The “substantial use of combustible wood panelling and drapery throughout the accommodation spaces” contributed to the extent of the damage from a fire on board offshore supply vessel Grand Sun, according to a report issued by the US National Transportation Safety Board (NTSB)
No pollution or injuries resulted from the fire, but the offshore support vessel (OSV) was declared a constructive total loss of US$1.6M. The NTSB determined that the probable cause of the fire on Grand Sun was a chest freezer or the receptacle powering it overheating, which was located in an accommodation space.
Built in 1981, 36.6-m Grand Sun, owned by Y&S Marine, was transiting the Chandeleur Sound in the US Gulf of Mexico, about 24 km from the Chandeleur Islands, Louisiana, on 8 October 2018 when the aluminium-hulled vessel caught fire. The four crew aboard attempted to fight the fire but were unsuccessful. They remained on the stern of the monohull vessel until they were rescued by an MH-65 Dolphin helicopter crew from the US Coast Guard. The fire burned itself out, and the US-flag OSV was later towed to port.
Based on a fire investigator’s findings, the likely origin of the fire was overheated electrical wiring, either in the chest freezer or in the bulkhead at the receptacle powering it. The on-watch deckhand discovered the crew’s foam work vests on fire on top of the chest freezer, and since the damage to the OSV was greatest in the interior main deck where the chest freezer was located and the wheelhouse above the chest freezer, it was likely that electrical components in or supplying the chest freezer were the source of ignition.
Combustible materials in the upper passenger compartment, including wood panelling, window curtains, and passenger lifejackets stowed overhead, allowed the fire to rapidly expand, consuming the superstructure and the accommodation spaces below the main deck. The fire damage caused the vessel to lose electrical power and then the fire pumps supplying the water hoses shortly after the crew began fighting the fire. The crew attempted to reach the fire extinguishers, but they were inaccessible due to the intense heat. Since there were no other accessible fire pumps aboard, the crew was unable to fight the fire effectively and was forced to retreat to the stern of the OSV.