NTSB: Fire on laid up Dive Support Vessel

The fire occurred in April 2020 while the vessel was docked at a shipyard in the United States.  It started during the hours of darkness and was extinguished by local firefighters.  No one was aboard the vessel at the time of the fire. No pollution or injuries were reported. Damage to the vessel was estimated at greater than US$900,000.

Simultaneous operations including various hot work had been conducted on the vessel on the day before the fire. All personnel had left the vessel by 1800 hrs, but shore-side power remained connected. The fire was reported at 0110 that night. The shore-based firefighters boarded the vessel and fought the fire with water hoses. At 0225, the fire was extinguished with no injuries. About 0900 the next morning, shipyard personnel found an area still emitting smoke behind the fuel tank on the starboard side of the generator room, but it was quickly extinguished.

• There were no personnel on the vessel overnight.
  
  
• The vessel’s fire detection system had been secured (switched out or off) while work was being conducted within the vessel to prevent false alarms from smoke and dust.
  
  
• In addition, there was no shipyard policy or vessel owner policy in place to have shipyard personnel or vessel crew members conduct safety rounds after hours when there was no work being done on the vessels at the shipyard.

The NTSB noted that the fire started in the generator room on the wall area common to the mess area, and that the investigators could not rule out the possibility of an electrical short as the potential source of the fire 

The NTSB notes that based on the location of the hot work and the initial location of the fire within the generator room (as determined by the investigator’s report), the hot work conducted on board the vessel was not the source of the fire.

The National Transportation Safety Board determines that the probable cause of the fire aboard the DSV was an electrical short from an unidentified source located on the forward bulkhead within the generator room. Contributing to the undetected propagation of the fire was the lack of continuous monitoring of the vessel while it was docked at the shipyard.