Two recent casualties involving DUKW amphibious vehicles modified to carry passengers
The UK MAIB has issued Safety Bulletin including safety recommendations on two recent casualties involving DUKW amphibious vehicles modified to carry passengers:
- the sinking of the WACKER QUACKER 1 (WQ1) in Salthouse Dock, Liverpool on June 15, 2013
- the fire on board the CLEOPATRA on the River Thames, London on September 29, 2013
Images credit: MAIB Safety Bulletin – October 2013
The sinking of Wacker Quacker
1On 15 June 2013, Wacker Quacker 1 (WQ1) sank in Salthouse Dock, Liverpool, resulting in the DUKW’s31 passengers and two crewmen abandoning into the water; fortunately all were recovered withoutserious injury. After WQ1 was recovered ashore, it was apparent that the vehicle had flooded becausetwo large holes had been torn in the hull as a result of the forces generated when the vehicle’s propellerbecame fouled by a tyre. As was the case with WQ4, WQ1 sank because the volume ofbuoyancy foam fitted was insufficient to keep it afloat when flooded.
Some of the potential adverse outcomes identified were:
fouling and overheating of moving parts
overheating of the engine
lack of access for routine maintenance
inability to visually inspect the internal steel hull
blocking of bilge pumps
contamination of foam by oils, greases and sea water
acceleration of hull corrosion.
These observations, made during the foam fitting process prior to the tests and subsequent trials, raisedserious questions about whether the operators of DUKWs could fit sufficient foam internally to complywith the current requirement for 110% buoyancy without compromising the safe operation and thepractical day to day maintenance of these vehicles.
Therefore, on 5 August 2013 the Chief Inspector of Marine Accidents recommended the Maritime andCoastguard Agency to: ” Require operators of DUKW passenger vessels in the UK to demonstrate that they areable to provide 110% effective residual intact buoyancy in their vessels, and wherebuoyancy foam is fitted for this purpose, the quantity installed is measured by volumeand the foam does not impede the operation or maintenance of key equipment.”
The fire on board Cleopatra
On 29 September 2013, a fire broke out inside the hull of the DUKW Cleopatra, an amphibious vehicleoperated on the River Thames by LDT. The master was able to beach the vehicle prior to ordering theevacuation of his passengers and crewman. There were no serious injuries.
At the time of this accident, LDT had still to demonstrate to the MCA that its DUKWs could be fitted withsufficient buoyancy foam and still be operated safely.
The ongoing MAIB fire investigation has established that the seat of the fire was located under the crewseating platform close to a drive shaft coupling. Foam in the area was found to be heavily contaminatedwith grease and had fuelled the fire, generating thick black smoke.
A report commissioned by the London Fire Brigade and completed by Bureau Veritas’ Fire ScienceDepartment concluded that:”There was no obvious ignition source in the vicinity of the buoyancy foam, and therefore themost likely cause of fire was the action of the rotating drive shaft (or other moving parts) on the oilcontaminated surfaces of the buoyancy foam blocks.”
For more information, please click the MAIB Safety Bulletin – October 2013