A generator explosion in the engine room of the Gulf of Mexico shrimp trawler Master Dylan triggered a fire that forced the crew to abandon ship on Dec. 1, 2020. Despite rescue and firefighting efforts by responding vessels, an initial knockdown of the fire ended with a flareup as the boat was under tow, leading to a total $300,000 loss, according to a National Transportation Safety Board report.

NTSB investigators found the Master Dylan crew was unable to cut off diesel fuel lines feeding the fire because the valves were inside the burning engine room. The agency recommended that fishermen, boat designers and builders should think about putting cut-off valves for fuel and lubrication oil outside of engine rooms where they can be closed off in an emergency.

When an engine room fire erupts, “it is imperative to remove the source of available fuel to the fire found in the fuel oil and lube oil systems,” according to the NTSB report. “In this accident, the vessel had no remote emergency cut-off valves outside the engine room, and thus fuel to the fire could not be stopped and the vessel was eventually consumed by the flames. Vessel designers, builders, owners, and operators are encouraged to install, regularly test, and have emergency drills that incorporate remote cut-off valves for fuel and lube oil lines.”

The Master Dylan was trawling around 7:45 a.m. when one of two 70 kW John Deere generators apparently had an explosion in the engine room. The crew’s attempt to fight the fire was unsuccessful, so the captain ordered them to abandon ship to another shrimp fishing vessel that came to their aid.

Responding vessels fought the fire under control, and the Master Dylan was taken under tow. But aas the boat ran aground on a sandbar, the fire flashed up again. The Master Dylan rolled an sank on the bar, a total constructive loss with an estimated value of at $300,000, according to the NTSB.

Built in 1996 by Master Boat Builders in Coden, Ala., the Master Dylan was an 83.5-foot steel fishing vessel with a 765-hp Caterpillar diesel turning a single propeller. Maximum fuel capacity was 29,000 gallons, but accident investigators were unable to determine how much was in the tanks on the final voyage.

With its captain and three crew members, the Master Dylan departed the Dustin Gulf Seafood Dock at Sabine Pass in Port Arthur, Texas, at about 1 p.m. local time on Nov. 29, 2020. While steaming to shrimping grounds off the Louisiana coast the crew noted nothing unusual, and around 7:30 a.m. on Dec. 1 they deployed nets for the first set of the trip.

After making the set, the captain made a routine inspection of the engine room where the main engine and the starboard generator were running. He found nothing unusual and returned to the wheelhouse at around 7:40 a.m.

About five minutes later the crew heard a loud explosion in the engine room, and saw fire and black smoke. The captain rushed from the wheelhouse to the engine room door.

Smoke and flames kept him from entering, so he tried discharging a B-2 dry chemical fire extinguisher through the open engine room door. It had no effect on the intensity of the fire, and the captain and crew could not reach engine fuel supply valves, or shut the engine room door or any doors to the deckhouse due to the fire and smoke.

At that point the captain decided the fire was out of control, and went to the aft deck and ordered rhe crew to put on their lifejackets and prepare to abandon the vessel.

Once everyone had a lifejacket on, the captain directed the crew to raise the nets out of the water so they would not be in the way if the crew had to deploy the liferaft alongside. The crew engaged the winch and were able to maneuver the nets, while the master retrieved the emergency position indicating radio beacon (EPIRB) from the starboard side of the bridge.

After securing the nets, the crew mustered on the stern in preparation to abandon ship, and the captain activated the EPIRB. The EPIRB signal was received by the Coast Guard Rescue Coordination Center New Orleans at 9:09 a.m.

About one mile away from the Master Dylan, the captain of the fishing vessel Johnny LE, also engaged in shrimping, saw the smoke, stopped fishing, and proceeded to the Master Dylan to assist. The crew of the Master Dylan were prepared to deploy their liferaft but saw the Johnny LE heading towards them and decided to wait.

At about 9:15 a.m. the Johnny LE’s captain maneuvered the stern of the Johnny LE up against the stern of the Master Dylan, and its crew were able to climb over.

Once on the Johnny LE, the Master Dylan captain uswed the radio to contact the Master Dustin II, a vessel owned by the same fishing company, to come and assist with trying to save the burning boat. About 90 minutes later the Master Dustin II arrived, picked up the captain and crew of the Master Dylan and headed back to their stricken vessel.

Meanwhile the offshore supply vessel FMS Courage crew had spotted smoke from the fire and made way to the scene, where they turned fire monitors and hose on the Master Dylan and extinguished the blaze.

At 11:40 a.m., with the fire apparently out and only white smoke coming out of the vessel, the Master Dustin II maneuvered alongside to secure a tow line without boarding anyone back onto the Master Dylan.

The boat was taken under tow to the nearest point of land, but about an hour later at 12:40 p.m. the Master Dylan ran aground on a sandbar the towing vessel had safely passed over. The fire soon re-flashed, but no further firefighting efforts were made.

At 11 a.m the next day the Master Dylan, still smoking, rolled over and sank, and was not salvaged.

Investigators learned the Master Dylan’s main engine, a 765-hp Caterpillar, and the two 70-kW John Deere generators were rebuilt during a scheduled maintenance period five months before the accident voyage, but they could not determine the extent of the overhaul and the condition of replacement parts through records.

The owner of the vessel told investigators that there were no previous issues with the engines since the overhaul. While the vessel was under way, the crew typically would switch the electrical power between the two generators every three days.

On November 30, the day before the explosion, the crew switched the vessel from the port generator to the starboard generator. The crew told investigators that there were no operational problems with the main diesel engine or the two diesel generators either on the previous voyage following the maintenance or during the accident voyage.

The exact cause of the fire in the engine could not be determined as the Master Dylan was not salvaged. But because the crew was able to retrieve the nets using the winch’s clutching mechanism, which operated off the main diesel engine, investigators decided “the main engine was still operating and therefore could not have been the source of the explosion.”

“Because investigators could not determine if electrical power was lost, they could not confirm if the fire source was a generator malfunction. However, a mechanical failure could have catastrophically damaged the operating starboard generator’s engine and breached its crankcase, producing the reported explosion. The generator’s lube oil simultaneously releasing would have ignited off a hot surface, starting the fire,” the report states.

“Additionally, the engines fuel supply lines may have been damaged, and since the vessel’s fuel shutoff valves were in the engine room, the crew had no way of securing the fuel supply from tanks to the diesel engines to stop fuel from feeding the fire. The wooden frames and furniture within the house, as well as the dry supplies located inside the forepeak, likewise would have provided additional fuel to sustain the fire as it spread beyond the engine room.”

The NTSB laid probable cause of the fire on catastrophic failure of the diesel generator, with the location of the fuel shutoff valves within the engine room as a contributing factor.