The US National Transportation Safety Board (NTSB) has said that the probable cause of the ‘Carnival Liberty’ engine room fire was improperly tightened bolts on a fuel inlet flange.
During the morning of 7th September, 2015, the cruise ship was berthed at the Charlotte Amalie cruise terminal on St Thomas, US Virgin Islands.
At 1133 hours, fuel pressure alarms and fire alarms went off for the vessels No 4 diesel generator, located in the aft engine room. The third engineer activated the space’s HI-FOG fire suppression system within one minute of the alarm, and the second engineer switched the ship’s electrical load over to No 2 generator, which is located in the ship’s forward engine room.
Shortly thereafter, the Chief Engineer arrived at the machinery control room and authorised the closure of fuel and lube oil shut-off valves for generators Nos 4-6. By 1137, the engineering team had also closed off fans and dampers to the aft compartment.
The Master was notified of the fire, and as a precautionary measure, he ordered passengers to disembark onto the pier. He called for the CE to muster and account for all engine room personnel, and once the head count was complete, he authorised the use of the CO2 fire suppression system, which successfully extinguished the blaze. By 1236, temperature readings on the outside of the compartment’s watertight doors indicated that the fire was out, the report said.
NTSB determined that the fire originated from a leak at the fuel supply inlet flange for a fuel injection pump. One bolt was missing and another was loose. Investigators found the lost fastener below in the gallery for the cylinder bank. Laboratory analysis found nothing wrong with the bolts, and NTSB concluded that the probable cause of the fuel leak was improper tightening.
While the engineering crew’s response was rapid, NTSB noted that the team was not aware of the limitations of the HI-FOG system, which was only meant to supply water mist to one compartment at a time. The Third Engineer activated it for both compartments, leading to low water pressure at the discharge heads.
A number of equipment malfunctions was also noted: the hydraulically-actuated valve to divert the CO2 stream to the aft compartment malfunctioned, requiring manual intervention; and the integrated emergency display screen on the bridge froze, forcing crew to rely on multiple sources to evaluate and respond to the situation.
In addition, NTSB highlighted problems that the crew encountered with mustering and accounting for passengers on the dock. At the time of the fire, many of the passengers were ashore, and the crew had to subtract this group from the full passenger manifest to create a muster list of those still on board.
Even once this adjusted passenger manifest was ready, the scene on the pier created a difficult situation for getting an accurate head count: passengers who were already ashore at the time of the fire trickled in to join the evacuees, while some of the evacuated passengers wandered away from the muster areas. The crew searched the ship and made sure that no one remained on board, but the confusion made it hard to verify that all passengers who had been on the ship were present on the dock.
In conclusion, NTSB called on Carnival to develop specific procedures for handling passenger evacuations when in port, and it recommended familiarisation training on water-based fixed firefighting systems for Carnival’s engineers.