Superyacht engine room blaze

Marine accident investigators in the US have called for remotely controlled ventilation in all fire-protected spaces following a devastating fire aboard a 100ft motor yacht. 

In March 2021, the three-decked superyacht La Dolce Vita was anchored one mile north of Marquesas Keys in the Gulf of Mexico, 17 miles west of Key West, Florida, when a fire was discovered in its engine room. After an unsuccessful attempt to get the fire under control, the four crew and two passengers eventually abandoned the 100ft (30m), into its 20ft (6m) tender, before being rescued swiftly by the US Coast Guard. The motor yacht burned down to the waterline and sank. No injuries were reported, but an extensive sheen of diesel fuel was released. The vessel was written off as a total loss with an estimated value of $3.9m.  

Billowing smoke 

The incident began mid-afternoon on March 16th, when the first mate detected an unfamiliar smell coming from the main cabin, which he would later describe to investigators as being “like plastic burning”. He immediately proceeded towards the engine room and noticed smoke coming from the sound-deadening enclosure surrounding the starboard generator.  

The captain, meanwhile, also noticed smoke coming out of the port engine room vents and ran down to the engine room. When he opened the engine room door, he saw smoke billowing out and flames rising up from the starboard generator. He quickly closed the door and told the first mate to get fire extinguishers. When the first mate returned with three dry chemical fire extinguishers, the captain took one, put a wetted towel over his mouth and nose to protect himself from the toxic smoke, and reached into the engine room space where he was able to stop both generators via their cut-off switches either side of the door.  

He then discharged one extinguisher into the space between the aft bulkhead of the engine room and the starboard generator before discharging a second extinguisher onto the inboard side of the starboard generator, then firmly closing the door. 

After-fire remains of La Dolce Vita before the salvage operation (Credit: US Coast Guard) 

Fire suppression system 

Using a small access panel to look inside the engine room the captain realised that the extinguishers had had no effect. He told the mate to muster the passengers and crew and to get the tender ready. He then reached above the engine room door and pulled the plunger that deployed the superyacht’s fixed fire-suppression system into the engine room.  

After hearing the extinguishing agent release, the captain went to the bridge to notify the Coast Guard. He told the passengers and crew to abandon ship before making one last trip to the engine room and saw, through the door’s window, that the flames were still active.  

The captain decided to open the door and discharge another chemical fire extinguisher into the flames. Then, believing that he now had no hope of saving the vessel, he joined the others aboard the tender and then took the tender a safe distance away from the burning yacht. A Coast Guard response craft quickly arrived on scene to help. 

La Dolce Vita burned throughout the night into the early hours of the next morning, when it sank to the seabed, landing on its keel, with its starboard anchor still holding the bottom. The wreck was eventually lifted to the surface, using air bags, and towed to a nearby marina.  

Accident investigation 

The captain and mate told accident investigators from the National Transportation Safety Board (NTSB) that the odour of the smoke coming from the starboard generator was “like burning plastic as though the insulation from wires was smouldering”. The captain added that it definitely “didn’t smell like a fuel-fed fire”. This, combined with the captain’s and mate’s descriptions of where the smoke and flames emanated from, suggested to the investigators that the fire may have originated inside the electric generator end of the starboard genset enclosure. However, due to the extent of the fire damage, they were unable to conclusively determine the exact source of the fire within the genset enclosure. 

Probable cause 

The final report determined that the probable cause of the fire was an undetermined electrical source within the sound enclosure of the starboard generator. Contributing to the severity of the fire and loss of the vessel was the inability to secure ventilation to the engine room, which, in turn, reduced the effectiveness of the fire extinguishing system, allowing the fire to spread beyond the engine room. 

Lessons learned 

The report points out that fixed fire-extinguishing systems in machinery and hazardous spaces require a minimum concentration of extinguishing agent to halt the chemical reaction producing the fire or displace the oxygen feeding the fire. 

To ensure the effectiveness of the system and prevent the reintroduction of oxygen to the space, the report says, vessel designers and owners should ensure that ventilation — both natural and forced — can be completely and remotely managed to all fire-protected spaces, and that all machinery within fire-protected spaces can be stopped remotely.  

Read the full NTSB accident investigation report into La Dolce Vita's engine room blaze. 

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Dennis O’Neill is a freelance journalist specialising in maritime.