUKWswererequiredtohavesufficientbuoyancytoremainafloatwhenfullyflooded.Toachievethis,thevehicle’seffectiveresidualintactbuoyancyhadtobeatleast1.1timesitsintactvolumeofdisplacement(110%buoyancy).
Compliancewiththebuoyancytestsurvivabilitystandardcouldbedemonstratedthroughpracticalfloodingtrialsorbydetailedtheoreticalcalculations.Inadditiontoremainingafloatinafullyfloodedstate,thevehicleswererequiredtoremainuprightandstable.
MSN1699(M)alsostipulatedtheminimumrequirementsfortheconstructionofwatertightbulkheads,bilgepumpingsystems,emergencyelectricalpowerarrangements,fuelsystems,steeringgearandhullpenetrations.Accordingtotheregulations, WQ1wasrequiredtohaveatleastonepoweredbilgepump(whichcouldbeengine-driven)andahandbilgepump.
1.9 BUOYANCY FOAM
UKregisteredClassVDUKWAPVoperatorsusedacombinationoflowandhighdensityclosedcellpolyethylenefoamtoprovidetherequiredlevelofresidualbuoyancy.Thefoamusedwassuppliedinsheetformandwasindividuallycuttofitintonominatedvoidspaceswithinthevehicle’shull.MSN1699(M)requiredownerstoensurethatthebuoyancyfoamwas:
• protected against deterioration;
• adequatelysecuredagainstmovement;and
• installedinsuchawayastoprovidethegreatestpracticablecontributionstothestabilityandsurvivaloftheshipinthefloodedcondition.
TheoriginalbuildspecificationforWQ1’s conversion also emphasised that the foam neededtobetightlypackedandsecuredagainstmovement,andnotbeincontactwith moving parts.
Thevolumeofbuoyancyfoamrequiredtomeetthebuoyancytestsurvivabilitystandardwasdependentonthevehicle’sweightandtheinherentbuoyancyprovidedbyitstyresandotherfixturesandfittings.TheoriginalamountoffoamfittedintotheLiverpoolDUKWsisunknown.Theonlyinformationfoundintheowner’srecordsandtheMCA’sfilesrelatingtobuoyancyfoamrequirements,wasasetofcalculationsundertakenbyBurnessCorlett&Partners Ltd10onbehalfoftheLondonFrogCompanyin1999.ThesecalculationsformedpartoftheLondonbasedcompany’sinitialsubmissionstotheMCAandwerebasedonanumberoftheoretical assumptions and a vehicle weight of 7.2t.
10 BurnessCorlett&PartnersLtdlatermergedwithThreeQuaysMarineServicesLtdtoformBurnessCorlettThree Quays Ltd.
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FollowingthesinkingofWQ4, BCTQ calculated that WQ2 required9.7m3 ofbuoyantmaterialtobeinsertedintoitshullinordertomeetthedamagedsurvivabilitystandard.Thiswasbasedonaweighbridgeweightof8.3t,passengerandcrewweightof75kgperperson,andanestimatedinherentbuoyancyof2.3t.TheBCTQreportidentified14locations(Table 1) wherethebuoyantmaterialcouldbeinserted.Itsreportalsoexplainedthatitscalculationsweretobeusedforguidancepurposesonly,andthatallvehiclesinthefleetshouldbeaccuratelyweighedandanindividualreservebuoyancycalculatedforeach.
Concerned that 9.7m3 mightnotbesufficienttomeetthesurvivabilitystandard,andwantingtoensurethattheDUKWsremaineduprightinthefullyfloodedcondition,theMCAaskedBCTQtocalculatethemaximumspaceavailablefortheinsertionofbuoyancyfoam.UsingalaserscanofaLondonDUKW(Portia),BCTQidentified22locationswhere,accordingtoitscalculations,about12m3 ofbuoyantmaterialcouldbeinserted.Therevisedcalculationsrequiredanadditional1.1m3 offoamtobefittedinthespacesbelowthepassengercompartmentandcrewcabdecks;almosthalfofwhich was designated to the centre void space. The revised volume in and around theenginecompartmentwasalmostdoubled,from1.56m3to3.06m3.
TheMCAinstructedTYDtopack12m3 ofbuoyancyfoamintoallitsvehicles;thiswastheamounttheMCA’sLiverpoolMarineOfficeunderstoodhadbeenfittedwhenit allowed the company to resume its operations on the water.
1.10 POST-ACCIDENT INSPECTIONS, TESTS AND TRIALS
1.10.1 MAIB and Maritime and Coastguard Agency inspections
Followingtheaccident,MAIBinspectorsandMCAsurveyorsfromtheLiverpoolMarineOfficeexaminedWQ1 and TYD’s other DUKWs at the operator’s vehicle maintenancegarage.TheMCAsurveyorsinspectedthedamageandoversawtheremovalandmeasurementofthebuoyancyfoamfromWQ1, WQ2 and WQ8(WQ4 wasstillbeingrefittedatthetimeanddidnotcontainanybuoyancyfoam).
WQ1’shullwasfoundtocontainabout6m3 ofbuoyancyfoam.Similaramountswerefound in WQ2 and WQ8.Alargeproportionofthefoamremovedwascoatedinoilandgreaseandtherewasevidencethatsomeblocksoffoamhadmeltedasaresultof contact with moving parts (Figure 19).
TheDUKWswerefoundtobeinapoormaterialstate:theyweredirty;theinternalpaint coatings had lifted in many places; large sections of the vehicles’ electrical wiring was unsecured and in poor condition; and many of the instrumentation gaugesfittedtotheconsoleswerefoundtobedefective(Figure 20).
Therewereahighnumberofexternalpatchrepairsanddoublers11 in place on WQ1’s hull. These were particularly evident in the propeller shaft tunnel (Figure 21). There were two large holes in the propeller tunnel plating where the v-strut support shoeshadbeentornfromthehull.Oneholemeasuredabout110mmx140mmandtheotherabout220mmx143mm(Figure 21). The v-strut was hanging freely from the propeller shaft with its pressed steel support shoes still attached (Figure 22). There were several other holes in the hull where the tips of the rotating propeller bladeshadmadecontactwiththetunnelplating.
11 TheMCA'sInstructionsfortheGuidanceofSurveyorsexplainsthat:doubling plates may be acceptable but normally only as a temporary repair in certain circumstances. For example, to increase the strength of plating and stiffeners but not bottom plating (excluding temporary repairs) and only if there is sufficient material in the parent plate to effect a good weld.
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Meltedfoam
blocks
Recoveredfoam
stackedandmeasured
Figu
re 1
9:Foamremovedfrom
Wac
ker Q
uack
er 1
, Wac
ker Q
uack
er 2
and
Wac
ker Q
uack
er 8
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Figure 20: Wacker Quacker 8driver’scabinstrumentationandelectricalwiring
Loose wiring under dashboard
Loose wiring in aft buoyancyvoidspace
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1.10.2 Metallurgical analysis of hull plating
Two sections of the propeller tunnel plating and a section of the aft transverse bulkheadwerecutfromthehullofWQ1 and were sent, along with the propeller shaft v-strut (Figure 23),toTheTestHouse(Cambridge)Ltdformetallurgicalanalysis.Oneofthetunnelsectionsincludedthetwoholeswherethev-strutfeethadbeenattached.Theothersectionincludedlargeareaswhereitwasevidentthatprevioushullrepairshadbeencarriedout.Thesectionoftransversebulkheadincludedtheareawherethev-strutsupportshoeshadbeenattached.
Figure 22: V-strut suspended from Wacker Quacker 1’s propeller shaft
V-strut support shoes
V-strut
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Sectionsofhullplatingremoved for analysis
Transversebulkhead
Propeller tunnel
V-strut
Figure 23: Sectionsofpropellershafttunnelandafttransversebulkheadcutawayanddespatched for metallurgical analysis
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AtTheTestHouse(Cambridge)Ltd,specimensofthehullplatingwerecutout,polishedandsubjectedtomicro-structuralexamination,chemicalanalysisandtensile tests. The metallurgical analysis report concluded that:
• ThetwoU-sectionpressedsteelreinforcementribsweldedtotheforwardfaceofthetransversebulkheadhadsufferedextensivecorrosionwastage.
• Theweldconnectingthetransversebulkheadtothepropellertunnelplatinghad largely corroded away.
• The corrosion wastage had occurred sometime prior to the casualty and had compromisedthehull’sstructuralintegrity;inparticularthestructure’sabilityto counteract any torsional stressing induced via the propeller shafting.
• Thepropellertunnelplatinginwayofthesterncompartmentbulkheadandrudderstockhadsufferedwidespreadcorrosionwastage,whichhadbeenaddressedbymultiplephasesoffilletweldedpatchplaterepairs(doublers).
• Evidencesuggestedthatsomeofthehullrepairshadnotbeenfullyeffective,necessitating over-patching at some locations (Figure 24).
• Theoriginalparentshellplatingwaslowstrength,low-carbonrimming12 steel. Thiscontrastedwiththepatchrepairplates,whichappearedtobeofamoremodern low strength fully killed13 steel.
The metallurgical analysis report explained that production of the type of rimming steels seen in the samples was phased out in the 1970s. The report concluded that thebasesteelwaseitheroforiginalconstruction,orveryoldrepairsdatingbacktothe 1970s or earlier.
1.10.3 Stability tests and flooding trials
On30and31July2013,theMAIBusedWQ1 to conduct a series of practical stabilitytestsandfloodingtrialsattheCammellLairdshipyard,Liverpool(Figure 25).InadditiontoMAIBstaffanditsshorecontractors,thetestsandtrialswerewitnessedbyrepresentativesfromtheMCA,TYD,BCTQandLondonDuckToursLtd(LDT).
The aims of the trials were to:
• verifytheresultsofthetheoreticalbuoyancyassessmentsconductedbyBCTQ;
• identify any potential adverse effects associated with the insertion of buoyancyfoamand;
• carryoutareconstructionofthe15June2013floodingincident.
12 Rimmingsteel,alsoknownasdrawingqualitysteel,isatypeoflow-carbonsteelthathasanexcellentsurfacefinishandiscommonlyusedforcold-bendingandcoldforming.
13 Fullykilledsteelhasbeenprocessedsothatthereisnooxygenleftinthesteel.Itisthestrongesttypeofsteeland is normally used in the construction of ships and vessels.
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Figure 24: Analysisofpropellertunnelplatingandweldedrepairs
Layers of welded patch repairs Plate thicknesses around the holes where v-strutfeethadbeenattached
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Beforethetrialscouldtakeplace,MAIBinspectorsoversawtherepairofWQ1’s propellertunnelandtheinsertionofbuoyancyfoamintothedesignatedvoidspaces.Asteelinsertplatewasformedandbuttweldedintothepropellertunnel,inplaceofthesteelthathadearlierbeenremovedandsentformetallurgicalanalysis.Two 150mm diameter holes, designed to replicate those found in the hull after the sinking, were cut into the steel plate (Figure 26).Ashortlengthofthreadedsteelpipe,withablankingcap,wasweldedtoeachholetoallowthehulltobemadewatertightfortheinitialstabilitytests.
Thebuoyancyfoamsheetsusedforthetrialswereindividuallymeasuredandweighedbeforeinsertion.Thefoamwasfoundtobeabout5%denser,andtherefore5%heavier,thanthatgiveninitsspecification(33kg/m3).Whenthehighdensityfoam recovered from WQ1wasweighed,itwasfoundtobe20%denser.
Ittookteamsof4men7days(approximately280manhours)toinsertthenewbuoyancyfoamintothehullofthevehicle.Thefoamsheetswereindividuallycuttosizeandtightlypackedintothespacesidentifiedfortheinsertionof9.7m3 ofbuoyantmaterialinBCTQ’sinitialbuoyancyassessmentreport(Table 1). Care was taken not to compress the foam (Figure 26).Inordertoensurethemaximumamountoffoamwasinserted,theoperationalrequirementsofthevehiclewerenottakenintoaccountandfoamwasdeliberatelypackedupagainstmovingparts.Thetotalquantityoffoamfittedwas7.93m3 (Table 2); almost 2m3 less than the calculated amountrequiredtoprovide110%buoyancyand 4m3lessthanthatrequiredbytheMCA.
WQ1beingcranedintoCammell Laird dry dock
Figure 25: MAIBfoaminsertiontrialsandfloodingreconstruction
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Figure 26: Hull preparations and foam insertion process
Foaminsertionprocess
Repairedpropellertunnel
Floodingplugs
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Location Volume (m3)Aftbuoyancyspace 2.35Aftportbuoyancyspace 0.38Aftstarboardbuoyancyspace 0.38Portbuoyancyspace 0.84Starboardbuoyancyspace 0.84Centre void space 1.19Port vent space 0.28Starboardventspace 0.28Portsideshellandbox 0.60Starboardsideshellandbox 0.60Forwardbuoyancyspace 1.00Twoaftseatboxes 0.28Twelveseatboxes 0.84Driver and crew seats 0.10Total volume 9.96
Table 1:SpacesidentifiedbyBCTQaslocationstofitbuoyantmaterial
Location Volume (m3)Aftbuoyancyspace 1.6Aftportbuoyancyspace 0.38Aftstarboardbuoyancyspace 0.33Portbuoyancyspace 0.87Starboardbuoyancyspace 0.84Centre void space 1.24Port vent space 0.28Starboardventspace 0.28Portsideshellandbox 0Starboardsideshellandbox 0Forwardbuoyancyspace 1.00Twoaftseatboxes 0.24Twelveseatboxes 0.87Driver and crew seats 0Total volume 7.93
Table 2: VolumesandlocationsofbuoyancyfoaminsertedpriortoMAIB floodingtrials
Theamountoffoamthatcouldbefittedinthreelocationswassignificantlylessthanthequantitiescalculated.Thetotalamountoffoamfittedintheaftbuoyancyspacewas1.6m3,whichwas32%lessthanthe2.35m3 stipulated in the consultant’s report.Hadtheoperationalrequirementsforthesteeringgearbeentakenintoaccount,thequantityoffoamfittedwouldhavebeenfurtherreduced.According
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totheconsultant’sreport,TYDwasrequiredtofit0.6m3 of foam into the port and starboardsideshellboxpanels.However,themaximumspaceavailableineachofthetwospaceswasnomorethan0.06m3.Althoughtheshortfallsinthecalculatedvolumesoffoamweremainlyattributedtothesethreespaces,hadthevehicle’soperationalrequirementsbeentakenintoaccount,thetotalamountoffoamfittedwouldhavebeensignificantlylessthanthe7.93m3 achieved.
Oncompletionofthebuoyancypackingprocess,WQ1wasweighedtoestablishabaselinebeforeweightswereaddedtoreplicateitsApril2013weighbridgeweight.Weights were then placed on the vehicle’s seats to replicate the passenger and crewweight,andthefueltankwasfilledwithwater.Theremaining2m3ofbuoyancyfoamthatcouldnotbefittedintothedesignatedvoidspaceswasevenlydistributedaround the passenger compartment and secured in place (Figure 27). WQ1 was thencranedintothewaterandaseriesofstabilitytestswascarriedout.Oncethestabilitytestsandaninitialbaselinefloodingtrialhadbeencompleted,theexcessfoamwasremovedandthemainfloodingtrialwascarriedout.Thetrialwasdesignedtosimulatethebestpossiblecircumstancesforthesurvivabilityofthefullyladenvehicleandreconstructthefloodingsequenceexperiencedon15June2013.
Withthecapsremovedfromthetwo150mmfloodingpipes,WQ1 was craned into thedock.Ittookabout5minutesforWQ1tofullyflood(Figure 27). The DUKW assumedastarboardlistbutremainedafloatwiththewaterlevelsettlingabout50mmbelowtheforwardupperedgeofthepassengerspacesidecoaming.WQ1 wasobservedinthisstatefor30minutesbeforeitwascranedoutofthedock.
1.11 THE YELLOW DUCKMARINE SAFETY MANAGEMENT SYSTEM
1.11.1 Safety Policy and General Safe Operational Procedures manual
PearlwildLtdwasrequiredtoproduceasafetymanagementsystemforitsTYDoperationthatcompliedwiththeUK’sDomesticPassengerShip(SafetyManagementCode)Regulations2001(DSMCode).InaccordancewiththerequirementsoftheDSMCode,thecompanyproduceditsSafety Policy and General Safe Operational Procedures manual.
Themanualcomprised15sectionsand3annexesandhadbeenupdatedseveraltimesovertheyearstoreflectchangesincompanypolicy,proceduresandkeypersonnel.Section4ofthemanualsetoutthemasters’responsibilities;Section7includedtheproceduresrelatingtoemergencypreparedness;Section10containedthetextforthepassengersafetyannouncements;andSection14describedthe company’s maintenance management system. The company’s generic risk assessments were attached as an annex to the manual.
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Fullyflooded
WQ1beingcranedoutofdock
Weights used to simulate passengers & crew
Excess foam
Figure 27: Wacker Quacker 1floodingreconstruction
41
1.11.2 Emergency preparedness
TheproceduressetoutinSection7ofthemanualincludedthosetodealwithemergency situations such as fire, abandon ship, man overboard, collision, and main propulsion or steering failure. The documented procedure for abandon ship was:
• On the command of the Master the crew person is to broadcast to passengers that there is an emergency and they are to prepare to abandon ship.
• The master is to raise the alarm to the Duty Manager via the mobile phone.
• The crew person is to assist passengers to put on lifejackets and release the passenger compartment side curtains.
• Launch floatation rafts – one either side of the vessel and attach to the vessel.
• Launch lifebuoys.
• Order all passengers into the water and to hold onto floatation rafts or lifebuoys.
• Release floatation raft lines.
• Master and crew person into the water, one each side of vessel.
• Check persons in the water.
• Administer first aid as required.
• Maintain lookout for vessels coming to assistance.
• Guide all in the water to the nearest landing point or dock wall ladder/safety chains. [sic]
WQ1’s master and driver had participated in the company’s emergency drills and training programme and had experience of evacuating passengers onto pontoons andtheslipway,buttheywerenotfamiliarwiththeabandon ship procedure describedinthemanual.
1.11.3 Passenger safety announcements
Section10ofTYD’ssafetymanagementmanualincludedtwopassengersafetyannouncements:onetobegivenpriortosettingofffromthepick-uppoint,andonetobegivenwhilestoppedpriortodrivingdowntheslipway(pre-splashdownbrief)(Annex B).
Themanualinstructedthecrewpersontostartthepre-splashdownbriefbymakingajokeaboutgettingoffthevehicle.Duringthesafetybriefthemasterwasexpectedtoexplainthattherewasalifejacketonboardforeveryone;pointoutthelocationofthelifejackets;andtellthepassengersthat ‘in the unlikely event that we need to use them’,amemberofthecrewwillinstructthemontheiruse.Themanualrequiredpassengerstobegiventheopportunitytochoosetowearalifejacketwhileonthewater.Thebriefshouldalsohaveexplainedtheemergencyescaperoutes,
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themethodofreleasingthesidecurtains,andtheneedtobracethemselvespriortothesplashdown.Accordingtothemanual,thecrewperson’sinitialwaterbasedcommentaryinSalthouseDockshouldincludedetailsaboutthevehicle’slife-savingequipmentandvariousbilgepumpingarrangements.
InearlieriterationsofTYD’sSafety Policy and General Safe Operational Procedures manual (Annex C)thecrewpersonwasrequiredtogiveapracticaldemonstrationofhowtoputonalifejacket.Theearlierbriefsalsomadereferencetobuoyancyfoam.
Thepre-splashdownsafetybriefwasusuallygivenwiththevehicleparkedontheroadoppositetheSalthouseDockslipway.
1.11.4 Pre-splashdown safety checks
FollowingthesinkingofWQ4, the company introduced a procedure for the crew person to check that the hull drain plugs were in place prior to each splashdown. Thiswasdoneduringthemaster’ssafetybrief.ItwasapparentfromtheSouthDocksclosed-circuittelevision(CCTV)footagethatthiswasnotcompletedwhenWQ1 was parked on the top of the slipway at 1530 on 15 June 2013.
1.11.5 Life saving appliances
WQ1carried2,12personbuoyantapparatus14(solidfoam-filledflotationrafts)and4lifebuoys15.Thismetthelifesavingappliances(LSA)requirementsfor32personsassetoutintheMerchantShipping(Life-SavingAppliancesForPassengerShipsOfClassesIIIToVI(A))Regulations1999.Theflotationraftswerestowedontheroofofthevehiclesothattheycouldfloatfreeifthevehiclesankorcapsized.
WQ2carriedthesameLSAasWQ1but WQ4 and WQ8 carried one 20 person flotationraftand4lifebuoys.ThisdidnotmeettheregulatoryrequirementsasitonlyprovidedsufficientLSAfor28people.
1.11.6 Personal flotation devices
TYDwasrequiredtoprovidesufficientpersonalflotationdevices(PFD)16 for everyoneonboardandensurethattheywerereadilyaccessibleandtheirpositionswereclearlyindicated.Upuntil2012,TYDvehiclescarriedsolidfoambuoyancyaids,butatthetimeoftheaccidentWQ1 was carrying manually-activated gas-inflationlifejacketsforitsadultpassengers(passengersweighing32kgandover).Thegas-inflationlifejacketsprovided150Nofbuoyancy.
Thelifejackets (Figure 28)werepackedintransparentplasticbagsandstowedinaboxunderoneoftheinwardfacingbenchseatsatthebackofthevehicle.Solidfoamlifejacketsforchildrenweighinglessthan32kgwerealsoprovided.ThelifejacketsonboardWQ4 and WQ8werestowedinnetsabovethepassengerseats(Figure 28);whentheDUKWswereinspectedbytheMAIBandMCAsomeofthelifejacketswerestillintheirvacuumsealedpackaging.
14 Buoyantapparatus-flotationequipment(otherthanlifebuoys,lifejacketsandbuoyancyaids).15 Thebuoyantapparatusmaybesubstitutedbylifebuoysuptoamaximumof60percentofthevessel’sbuoyantapparatusrequirement,witheachsuchlifebuoybeingsuitabletosupporttwopersons.
16 Personalflotationdevicesaredividedintothefollowingtwomainclasses:thosewhichprovidefaceupin-watersupporttotheuserregardlessofphysicalconditions(lifejackets);andthosewhichrequiretheusertomakeswimmingandotherposturalmovementstopositiontheirfaceoutofthewater(buoyancyaids).
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Child’sbuoyancyaid Adultlifejacket
Plasticbag
Lifejacketdonninginstructions
Adultlifejacketsinvacuumsealed packaging WQ8
Figure 28: TheYellowDuckmarinelifejacketsandbuoyancyaids
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1.12 THE YELLOW DUCKMARINE MAINTENANCE MANAGEMENT SYSTEM
1.12.1 Planned maintenance routines
TomeettherequirementsoftheMCAandVOSA,TYD’sgaragestafffollowedanintegratedpassengervesselandPSVplannedmaintenanceregime.Thepaper-basedmaintenancemanagementsystemallowedthemechanicstorecordthemarine and road routines on a common set of maintenance sheets. The mechanics’ daily,weeklyandmonthlymaintenanceroutineswererecordedonthecompany’sA,B and C safety inspection and service sheets (Annex D).
Anydefectsfoundduringtheinspections,andtheactionstakentorectifyormitigatethem,hadtoberecordedonthemaintenancesheets.Themechanicorengineerwho had completed the inspection, and carried out the service and repairs, was requiredtosignadeclarationconfirmingthattheworklistedhadbeencarriedoutandthathe/sheconsideredthevehicletoberoadworthy.
Thecompanyhadalsoprovidedtwodailychecklists:oneforthemaster/driverandoneforthecrewperson/tourguidetocomplete(Annex A) prior to driving the vehicle out of the garage each day.
1.12.2 Unplanned breakdown repairs
AsdescribedinSection1.12.1,themajorityoftheunplanneddefectmaintenancewasrecordedbythemechanicsontheplannedmaintenancerecordsheets.Theengineeringmanagersalsomadecontemporaneousnotesinhandovernotebooksdetailinganyunusualdefectsthathadbeenidentifiedduringtheirshift.
Ifthemastercalledthegaragetoreportaproblemontheroadoronthewater,the engineering manager would deploy a mechanic, or team of mechanics, in the garage’sbreakdownresponsevan.IfavehiclewasimmobilisedonthewaterasecondDUKWorthecompany’srescueboatmightbeusedtoassist.
AreviewofTYD’srecordsestablishedthatthethreemostcommonproblemsonthewater involved leaks due to hull corrosion, loss of steering and the failure to engage six-wheeldrive.Theseproblemsoccurredonaregularbasis.Thefailuretoengagesix-wheeldriveoftenresultedinthevehiclebeingunabletoclimbtheSalthouseDockslipwayandtheneedtoexitthewaterfromCoburgDock.Onthedayoftheaccident, WQ2 and WQ8werebothexitingthewaterfromCoburgDock.
On14June2014,thedaybeforetheaccident,WQ1loststeerageandhadtobetowedalongside.Thebuoyancyfoaminthesterncompartmenthadshifted,causingtherudder’stillerarmtojam.Thegarageteamremovedsomeofthebuoyancyfoamandrepositionedtherest.Accordingtothemaintenancerecords,someoftheadditionalfoamfittedaftertheWQ4sinkingwasalsoremovedfromthebowcompartmentandthecentralvoidspacebecauseithadcausedtheenginetooverheatandhadmadecontactwithrotatingshafts.TheMCAhadbeenmadeaware of the overheating issue and had authorised the removal of some foam from thebowcompartment.
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1.13 VEHICLE SURVEYS AND INSPECTIONS
1.13.1 Maritime and Coastguard Agency
Asaminimum,theMCA’spassengershipcertificateshadtoberenewedat5-yearlyintervals.Toensurecompliancewiththeapplicablemerchantshippingregulationsforpassengershipconstruction,LSAandcollisionavoidance,theMCAsurveyedeachofTYD’svehiclesannually.ItalsocarriedoutannualinspectionstocheckcompliancewiththerequirementsoftheDSMCode.WQ1 was last surveyed on 25 May2013,followingthemodificationsmadeasaresultoftheWQ4 sinking.
Inordertocheckthewatertightintegrityofthevehicle’shulltheMCAsurveyorscarried out ‘dip’ tests. The dip tests were carried out during each annual survey and involvedtheinternalvisualinspectionofthehullwiththevehicleinthewater.On15February2013,severalpinholeswereidentifiedinWQ1’s hull during an annual surveydiptest.Thesurveyorraisedadeficiencyandinstructedthecompanytorectifythedefectbeforeallowingthevehiclebackonthewater.Thecompany’smaintenance records showed that similar corrosion related leaks were not uncommonandthatthegaragestaffhadfrequentlycarriedouttheirowndiptests.
TheMCAalsocarriedoutrandomincognitoinspectionsofthevehicleswhiletheywereinservice.ThemostrecentincognitoinspectiontookplaceonboardWQ4 on 7May2012.Priortosplashdown,thecrewmadeapointoftellingthepassengersthat a wave of water would enter the vehicle through the door and wash through the passenger space. The surveyor noted that the crew did not close the aft doorway and, when challenged, they confessed that they had not done so for some time anddidnothavethedoorwaysplashguardonboard.Oncompletionofthetour,thesurveyoridentifiedhimselftothemasterandinstructedhimtoceaseoperationsand return to the garage. The surveyor wrote to the owner advising him of his observations.Inhisletter,thesurveyorpointedoutthatthepassengerswerenotgivenalifejacketdonningdemonstration.Healsowarnedthatreferencesmadetothe sinking of the TitanicandthefilmThe Poseidon Adventure might cause offence to some passengers.
1.13.2 Vehicle and Operator Services Agency
VOSAcarriedoutannualinspectionsofTYDvehiclesatitscommercialvehicletestcentreinLiverpool.Italsocarriedoutrandomroadsidevehicleandgaragebasedmaintenance inspections.
Inthe5yearsprevioustotheaccident,VOSAinspectorshadcarriedoutninerandominspectionsofTYDvehicles(8ontheroadand1atthegarage)andhadissuedprohibitionnoticestothecompanyduringsevenofthem.Fiveofthesevenprohibitionnoticeswereissuedforsteeringrelateddefects.Thegaragebasedinspectionidentifiedthatthecompanywasnotcomplyingwiththemaintenanceregimedescribedinitsstatementofintent.TheprohibitionrateforTYDvehicleswas88%,whichwasalmostfivetimesthenationalaverage(18%).Asaconsequence,TYDwassubjecttoaTrafficCommissioners’publicenquiry,whichhadbeenscheduled to take place the week after the WQ1 sinking.
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1.14 INDUSTRY GUIDANCE AND INSTRUCTIONS FOR SURVEYORS
Atthetimeoftheaccident,therewereseveralothertypesofAPVsbeingoperatedwithintheUK.TherewerealsootherconvertedDUKWsbeingoperatedascodedvessels, which were permitted to carry a maximum of 12 passengers, that had nobuoyancyfoamfitted,anddidnotmeetthemandateddamagedsurvivabilitystandard.TherewasnoindustrybodyoranAPVoperators’codeofpracticetorefertoforbestpractice.
TheMCAandVOSAhadworkedtogetherinthepasttofacilitatethesafeintroductionandoperationofAPVs.However,by2013bothorganisationswereworkinginisolationandneitheremployedstaffwithdesignatedAPVexpertise.
Tofacilitatesurveysandensureconsistency,eachMCAsurveyorwassuppliedwiththeMCA’sInstructions for the Guidance for Surveyors. This was a detailed document that covered the numerous areas surveyors could expect to encounter duringvesselsurvey.Theguidecontainednospecificguidelinesrelatingtoamphibiousvehiclesandnoinformationregardingtheinstallationofbuoyancyfoam.
1.15 PASSENGER QUESTIONNAIRES AND FEEDBACK
Followingtheaccident,theMAIBinterviewedseveralofthepassengersandgatheredadditionalfeedbackusingpassengerquestionnaires.Allthosewhowereinterviewedandthosewhocompletedthequestionnairesraisedconcernsrelatingtothequalityofthesafetybrief.Mostsaiditwastooquick,unclearandnottakenseriouslybythecrew.
Ofthosewhorespondedtothequestionnaire(12passengers),62%thoughtthattherewerenotenoughlifejacketsonboardandhalfsaidtheydidnotknowhowtoput them on or operate them. The father of the 2 year old child struggled to put a buoyancyaidonhisdaughterbecausethewaiststrapwasbuckledshut(Figure 28) andhadnotbeenextended.
Therewasnopositivefeedbackinthequestionnairesrelatingtotheactionsofthecrewand38%ofrespondentssaidthatthecrewpanicked.Duringinterview,several of the passengers empathised with the crew and said that the speed with which WQ1flooded,thelocationofthelifejacketsandtheconfinednatureofthepassengerspacemadeitalmostimpossibleforthemtoco-ordinateandcontroltheevacuation process.
1.16 SIMILAR INCIDENTS AND ACCIDENTS
1.16.1 The Yellow Duckmarine
TheMAIB’sdatabasecontainedrecordsoftwopreviousaccidentsinvolvingTYDDUKWs.ThefirstwasacollisionbetweenWQ2andtheTYD’spassengerboatSkylarkinWappingDockon28January2013;thesecondwasthesinkingofWQ4.
TheTYD’sinvestigationintothecollisionbetweenWQ2 and Skylark found that the skipper of Skylarkhadbeenfoolingaround.Hehaddeliberatelymanoeuvredhisvessel at speed, in close proximity to WQ2, in order to create a wake and induce a rollonboardtheDUKW.
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WQ4 sank while under tow very close to where WQ1 sank (Figure 2). Prior to thesinking,thevehiclehadsufferedasteeringfailureandhadbeentowedontoapontooninSalthouseDockbyanotherDUKW.Duringtherecovery,thecrewstoppedtheengineandthenrealisedthatwaterwasenteringthebilges.Uptothatpoint, the vehicle’s chain-driven Higginspumphadbeencontrollingthelevelofwaterinthehull.Oncealongside,thepassengerswerelandedandsupportarrivedfromthegarage.Unabletorestarttheengine,theydecidedtousetherescueboattotowthefloodingvehicletotheSalthouseDockslipway,andwhileundertowitsank.When WQ4wasrecoveredfromthedockitbecameapparentthatoneofthehulldrain plugs was missing.
Inadditiontothelackofbuoyancyfoam,theMCAinvestigationintothesinkingofWQ4 highlighted that: the company’s maintenance standards, the crew’s knowledge ofthevehicles’bilgesystems,andtheimplementationofthecompany’sproceduresfellwellshortofreasonableexpectations.Asaresultofitsfindings,theLiverpoolMarineOfficerecommendedthatthefindingsofitsinvestigationreportbetakenintoaccountatacentralpolicylevelandthattheOrpingtonMarineOfficecarryoutafullreviewofthebuoyancyarrangementsonboardtheLDTvehicles.
Duringtheinitialstagesofthisinvestigation,itbecameapparentthatseveralotheraccidentsandincidents,whichhadnotbeenreportedtotheMAIBortheMCA’sLiverpoolMarineOffice,hadoccurredinthemonthsleadinguptothesinkingofWQ1.Notably,inJanuary2013anincidentoccurredthatrequiredpassengerstobeevacuatedfromaDUKWinSalthouseDock,andon1June2013WQ2 suffered a hull failure.
Thefirstincidentoccurredafterasteeringfailure.Insteadofcallingthegarageandarrangingtobetowedtoapontoon,themasterdecidedtoattempttomanoeuvrehis vehicle astern onto the slipway, using his front wheels to steer through the water. Ashisvehicle’srearwheelslandedontheslipwaythevehicleveeredtoport,felloffthe concrete ramp, heeled over, and then wedged itself against the dock wall. The passengers were evacuated onto the dock side through the aft door.
TwoweeksbeforeWQ1 sank, WQ2 suffered a hull failure around one of the propeller shaft v-strut support shoes (Figure 29).Thefailurewasidentifiedbythegaragestaffafterthemasterhadreportedheavyflooding.Thehullplatingaroundthestarboardv-strutfootwasfoundtobeheavilycorroded,andtheaffectedsectionof steel was cropped out and an insert plate was welded in place (Figure 30).Adoublerplatewasfittedontheinsideofthehullandsealedusingasiliconbasedcompound.Thev-strutwasboltedtothehulldoublerplate,butthedoublerplatewasnotconnectedtotheafttransversebulkhead.TheMCAwasnotmadeawareofthe repair.
TYDalsohadseveralincidentsontheroad.InSeptember2010,fourpassengerswereinjuredandtakentohospitalwhenawheelfelloffWQ2 whileitwasbeingdriven along a city centre street.
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Figure 29: SimilarhullfailurediscoveredonboardWacker Quacker 2 two weeks earlier
1 June 2013
Starboardv-strutfoot
V-strut support shoe
Hole torn in propeller shaft tunnel plate
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External repair
Resinsealant
Insert
Internalrepair
Siliconesealant
Steelplate
Figure 30: Hullrepairscarriedoutbygaragestaff
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1.16.2 Beatrice
On31March2001,theLondonFrogCompany’sDUKWBeatrice suffered a hull failure17andstartedtotakeonwaterwhenitspropellerwasfouledbyalargefloatingobject.ThemasterraisedthealarmandthenbeachedhisvehicleonthenorthbankoftheRiver,oppositeLambethFireStation.Beatrice’s 29 passengers were safely evacuatedontoaLondonFireBrigadevessel.
Beatricesufferedsevereunderwaterdamage.Itspropellershaftwasbent,andthev-strutmountingshadbeenrippedoutofposition.Thiscausedthepropellertunnelplatingtoruptureandthehulltostartflooding.Thepassengerswereawareofthewaterenteringthehullandtookituponthemselvestostartdonninglifejackets.Theyhadnotbeengivenalifejacketdemonstrationandfounditdifficulttoputthemon,particularlyasthestrapshadnotbeenextended.
DamagedsurvivabilityandtheuseofbuoyancyfoamwasnotdiscussedintheMAIBinvestigation report of the accident.
AsaresultoftheaccidentTheLondonFrogCompanyreplacedalargesectionofthepropellertunnelplatingonallitsvehicleswithheaviergaugesteel.Itfurtherreinforcedtheareaaroundthev-strutmountingbyweldingandrivetinganadditionalthree layers of 2mm thick plate to the propeller tunnel (Annex E).
The propeller tunnel plating was not strengthened on the Liverpool DUKWs. FollowingthesinkingofWQ4, LDT had written to TYD to offer its help and make some recommendations to improve future safety. The strengthening of the propeller tunnelplatingwasoneoftherecommendationsmadeintheletter.AcopyoftheletterwaspassedtotheMCAatthetime.
1.16.3 Miss Majestic
On1May1999,theDUKWAPVMiss Majestic (Figure 31) sankbythestern,withadriverand20passengersonboard,duringaregularsightseeingtouronLakeHamilton,Arkansas,USA.About7minutesafterenteringthewaterthevehicleflooded,listedtoportandrapidlysankbythesternin19mofwater.Thedriverandsevenpassengersescapedfromthesinkingvehicleandwererescuedbypleasureboatersinthearea.Theremaining13passengers,3ofwhomwerechildren,losttheir lives.
ThemajorsafetyissuesidentifiedintheUSGovernment’sNationalTransportationSafetyBoard’s(NTSB)investigationreport18 related to:
• Vehicle maintenance• CoastGuardinspectionsofMiss Majestic• CoastGuardinspectionguidance• Reservebuoyancy,and• Passengersurvivability.
17 MAIBinvestigationreportnumber3/2001–Report on an investigation of a propulsion failure and subsequent beaching of the Class V amphibious passenger craft Beatrice on 31 March 2001, opposite the River Thames Fire Station, Lambeth.
18 NTSB/MAR-02/01–SinkingoftheAmphibiousPassengerVehicleMiss Majestic, Lake Hamilton, Near Hot Springs,Arkansas,May1,1999.
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When Miss Majesticwasinspectedaftershehadbeenrecoveredfromthelakebed,theinvestigatorsdiscoveredthatthereardriveshafthousing’saftrubberboothadworkedloosebecauseithadnotbeenfittedcorrectly(Figure 31).
TheUSDUKWswerenotfittedwithbuoyancyfoamandreliedonbilgepumpstoprovidedamagedsurvivability.TheNTSBreportstatedthatthelackofreservebuoyancyneededtokeeptheDUKWafloatinthefloodedconditionwasaflawinitsdesignwhenoriginallyconvertedforpassengerserviceandwasamajorcontributoryfactor.
TheNTSBinvestigationfounddeficienciesintheoperator’smaintenanceproceduresandthestandardofUSCoastGuardinspections.Thereportalsoidentifiedproblemswiththeaccessibilityofthelifejacketsandhighlightedthatthepassengers were not shown how to don them.
View after the accident of the vehicle’sreardriveshafthousingboot
Miss Majestic after its conversion to a commercialamphibiouspassengervehicle
Figure 31: SinkingofDUKWMiss Majestic on1May1999
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TheNTSBreportconcludedthat:
• TheprobablecauseoftheuncontrolledfloodingandsinkingofMiss Majestic wasthefailureofthevehicleoperatortoadequatelyrepairandmaintaintheDUKW.
• Miss MajesticsankbecausetheDUKWhadnowatertightbulkheadsandnoreservebuoyancy,andbecauseitsHiggins pump failed.
• Thecanopywasamajorimpedimenttothesurvivalofthepassengers.
• TheCoastGuard’sinspectionprogramforMiss Majesticwasinadequateandcursory.
• ThelackofCoastGuardguidanceandtrainingfortheinspectionofDUKWscontributedtotheinadequateinspections.
• Thewearingoflifejacketsbeforethevehicleentersthewater,wherecanopiesare removed, would improve passenger safety.
Priortopublishingitsreport,theNTSBissuedthefollowingrecommendationtotheoperatorsandrefurbishersofAPVs:
Without delay, alter your amphibious passenger vessels to provide reserve buoyancy through passive means, such as watertight compartmentalization, built in floatation, or equivalent measures, so that they will remain afloat and upright in the event of flooding, even when carrying a full complement of passengers and crew.
Onlyoneofthe30APVoperatorsintheUSacceptedthisrecommendation.TheDUKWoperatorsarguedstronglythatcompartmentalizationwouldintroduceunacceptablelevelsofstressinthehullwhenoperatingontheroad,andtheinsertionofbuoyancyfoam wasnotpracticalandwouldintroducemanyproblems.
In2001,theUSCoastGuardpublisheditsNavigationandVesselInspectionCircular19(NVIC)1-01,Inspection of Amphibious Passenger Carrying Vehicles. The aimoftheNVICwastoprovideaguidetobestpracticefortheinspection,operationandmaintenanceofAPVssothataconsistentapproachcouldbetakenacrossallregionsoftheUS.Theguidanceforhullsurveysincludedalistofareasofconcern,one of which was the propeller shaft v-strut and its connection to the hull.
TheNVICalsoprovidedguidanceontheinstallationofbuoyancyfoam.TheCoastGuardacknowledgedthatbuoyancyfoamcouldbeusedtoaugmentsubdivision,butwarnedthatitsinstallationgenerallyaggravatesmaintenanceproblemsbyrestrictingaccess. The guidance also pointed out that, as foam deteriorates with age, periodic samplingisrequiredtodetermineitscondition.
WhentheNTSBreportwaspublishedin2002itreissueditsearlierrecommendationbutprovidedalistofrecommendedinterimmeasuresforoperatorswhohadyettoprovidereservebuoyancy.Theseincluded:
19 TheUSCoastGuardHeadquartersissuesNVICstodisseminaterecommendedpolicy,requirements,procedures,orguidanceforCoastGuardmarinesafetypersonnelandthemarineindustry.
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• Removalofcanopieswhenonthewater.
• Removalofunnecessaryhullplugsandreductioninsizeofhullpenetrations.
• Installationofindependentlypoweredelectricbilgepumpstosupplementthechain-driven Higginspump(orsimilarcapacitydewateringpump).
• Installationofhighlevelbilgealarms.
• CompliancewiththeprovisionsoftheUSCoastGuard’sNVIC1-01.
When WQ1sank,mostoperatorsoforiginalDUKWAPVsintheUShadimplementedtheinterimmeasuresprescribedintheNTSBreportbuthadnotmetthereservebuoyancystandardsrecommended.
1.16.4 DUKW 34
On7July2010,abarge(The Resource),beingpushedbythetugboatCaribbean Sea,collidedwiththeanchoredAPVDUKW 34ontheDelawareRiverinPhiladelphia,USA.DUKW 34 sank and two of its 35 passengers drowned. The APVhadsufferedanenginecoolingproblemthatthemasterhadinitiallythoughtwasafire.Themasterstoppedhisengineandshutdowntheenginecompartmentbeforeanchoringintheriver.Thecauseofthecollision(Figure 32)wasattributedtoafailuretomaintainanappropriatelookoutbythecrewonboardthetugthatwaspushing The Resource.TheNSTB’sinvestigationreport20 explained that DUKW 34’s master did not fully appreciate the risk of collision when he anchored in a navigation channel.Thereportalsocommentedonthejocularnatureofthemaster’ssafetybriefandthefactthatcontrarytocompanyprocedurehedidnotdonalifejacketduring the demonstration.
20 NTSB/MAR-11/02–CollisionofTugboat/BargeCaribbean Sea/The ResourcewithAmphibiousPassengerVehicle DUKW 34 Philadelphia, Pennsylvania, July 7 2010.
Figure 32: Collisionbetweentugboat/bargeCaribbean Sea/The Resource and DUKW 34 on 7 July 2010
Barge The Resource running over DUKW 34
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1.16.5 Lessons learned during World War 2 operations
In1944,theUSarmyreviewedthelessonslearnedduringthefirst2yearsofDUKWoperationsinEuropeandthePacificandcarriedoutapracticalstudy.Itsfindingswere used to produce a revised set of standing operating procedures and technical data, which was documented in The DUKW, Its Operation and Uses manual.
Themanualprovidedup-to-dateinformationdesignedtopromotethemostefficientutilizationofDUKWs,andprescribedseveralmodificationstoreducethelikelihoodofvehiclebreakdowns,floodingincidentsandfires.Themodificationsincludedtheretrofittingofbottomplugstowageracksinthedriver’scompartment,andpropellerguards (Figure 33).
Themanualwarnedofthedangersofenteringthewaterwithoutfirstcheckingthebottomplugsareinplace,andinstructedtheDUKWengineerstopaintwarningnotices next to the plug stowage racks. The army had discovered that the DUKWs wereparticularlysusceptibletopropellerfoulingandprovidedinstructionsforthefittingofpropellerguards.
Drain plug stowage and caution notices
Figure 33: World War 2 operations manual
Propeller guard for DUKW
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SECTION 2 – FACTUAL INFORMATION CLEOPATRA
2.1 PARTICULARS OF CLEOPATRA AND ACCIDENT
SHIP PARTICULARSVessel’s name Cleopatra
Flag UKCertifying authority MaritimeandCoastguardAgencyVessel type Class V passenger vesselVehiclechassisnumber 3536279Vehicle type DUKWamphibiouspassengervehicleYearofbuild 1945(convertedtoAPVin1999)Registeredowner London Duck Tours LtdConstruction SteelHull length 9.45mLength overall 10.35mWidth overall 2.48mHeightofcanopy(fromtheroad) 3.8mOnroadweight 8.66t(2009weighbridgeweight)VOYAGE PARTICULARSPort of departure Lacks Dock, London Port of arrival Lacks Dock, LondonType of voyage Sightseeingtour,tidalriverestuaryManning 2MARINE CASUALTY INFORMATIONDate and time 29September2013atabout1154Type of marine casualty or incident VerySeriousMarineCasualtyLocation of incident RiverThamesnearTowerGardens,Westminster
Placeonboard Enginebay,shafttunnelandpassengercompartment
Injuries/fatalities NilDamage/environmentalimpact NilShipoperation SightseeingtoursVoyage segment Transit
Environment Daylight;fair;lightwinds;ebbtidestream<1.75knots
Personsonboard 30(2crew+28passengers)
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2.2 BACKGROUND
On20June2013,twosurveyorsfromtheMCA’sOrpingtonMarineOfficeattendedtheLDTfleetmaintenancegaragetodeterminethevolumeofbuoyancyfoampresentintheLDTvehicles.Thebuoyancyfoamwasremovedfromtherandomlyselected DUKW Rosalind and weighed. Having estimated the foam density, the surveyorscalculatedthatthevehiclehadcontainedabout6m3offoam.Asimilarexercise carried out on DUKWs Titania and Elizabeth determined that they containedabout5.5m3and5.8m3 of foam respectively.
FollowingdiscussionswiththeMCA,LDTsuspendeditswaterborneoperationsandundertooktoincreasethelevelsofbuoyancyfoamfittedtoitsvehiclesto9m3.On1July2013,theMCAinstructedLDTtofurtherincreasethevolumeofbuoyancyfoamineachvehicleto10.6m3.
On7August2013,followingtheanalysisoftheresultsofthepracticaltrialsconductedbytheMAIBinLiverpool[Paragraph 1.10.3],theMAIBmadearecommendation(2013/221)totheMCA:
require operators of DUKW passenger vessels in the UK to demonstrate that they are able to provide 110% effective residual intact buoyancy in their vessels, and where buoyancy foam is fitted for this purpose, the quantity installed is measured by volume and the foam does not impede the operation or maintenance of key equipment.
Bythistime,sixofLDT’svehicleshadbeenreturnedtothewater.Cleopatra was re-packedwithfoambetween12and22Augustand,on24August2013,returnedtothewaterwith10.6m3ofbuoyancyfoamonboard.On24September2013,ateamofMCAsurveyorsarrivedattheLDTgaragetowitnessandassesstheinsertionofbuoyancyfoamintoDUKWPortia.
2.3 NARRATIVE
At1110on29September2013,DUKWCleopatra (Figure 34)leftitsSouthbankdeparture point and commenced a standard tour of the Westminster area of London, England.Onboardwerethedriver,thetourguideand28passengers.Uponcompletion of the on-land portion of the tour, the vehicle arrived at Lacks Dock slipway, Vauxhall, where the driver handed control of the vehicle to its master for the river section of the tour. While the driver and master carried out their routine handover inspection, the tour guide gave the passengers a pre-splashdown safety brief,whichincludedademonstrationofhowtodonthepassengerbuoyancyaids.
At1145,themasterdroveCleopatradowntheslipwayintotheRiverThamesandheadeddownriver.AsCleopatraapproachedLambethBridge(Figure 35), the tour guide noticed an unusual smell. He told the master, who then checked thatthevehicle’shandbrakewasdisengaged.Thesmellsoondispersedandthemaster continued on with the tour. When Cleopatra approached Westminster Bridgethemasterturnedthevehiclearoundandcommencedthereturnjourneyupriver.AsCleopatra passed the Houses of Parliament, the tour guide noticed the unusual smell again, and saw wisps of light grey smoke coming from the engine compartment’s cooling air inlet (Figure 36).Ataboutthesametime,someofthepassengersnoticedlightgreysmokerisingfromthefloorclosetothetourguide’sleft leg.
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Initially,themasterthoughtthatthesmokemighthavebeencausedbyanengineexhaustproblemand,asaprecaution,heangledCleopatra towards the shore. The tour guide then made an announcement to the passengers informing them that there wasaproblemwiththevehicle.Thesmokeincreasedinthickness,darkenedincolourandbegantobillowoutoftheenginecompartment’sstarboardextractionfanvent (Figure 36).Atthispointapassengertowardstherearofthevehicleshouted,“Fire! Fire!”
Figure 34: LondonDuckToursamphibiouspassengervehicleCleopatra
ImagecourtesyofPhilipBisset
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Figure 35: ThewaterbornesectionoftheLondonDuckTourssightseeingroutes
LambethBridge
LacksDockSlipway
ReproducedfromAdmiraltyChartBA3319-0bypermissionoftheControllerofHMSO
Siteofgrounding
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Engine compartment forward cooling air outlet vent
Engine compartment cooling air inlet vent
Engine compartment extraction fan vent
Figure 36: Engine compartment cooling air vents on a similar London Duck Tours vehicle
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At1154:20themastercalledthePortofLondonAuthority(PLA)VesselTrafficServices(VTS)byradioandaskedfortheassistanceofthefirebrigade.BeforeVTScouldacknowledgethecall,theradioonboardCleopatra ceased functioning. Nevertheless,thebriefbutanxiousradiocallhadbeenheardbynumerousrivercraftoperatorsandanunknownsourceadvisedthePLAVTSbyradiothatCleopatra wasonfireclosetotheHousesofParliament.ThetransmissionwasoverheardbyThamesCoastguard,anditimmediatelynotifiedtheLondonFireBrigade(LFB)andtheRoyalNationalLifeboatInstitution’s(RNLI)TowerPierandChiswicklifeboatstations.ThecoastguardthenadjustedthepositionofaWestminsterCCTVcameraandbegantomonitorthesituationonitsvisualdisplayscreen.
The master continued to steer Cleopatra towards the shore until the vehicle’s front wheelstouchedbottombyVictoriaTowerGardens(Figure 35).Onceonthemud,the master kept the propeller engaged ahead to keep the craft pressed against the shore.Asthefireescalated(Figure 37),manypassengersfledinpanictowardstherear of Cleopatra,somegrabbingbuoyancyaidsastheydidso.Otherpassengersclimbedoutofwindowswhentheyrealisedthatthiswastheireasiestandquickestescaperoute.Thepassengerwhohadfirstraisedthealarmsucceededinpartiallyopeningthereardoorbutwasquicklypushedasidebyotherpassengers,separatinghim from his family.
The tour guide physically pushed his way through the passengers with the intention ofloweringtheboardingladdertoassistevacuation.However,theweightoftheescaping passengers standing upon the raised port ladder prevented the guide from untyingthesecuringropeandloweringtheladder.Duetothebarrierpresentedbythepartiallyopendoorontheboardingplatform, peoplehaddifficultyaccessingandloweringthestarboardladder,resultinginmanyhavingtojumpintothewater.Aspeopledispersedfromtheboardingplatform,thestarboardladderwaseventuallylowered and the door fully opened, allowing the last evacuees to descend the stairs to the water.
Themasterwasthelastpersontoleavethevehicle,andonlydidsoafterconfirmingthat the passenger compartment was empty of people.
Within 3 minutes of the master’s incomplete radio transmission, three rigid-hulled inflatableboats(RIB)fromtheThamesRIBExperienceCompany21 arrived on scene. By this time, some passengers had managed to wade to shallower water. SomeofCleopatra’spassengersabandoneddirectlyontotheRIBsandtherestwere recovered from the water (Figure 37). Within 2 minutes of their arrival, all passengersandcrewhadbeenrecoveredontotheRIBs.
At1159,theLFBfireboat,Fire Dart,arrivedatthescene,closelyfollowedbyalandapplianceontheriverbank,adjacenttoCleopatra.Thefirewasquicklybroughtundercontroland,by1201,itwasextinguished(Figure 37).
TherescuevesselscarriedthesurvivorstoLFB’sLambethRiverFireStationpontoonwhereall30weredisembarkedandmetbyambulancestaff.Threeofthepassengersweretakentohospitalforfurthermedicalexamination,butweredischarged later that day.
21 TheThamesRIBExperienceCompanyoperatedhighspeedRIBtoursfortouristsontheRiverThames.
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Figu
re 3
7:Abandonshipandrescuesequence
ImagescourtesyofD
ailyMailonline©Tony.MargiocchiBarCraftmedia
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2.4 ENVIRONMENTAL CONDITIONS
Itwasadryday,withamoderate(11-16kts)east-north-easterlywindandaneaptide.ThedepthofwaterbetweenLambethBridgeandWestminsterBridgeathighwater(0915)was5.2m.Atthetimeoftheaccident,theebbingtidalstreamadjacenttotheHousesofParliamentatmid-streamwasabout1.75kts.
2.5 LONDON DUCK TOURS
InNovember2001,theLondonFrogCompanyLtdceasedtradingandwentintoliquidation.InMay2002CapitalFrogsLtd,whohadtakenownershipoftheliquidatedcompany’sassets,re-introducedtheAPVsightseeingtourservice.In2004CapitalFrogsLtdwasrebrandedandchangeditstradingnametoLondonDuckTours.Between2006and2012LDTincreaseditsfleetofDUKWAPVsfrom5to9.LDT’sconvertedDUKWswerecertifiedbytheMCAtooperateduringdaylighthours on Category C22 waters as Class V passenger vessels.
Atthetimeoftheaccident,LDTemployed74people,includingofficestaff,fleetmaintenance operatives, road drivers, river masters, tour guides and freelance staff. ThecompanyhadanofficeandabookingshopinWaterloo,closetotheLondonEye,andafleetmaintenancegarageinBattersea.
LDT’s route covered the Westminster area of London and its guided sightseeing tourlastedabout1hour,whichincluded25minutesontheRiverThames.Thepassengerpick-upanddrop-offpointwaslocatedonChicheleyStreet,directlyinfrontofthecompany’sbookingshop.Thevehiclesenteredandexitedtheriveratthe Lacks Dock slipway, Vauxhall, and cruised as far as Westminster Bridge (Figure 35).
2.6 THE CREW
TheLDTvehicleswerecrewedbytwopeopleatalltimes.Ontheroad,thevehiclewasmannedbyadriver(PSVlicenceholder)andatourguide;ontheriver,itwascrewedbyamasterandatourguide.Thedriverhandedthevehicleovertothemaster at Lacks Dock prior to the vehicle entering the water. During the handover thecrewwererequiredtocarryoutasetofpre-entrychecksanddeliverthesafetybrieftotheirpassengers.
2.6.1 Master
Cleopatra’smasterwasBritishandwas71yearsofage.Hehadbeenawaterman23 and lighterman24ontheRiverThamesformostofhisworkinglife.HehadbeenanLDTDUKWmasterfor18monthsandheldanMCAapprovedTier1Level2Boatmasters’ Licence.
WhenhejoinedLDT,themasterundertookdedicatedfamiliarisationtrainingonDUKWhandlingandhadsincetakenpartinregularemergencydrills,includingfireandabandonment.
22 CategoryCwaters-tidalrivers,estuariesandlarge,deeplakesandlochswherethesignificantwaveheightcouldnotbeexpectedtoexceed1.2matanytime.
23 Waterman - a river worker who transfers passengers across and along city rivers and estuaries in the United Kingdom.
24 Lighterman-acrewmanwholoadsanddischargescargoesonlighterbarges.
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2.6.2 Tour guide
The tour guide was British and was 27 years of age. He had worked for LDT for 4 months. Prior to working for LDT, he had some experience with watercraft and heldmilitaryqualificationsinthisarea.Duringhis4monthsasatourguidehehadbeengiveninductiontrainingontheDUKWoperationsandhadparticipatedinanemergencydrilllessthan3weeksbeforethefire.
2.7 CLEOPATRA
2.7.1 General description
Cleopatra’s external appearance and passenger compartment layout was similar to that of WQ1.However,asaresultofthedesignmodificationscarriedoutbyLDT,theLondonbasedAPVsweresignificantlydifferenttothoseoperatedinLiverpool.
Cleopatrahadan88kWIvecoBeta120,6-cylinder,naturallyaspirateddieselengineandanAlisonAT545automaticgearbox.Itwaspropelledthroughthewaterbyasingle,4-bladed,clockwiserotatingpropeller,andhadasinglespade-typerudder.
Thecontrolsandinstrumentationforbothroadandrivertransitswerepositionedinfrontof,andadjacentto,themaster/driver’sseat.Thefloorplatesaroundthedriver’sseat had several open penetrations to accommodate the drivetrain gear levers and steering linkages.
Cleopatrawasequippedwithaveryhighfrequency(VHF)digitalselectivecalling(DSC)radioforcommunicationwiththePLA,LDTandothervessels.Navigationonthewaterwascarriedoutvisually.Thevehiclewasequippedwithanautomaticidentificationsystem(AIS),interfacedwithaglobalpositioningsystem(GPS),whichalloweditspositiontobemonitoredremotelybythePLA,LDTandotherAISenabledcraft.ThevehiclewasalsofittedwithalandbasedtrackingsystemthatallowedLDTstaff to monitor its position on the road.
2.7.2 Hull
Cleopatra’sbasichulllayoutwassimilartothatoftheoriginalDUKWandLiverpoolAPVs,buttheminimumshellplatethicknessoftheLDTvehicleshadbeenincreasedto3mm.TheshellplatinginthepropellershafttunnelhadbeenstrengthenedfollowingthelessonslearnedfromthehullfailuresufferedbyDUKWBeatriceinMarch2001(Paragraph 1.16.2).
ItwasastatutoryrequirementforaccommodationspacesonboardClassVpassenger vessels such as Cleopatra,tobeseparatedfrommachineryspacesbygas-tight,insulatedfireprotectionbulkheads.Thisrequirementwashighlightedin1999byBurnessCorlett&PartnersLtdinitsinitialdesignsubmission.Duetoperceivedtechnicaldifficulties,theDUKWoperatorswereexemptedfromtherequirementontheunderstandingthattheopeningsforthevehicles’driveshaftsandcontrollinkageswouldbekepttoaminimum.
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2.7.3 Propulsion drivetrain
AsimplifiedillustrationofCleopatra’s propulsion drivetrain arrangements is shown in Figure 38.Theoutputdrivefromtheautomaticgearboxwasconnectedtothemarinetransferbox(MTB)byaslidingsplinedshaftviatwoType2030universaljoints(UJ)(Figure 39).ThemainoutputshaftfromtheMTBwasconnectedtotheroadtransferbox.Anarticulateddrivewastakenfromtheroadtransferboxtodrivetheforwardwheelswhileafurtherdrivewastakenaft,throughaband-typehandbrakeassembly,todrivetheaftertwosetsofwheels.Theforwardwheelscouldbeindependently engaged and disengaged from the master’s position to provide a four orsix-wheeldriveconfiguration.
ThepropellershaftwasbroughtintousejustpriortoenteringthewaterbymanuallyengagingtheMTBfromthemaster’scontrolposition.Thepropellershaftwassupportedinternallyalongitslengthbyaplainjournalbearingandapropellerthrustbearing.
The maximum engine speed while on the road was approximately 2200rpm. When thevehiclewasinuseontheriverfirstgearwasmanuallyselectedontheautomaticgearboxandtoachievenormalcruisingspeedtheenginewassetatapproximately1200rpm.TheresultantspeedoftheoutputshafttotheMTBwasapproximately650rpmwithapropellershaftspeedofabout850rpm.
2.7.4 Rudder control
TheLDTfleethadbeenfittedwithelectro-hydraulicsteeringgear.Therudderwascontrolledusingajoysticklocatedonthedashboardnexttothesteeringwheel.Itcouldalsobecontrolledmanuallyinanemergencyfromthebackofthe vehicle, using a handwheel. The emergency steering system had a 25-litre hydraulic oil header tank, which was positioned on the port aft end of the passenger compartment.
2.7.5 Brake system
Thewheelbrakeswereair-assistedandwereoperatedbydepressingthefootpedalat the master’s control position. The engine-driven air compressor charged three, 20-litreairreservoirstoapproximately10bar.Thereservoircylinderswerelocatedunderthepassengercompartmentdeckbehindthemaster’sseat(Figure 40). Flexiblepipesconnectedthecylinderstothefootpedaloperateddistributionvalve,andfromtheretothebrakes.
2.7.6 Engine compartment
Cleopatra’senginecompartmentlayoutwaslastmodifiedin2012;thiswastoaccommodatethevehicle’snewIvecoBeta120engineandAlisonautomaticgearbox.Themodificationsincludedtheenlargementofthedriveshaftholeintheforwardtransversebulkhead,therepositioningoftheengineradiatorandflowalterations for the engine and engine compartment cooling air system.
Aswithmostroadvehicles,Cleopatra’s engine was water cooled and its cooling watertemperaturewasregulatedbyanaircooledradiatorandthermostaticby-passvalve. Traditionally, the radiator is positioned at the front of a road vehicle and air is forcedthroughitbythevehicle’sforwardmotion.TheDUKWradiatorwasencased
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1 Differential gearboxes
Universal joint couplingsNote: Revolutions relate to “on water” operation.
4-bladed propeller(850rpm)
V-strut support bearing
Stern gland
Thrust bearing
1
Gland
Band brake
Plain bearing
Road transfer box
Marine transfer box
Splined driveshaft 650rpm
Alison AT545 automatic gearbox
Iveco Beta 120 engine (1200rpm)
Rear transmission box
1
1
Wheel
Propeller shaft
Figure 38: SimplifiedillustrationofCleopatra’s drivetrain
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Splineddriveshaft
Universaljoint
End cap and needle bearings
Figure 39: Typicalslidingsplineddriveshaftanduniversaljointarrangement
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inasteelhullandthecoolingairhadtobeforcedthroughitbyanengine-drivenfan.The vehicle also had a keel water cooler, which was externally mounted under the bowtosupplementtheengine’saircooledradiator.
OntheoriginalDUKW,coldairwasdrawnintotheenginecompartmentthroughanopendeckgratinginthecargocompartmentbehindthecrewseats(Figure 41). Thecoolingairpassedunderthedriver’scab,acrosstheenginecompartment,andthroughtheradiatorintothebowcompartment.Thehotairthenpassedthroughtheportandstarboardcoolingairpassagesandexhaustedtoatmospherethroughthesideventilationgrilles.Inadditiontocoolingthewaterintheradiator,thecoolingairalso cooled the engine compartment. Earlier DUKW models had an auxiliary cooling airinletflapfittedattheaftendoftheenginecompartmentaccesshatch.Thiscouldbeopenedtoprovideextracoolingairinhotclimates.
When the cargo compartment was converted into the passenger space the original maincoolingairinletgratingwascoveredupandtheenginecompartmentandbowcompartmenthatchcoversweremodifiedtoaccommodateaftfacingcoolingairsupply and exhaust vents (Figure 36). During their 13 years in operation, the cooling airflowsontheLDTDUKWshadbeenalteredseveraltimes.Atthetimeoftheaccident,theoriginalenginecompartmentcoolingairpassageshadbeenremovedfrom Cleopatra. The cooling air was drawn into the compartment through its aft hatch cover vent and, having passed through the radiator, exhausted to atmosphere throughtheforward(bowcompartment)hatchcovervent.
Inordertopreventthebuild-upofhotairattheafterendoftheenginecompartment,electrically-drivenextractionfanswerefitted(Figure 42). The hot air was drawn into theportandstarboardventilationvoidspacesandexhaustedtoatmospherethroughthe vehicle’s original side vents.
Flexiblepipes
20 litre air reservoirs
Figure 40: Braking system air reservoirs
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Themainengineexhaustpipewasrouteddownthestarboardsideoftheenginecompartment.Itpassedthroughtheupperpartofthestarboardventilationvoidspaceandterminatedonthedeckatthestarboardforwardcornerofthecrewcab.Thesectionoftheexhaustpipewithintheenginecompartmentwaslaggedbutthesection that passed through the void space was not (Figure 43).
Bow
com
partm
ent
Auxilliarycoolingairinletflap
Starboardcoolingairoutletgrille
Coo
ling
air i
nlet
gra
ting
Bow
com
partm
ent h
atch
cov
erE
ngin
e ra
diat
orP
ort c
oolin
g ai
r pas
sage
Por
t coo
ling
air o
utle
t gril
leC
argo
com
partm
ent
Figu
re 4
1:OriginalDUKWenginecompartm
entcoolingairsystem
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Airextractionfan
Eng
ine
com
partm
ent v
entil
atio
n vo
id s
pace
Coo
ling
air o
utle
t and
hot
air
extra
ctio
n
Coolingairinletandflow
throughtheengineradiator
Simplifiedillustration
Figu
re 4
2:Modifiedenginecoolingairflow
andenginecompartm
enthotairextraction
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Engine compartment
Lagged section of the engine exhaust pipe
Unlagged section of the engine exhaust pipe
Cleopatra’sstarboardventilationvoidspacefollowingthefireandresidualfoamremoval
Figure 43: Cleopatra’s engine exhaust pipe
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2.7.7 Engine compartment extraction fan controls
Theextractionfanswereconfiguredforautomaticstartandmanual-overridecontrol.Thestarboardextractionfanwaswiredtostartautomaticallywhentherudder’selectro-hydraulic steering system was started in readiness for river operations. The portextractionfanwasconfiguredtostartiftheenginecoolingwatertemperaturereached95ºC.Themastercouldindependentlystarttheportextractionfanfromhisseatedpositionifnecessary.Itisunderstoodthatthestarboardfanwasrunningandtheportfanwasstoppedwhenthefirebrokeout.
2.7.8 Passenger compartment
Cleopatra’s passenger and crew seating arrangements (Figure 44) were similar to those of WQ1. The side curtains were also similar in design and secured in the closedpositionbyVelcro,butdidnothavetheadditionalelasticatedcords.Theforwardwindscreenandsidewindowsadjacenttothemaster’sandtourguide’sseatsweretoughenedglassinlinewithPSVrequirements.Thesteelfloorplatesunderthecrewseatswerecoveredbyasyntheticcarpet.
Accessandegresstothepassengercompartmentwasbywayofaboardingplatformatthebackofthevehicleandanaftwatertightdoor.UnliketheLiverpoolDUKWs,theboardingplatformhadtwofoursteppedladders,oneontheleftandoneontherighthandsideoftheboardingplatform.Eachladdercouldberaisedorloweredbymeansofarope,whichwassecuredtoasmallsetofcleatsontheaftbulkhead(Figure 45).Duringroadjourneys,oneladderwasrequiredtobeleftintheloweredposition,whereasontheriverbothladderswerestowedintheirraisedposition.Generally,forroadsideembarkationanddisembarkation,thevehiclewasparkedontheleftsideoftheroadandtheleft(port)ladderwasused.Tofacilitatethis,thedoorwassecuredat90ºtotheaftbulwark(Figure 45).Thedoorcouldalsobeopenedthrough180ºandsecuredflatagainstthebulwarktoallowaccessandegressviatherightsideladder.
Priortothefire,thetourguidewasseatedfacingthedriver,withhislegsinthecompanionway so that he could interact and maintain eye contact with passengers. The vehicle’s side curtains were secured in the open position.
2.7.9 Engine fuel oil system
Cleopatrahada160litrefueltank,whichwaslocatedintheaftcompartmentunderthestarboardinboardfacingpassengerseat.Theenginefuelsupplyandspillreturnlineswerefittedtothetopofthetank.Bothlinesranforward,underthefloorplating,downthestarboardsideofthevehicle.Thespilllinepasseddirectlyintotheenginecompartmentwhilethesupplylinewasroutedunderthecrewcabdashboardtotheportsideofthevehiclebeforepassingintotheenginecompartment.Underthedashboard,aflexiblebraidedpipehadbeenusedtoconnectthecoppersupplylinetoaball-typeemergencyshut-offvalve.
Theengine-drivenfuelliftpumpdrewthefuelthroughacombinedwaterseparator/filterandafinefilterbeforedeliveringittothefuelinjectionpump.Thespillreturnlinewasdirectlyconnectedtothefuelinjectionpump.Whentheenginewasrunning,thefuelsupplylinebetweenthefuelstoragetankandthefuelliftpumpinletwasunder negative pressure; after the lift pump, the system was under positive pressure (Figure 46).
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Vehicleboardingplatform
StarboardladderPort ladder
Stairwaysecuringcleat
Passenger compartment door in its closed position
Passenger compartment door open - port ladder in use
Figure 45: Boarding platform and ladders
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2.7.10 Electrical distribution system
Cleopatrahadtwoseparate24Velectricaldistributionsystems:oneforstartingthe engine and one to provide power to the vehicle’s auxiliary systems. Each was suppliedwithpowerfromtwo,12V,55ampere-houracidgelbatteriesconnectedinseries.Eachsetofbatterieswasre-chargedbythesameengine-drivenalternator,butthesystemscouldnotbecross-connected.
Theenginestartingbatteriesandmainbatterycontactorwerelocatedinanenclosureunderthefront,portsidepassengerbenchseat.Inadditiontoenginestarting,thesystempoweredthedashboardinstrumentation,lightingandthefuelsupply valve solenoid through fused protected circuits.
Eng
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Theauxiliarybatterieswerelocatedinanenclosureunderthefront,starboardsidepassengerbenchseat.Amanually-operatedswitchwasfittedtoisolatethebatteriesfromtheelectricaldistributionsystemandthebatterieswereprotectedfromhighcircuitcurrentconditionsbya100Afuselocatedinthebatteryenclosure.Thebatterypowercableswereroutedunderthepassengerdecktoensuretheywerewell away from sharp edges and were secured to the deck angled-support structure. Theauxiliaryservices,whichincludedtheVHFradio,passengerannouncementsystem,electro-hydraulicruddercontrols,bilgepumpsandlighting,wereprotectedbyappropriatecapacityspade-typefuses.
2.8 FIRE-FIGHTING ARRANGEMENTS
2.8.1 Fire-fighting appliances
Cleopatracarriedthree9litrefoamandone2kgdrypowderportablefireextinguishers.Thefoamextinguisherswerestowedonthestarboardsideofthevehicle:oneinfrontofthetourguide’sseat,onebehinditandoneatthebackofthepassengercompartment close to the access door. The dry powder extinguisher was stowed on theportsidebehindthedriver’sseat.
Theenginecompartmenthadafixedfire-extinguishingsystem,whichcompriseda9litrefoamextinguisherconnectedtodistributionpipeworkfittedwiththreedischargenozzles(Figure 47).Thesystemwasactivatedbyamanual-pulllever,whichwaslocated on the left hand side of the master’s seat.
Noneoftheportablefireextinguisherswereusedduringthefireandtheenginecompartment’sfixedfire-extinguishingsystemwasnotactivated.
2.8.2 Engine compartment shut-down
Inthecaseofanenginecompartmentfire,thefuelsupplytothecompartmentcouldbeisolatedbyclosingoneofthevehicle’stwoemergencyfuelshut-offvalves.Oneoftheemergencyshut-offvalveswaslocatedunderthecrewcabdashboardandcouldbeclosedbythecrewfromtheirseatedpositions.Theotherwasfittedoutsidethevehiclebelowtheportsideofthewindscreen(Figure 48).
Theenginecompartmentcoolingairinletcowlingandtheportandstarboardventilationvoidspaceventswerefittedwithremotelyoperatedfiredampers.Thefiredamperscouldbeclosedbythecrewfromtheirseatedpositionsbypullingindividualwire-pullhandles (Figure 48).Themaincoolingairoutletontopofthebowcompartmenthatchcoverwasnotfittedwithafiredamperandcouldnotbeclosedintheeventoffire.TheLiverpoolDUKWshadasimilarcoolingairinletarrangementfittedtotheirenginecompartmenthatchcoversbuttheydidnothavefiredampers.
Neitherofthefuelshut-offvalveswereclosedbeforetheabandonment.Thecrewattemptedtoclosetheportandstarboardventilationvoidspacefiredampersbuttheywereunabletoreleasethesteel“R”clipsthatsecuredthewirepullhandlesbecausetheyweretoohot.Themasterwasunawareofthecoolingairintakefiredamperandtherefore did not attempt to close it. During the post-accident inspections of the wire pullarrangementsonotherLDTvehicles,MAIBinspectorsfoundthatseveraloftheRclipsweredifficulttoremoveundernormalconditions.
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Buoyancy foam
Foamdistributionpipe
9 litre foam extinguisher
Figure 47: TypicalLondonDuckToursDUKWenginecompartmentfixedfire-fightingsystem
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R-clip
External fuel shut-off valve
Fuelshut-offvalve
Enginecompartmentventilationfiredamper release handles
Figure 48: Emergencyfuelshut-offvalvesandfiredamperreleasehandlesinasimilarvehicle
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2.9 LIFE SAVING APPLIANCES
Cleopatracarried:2buoyantapparatus(1x20personand1x12person),4lifebuoys,30adultbuoyancyaids,2infantbuoyancyaids,and2manually-activatedgas-inflationlifejackets.
Thebuoyancyaidswereprovidedforthepassengersandtheinflatablelifejacketswereforthecrew.Theadultandinfantbuoyancyaidswereofthesolidfoamtype,theyprovided100Nand50Nofbuoyancyrespectively,andwerestowedinracksabovethepassengerseats.Thecrewlifejacketsprovided150Nofbuoyancyandwerestowedclose to their seats.
Thebuoyancyaidswerestoredinrobusttransparentplasticbags,manyofwhichweretightlyfittedand,accordingtothepassengerfeedback,weredifficulttoremove(Figure 44). Prior to Cleopatra enteringtheriver,passengersweregivenabuoyancyaid donning demonstration in accordance with the company’s operating procedures. Donninginstructionswerealsoprovidedonthebackofthepassengerseats.
Themajorityofthepassengersabandonedwithbuoyancyaids,howeverfewhadthemsecuredproperlyandsomesimplyheldontothem.One4yearoldchildabandonedwithoutabuoyancyaid.
2.10 VESSEL SURVIVABILITY
2.10.1 Buoyancy foam
TheinitialbuoyancycalculationscarriedoutbyBurnessCorlett&Partners Ltd in 1999 (Paragraph 1.9),werebasedonseveraltheoreticalassumptions.Thecalculations were intended to provide an indication of how the converted DUKW couldbeconfiguredtosatisfythedamagedsurvivabilityrequirementssetoutinMSN1699(M).Otherthanthoseprovisionalcalculations,LDTandtheMCAwereunabletoprovideanyrecordsrelatingtotheoriginalagreedvolumesanddistributionofbuoyancyfoamfittedwithinthehullsoftheLondonbasedDUKWs.
InNovember2008,theMCAraisedconcernsaboutprogressiveincreasesintheweightoftheLDTDUKWsasaresultofseveralstructuralmodifications.Inresponse,LDTinstructedBCTQtore-assessthebuoyancyrequirementsforitsvehicles.Duringtheprocess,theMCAremindedLDToftheneedtotakeaccountofthepositionofthevehicles’driveshaftsandgearboxlinkageswheninstallingfoam,andexplainedthattheuseofpre-formedblocksoffoamwouldbepreferabletotheexisting method of cutting and layering individual sheets of foam.
BCTQ used DUKW PortiatoreassessthebuoyancyfoamrequirementsfortheLDTfleet.Basedonavehicleweighbridgeweightof8.82tandapassengerandcrewweightof80kgperperson,itwascalculatedthat12.22tofbuoyancywasneededtoprovidethestatutory110%buoyancyforthevehicleinitsfullyladencondition.BCTQestimatedthatthevehicleitselfprovided3.17tofinherentbuoyancy,andconcluded that 9.05m3ofbuoyancyfoamneededtobeinserted.
UsingtheoriginalresultsfromBurnessCorlett&PartnersLtd'scomputermodeltohelpcalculatetheavailablespacewithinthevehicle’shull,BCTQidentified13separate locations that it estimated, collectively, could hold 10m3 of foam (Figure 49). The BCTQ report re-emphasised the need to ensure that the foam in the central void space was securely fastened to prevent it making contact with the rotating drive shafts.
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TheMCAconsideredPortiatoberepresentativeoftheLDTvehiclesandaccepted9m³asthestandardvolumeoffoamfortheLDTfleet.Accordingtoweighbridgerecords, Cleopatraweighed160kglessthanPortiain2009.In2012,DUKWElizabeth,withaweightof9.16t,wastheheaviestvehicleintheLDTfleet(340kgheavier than Portia).
2.10.2 Addition of buoyant foam following the sinking of Wacker Quacker 1
TheMCA’sdecisioninJune2013toincreasetheLondonDUKWs’buoyancyfoamrequirement,from9m3to10.6m3,wasbasedoncalculationscarriedoutbyitsinternalstabilityunitfollowingthesinkingofWQ1.TheincreasedrequirementmeantthatLDThadtoidentifynewlocationstoinstallfoam,andtofitincreasedvolumesoffoam,wherepossible,intothespacespreviouslydesignatedinBCTQ’s2008report.Toensurethemaximumvolumeoffoamwasfittedinthehullspacesbelowthe passenger compartment deck, LDT packed additional foam into the central void spaceabove,below,andonbothsidesofitsvehicles’rotatingdriveshaftsandUJs(Figure 50).
Oncethesespaceswerefull,thecompanypackedfoamintootherspaces,suchas the passenger compartment and the engine compartment’s ventilation void spaces (Figure 51). The foam in the cooling air void spaces was packed close to theunlaggedengineexhaust,andgapshadbeenlefttocreatechannelstoallowairfromtheenginecompartment’sextractionfanstoflowoutofthesidevents.Toprevent the foam moving within the ventilation void spaces, the garage mechanics glued the individual pieces of foam together.
The insertion of additional foam within the central void space, the engine compartment and its ventilation void spaces also increased the level of thermal and acousticinsulationsurroundingtheenginecompartment.Priortofittingtheextrafoam,itwasnotunusualforthepassengercompartmenttobecomeoverlywarm,requiringthemastertoswitchonthecompartment’scoolingfans.Followingthefittingoftheadditionalfoam,itwasnotedthatthepassengercompartmentwasmuch cooler and the fans were seldom used.
2.10.3 Types of buoyancy foam
ThebuoyancyfoamusedonboardCleopatra was a mix of:
• singlesheetand3-plylaminate,closedcell,low-density,non-flameretardantPlastazoteLD18polyethylenefoam;and
• singlesheethigh-density,closedcell,flame-retardantMicrolenPE-30XFRpolyethylene foam.
Thelow-densityfoamwaspackedintothepassengercompartmentbulkheads,aroundseatingandunderthepassengercompartmentfloorplatesinwayofthe propulsion drive shafts. The high-density foam was packed into the engine compartment and in its ventilation void spaces.
Thelow-densityfoamhadameltingpointof107ºCandaflashpointof>300ºC;themeltingpointofthehigh-densityfoamwasunknownbutitsburningpoint25 was estimatedtobe430ºC.
25 TheSpanishmanufactureroftheproductconfirmedthattheterm“burningpoint”,referredtointheMSDS,isthesameas“flashpoint”.
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Universaljoint
Lowdensitybuoyancyfoam
Shardsofgreasecontaminatedfoam
Universaljoint
Figure 50: Buoyancy foam packed around the drivetrain in the centre void space of a London Duck Tours DUKW
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2.11 FIRE INVESTIGATION
2.11.1 Overview
MAIBinspectorsandmembersofLFB’sFireInvestigationTeamconductedajointexamination of Cleopatra,atLDT’sfleetmaintenancegarage,duringtheperiod29-30September2013.
Ventilation space Outletvent
Extraction fan housing
Figure 51: Buoyancy foam packed into the engine compartment ventilation void spaces
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Adetailedvisualexaminationwasconductedofallareasofthevehicle.Initially,allexternalandnormallyaccessiblespacesandcompartmentswereexamined.Oncompletion,thepassengercompartmentfloorplateswereliftedtoexposethebuoyancyfoam,andallowaccesstothevehicle’sdrivetrainarrangementsandauxiliarysystemslocatedinthevoidspacesbelow.
Itwasapparentfrominsidethepassengercompartmentthatthefiredamagewasconfinedtothecrewcabareaandthefronttworowsofpassengerseats.Thebuoyancyfoaminthecentralvoidspacewascarefullyremoved,startingatthehand-operatedbandbrakeassemblyandworkingforward.Thefoamunderthecrewcabandthefronttworowsofpassengerseats,eithersideofthecentralvoidspace,was also removed.
Theinitialfindingsindicatedthattheseatofthefirewaslocatedwithinthecentralvoidspace,beneaththecrewcab,immediatelyaftoftheenginecompartment’snon-continuoustransversebulkhead.Detailedexaminationandexternallaboratorysupportwasnecessarytodeterminetheprobablesourceofignition.
2.11.2 The external hull
Theouterhullpaintworkinthevicinityoftheenginecompartment’sstarboardventilation void space, and in the area where the engine exhaust pipe exited onto thedeck,hadbeenpartiallyconsumed.Lightsmoke-damagewasevidentontopofboththeengineandbowcompartmentaccesshatchesbuttherewasnoevidenceofpaintblistering.Thewindscreenandthesidewindowsadjacenttothetourguide’sseatweremissingbutthoseadjacenttothemaster’spositionremainedintact.Thepaintontheportsideofthevehiclewasunmarkedbyfireorsmokedamage.Theenginecompartmentairintakeandtheportandstarboardventilationvoidspacefiredampers were in the fully open position.
2.11.3 Crew cab area and passenger compartment
Thefirehadtotallyconsumedthemaster’sandtourguide’sseats,leavingonlythesteelframework,andhadpartiallyconsumedthefirsttworowsofthepassengerseatsandthecarpetedfloorcoveringinthisarea(Figure 52).Thedashboardwasseverelyfire-damagedwiththeareainfrontofthetourguide'sseatbeingtheworstaffected.
Therewassignificantcombustiondebrisandheatdamageinthecentresectionofthecrewcabfloorplates.Thedamageinthisareawasfarmoreseverethaninanyother area of the passenger compartment.
Thebuoyancyfoamfittedtothehull,outboardofthestarboardforwardpassengerseatshadalsobeeninvolvedinthefireandhadbeenpartiallyconsumed.Therewasalsowiderangingheatdamagetotheportandstarboardsidecurtains.
2.11.4 Engine compartment
Theundersideoftheenginecompartmentaccesshatchhadbeenfiredamagedandwascoatedwithsoot,aswasthecompartment’safttransversebulkhead.Theengine’sfuelfilter/water-separatorbowlhadpartiallymelted.Theengineandautomaticgearboxoillevelswerecheckedandfoundtobeatthecorrectrunninglevels.
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Thestarboardextractionfanhadsufferedextensiveheatdamagewithmostofitsplastic grille consumed. The fan had fallen from its fastenings and was found on the wheel arch (Figure 53).Theportextractionfanremainedintactbutitsplasticprotective grille had suffered minor heat damage and was covered in soot deposits.
Crewcabarea
Passenger compartment
Figure 52: Firedamagedpassengercompartmentandcrewcab
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2.11.5 Engine compartment cooling air ventilation void spaces
ThestarboardvoidspacehadsufferedseveredamageconsistentwiththeimagesofthesmokeandfireseenonCCTVandvideofootageevidence.Themajorityofthehigh-densityflame-retardantbuoyancyfoamfittedintheareahadbeenconsumed.Thatremainingwasextensivelyburnt (Figure 53). There was no evidence that the firehadmigratedintotheportvoidspace.
Port ventilation extraction fan
Starboardventilationvoid space
Remnantsofhighdensitybuoyancyfoamwithintheventilation void space
Remainsofthestarboardventilation extraction fan
Figure 53: Firedamagewithintheenginecompartmentandstarboardventilationvoidspace
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2.11.6 Central void space
Beforethecrewcabandpassengercompartmentdeckplatingwasremoved,the forward section of the central void space was examined from the engine compartment.Itwasapparentfromviewingtheareathroughthenon-continuoustransversebulkheadthattheareaaroundthedriveshaftconnectingtheautomaticgearboxtotheMTBhadsufferedconsiderablefiredamage.
The internal hull coating under the plates was largely consumed, and that remaining wasblistered.Thenon-flame-retardant,low-densityfoam,whichhadbeenfittedaroundthedriveshaft,hadbeentotallyconsumedbythefire(Figure 54) with most oftheremainingexposedfoamsurfaceshavingmelted.Whenthefloorplateswereremovedfromabovethedriveshaftitbecameevidentthatthedamagewasmorepronouncedonthestarboardsideoftheshaft.
Thesurfaceofthesplineddriveshaftwascoveredinwhatappearedtobemoltenfoam.TheshaftwasintactandstillconnectedtotheautomaticgearboxandMTBbyitsUJs,andtheshaftwasabletobeturnedbyhand.Thedriveshaft,completewithitstwoUJs,wasremovedfordetailedanalysis,thefindingsofwhicharedetailedatParagraphs 2.12.1 and 2.12.2.
Oncetheshafthadbeenremoved,theareaofdeepseatedburnwasfullyrevealed.ThesiteofdeepestburnwasfoundtobeunderthepositionoftheforwardUJ,whichhadbeenconnectedtotheoutputflangeoftheautomaticgearbox.Apithadformedinthefoaminthisareaandthefoamhadbeenalmosttotallyconsumed(Figure 55).
Theoillevelsinthemarineandroadtransferboxeswerecheckedandfoundtobeat their correct running levels.
2.11.7 Hydraulic steering system
Althoughtheheadertankfortheelectro-hydraulicsteeringsystemwaslocatedattherearofthevehicle,itslevelwascheckedtodeterminethepossibilityofoilleakagefeedingorcontributingtothefire.Thelevelwasfoundtobenormal.
2.11.8 Engine fuel oil system
Asectionofflexiblehose,locatedunderthedashboard,whichhadconnectedthefuelsupplylinetotheinternalemergencyfuelshut-offvalve,hadbeencompletelyburntthrough(Figure 56).Thelinewasabovethelevelofthefueltankandwouldnothavebeenunderpressureatthetimeofthefire.TheflexiblehosedidnotmeettheMCA’sminimumfireteststandards.
The engine fuel supply and spill pipework was pressure tested to 70kPa; the testpressurewasheldsuccessfullyfor10minutes.Allconnectionsfromthefuelinjectionpumptothefuelinjectorswerecheckedandfoundtobetightandtherewas no evidence of fuel leakage. Both emergency fuel shut-off valves were found to beopen.
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View
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Alisonautomaticgearbox
View looking forward towards the engine compartment with the drive shaft removed
Figure 55: Areaofdeepestburnwithincentralvoidspaceaftoftheautomaticgearbox
Figure 56: Burntthroughsectionofflexiblehose
Fuelisolationvalve Flexiblehose
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2.11.9 Electrical distribution system
Theauxiliarybatterieshadsufferedlightheatdamagetotheircasings,cabling,plasticterminalcovers,andsecuringstraps.Theprotective100Afusewasfoundtohaverupturedbutallconnectionswerefoundtobetight.Theinsulationonthecablesthatranunderthefloorplatesclosetothecentralvoidspacehadbeenconsumed.Therewassignificantdamagetothewiringloomunderthedashboard.
2.11.10 Hand-operated band brake
Noneofthelow-densityfoamremovedfromaboveandaroundthebandbrake,orthatundertheoutputshaftfromtheroadtransferboxwasfiredamaged.Thebandbrakeshowednosignsoffiredamageoranyevidenceofoverheating.SignificantgreasedepositswerefoundontheremovedfoamandinthevicinityofthebandbrakeconnectingUJs (Figure 57).
2.11.11 Brake system air reservoirs
Thefloorplatesandfoamcoveringtheairbrakereservoirswereremoved.Whiletherewasnofiredamageinthisimmediatearea,theflexiblepipesconnectedtothefootoperatedairdistributionvalve,adjacenttothefootpedal,hadbeenconsumedbythefire.Therewasnocompressedairchargeremaininginthereservoirs.
2.12 EXTERNAL FIRE INVESTIGATION SUPPORT
2.12.1 Bureau Veritas Fire Science Department fire investigation report
Inordertodeterminethemostlikelysourceofignition,thepreliminaryfiresceneexaminationidentifiedaneedto:
• Determinetheignitabilitycharacteristicsofsamplesofcontaminatedandnon-contaminatedlow-densityandhigh-densitybuoyancyfoam.
• ConductavisualexaminationofthesplineddriveshaftassemblyandtheUJsthathadconnectedtheautomaticgearboxoutputshafttotheMTB.
• Establishiftheenginecompartment’sstarboardextractionfanwasdamagedby,orwasapotentialcauseofthefire.
Toachievethis,LFBcontractedtheLondon-basedBureauVeritas(BV)FireScienceDepartmenttoundertakeaseriesofthelaboratorytestsandexaminations.
TheBVFireScienceDepartmentreport26 found that:
• Theedgesofboththelowandhigh-densityfoamcouldbeeasilyignited,especiallythosewhichhadbeencontaminatedwithoilorgrease.
• Onceaflamewasestablisheditspreadreadilyacrossthefoam.
• Smallersectionsofbothfoamtypesweresignificantlyeasiertoignitethantheirbulksurfaces.
26 Fire Investigation – London Duck Tours, River Thames, near the Palace of Westminster - LFB/13-595 dated 9 December 2013.
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• Thehigh-densityflame-retardantfoamproducedmuchmore,anddenser,blacksmokethanthelow-densitynon-flame-retardanttype.
• The surface of the drive shaft and its UJs was covered in melted foam.
• Therewasnoobservablephysicaldamagetothedriveshaftassembly.
• Theenginecompartment’sstarboardextractionfanhadnopre-existingelectricaldefectsandwasnotcausaltothefire.
Bandbrake
Foamremovedfromaroundthebandbrake
Excess grease
Excess grease
Figure 57: Greasecontaminatedfoamremovedfromaroundthebandbrake
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Thelaboratoryreportconcludedthat:
“There was no obvious ignition source in the vicinity of the buoyancy foam, and therefore the most likely cause of the fire was the action of the rotating drive shaft (or other moving parts) on the oil contaminated surfaces of the buoyancy foam blocks.”
2.12.2 Metallurgical analysis of Cleopatra’s drive shaft and UJs
FollowingBV’svisualexaminationofthedriveshaftassembly,theMAIBcontractedHampshire-basedMaterialsTechnologyLimited(MTL)toconductdetailedmetallurgicaltestingofthesplinedsteelshaftanditsUJs.MTLwastaskedto:
• X-ray,dismantleandexaminethedriveshaftandbothUJsfordefectsandsigns of overheating.
• Examinetheneedlebearingrollersandcontactsurfacesforwear.
• DeterminethetypeofgreaseusedtolubricatetheUJs.
TheMTLlaboratoryreportfoundthatbothUJshadsufferedwhatappearedtobefrettingcorrosionindicativeofmisalignedin-serviceloading.ItwasevidentfromtheextentofthewearonthesurfacesoftheUJjournalbearingsthatthiswouldhavebeenpresentpriortothefire.Theexcessivewearhadcausedcircumferentialcrackingtooneofthejournalcapscontainingtheneedlebearingrollers(Figure 58),andresultedinelevatedtemperaturesofbetween300-400°C,asconfirmedbybluingoftheneedlebearingrollers.
FouriertransforminfraredspectroscopyanalysiswascarriedoutonthesamplesofburntgreaseontheexternalsurfacesoftheUJsandthatcontainedwithinthebearingcaps.TheresultshadsimilarcharacteristicstotheexemplarCastrolHeavyDuty Plus grease.
TheMTLreportconcluded:
“… the overheated bearings, indicated by the evidence of bluing on the needle bearings, can be considered to be a possible cause of ignition where the environment is suitable and where flammable materials with the appropriate properties/characteristics are in contact or in close proximity…”
2.13 SAFETY MANAGEMENT SYSTEM
InaccordancewiththerequirementsoftheDSMCode,LDThadproducedanOperationalProceduresManualandhadidentifieditsmanagingdirectorasthecompany’sDPA.Themanualincludeddedicatedsectionsforreactingtofireandinstructionsforabandonment.Italsostatedtherequirementforcrewtraining,including the need for emergency drills.
Section16oftheOperationalProceduresManualdescribedtheactionstotakewhenafirewasidentified.Thecrewareinstructedto:
1. Check on the passengers and raise the alarm.
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2. Put out a call on VHF channel 14.
3. Tackle the fire.
4. In the event of a fire in the engine bay, close the air vents and turn on the automatic emergency fire extinguisher.
5. Steer the craft to minimise the effect of the wind on the fire and warn other craft (a series of short blasts).
6. IF THE FIRE IS A DANGER TO PASSENGERS AND CREW THEN PREPARE TO ‘ABANDON SHIP’.
Figure 58: Laboratoryanalysisoftheforwarddriveshaftuniversaljoint
Wearonjournals
Wear induced pitting on surfaceofneedlebearingrollers
Bluing oxidation on needle bearingrollers
Fracturedbearingcap
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Sections17and20ofthemanualdescribethe"Mayday"distressprocedureandabandonshipproceduresrespectively.TheguidancegiveninSection17statedthat,if in the opinion of the master it is an extreme and absolute emergency, the crew should:tunetheVHFradiotochannel16;waitforagapintransmission;transmitadistresscall.LDT’sabandonshipprocedurewas:
1. Make a ‘MAYDAY’ distress call on VHF channel 16.
2. Order all passengers and crew to don lifejackets.
3. Order second crew member to climb onto the upper deck (i.e. the roof of the passenger compartment) and pass down the buoyancy apparatus to the rear of the vessel. If time is of the essence then instruct that the three skull craft be thrown overboard.
4. Assemble passengers and ensure that less able passengers are paired up with more able passengers.
5. Disembark passengers and crew onto buoyant apparatus using the rear steps of the vessel if it is safe to do so.
6. If by opening the rear bulkhead door it would aggravate the position by increasing the volume of water being taken on board then instruct that the emergency exits are used.
7. If buoyant apparatus is full then assist remaining passengers into water.
8. Take a head count and keep a constant check of numbers.
9. Maintain watch for other vessels.
10. STAY CALM AND KEEP UP MORALE.
2.14 VEHICLE MAINTENANCE
2.14.1 Maintenance management system
SimilartotheTYDoperationinLiverpool,theLDTvehicleswereinspected,servicedandmaintainedin-housebythecompany’sgaragestaff.Thegaragemechanicsfollowed a maintenance management regime that was designed to comply with bothMCAandVOSArequirements.Paperrecordsweremadeoftheplannedandunplanned maintenance carried out on each vehicle.
2.14.2 Planned maintenance
Eachmorning,thecompany’sengineerswererequiredtoensurethatallvehicleswereroadandriver-worthybeforeallowingthemtoleavethegarage.Beforedeparture,thedriverhadtocomplete,signanddateacombinedvehicle and vessel checklist.
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Aspartoftheweeklymaintenanceroutines,thegaragemechanicshadtoinspectandmanuallygrease/lubricatethedrivetrainbearingsandUJs.Theyalsocheckedtheoillevelsintheengine,automaticgearbox,transferboxesandsteeringsystem.This was last carried out on Cleopatraon23September2013,6dayspriortotheaccident.
Thevehicles’internalUJswerelubricatedwithCastrolPremiumHeavyDutyPlusgreasewhichhadaflashpointof232ºC.TheexternalbearingsandUJswerelubricatedwithLintonLubricants’ProtexBluegrease(flashpointof>200ºC).
To allow the garage mechanics to carry out their weekly maintenance tasks, they had to remove the tightly packed foam from each DUKW’s central void space (Figure 59). The need to remove and then reinstall the foam to grease the drive shaftbearingsandUJsmeantthatthetimetakentocompletethevehicles’weeklymaintenanceroutinesincreasedsignificantlyandrequiredthevehiclestobetakenout of service for a full day.
When the greasing procedure was demonstrated using DUKW Desdemona, it was notedthatthefoamsectionsweredifficulttoremoveandwereincloseproximitytotherotatingshaftassemblies.SimilartoCleopatra, there was extensive evidence of greasecontaminationofthefoam.Itwasalsonotedthatthepositionsofeachfoam
Figure 59: Tightly packed foam in central void space
Greaseimpregnatedcrumbsoffoam
Foamcontactwith shaft
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blockorsheethadnotbeenmarkedandforcehadtobeappliedtoreinstatethefoam.Oncerefitteditwasnotpossibletoidentifyifthefoamwasincontactwiththerotating parts.
2.14.3 Unplanned breakdown repairs
The unplanned maintenance work was also recorded on the paper record sheets. Followingtheinsertionofadditionalbuoyancyfoam,thegaragestaffexperiencedseveralrelatedissuesthatrequiredunplannedmaintenanceaction.
DuringtheinspectionoftheLondonDUKWs,itwasobservedthatthefoamfilledspacescontainedfineshardsor“crumbs”offoam(Figures 50 and 59).Mostofthecrumbswerecreatedwhenthegaragestaffcuttheindividuallysizedblocksoffoaminsitu.Itwasalsoevidentthat“crumbs”hadbeencreatedbytherubbingactionbetweentheblocksoftightlypackedfoamduringtheremovalandrefittingprocess,andasaresultofcontactbetweenthefoamandtherotatingdrivetrain.Thefoamcrumbshadatendencytobuildupinthebilges,andhadoccasionallyblockedthebilgepumpsuctions.
2.15 SURVEYS AND INSPECTIONS
TheLDTwaterborneoperationwasoverseenbytheMCA’sOrpingtonMarineOffice,anditssurveyorsappliedasimilarsurveyandinspectionregimetothoseinLiverpool.UponnotificationofanMCAsurveyorinspection,thegaragestaffpreparedthevehicle(s)byremovingfoam,asnecessary,frompre-selectedlocations.Thisenabledthesurveyortogainaccesstoandinspectareassuchasthehullandthedrivetrainarrangements.Oncompletionofsurvey,andtypicallyfollowingthe surveyor’s departure, the foam was reinserted.
The most recent survey of Cleopatra tookplaceon3October2012.Duringthesurvey,itwasidentifiedthatthevehiclewasoverdueastabilityheeltest,whichwassubsequentlycompletedwithinthe4monthsallottedbythesurveyor.ThetotalquantityandconditionofbuoyancyfoamwasnotcheckedbytheMCAatthesesurveys and inspections.
2.16 EMERGENCY RESPONSE
2.16.1 Thames RIB Experience
ThamesRIBExperiencewasoperatingitsthreeRIBs-Ultimate, Experience and Adrenaline - closebywhenthefirebrokeout.TheskippersofthethreeRIBsheardCleopatra’srequestforassistanceandimmediatelywenttoitsaid.AllofCleopatra’s passengersandcrewwererescuedfromthewaterbeforeFiredartandtheRNLIlifeboatsarrivedonscene.
2.16.2 Royal National lifeboat Institution
ThenearestRNLIstationtoWestminsterwasatTowerPier.Thelifeboatfromthisstationwasunabletoimmediatelyassistasitwasattendinganotherincident.Inviewofthis,theChiswicklifeboat,whichwasseveralmilesupstreamwastasked.
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Towerlifeboathastilycompleteditsearlierdeploymentmissionandwasonthesceneofthefireat1206.Chiswicklifeboatarrivedat1208.ThelifeboatscarriedoutariversearchforpossiblecasualtiesuntilitwasconfirmedthatallCleopatra’s occupants were safely on shore.
2.16.3 Police
Atthetimeoftheaccident,theMarinePoliceUnithadonevessel,MP2, on duty. However,thiswasattendingthesameincidentastheTowerPierRNLIlifeboat.MP2 initiallybecameawareoftheincidentfromoverheardradiotransmissions.Thiswaslaterconfirmedbythepolice’scomputeraideddispatchnotificationservicefromLambethpolicestation.Anairbornepolicehelicopterwasnotifiedoftheincidentanddiverted to the scene. The helicopter arrived on scene at 1200 and provided a live video link direct to the coastguard.
2.16.4 London Fire Brigade
Inadditiontoconventionallandbasedfireappliances,theLFBhadtwofireboats,onedutyvesselandonereserve.ThesewerestationedatLambethFirePontoonabout400mfromthefirescene(Figure 35).
ThefireboatFiredartwasnotifiedoftheincidentbythecoastguard.Aroundthesametime,amemberofthepublicmisinformedtheLFBcontrolofabusfireneartheHousesofParliamentandalandbasedappliancewastaskedtoattend.
Firedartarrivedonsceneat1159,quicklyfollowedbythelandbasedappliancetaskedtotheerroneousbusfire.Afterextinguishingthefire,Firedart towed Cleopatra away from the scene.
2.17 PASSENGER FEEDBACK
Aspartoftheinvestigationandinformationgatheringprocess,theMAIBpostedquestionnairestothe28passengers’declaredaddresses.Fourteenpassengers(50%)respondedbycompletedquestionnaireorwrittennarrative,whileafurther6(21%)communicatedtheirthoughtsbytelephonetoMAIBinspectors.
Alloftherespondersstatedthatasafetybriefandbuoyancyaiddonningdemonstrationhadbeengivenbytheguide.Theyalsocommentedonthelight-heartednatureofthesafetybrief.However,15%oftherespondersfeltthatthepassengersdidnotgivethebrieftheattentionitdeserved.Someofthepassengersthoughtthiswaspossiblyduetothejocularnatureofitsdelivery.
Alltherespondersexpressedconcernaboutthebuoyancyaidsbeingstowedinstrongpolythenebags.Nineteen(70%)oftheresponderssaid,oncetheyhadremovedthebuoyancyaidsfromthebags,theyhaddifficultyreleasingthestraps;5(19%)gaveup and entered the water without them.
Amixedresponsewasgiventothecrew’sactions,withsomerespondersthinkingthecrewdidlittletoassist,whereasothershighlypraisedtheirpositiveactions.Mostcommentatorsreferredtothelevelofpanicamongthepassengersfollowingthefire,andrecognisedthedifficultythecrewhadtryingtocontrolsuchasituation.
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2.18 SIMILAR ACCIDENTS
2.18.1 MAIB database
TheMAIB’sdatabasecontainedrecordsof52previouslyreportedincidentsinvolvingLDTvehicles.Ofthose,29wereattributedtomechanicalandelectricalfaults,2resultinginfiresand3requiringthepassengerstobeevacuatedontoothervessels.The records also indicate that 9 of the mechanical failures were related to drivetrain issueswith2ofthemspecifyingUJfailures.Threecollisionsand6groundingshavealsobeenreported.
ManyoftheaccidentslistedontheMAIBdatabasewerenotreportedtotheMAIBbythecompany.AccordingtoMCArecords,itwasawareofanadditionalsixincidentsbetween2010and2013thathadnotbeenreportedtotheMAIB,whichresultedinLDTDUKWsbeingtowedofftheriver.Ofthose,fourweretheresultofmachinerybreakdownsandonewasafouledpropeller.
On17May2013,theLFBfireboatFireflashself-launchedinresponsetoafireonboardDUKWDesdemona.Atthetime,Desdemona was ashore at the Lacks Dock slipwayandthefirehadbeenextinguishedbythetimethefirecrewarrived.TheincidentwasnotreportedtotheMAIB,butoverheatingofthevehicle’shandbrakewasunderstoodtobethecause.
2.18.2 Elizabeth
On12July2013LDT’sDUKWElizabethwastowedfromtheRiverThamesfollowingthefailureofonetheUJsconnectingtheautomaticgearboxoutputtotheMTB.AccordingtoLDT’smaintenancerecords,thiswasanuncommonoccurrence.Elizabethwasnotinserviceatthetimeoftheaccident,ithadrecentlybeenpackedwithadditionalfoamandwasbeingusedtodelivercrewtrainingpriortobeingputbackintoservice.TheincidentwasreportedtotheMAIBbythePLAand,followingarequestformoreinformation,LDTadvisedtheMAIBthatitsinternalinvestigationhadidentifiedthattemperatureswithintheenginecompartmentandsurroundingareashadincreasedfollowingitsventilationmodificationsandtheinsertionofadditionalbuoyancyfoam.Asaresult,itwasconsideredlikelythattheUJhadoverheatedandrundryoflubricant.
ItwastheDPA’sunderstandingthat,asaresultofthisincident,newlysourcedhigh-temperatureresistantgreasewasbeingusedacrosstheDUKWfleettolubricatetheUJs.However,thisinvestigationhasidentifiedthatthereplacementhigh-temperature grease had the same properties as that previously used.
2.18.3 Mistress Quickly
At1125on5June2008,LDTDUKWMistress Quickly suffered a mechanical breakdownontheRiverThames.Initially,aknockingnoisewasheardcomingfromtheenginecompartment,afewminuteslatertheengineseized.ThemasterimmediatelyreportedtheincidenttotheThamesVTSanddroppedanchor.ThiswasobservedbythecrewofanLFBfiretender,anditwassubsequentlymanoeuvredalongside to provide assistance.
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Mistress Quickly’smasterobservedsmokeandsparkscomingfromtheenginecompartment vents and immediately isolated the fuel supply line and closed the inletventfiredamper.Theninepassengersandtwocrewthenevacuatedontothefiretender.TheLFBcrewclimbedonboardtheDUKWandoperateditsfixedfireextinguishingsystem.Whentheyopenedtheenginecompartmenthatchthefirewasstillburning,sothefirefightersextinguisheditusingtheirownportableextinguishers.
Followingtheincident,theChiefInspectorofMarineAccidentswrotetoLDTinstructingittoensurethatmastersofitsvesselsarefullyacquaintedwith,andregularly exercised in the emergency procedures contained within the company’s operational procedures manual.
2.18.4 World War 2
DUKWs have always had engine and engine compartment cooling issues, particularlyinhotclimates.TheUSarmy’sThe DUKW, Its Operation and Uses manualwarnedagainstthedangersofrestrictingthecoolingairflowtoandfromtheenginecompartment.Themanualspecificallywarnedagainstputtinganythinginthe forward compartment or within the air passages, pointing out that the heat of the engine cooling air plus the heat of the exhaust piping is almost certain to start a fire.
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SECTION 3 - ANALYSIS
3.1 AIM
Thepurposeoftheanalysisistodeterminethecontributorycausesandcircumstancesoftheaccidentasabasisformakingrecommendationstopreventsimilar accidents occurring in the future.
3.2 OVERVIEW
The causes and circumstances of WQ1’shullfailureandsubsequentsinking,andthefireonboardCleopatrawillbeconsideredinthissection.Theunderlyingcontributoryfactorsassociatedwiththeseadverseoutcomeswillbediscussedandthevehicleabandonmentsandemergencyresponseswillbeanalysed.
ThebodyofevidencetosupporttheanalysiswascomprehensiveandincludedvideoandCCTVfootage,witnessaccounts,scientificanalysisofphysicalevidence,practicaltrialsandreconstructions,anddocumentedrecords.TheMAIBalsoreceivedahighlevelofco-operationandexpertinputfromanumberofotherAPVoperatorsanddesignersfromwithintheUKandabroad.
3.3 THE SINKING OF WACKER QUACKER 1
3.3.1 Overview
WQ1sanksuddenlybythebowinSalthouseDock,Liverpool,because:
• Itsufferedmassivefloodingthroughtwolargeholesinitsouterhullplatingbelowthewaterline,andthevehicle’selectricpoweredbilgepumpsdidnothave the pumping capacity needed to cope with the rate of water ingress.
• Oncefullyflooded,WQ1didnothavesufficientresidualbuoyancytoremainafloat.
The holes in WQ1’s hull were created as a result of the forces generated when its propellerbecamefouledbyanolddiscardedcartyre.WQ1’s 31 passengers and 2 crewabandonedthevehicleandeitherswamashoreorwererescued.Noonewaskilledorseriouslyinjured.
3.3.2 The hull failure
When WQ1’s propeller picked up the car tyre, the resultant forces were transferred to the vehicle’s hull through its propeller shaft v-strut. The structural strength of the hullwasnotsufficienttoabsorbtheforcesgenerated,allowingthev-strutfeettoberippedfromtheirmountings.Thiscreatedtwolargeholesbelowthewaterlineinthepropeller tunnel plating.
The v-strut was designed to support the propeller shaft and transfer the transverse forces acting on the propeller to the vehicle’s hull. The internal v-strut support shoes were designed to spread the load and transfer dynamic forces acting on the v-struttothevehicle’safttransversebulkhead.However,theweldsthatfastenedtheinternalshoestotheafttransversebulkheadstiffenershadcorrodedaway,ashadtheweldsbetweenthebaseofthebulkheadandtheoutershellplating(Figure 60).
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This meant that the full weight of the forces acting on the hull through the v-strut wasbeingtakenentirelybytheshellplating.Thepropellertunnelplatingitselfhadsufferedseverecorrosionwastageandthereforehadbeensignificantlyweakened.
Figure 60: Hull corrosion within Wacker Quacker 1’s aft void space
Starboardafttransversebulkheadv-strutshoestiffener
Afttransversebulkhead
Propeller tunnel
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RegardlessofWQ1’s material condition, the DUKW’s hull plating was never designedtoabsorbsuchforces.ThispointwasidentifiedbytheUSarmy’srecommendationtofitpropellerguards(Paragraph 1.16.5) and reinforced when the propeller of DUKW BeatricewasfouledontheRiverThamesin2001(Paragraph 1.16.2). Had TYD learned lessons from previous accidents, or acted on the advice of LDT after the sinking of WQ4, and reinforced the propeller tunnel plating, it is possiblethatthefoulingofthepropellerwouldnothaveresultedintherupturingofthe vehicle’s hull.
3.3.3 The fouling of the propeller
WQ1’spropellerdriveshaftseizedshortlyafterthevehiclehadrolledbackintothewaterfollowingthedriver’sabortedattempttoclimboutofSalthouseDock.Thepolicediversfoundseveraldiscardedcartyresandotheritemsofdebrisonthedockbedatthebottomoftheconcreteslipwayandclosetothesunkenvehicle.
ItislikelythatthetyrewasdisturbedfromthedockbedbyWQ1’s wheels as it rolled backdowntheslipway,andwaspickedupbythepropellerasthedrivertriedtomanoeuvre the vehicle astern.
PropellerfoulingwasaforeseeablehazardthatwouldhavebeenidentifiedhadtheriskstoTYD’swaterborneoperationsbeensystematicallyassessed.Thelikelihoodofthehazardbeingrealisedwouldhavebeensignificantlyreducedifstepshadbeentakentoperiodicallyinspectandcleardebrisfromthebottomoftheslipways.Thefittingofapropellerguardmightalsohavereducedthelikelihoodofthetyrefoulingthe propeller.
3.3.4 Material condition of Wacker Quacker 1 and The Yellow Duckmarine fleet
Followingitssinking,WQ1wascloselyexaminedbyMAIBinspectorsandMCAsurveyorsandwasfoundtobeinanextremelypoormaterialcondition.Internallyits hull was heavily corroded (Figure 60);largesectionsofitselectricalcablingwasfoundtobehangingloose,andwereunprotected;andmuchofitsinstrumentationdid not work. Externally its hull was covered in a patchwork of welded repairs (doublers)thathadnotbeenapprovedbytheregulatoranddidnotmeetbasicmaritimestandards.Itwasalsoevidentfromthecompany’smaintenancerecordsthat WQ1’ssteeringsystemanddrivetrainarrangementswereunreliableandproneto failure.
TheothervehiclesintheLiverpoolfleetwereinasimilarconditiontoWQ1.Itwasapparent that the garage staff had worked long hours to keep the TYD vehicles in service. However, it was also clear that they were under-resourced and WQ1, and therestoftheLiverpoolfleet,hadbeenallowedtodeterioratetoanunsafeconditionover a prolonged period of time.
OperatinginseawaterexposedthehullsofTYD’svehiclestoahighriskofcorrosionandtheirthinshellplatingmadethemparticularlysusceptibletocorrosionrelatedhullfailure.AlthoughthefoulingofWQ1’s propeller triggered the hull failure in this instance, the hull was close to failing under normal operating conditions, as was the case with WQ2 only 2 weeks earlier (Paragraph 1.16.1). WQ1hadbeenpoorlymaintained,anditshouldnothavebeenoperatingonthewater.
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3.3.5 Maintenance management
TYD’spaper-basedmaintenancemanagementsystemwasdesignedtosatisfytherequirementsofboththemaritimeandtheland-basedregulators.Itallowedthe company’s garage mechanics to record their scheduled inspections, planned maintenance routines and defect repairs on daily, weekly and monthly record sheets.
The records showed that the DUKW masters often reported excessive levels of floodingandthatthemechanicsfrequentlydiscoveredandrepairedholesinthevehicles’ hulls. The types of hull failures the garage staff were discovering should havebeenreportedtotheMCAandtheMAIB.Thehullrepairsshouldhavemetrecognisedmaritimestandardsandshouldhavebeenoverseenorapprovedbytheregulator.
The maintenance management system successfully captured the day to day issues thegaragestaffhadtodealwith.Thenumberofmachinerybreakdowns,hullfailuresandfloodingincidentsinthemonthsleadinguptothesinkingofWQ1 was remarkablyhigh.ThesinkingofWQ4andthewarningsissuedbytheMCAfollowingits most recent incognito inspection, meant the company was fully aware of the waterbornerisksitwasrequiredtomanage.Despitethis,TYDdemonstratedthatitwaspreparedtotakepassengersontothewaterinseverelysub-standardvehicles.
3.4 THE FIRE ON BOARD CLEOPATRA
3.4.1 Overview
Cleopatrasufferedamajorfireduringthewaterbornesectionofanamphibioussightseeingtour.Thefirequicklyspreadtothepassengercompartment,engulfingits28passengersand2crewinthickblacksmoke.ThisledtotherapidabandonmentofthevehicleintotheRiverThames.Noonewaskilledorseriouslyinjured.
3.4.2 Seat of the fire
Theexaminationofthefiredamagedvehicleandburnpatternsindicatedthattheseatofthefirewaslocatedinthecentralvoidspace,belowthecrewcab,immediatelyaftoftheenginecompartmenttransversebulkhead(Figure 55). This assessmentwassupportedbywitnessaccounts.
Smokewasfirstseencomingfromthecoolingairinletontopoftheenginecompartmenthatch,quicklyfollowedbysmokerisingfromunderthefloorplatesinthecrewcabarea.Theareaofdeepestburnwasaroundtheautomaticgearboxoutputshaft’sUJ,whichwasconsistentwiththelocusofthefirebeingdirectlyinthisarea.
3.4.3 Fire development
Oncethefireunderthefloorplateshadbecomeestablished,thetightlypackedgreasecontaminatedbuoyancyfoamprovidedareadysourceoffuel.Asthefoammeltedintothefirethevapoursreleasedwouldhavereadilyignited,addingtotheintensityofthefire.
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Theenginecompartment’sstarboardextractionfanandtheengineradiatorfanwouldhavedrawntheflamesandhotgasesintotheenginecompartmentthroughtheholesinthetransversebulkhead(Figure 61).Fromhere,thestarboardextractionfanforcedthesmokeandflamesthroughtheenginecompartment’sstarboardventilationvoidspace,pre-heatingandsubsequentlyignitingthebuoyancyfoamcontainedwithinit.Again,thisissupportedbywitnessaccountsthatdescribedthesmokeasbeinginitiallywhite/greyandthenturningblack.Thisisconsistentwiththefirelaboratory’sfindingsthat,whenburning,thelow-densityfoam(packedinthecentralvoidspace)andthehigh-densityfoam(packedintheenginecompartment’sventilationvoidspaces)producedlightgreyandblacksmokerespectively.
Thesmokeandflamesexitedthevehiclethroughthestarboardventilationvoidspace outlet vent. The fan would have continued to run until its wiring failed or its casingmelted.Afterwhich,thehotgasestravellingthroughthevoidspacewouldhave created a chimney effect; drawing cold air into the engine compartment throughtheventsinthehatchcoverstofeedthefire.Thefireunderthefloorplatesalsoburntthroughtheflexibleairhosesthatsuppliedthecompressedairtothefootbrakedistributionvalve.Thesubsequentreleaseofthecompressedairwouldhaveaddedtotheintensityofthefireforashortperioduntilthethreeairreservoirsemptied.
Asthefiredeveloped,itspreadtothepassengercompartment,causingthesidecurtainsandforwardsectionofseatingtobeconsumed.Theflexiblefuelhoselocatedunderthedashboardburntthroughbecauseitdidnotmeettherequiredfireteststandard.Thiswouldhavecausedasmallamountofdieselfueltofeedthefireuntil the fuel supply line emptied.
Thelargeholeinthetransversebulkheadbelowthecrewcaballowedthefiretospreadquicklytothestarboardventilationvoidspace.HadtheconvertedDUKW'spassengerspaceandenginecompartmentbeenseparatedbyaninsulated,gas-tightbulkhead,inaccordancewiththeregulatoryrequirements,thefirewouldnothavespreadsoquickly.
3.4.4 Source of ignition
IndeterminingthecauseofthefireonboardCleopatraanumberofpotentialignitionsources were considered against the circumstances prevailing at the time. These included:
• Contactbetweenthebuoyancyfoamandtheunlaggedsectionoftheengineexhaustintheenginecompartment’sstarboardventilationvoidspace.
• Overheatingofthebandbrake.
• Leaks from the engine fuel oil system, the hydraulic oil steering system and drivetraingearboxes.
• Electrical short-circuit, overload and component defects.
Thefireinvestigationdeterminedthatnoneoftheabovewerecontributory.
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Self-heating27ofthegreaseonthebuoyancyfoamandheatgenerationasaresultoffrictionbetweenthefoamandthedriveshaftarrangementswerealsoconsidered.
LaboratoryanalysisoftheUJs(Paragraph 2.12.2) used to connect the splined driveshafttotheautomaticgearboxandtheMTBdeterminedthatbothhadsufferedexcessivewear.Inparticular,thelaboratoryreportidentifiedthatthejournalcapsupportingtheneedlerollerbearingsononeofthearmsfittedtotheforwardUJhadfracturedcircumferentiallyandthattheneedlerollerbearingshadsufferedfrompre-existingoverheating.Thereportidentifiedthattemperaturesofbetween300and400°Cwouldberequiredtocausethebluingthatwasevidentontheneedlerollers.Thesetemperatureswouldhavebeensufficienttoignitethefoam,particularlythefineshardsofgreasecontaminatedfoamthatwerepresentatthetime.
Havingconsideredalltheevidence,theMAIBfireinvestigationconcludedthatthemostlikelysourceofignitionwascontactbetweenthegreasecontaminatedbuoyancyfoamandtheoverheatingUJthatconnectedtheMTBdriveshafttotheautomaticgearboxoutputshaft.Regardlessofthemechanismofignition,itisalmostcertainthatthepackingofunsecuredandunprotectedbuoyancyfoamaroundmoving machinery in the central void space introduced the circumstances that led to thefire.
3.4.5 Failure of the universal joint
Thepackingofadditionalbuoyancyfoamaroundthedrivetrainandwithintheventilationvoidspacesmadeitmoredifficulttocarryoutbasicgreasingroutines.Italso changed the characteristics of the environment within the engine compartment and in the spaces surrounding it. The foam created an insulating effect that had increasedtheenginecompartmenttemperatureandreducedtheflowofairoverthe shaft lines. This reduced the dissipation of heat from the central void space. This phenomenon was evident from the reduced temperatures experienced in the passengercompartmentandwasacknowledgedbyLDTwhenDUKWElizabeth suffered a similar UJ failure a couple of months earlier (Paragraph 2.18.2).
The temperature increase around the drivetrain would have reduced the viscosity of the grease within the UJs, and increased the likelihood of the grease deteriorating or beingexpelledfromtherotatingUJs.ThemostcommoncausesofUJfailuresarelackoflubricationandshaftmisalignment.BothwillcausetheUJtooverheatandturnblue.Thejointsstarttosqueakandcausevibrationthatincreaseswithspeed,beforetypicallyfailingwithaloudclunk. This was the case with Elizabeth and would almost certainly have happened on Cleopatrahadthefirenotbrokenout.
LDTwasunderpressuretomeetthedamagedsurvivabilitystandardandgaveinsufficientattentiontotheadverseeffectsandtherisksassociatedwithpackingfoam close to the unguarded drivetrain and unlagged exhausts. The DUKW operator chosetoaccepttheincreasedmaintenanceburdenandcontinuedtooperateitsvehicleswithanelevatedriskofmechanicalfailureandfire.
27 Self-heatingoflubricationproductsonopencellinsulationisarecognisedproblemandtypicallyoccursinareaswithahighambienttemperature.
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3.4.6 Material condition of Cleopatra and London Duck Tours fleet
AfterCleopatra’sfire,theLDTfleetwassubjecttoasimilarlevelofscrutinytothatofthevehiclesinLiverpool.Ingeneral,theLDTvehicleswerefoundtohavebeenwellmaintainedandinasoundmaterialcondition.Itwasalsoevidentthatthecompanyhadinvestedsignificantresourcestoimprovetheoperationalperformanceandcorrosion resistance of its vehicles.
3.5 VESSEL SURVIVABILITY
3.5.1 Regulatory compliance
TomeetthedamagedsurvivabilitystandardsetoutinMSN1699(M),theUK’sClassVDUKWswererequiredtohavesufficientresidualbuoyancytoremainafloatanduprightinthefullyfloodedcondition.Toachievethis,theLiverpoolandLondonbasedoperatorsundertooktoinsertbuoyancyfoamintothehullsoftheirvehicles.Inadditiontoproviding110%buoyancy,theoperatorswererequiredtoensurethatanybuoyantmaterialusedwassecuredagainstmovementandprotectedagainstdeterioration.
FollowingtheMCA’sinterventioninLondonin2008,BCTQcalculatedthatabout9m3ofclosedcellfoamwasneededtoprovide110%buoyancyonboardtheLDTDUKWs. Despite this, and the sinking of WQ4 and WQ1, LDT continued to operate itsvehiclesontheRiverThameswithlessthan70%ofthecalculatedquantityofbuoyancyfoamrequiredtostayafloatinthefullyfloodedstate.LDTonlytookstepstoaddresstheshortfalloncethelong-standingnon-compliancehadbeenidentifiedbytheMCA.
The evidence compiled during this investigation overwhelmingly showed that the UKoperatorshadnot,andcouldnotachievethemandateddamagedsurvivabilitystandard.HadoneofLDT’sDUKWssufferedasimilarleveloffloodingtothatofWQ1,itwouldprobablyhavesunkequallyasfast.
3.5.2 The use of buoyancy foam
The military DUKW was designed over 70 years ago for mass production during WW2 and was expected to have a very short operational life. DUKWs had an open hull with no watertight segregation and relied wholly on high capacity de-watering pumpstosurviveincidentsofflooding.
InitsreportintothesinkingofMiss Majestic in 1999 (Paragraph 1.16.3),theNTSBconcludedthatithadbeenaflawinthedesignofDUKWs,whentheywereoriginallyconvertedforuseasAPVs,nottoprovideadequatereservebuoyancytoensurethevehiclesremainedafloatinthefloodedcondition.DespiteitsrecommendationtoUSoperatorstoretrospectivelyprovidereservebuoyancythroughpassivemeans,themajorityofUSoperators(andothersacrosstheworld)haveyettosatisfythesurvivabilityrequirementsthathavealwaysbeenpresentwithintheUK.ThisisnotanindicationthattheregulatorsandoperatorsintheUS,andothercountries, are willing to accept lower standards and a higher level of risk, more an acknowledgementthatthesevintagevehiclescannoteasilybemodifiedtomeetmodernsurvivabilitystandards.
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DUKWshaveaveryhighweighttosizeratioand,asopenboats,ahighvolumeofbuoyancyfoamisneededtosatisfythedamagedsurvivabilitystandard.Insertingsuchlargequantitiesofbuoyancyfoamintroducesmanyproblemsfortheoperatorsandforsurveyors.Specifically,itimpedesaccessforroutinecleaning,maintenanceand inspection, and increases the risk of water entrapment and resultant corrosion. The use of individually cut foam sheets, rather than the previously recommended pre-formedsolidfoamblocks,compoundstheproblemasthefoamtakeslongertoremoveandrefit,andincreasestheriskofmovement.
3.5.3 Buoyancy foam calculations
OncetheMCA’sinvestigationintothesinkingofWQ4establishedthattheLiverpoolDUKWsweredeficientofbuoyancyfoam,TYDsoughttheassistanceofBCTQ.BCTQwascontractedtoprovideareservebuoyancycalculationforatypicalLiverpoolDUKW,andidentifylocationsandapproximatethespaceavailabletofitbuoyantmaterial.BCTQfollowedasimilarprocesstotheoneithadadoptedinLondonin2008,andestimatedthat9.7m3ofbuoyancyfoamwasneededforan8.3tvehicle.
The sinking of WQ1sosoonaftertheMCA’sinterventionwasofgreatconcern.ItcastdoubtonthevalidityofthetheoreticalcalculationsconductedbyBCTQandthepracticalitiesofinsertingandmaintainingtheprescribedquantitiesofbuoyancyfoaminthehullofaDUKW.WhentheMCAdiscoveredthattheLDTvehicleswerealsodeficientofbuoyancyfoam,LDTinitiallyincreasedthequantityoffoaminitsvehiclesto 9.05m3;thevolumecalculatedbyBCTQin2008.Thiswas0.65m3 less than that calculatedforan8.3tLiverpoolDUKW;however,theweightofsomeoftheLondonvehicleshadincreasedtoover9t.ThesediscrepanciesledtheMCAtocarryoutitsowncalculationsandinstructLDTtofurtherincreasethevolumeoffoamto10.6m3.
ItwasclearfromthepracticaltrialsandreconstructionconductedbytheMAIBinJuly 2013 (Paragraph 1.10.3) that:
• Thecalculatedvolumeoffoamrequiredtoprovide110%buoyancycouldnotphysicallybefittedintothelocationsdesignatedintheBCTQreport.
• The insertion of 7.93m3 of foam into the designated locations kept WQ1 afloat28butrenderedthevehicleinoperable.
• TheclosedcellbuoyancyfoamusedbyTYDwasbetween5and20%denser(heavier)thanitsspecificationindicatedandthereforecalculatingthevolumeoffoambyweightcouldnotbereliedupon.
• Atbest,WQ1couldonlyhavehadabout7m3ofbuoyancyfoamonboardwhentheMCAalloweditbackontothewater.
• The assumption that TYD’s DUKWs had the space to insert 12m3ofbuoyancyfoam was wholly unrealistic.
Despitethesefindings,andMAIBrecommendation2013/223(Paragraph 2.2), LDT continuedtostuffincreasedquantitiesoffoamintoitsvehicleswithoutthepotentialadverseconsequencesbeingproperlyassessed.
28 AsevidentfromBCTQ’sbuoyancyassessmentsforbothTYDandLDTvehicles,theinherentbuoyancyofeachconvertedDUKWcanvarysignificantly,andthereforetheresultsoftheMAIB’sreconstructionshouldnotbeusedasabenchmarkforothersimilarvehicles.
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TheoreticalcalculationshadindicatedthattheUK’sconvertedDUKWswereabletomeetthedamagedsurvivabilitystandardthroughtheinsertionofbuoyancyfoamalone.However,historicalevidenceandpracticaltrialsconductedbytheMAIBdemonstrated that they could not.
3.6 PASSENGER AND CREW SURVIVABILITY
3.6.1 Risk of entrapment
When WQ1 sank, the driver and several of the passengers were still inside the vehicle.Fortunately,whenthebowofthevehicletouchedbottom,thesternremainedabovewaterandtheywereabletoescapethroughthesideandsternwindows.Thelastpassengertoescape,themotherofthe2yearoldchild,climbedoverthepassengercompartmentaccessdoorontotheboardingplatform(Figure 62).
TheNTSB’sMiss Majestic reportidentifiedthatthevehicle’scanopyhadprobablyhampered the escape of many of those who died. The guidance provided in the USCG’sNVIC1-01containedseveralrecommendationsaimedatreducingtheriskofentrapment.ThisledAPVoperatorsintheUS,andinothercountries,toredesign their vehicles’ canopies, windscreens and side curtains, and improve their procedurestohelpincreasepassengersurvivability.
WQ1 and Cleopatrabothhadsolidcanopyroofsandtransparentplasticsidecurtains.Haditbeenrainingatthetimeoftheaccidents,itislikelythatthesidecurtainswouldhavebeenclosed.Thiswouldhavemadeitsignificantlymoredifficulttoescapefromthepassengerspace.Similarly,hadthewaterinSalthouseDockbeendeeper,ortheadditionalfoamnotbeenfittedthepreviousmonth,thelikelihoodofentrapmentwouldhavebeenhigher.
3.6.2 The risk of drowning
Toassistthepassengers’survivalinthewatertheDUKWswereequippedwithPFDs,buoyantapparatusandlifebuoys.AccordingtotheTYDandLDTabandonshipprocedures,thecrewwererequiredtohelpthepassengerstodontheirPFDsandlaunchthebuoyantapparatusbeforeevacuatingtheirvehicles.Duringbothaccidents,theconfinednatureofthepassengercompartmentssignificantlyhamperedthecrews’abilitytoassistthepassengersandcontroltheabandonmentprocess.Inbothcases,thecrewdidnothavethetimetolaunchthebuoyantapparatus and most of the passengers, some of whom could not swim, and crew wereforcedtoenterthewaterwithoutaPFD.
ThedecisionconcerningwhentowearorinflateaPFDinanenclosedorsemi-enclosedboat,isaregulartopicofdebate.ItisobviousthatthemosteffectivewayofensuringthatpassengersarewearingcorrectlydonnedPFDswhentheyabandonaboatistoinsistthattheywearthematalltimesonthewater.However,itmightbearguedthatthiswouldfurtherincreasetheriskofpassengerentrapment;itmightalsodeterpotentialcustomersfromgoingonanamphibioussightseeingtrip.
AsthepassengerswereexpectedtodontheirPFDsbeforeevacuatingintothe water, and TYD offered the opportunity to wear one while on the water, the argumentagainstinsistingthatallpassengerswearaPFDduringthewaterbornesectionoftheDUKWtoursappearstobeweak.
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Motherofthe2yearoldchildevacuatingthe passenger compartment carrying a child’sbuoyancyaid
Figure 62: The last of the passengers to escape from Wacker Quacker 1’s passenger compartment
Fatherofthe2yearoldchildpassingher to the driver
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BothTYDandLDTDUKWshavebeenevacuatedsuccessfullyonanumberof occasions over the years following relatively minor accidents and incidents. However,thenatureofthecurrentUKDUKWfleetsmeansthatseriousfireandfloodingeventsgivetheoccupantsverylittletimeinwhichtoassimilatethedanger,preparethemselvestoabandonship,andtoactuallyabandon.WearingPFDsthroughoutthewaterbornejourneywouldsignificantlyreducethetimeneededtoprepareforabandonmentshoulditbecomenecessary,butonlyifthisdoesnotresult in an increased risk of entrapment.
3.6.3 The Irish model
InIreland,APVoperatorshavebeenpermittedtooperatevintageDUKWswithouthavingtoprovideanyresidualbuoyancy.Tomitigatetheconsequencesofseriousflooding,theIrishregulatorrequiredtheoperatorsto:
• Fitexternalbuoyancytubes(Figure 63) designed to slow the sinking process andmakethevehiclesinkbodily.
• Retractthecanopyroofandopenthesidecurtainspriortoenteringthewater.
• RequirepassengersandcrewtowearPFDswhileonthewater.
Passengerswearingbuoyancyaids
Openroofandopensides
Externalbuoyancytubes
Crewman
Figure 63: DublinDUKWsoperatingwithexternalbuoyancytubesandopencanopy
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• Provideafastrescuecraft,rescuecrewandaninflatableliferaftattheslipway.
• Limit operations to a non-tidal area.
Thisapproachfocusedonpassengersurvivabilitybyreducingtheriskofentrapmentanddrowning,ratherthanvehiclesurvivability,andintroducedseveraloftheinterimmeasuresrecommendedbytheNTSBfollowingthesinkingofMiss Majestic (Paragraph 1.16.3).TheIrishmodeldemonstratesthatopentoppedAPVscanbeoperated successfully in similar weather conditions to those experienced in the UK, andthatpassengersarewillingtowearPFDs.
3.7 ROLE OF THE REGULATORS
3.7.1 Effectiveness of survey and inspection regimes and unscheduled interventions
ItwasapparentfromMCArecordsthatthemaritimeregulatorhadlong-standingreservations over the safe operation and seaworthiness of DUKWs. Despite these concerns, and the maritime regulator’s periodic survey and inspection regime and its unscheduled interventions, the Liverpool and London DUKWs continued to operate foroveradecadewithoutcomplyingwiththemandateddamagedsurvivabilitystandard.
Prior to the sinking of WQ4 inMarch2013,surveyorspaidlittleornoattentiontotheconditionorquantityofbuoyancyfoamduringtheirperiodicinspections.This was particularly apparent in Liverpool, where the originally agreed volume offoamrequiredtomeetthestandardwasunknown.Thefoamthatwasinplacewas typically removed prior to the surveyors’ arrival at the operators’ maintenance garagesanditwasrefittedaftertheyhadleft.Thefoamthathadbeenremovedwasnotmeasuredanditsconditionwasnotassessed.FollowingWQ4’s sinking, the MCA’sLiverpoolMarineOfficeinvestedsignificantresourcestooverseeandverifyTYD’sbuoyancyfoampackingprocess.Havingdoneso,itisdifficulttoexplainhowits surveyors concluded that 12m3offoamhadbeenpackedintothevehicles.
AlthoughtheMCA’sinterventiondidnotachieveitsaimofkeepingafloodedvehicleafloatandupright,fittingmorefoamintothevehiclesdidslowthesinkingprocessand helped keep the stern section of WQ1’scanopyabovewater.Thisgavethepassengersandcrewvitalextrasecondstoabandonthevehicleandprovidedaplatform to keep the 2 year old child out of the water (Figure 62). Those two positive outcomes almost certainly helped to save lives.
Buoyancy issues aside, it was clearly apparent from external visual inspection thattheLiverpoolDUKWshadbeenpoorlymaintained,andoncloserinspectionitwasobviousthattheywerenotfitforuseaspassengercarryingvesselsonthewater.TheLiverpoolDUKWshadbeenallowedtodeteriorateprogressivelyoveraprolongedperiodoftime.ThisgoesbeyondnicheAPVspecificissuesandraisesseriousconcernsabouttheoveralleffectivenessoftheMCA’ssurveyandinspectionregimeappliedtoAPVsoperatinginLiverpool.
HadtheMCA’ssurveyandinspectionregimeofDUKWAPVsbeenmoreeffective,theimpactoffittingtherequiredamountoffoamtoachieve110%buoyancyontheoperabilityofthevehicleswouldhavebeenimmediatelyapparentandalternative
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solutionssought.Giventhatittookaround13yearstodiscoverthatbothTYDandLDT’sDUKWswereoperatingwithinsufficientbuoyancy,itisextremelyfortunatethat they did not suffer more serious accidents during this period.
3.7.2 Instructions, guidance and training
TheMCAdidnotprovideAPVspecificinstructions,guidanceortrainingtoitsmarinesurveyors.TherewasnoprescribedmethodforverifyingthequantityofbuoyancyfoamonboardanoperationalDUKW,orguidanceonhowitshouldbesecuredandprotected.
ThelackofguidanceandthepressureplacedontheMCAbytheoperators,resultedinareactiveapproachbeingtakentosolvealong-standingregulatorynon-conformity.Inshort,theMCAandtheDUKWoperatorsbecamefixatedwithtrying to stuff the necessary volumes of foam into the vehicles’ hulls without having properlyassessedtheconsequences.
HadtheMCAsurveyorshadadequateinstructionsandguidancetoreferto,amoreconsistentapproachtothesurveyandinspectionofDUKWsmighthavebeenachieved.Furthermore,itislesslikelythatTYDwouldhavebeenallowedtoresumeoperations on the water following the sinking of WQ4, and LDT might not have beenpermittedtopackunsecuredandunprotectedfoamsoclosetotherotatingdrivetrain.
3.7.3 Sharing of information
TheLiverpoolMarineOfficewrotetoMCAheadquartersfollowingthesinkingofWQ4andrecommendedthattheLondonMarineOfficebeinstructedtocheckthelevelsofbuoyancyintheLDTvehicles.ThisinformationwasnotacteduponandtheLDT vehicles were allowed to continue to operate unchecked.
VOSAhadsimilarlong-standingconcernsaboutthesafeoperationofvintageDUKWstothoseoftheMCA.ThefireonboardCleopatra occurred on water and thuscameundertheregulatoryjurisdictionoftheMCA;itcouldjustaseasilyhavehappened on the road 30 minutes earlier, or later, and therefore have come under theregulatoryjurisdictionofVOSA.However,theroadregulatorwasnotconsultedduring the foam packing process.
Neitheroftheregulatorshadadesignatedamphibiousvehiclepointofcontactorindustryspecificexpertise,andtherewerenoarrangementsinplaceforthetwoDfTagenciestosharetheirknowledgeorconcerns.TheAPVindustryhastocomplywithbothlandbasedandmaritimeregulations,andcompliancewithoneisoftenatoddswiththoseoftheother.Insuchcircumstances,compromisesintheformofequivalenciesneedtobeagreed.However,itbecameapparentduringtheinvestigationthattheAPVindustryoftenfounditdifficulttoidentifyfocalpointswithinthetwoDfTagenciesandtoobtainaclearandconsistentarticulationoftheirregulatoryobligations.
Whileitmightbeacceptableforhistoricvehiclestooperateonthehighwayundercertain conditions, the nature of the marine environment is such that more modern safetystandardsneedtobeapplied.Indeed,followingtheMarchioness disaster, LordJusticeClarke’sThamesSafetyreviewconcludedthat,ingeneral,newsafetyregulationsshouldbeappliedtoallvessels,whetherneworexisting.Giventhe
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potentialfortheretobetensionbetweenthesetwoapproachesthereisaneedfor the regulators involved to cooperate to agree a co-ordinated approach for the guidanceofAPVoperators.
3.8 ROLE OF THE OPERATOR
RegardlessofthechallengespresentedtotheMCAandVOSAbythisnicheindustry, the onus to comply with the UK’s regulations and deliver a safe sightseeing experienceliesfirmlywiththeoperator.BothTYDandLDT shouldhaveidentifiedthattheywereunabletosafelyfittherequiredvolumeofbuoyancyfoamintothespacesdesignatedbytheirnavalarchitect.Thisshouldhavebeenhighlightedtotheregulatorsandanalternativesolutionshouldhavebeensought.Operatorsshould not rely on regulators to provide through-life assurances that their vehicles remaincompliantandsafe.ItwouldbetotallyimpracticaltoexpectMCAsurveyorstooverseetheremoval,measurementandrefittingofbuoyancyfoamoneachvehicleduringtheirperiodicinspections;theMCAisnotresourcedtodoit,andtheoperatorswouldnotbepreparedtopaythemtodoit.
Inadditiontoneverhavingmetthedamagedsurvivabilitystandard,TYDandLDTwereslowtoreacttothesafetyissuesidentifiedfollowingpreviousaccidentsandincidents.SomeofthecircumstancesthatledtothesinkingofWQ4 and WQ1 and thefireonboardCleopatrahadbeenidentified70yearsearlierduringWW2andinmore recent accident investigation reports, some of which involved multiple fatalities.
FollowingthesinkingofWQ4, LDT wrote to TYD and offered its assistance and advice,butitwasapparentthatlittlehadbeendonepriortothattoworktogetherintheinterestsofpassengersafety.ItwasevidentduringthisinvestigationthatsomeoftheUKbasedAPVoperatorswerefiercelycompetitiveand,despitetheirgeographical separation, treated each other’s operations as commercial competition.
Amphibioussightseeingtoursareverypopularwithtouristsandthereappearstobeamarketfortheindustrytoexpand.However,theaccidentsinLiverpoolhadasignificantimpactonthecredibilityandreputationofotherAPVoperatorswithintheUKandabroad.ThiswasparticularlysoinLondonastheLDTvehicleshadavery similar appearance to those in Liverpool and the common perception was that bothcompaniesoperated70yearoldWW2vehicles.Asasmallnicheindustry,itisparticularlyimportantthatAPVoperatorsworktogethertopromotebestpractice,improvevehicleandpassengersafetyandre-buildpublicconfidence.
3.9 EMERGENCY PREPAREDNESS
3.9.1 General
Inordertominimisetheconsequencesofamarineaccident,avesselanditspassengersandcrewneedtobepreparedtodealwithavarietyofemergencysituations.VesselsarepreparedthroughdesignandtheprovisionofLSAandothersafetyequipment.Vesselownersandoperatorspreparetheircrewsbyprovidingthem with guidance and procedures, and through the delivery of training. To ensure traininghasbeeneffectiveandemergencyproceduresarefullyunderstood,ships’crews should conduct realistic emergency response drills on a regular periodic basis.
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Ships’crewspreparetheirpassengerstodealwithemergenciesthroughtheprovisionofinstructions,demonstrationsand,insomecases,thewearingofPFDs.TYDandLDTpreparedtheirpassengersthroughthedeliveryofverbalsafetybriefsandtheprovisionofPFDdonninginstructionsonthebacksofthepassengerseats.LDTalsogaveapracticalPFDdonningdemonstration.
3.9.2 Emergency preparedness – Wacker Quacker 1
ThelifejacketsonboardWQ1 were stored out of sight, in plastic packaging, under a seatatthebackofthevehicle.Thestrapsonthechildren’sbuoyancyaidshadnotbeenfullyextended.Thismeantthattheparentsofthe2yearoldwereunabletoputoneontheirdaughterbeforeevacuatingthepassengerspace.WQ1’sbuoyantapparatuswasstowedonthecanopyroof.ThecapacityoftheLSAonboardWQ4 and WQ8waslessthanthemaximumnumberofpersonsthevehicleshadbeencertifiedtocarry.
ThecrewonboardWQ1hadbothreceivedtrainingandhadparticipatedinemergencydrills,buttheabandonshipdrillscarriedoutbythecrewwerenotinaccordance with the procedure in TYD’s safety management system. During the drills the crew practised evacuating the passengers onto pontoons at the edge of thedocksratherthanintothewater.Themasterhadexperiencedproblemsonthewater in the past and on those occasions he had evacuated his passengers onto pontoons.Itwasevidentthatthemasterandhisdriverwerenotfamiliarwiththeprocedureforabandonmentonthewaterandthereforetheirtraininganddrillshadnotbeeneffective.
Priortoenteringthewaterinthebuild-uptotheaccident,WQ1 was parked on the roadatthetopoftheslipwayforjust15seconds.Thisindicatesthatthesafetybriefwaseitherextremelyshortorwasgivenontheroadpriortoarrivingatthedocks.ItwasapparentfromthefeedbackprovidedtotheMAIBbythepassengersthatthesafetybriefgivenbythecrewhadnotbeentakenseriously,andwasineffective.TheMCAhadrecentlywrittentoTYDlistingitsconcernsaboutthestandardofthecompany’spre-splashdownsafetybriefsandinstructedittoprovidealifejacketdonningdemonstration.However,thecompanycontinuedtodeliveritssafetybriefsinajocularmanneranddidnotshowpassengershowtodontheirlifejackets.Subsequently,themajorityofthepassengersdidnotknowwheretheirlifejacketswerestowed,howtoputthemonorhowtoinflatethem.
InearlieriterationsofTYD’sSafety Policy and General Safe Operational Procedures manual,thepre-splashdownsafetybrief(Annex C) was more comprehensive and included practical demonstrations. Passengers might have an expectation that they aregoingtobeentertainedbythecrewduringtheirtour,andmightnotwanttolistentoasafetybrief.Nonetheless,itisessentialthattheyaregiventhebestopportunitytounderstandthesafetyproceduresandknowhowtoputonanduseaPFD.Inordertoachievethis,thesafetybriefshouldbeclearandconciseandbedeliveredwith conviction and authority.
ItisclearthatWQ1,itscrewandtheirpassengershadnotbeenadequatelypreparedtodealwiththeemergencysituation.Thelifejacketswerenotreadilyavailable,manyofthepassengersdidnotknowhowtodonthemorinflatethemandthecrewwerenotfamiliarwiththeabandonshipprocedure.
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3.9.3 Emergency preparedness – Cleopatra
AswasthecaseinLiverpool,Cleopatra’s crew had little time to react to a rapidly escalating situation. However, the vehicle, its crew and their passengers had beenbetterpreparedtodealwithit.Itwasclearfromthepassengerfeedbackthat,althoughgiveninalight-heartedmanner,thesafetybriefwasmoreeffectivethanthatgivenonboardWQ1, and the passengers were shown how to don theirbuoyancyaids.Further,thebuoyancyaidsonboardCleopatra were readily accessibleinracksabovethepassengers’heads.However,thebuoyancyaidshadbeenstowedinplasticbagsthatweredifficulttoremoveandtheirstrapshadnotbeenfullyextended.TheobviousadverseimplicationsofthishadpreviouslybeenpointedoutintheMAIB’s2001Beatrice report (Paragraph 1.16.2).
ThecrewonboardCleopatrahadbothreceivedtrainingandhadparticipatedinemergencydrills.AccordingtoLDT’sabandonshipprocedurethecrewwereexpectedtolaunchthebuoyantapparatusandthenseatthepassengersontopofthem.Thebuoyantapparatuswasnotdesignedtosupporttheirratedcapacityofpeopleoutofthewater.Althoughitmightbeappropriatetoplacesmallchildrenorinjuredandweaksurvivorsontopoftherafts,attemptstoseatallthepassengersonthemwouldprobablybeunsuccessfulandwoulddelaytheabandonmentprocess.
3.10 EMERGENCY RESPONSE – WACKER QUACKER 1
3.10.1 Raising the alarm
The crew of WQ1wereunconcernedwhentheDUKWfailedtoclimbtheslipwayastheyhadexperiencedthisproblemearlierinthedayandonseveraloccasionsinthepast.Thedriverandthemasterthoughtthevehiclehadagearboxproblemandfocusedtheirattentiononresolvingit.Theydidnotinformtheoperationsofficeorexplain to the passengers what had happened.
When WQ1begantofloodthevehicle’selectricbilgepumpsstartedautomaticallyandsomeofthepassengerstriedtoalertthecrew.Initially,thecrewappearedtoignoretheshoutsfromthebackofthevehicleandthebilgepumpalarms.Again,they were used to water entering the hull and might have initially underestimated the rate of ingress.
When the crew realised the severity of the situation, the master made his way to the backofthevehicle.Thedriverwasunabletofindthemaster’smobilephoneandthereforedidnotalerttheoperationsofficeoremergencyservices.Fortunately,theincidentoccurredinaverybusypartoftheSouthDockscomplexwhereimmediateassistancefrombystanderswasavailable.
3.10.2 The abandonment
AsWQ1 sank,themajorityofthepassengersanditstwocrewenteredthewater,manywithoutlifejackets.Thosewhohadthemwereeitherunabletoputthemonproperlyorcouldnotinflatethem.Somepassengersswamashore,butthemajoritywererescuedfromthewaterbythepeopleonboardthreerecreationalnarrowboatsthathadbeenberthedinSalthouseDock.
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WQ1’s crew might have thought that they had time to co-ordinate and control the abandonmentprocessfollowingtherecentadditionofbuoyancyfoam.However,vitaltimewaslosttryingtopassthelifejacketsforwardtothepassengersatthefrontofthevehicleandhavingtoremovethemfromtheirpackaging.Instinctively,thepassengersusedtheirowninitiativeandabandonedWQ1 with or without theirlifejackets.Someoftheweakerswimmersandsmallerchildrenwereabletoholdontothebuoyantapparatusthathadbeenlaunchedearlierbya70yearoldpassengerwhowasgrandfathertotwoofthechildrenonboard.
WQ1’screwwereunabletoeffectivelyassistthepassengersbecauseoftheconfinednatureofthevehicleandabasiclackofemergencypreparedness.AccordingtoTYD'sabandonshipprocedure,thecrewwereexpectedtolaunchthebuoyantapparatusandhelpthepassengersdontheirlifejacketspriortoabandonment.Hadthecrewbeenabletocalmandcontrolthepassengers,andattemptedtofollowthecompany'sabandonshipprocedure,itislikelythatliveswouldhavebeenlostbecauseofthespeedatwhichthevesselsank.Giventhecircumstancesofthisaccident,thecompany'semergencyresponseproceduresprovedtobeunrealistic.
3.10.3 Shore based emergency response
Within10minutesofthealarmbeingraisedbymembersofthepublictheemergencyservices(police,fireandambulance)wereonsiteandhadtakencontrolof the incident. By this time, the passengers and crew had either swum ashore or beenrecoveredontothenarrowboats.
Duringtherescuephase,TYDdidlittletoassistanditsrescueboatremainedalongsideinSalthouseDock.Therewasnonominatedmusterpointandsomepassengersdispersedfromthescenebeforeaheadcountwascarriedout.Althoughtherewerenomajorinjuries,ittookthepoliceseveralhourstoaccountforeveryone.Hadthecompanypreparedamajorincidentresponseplanandcarriedoutregulardrillstochallengeandtestit,itscontributiontotherescueeffortmighthavebeenmoresignificant.
Theeffortsofthenarrowboatcrewswereinstrumentalinthesaferecoveryofmanyof those in the water, particularly as some were struggling to, or could not swim. TheyoungmanwhojumpedintothewaterfromthebowofPredator 3 (Figure 64) to assist those struggling in the water was fully aware of the risk he was taking, and shouldbecommendedforhisbravery.
3.11 EMERGENCY RESPONSE – CLEOPATRA
3.11.1 Raising the alarm
Atthefirstsightofsmokethetourguideadvisedpassengersofapossibleproblem,and the master steered CleopatratowardstheshoreinthebeliefthatCleopatra had anexhaustproblem.Thesmokesoonescalatedtofire,andjustoveraminutelaterthemasterattemptedtoraisethealarmusinghisVHFradio.Withinseconds,radiocommunication was lost and it took the intervention of an unknown third party to informVTSthatCleopatrawasonfire.
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Intheeventofavesselbeingingrave and imminent danger29, emergency protocol requiresastrickenvesseltotransmitadistressalert.InCleopatra’s case this did nothappen.Themaster’sverbaldistresscallwasnotprecededbythesignalword“Mayday”andwasnottransmittedonchannel16,thededicatedVHFchannelforsafety alerting.
ThedistressprotocolforvesselsfittedwithDSCenabledradiosisfortheradiooperatortosendaninitialalertbyDSCbeforecommencingvoicecommunications.OnmostradiostheDSCfunctionisactivatedbyapushbuttonthatneedstobehelddepressedforbetween3and5seconds.ThebasicDSCdistressalertthenautomaticallytransmitsthevessel’sidentification,itspositionandtimeoftransmissionwithoutanyfurtherinputfromtheradiooperator.Althoughitistemptingandcomfortingtouseverbalcommunicationsinsuchasituation,thesameinformationasgivenbyDSCcannotbeverballytransmittedin3to5seconds.Additionally,erroneouspositionalinformationisoftengivenduringverbalcommunicationsbyoperatorsunderpressure.Inmanycircumstances,thesevitalearlysecondscanmakethedifferencebetweenasuccessfulrescueandthelossoflife.
3.11.2 Fire containment and fire-fighting
Althoughthefirehadstartedunderthedeckplatesinthecrewcabarea,theearlyindicationswerethatthecrewweredealingwithaproblemwithintheenginecompartment.WhenitbecameobviousthattherewasafireonboardCleopatra, themastertookthedecisiontodrivehisvehicleontothenearestriverbank.Onceaground, the master’s initial priority was to use the engine to keep his vehicle
29 Theunambiguousinternationallyrecognisedinterpretationofavesselindistress.
Figure 64: MemberofthepublicjumpingfromPredator 3 to help passengers in the water
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pressedontotheriverbank.Whentheenginewasstoppedthecrewwereunabletoclosetheventilationvoidspacefiredampersbecausethe‘R’clipshadbecometoohotandtheheatandsmokegeneratedbythefirequicklyforcedthemtomoveawayfromthecrewcabarea.Theenginecompartment’sfixedfire-extinguishingsystemwasnotactivatedandnoneofthevehicle’sportablefire-extinguisherswereusedtofightthefire.
Thiswasaseriousfirethatspreadquickly,anditisforjustsuchemergenciesthatfiredrillsareconducted.Inthisinstance,onboardfire-fightingwouldhavebeenonlypartiallyeffectivebecausethefirewasnotintheenginecompartment.Therefore,themaster’sdecisiontodrivehisvehicleagroundprovedtobeasoundoneandsignificantlyreducedtherisktolifeduringtheabandonment.Nonetheless,itwouldhavebeenappropriateforthecrewtoisolatethefuelsupplies,closetheengineventfiredampersandoperatetheenginecompartment’sfixedfire-extinguishingsystemassoonaspossible.
3.11.3 The abandonment
WhenthefirebrokeoutonboardCleopatramostofthepassengersgrabbedbuoyancyaidsandmovedtowardsthebackofthevehicle,awayfromtheflames.Thetourguidewasunabletoassistorcontrolthepassengersandhadtoforcehiswaypastthemtogettothesterndoor.Unabletoopenthedoor,somepassengers,understandably,abandonedintothewaterwithoutgrabbingordonningabuoyancyaid.
Thespeedatwhichthefireescalatedgavelittleornotimeforthecrewtopreparethepassengersandthevehicle’sLSAforacontrolledabandonment.SimilartotheabandonmentofWQ1inLiverpool,thepassengersonboardCleopatra were forced to act on instinct and exit the passenger space under their own initiative. Had the sidecurtainsbeendown,theconditionswithinthepassengerspacewouldhavedeterioratedevenmorerapidlyanditwouldhavebeenmoredifficulttoescape.
3.11.4 Shore based emergency response
Within2minutesofthefirebreakingout,Cleopatra’spassengersandcrewhadbeenrecoveredfromthewaterbythecrewofthreepassengercarryingRIBs.LFB’sfireboat,Firedart,andashore-sidefireappliancewasonthescenewithin5minutes,andthefirewasquicklyextinguished.Thepoliceandambulanceservices,andtheRNLIwerealsoquicklyonthesceneandsoonestablishedthatallpassengersandcrewhadbeenrecovered and were safe.
Thelocationandtimeoftheaccidentwasextremelyfortuitous.Hadthefireandsubsequentabandonmenthappenedathighwater,orinmid-river,theoccupantswouldhavehadtoabandonintodeeperwater,whichwouldhaveincreasedthelikelihoodofseriousinjuryandlossoflife.Althoughtheemergencyservicesrespondedquickly,thecommendableactionsofthoseonboardtheThamesRIBExperienceboatswasfundamental to the safe recovery of Cleopatra’s passengers and crew.
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SECTION 4 - CONCLUSIONS
4.1 THE SINKING OF WACKER QUACKER 1
1. WQ1sankbecauseitsufferedrapiduncontrolledflooding,anddidnothavethemandatedlevelofresidualbuoyancyneededtokeepitafloatinitsfullyfloodedcondition. [3.3.1]
2. WQ1begantofloodwhentwoholesweretornintoitshullbytheforcesgeneratedwhenitspropellerwasfouledbyadiscardedcartyre.Itbecamefullyfloodedbecauseitselectricpoweredbilgepumpswereunabletocopewiththerateofwateringress. [3.3.1]
3. Had TYD learned lessons from previous similar hull failures or followed the advice of LDT and reinforced WQ1’s propeller shaft tunnel plating, the hull might not have failed. [3.3.2]
4. WQ1wasinanextremelypoorcondition.Itshullwasheavilycorrodedandwascoveredwithapatchworkofunapprovedsubstandardrepairs,itwasmechanicallyunreliable,andregularlyfailedtoclimboutofthedock.Thevesselwasnotseaworthyanditshouldnothavebeenoperatingonthewater. [3.3.4]
5. TYD'svehiclessufferedahighnumberofmechanicalbreakdowns,hullfailuresandfloodingincidentsduringthemonthsleadingtothesinkingofWQ1. The operatorwasawareofthepotentialconsequencesoffloodingbutcontinuedtotakepassengers onto the water in unseaworthy vehicles. [3.3.5]
6. TheMCA’ssurveyandinspectionregimeinLiverpoolprovedtobeineffective;thematerialconditionoftheTYDfleetwasallowedtoprogressivelydeterioratetoanunsafe condition over a prolonged period of time. [3.7.1]
7. WQ1,itscrewandtheirpassengershadnotbeenadequatelypreparedtodealwiththeemergencysituation.Thelifejacketswerenotreadilyaccessible,manyofthepassengersdidnotknowhowtodonthemorinflatethemandthecrewwerenotfamiliarwiththeabandonshipprocedure. [3.9.2]
8. TYDdidlittletoassisttheemergencyresponseeffort,itsrescueboatwasnotusedand a passenger headcount was not carried out. [3.10.3]
4.2 THE FIRE ON BOARD CLEOPATRA
1. ThelocusofthefireonboardCleopatrawasunderthecrewcabfloorplatesinthehull’s central void space. [3.4.2]
2. Thebuoyancyfoamthathadrecentlybeenpackedintothecentralvoidspaceprovided a ready source of fuel. [3.4.3]
3. Hadaninsulatedgas-tightbulkheadbeenfittedbetweenCleopatra'saccommodation areas and engine compartment, in accordance with passenger ship constructionstandards,thefirewouldnothavespreadsorapidlythroughtheenginecompartment to the passenger space. [3.4.3]
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4. Thepackingofunsecuredandunprotectedbuoyancyfoamaroundthevehicle'sengine compartment and drive shafts introduced the circumstances that led to the fire.[3.4.4]
5. Themostlikelysourceofignitionwascontactbetweengreasecontaminatedbuoyancyfoamandanoverheatingdriveshaftuniversaljoint. [3.4.4]
6. LDTgaveinsufficientattentiontotheadverseeffectsofpackingbuoyancyfoamclose to moving machinery and unlagged exhausts, and allowed its vehicles to operatewithanelevatedriskofmechanicalfailureandfire. [3.4.5]
7. Themaster’sdecisiontodrivehisvehicleagroundprovedtobeasoundoneandsignificantlyreducedtherisktolifeduringtheabandonment.[3.11.2]
8. Cleopatra,itscrewandtheirpassengerswerebetterpreparedtodealwithanemergencysituationonthewater.However,thespeedatwhichthefireescalatedgavelittleornotimetoconductacontrolledabandonment.[3.11.3]
9. Hadthefireandsubsequentabandonmenthappenedathighwater,orinmid-river,thelikelihoodofseriousinjuryandlossoflifewouldhavebeensignificantlyhigher.[3.11.4]
4.3 COMMON SAFETY ISSUES
1. Foroveradecade,littleattentionwasgiventobuoyancyfoambytheoperatorsandthe regulators, and the UK’s Class V DUKWs were operated without having met the mandateddamagedsurvivabilitystandardssetoutinMSN1699(M).[3.5.1]
2. HadaLondonDUKWsufferedasimilarleveloffloodingtothatofWQ1, it would probablyhavesunkequallyasfast.[3.5.1]
3. The UKs converted DUKWs could not safely meet the regulatory standards for damagedsurvivabilitythroughtheinsertionofbuoyancyfoamalone.[3.5.3]
4. ThecombinationofalackofguidanceandinstructionsandpressurefromtheDUKWoperatorsledtoareactiveapproachbeingtakenbytheMCAtoalong-standingregulatorynon-conformityandafixationwithstuffingfoamintorestrictedspaces. [3.7.2]
5. ThefireonboardCleopatra occurred on water and thus came under the regulatory jurisdictionoftheMCA.Itcouldjustaseasilyhavehappenedontheroad,andthereforehavecomeundertheregulatoryjurisdictionofVOSA.[3.7.3]
6. TheMCAandVOSAbothhadlong-standingconcernsaboutthesafeoperationoftheconvertedDUKWs,buttheydidnotsharetheirconcernsandknowledge,orcommunicate with each other to address common issues and minimise regulatory conflicts. [3.7.3]
7. Theconfinednatureofthepassengercompartmentmadeitextremelydifficultfor the crew to control and assist the passengers and increased the likelihood of entrapment. [3.11.3]
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8. ItwasextremelyfortunatethatallonboardWQ1 and Cleopatrawereabletoevacuateintothewaterunharmed.Inbothcasesthepassengerswereforcedtoacton instinct and exit the vehicles under their own initiative. Had:
• thequantityofbuoyancyfoamonboardWQ1notbeenincreased2monthsbeforetheaccident;
• thedepthofwaterinSalthousedockbeengreater;
• Cleopatra'smasterbeenunabletorunhisvehicleaground;
• itbeenrainingonthedayofeitheraccident(andhencethesidewindowsbeingclosed);or
• the crews of WQ1 and Cleopatrafollowedtheircompany'sabandonshipproceduresbycontrollingthepassengersandpassingoutlifejacketsbeforeleaving their vehicles;
theriskofentrapmentandthelikelihoodoflossoflifewouldhavebeenconsiderablyhigher. [3.10 and 3.11]
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SECTION 5 - ACTION TAKEN
5.1 MAIB ACTIONS
The Marine Accident Investigation Branch has:
• IssuedsafetybulletinSB3/201330,containingrecommendationS2013/233,whichrecommendedtheMCAto:
• In addressing recommendation 2013/221, ensure that the means used by DUKW operators to achieve the required standard of buoyancy and stability for their vessels does not adversely impact on their safe operation. Furthermore, these vessels should not be permitted to operate until satisfactory levels of safety can be assured under all feasible operating conditions.
5.2 ACTIONS TAKEN BY OTHER ORGANISATIONS
The Maritime and Coastguard Agency has:
• CarriedoutaninternalinvestigationintothefileandrecordmanagementinitsLiverpoolandOrpingtonMarineOfficeswithparticularattentiongiventoMCAoversightofDUKWAPVs.Asaresultofitsfindingsithas:
• Taken steps to improve the standards of record management at, and the sharingofinformationbetweenitsMarineOffices.
• RequiredAPVoperatorstosubmitdocumentaryevidencetodemonstratecompliancewiththeirstatutoryobligations.
• Producedamethodologyforensuringthecorrectquantityofbuoyancyfoamis in place.
• Commissioned an independent DUKW regulatory compliance study and outlined a phased approach to the development and implementation of a mandatory technicalstandardforamphibiouspassengervehicles.
• EnforcedtheregulatoryrequirementtofitaninsulatedfireprotectionbulkheadbetweentheenginecompartmentandaccommodationspaceonexistingDUKWs.
• HasworkedwithLDTtodevelopa‘referenceDUKW’standardand,asaresult,hasapprovedaseriesofdesignmodificationsandauthorisedthecompanytoresumeitsoperationsontheRiverThames.
DfT Traffic Commissioner has:
• WithdrawnPearlwildLtd’sPassengerServiceVehiclelicence.
30 SB3/2013–The sinking of the DUKW amphibious vehicle Wacker Quacker 1 in Salthouse Dock, Liverpool on 15 June 2013, and the fire on board the DUKW amphibious vehicle Cleopatra on the River Thames, London on 29 September 2013.
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Pearlwild Ltd has:
• PlacedTYDintoadministrationandisnolongeroperatingAPVs.
London Duck Tours Ltd has:
• ModifieditsDUKWstosatisfythedamagedsurvivabilitystandardbyusingacombinationofbuoyancymaterialandcompartmentalisation(Annex F). The modificationsinclude:
• Theinstallationofaninsulatedgastightandwatertighttransversebulkheadbetweentheenginecompartmentandthepassengerspace.
• Mountingthepassengerseatsontopofindividualairtightaluminiumbuoyancytanks.
• Replacementofthesteeldeckplateswithaluminium.
• Theprovisionofdedicatedvoidspacesfortheinsertionofbuoyancybytherelocation of the fuel tank and the ancillary machinery and services under the passengercompartmentfloorplates.
• BoxinginthedrivetrainjournalbearingsandUJs.
• The replacement of the original fuel lines with approved solid drawn and flexiblesteelpipework.
• Changes to the engine and engine compartment cooling air system.
• Theprovisionofafiredamperfortheforwardenginecompartmenthatchcooling air vent.
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SECTION 6 - RECOMMENDATIONS
The Maritime and Coastguard Agency and the Driver and Vehicle Standards Agency are recommended to:
2014/153 Identifysinglepointsofcontactforamphibiousvehicleissuesandputprocesses in place to allow them to work together, in consultation with the industry, to explore potential cross agency synergies, identify regulatory conflictsandagreeacoherentapproachtothesurveyandcertificationofnewandexistingamphibiouspassengervehicles.
The Maritime and Coastguard Agency is recommended to:
2014/154 Provideamphibiousvehiclesurveyguidanceandinstructionstoitssurveyors.
2014/155 Workwithindustrytodevelopanamphibiousvehicleoperators’codeofpractice.
2014/156 Ensure that measures to reduce the risk of passenger entrapment and improvethelevelsofpassengersurvivabilityareincludedinitsproposedtechnicalstandardforamphibiouspassengervehicles.
2014/157 RequireexistingDUKWoperators,whichmaychoosetorelyontheinsertionofbuoyancyfoamtomeettherequireddamagedsurvivabilitystandards,todemonstratethroughriskbasedanalysisthatthefoamdoesnotadverselyaffect the safe operation of the vehicles.
London Duck Tours Ltd is recommended to:
2014/158 Usethesafetylessonsidentifiedinthisreporttotakefurtheractiontoensure,asfarasisreasonablypracticable,itsvehicles,crewandpassengersarebestpreparedtodealwithemergencysituations.Inparticular,attentionshouldbegiven to:
• ThereadinessanduseofPFDs:thepracticalitiesofthecurrentarrangementsshouldbereviewedandconsiderationgiventorequiringallpassengerstowearPFDswheneverDUKWsarewaterborne.
• Establishingappropriateandachievableemergencyprocedures:theseshould include the marshalling of passengers, alerting potential responders andabandonment.
• Development of effective training drills.
• Enginecompartmentshut-downandfire-fighting.
• Lowering the risk of passenger and crew entrapment: assess in particular whether the current canopy arrangements are appropriate.
Safetyrecommendationsshallinnocasecreateapresumptionofblameorliability