In advance of completion of the investigation into a fire on the vehicle deck of the ro-ro ferry Commodore Clipper on 16 June, 2010, the UK’s Marine Accident Investigation Board says that operators of vessels carrying refrigerated trailer units should take immediate action to ensure that all power supply cables and fittings provided for refrigerated trailer units are in good condition and that electrical protection devices will activate at an appropriate level.
“Until such time as the exact causes of this fire have been established, make additional checks of refrigerated trailers powered by ships’ electrical systems to provide early warning of any overheating”, says the MAIB safety flier.
While the ro-ro ferry Commodore Clipper was on passage from Jersey to Portsmouth, a fire was detected on the main vehicle deck. The vehicle deck was loaded with unaccompanied freight trailers and crew identified that a refrigerated trailer unit, powered from the ship’s electrical supply, had caught fire.
The vehicle deck was fully enclosed and smoke built up quickly. The crew contained the fire using the vehicle deck water drenching system and boundary cooling from above, but were not able to extinguish it.
The vessel came into port and the crew assisted the local fire and rescue service in attempts to fight the fire. Freight trailers were packed closely on the vehicle deck and firefighters found it extremely difficult to reach the seat of the fire. Trailers had to be towed off before the fire, which had by now burned for about 18 hours and spread to four trailers, was finally put out.
Preliminary findings of the subsequent accident investigation indicate that the fire was caused by an electrical fault involving the power supply from the ship and the trailer’s refrigeration control system. The resultant sustained overheating led to the curtain-side of the trailer igniting. Although the ship’s electrical breakers were found to be working correctly, they did not trip before the fire started.
MAIB has also received other reports of power supply cables to refrigerated trailers becoming very hot while in use.