NTSB Issues Report On Miss Dorothy Fire
The engineroom fire that destroyed the mv. Miss Dorothy on March 17, 2021, was likely caused by the ignition of spraying diesel fuel from a main engine’s fuel system onto an uninsulated section of the engine’s exhaust system, according to the National Transportation Safety Board (NTSB).
The NTSB’s accident report, which was released March 8, found also that efforts to battle the fire were hampered by the crew’s inability to secure ventilation to the space and fuel to the affected engine.
The Miss Dorothy, of Western Rivers Boat Management Inc., was northbound on the Lower Mississippi River with 13 empty barges and one loaded equipment barge bound for a loading facility on the Cumberland River. At 12:45 a.m., when the tow was at Mile 249, fire alarms sounded in the engineroom and throughout the vessel. Within 30 seconds of the alarm sounding, the pilot could see rapidly intensifying smoke coming from the engineroom, and he activated the vessel’s general alarm. The mate, looking through the engine control room window, could see smoke and flames coming from the starboard main engine.
Crew members began running out fire hoses on the starboard side of the main deck to fight the fire. Meanwhile, the captain relieved the pilot in the pilothouse. Radio communications, both within the boat and externally, were unreliable during the fire, and the captain didn’t receive a response when he tried to notify the Coast Guard of the fire. He was, however, able to establish communications with the mv. Christopher Wilson, also owned by Western Rivers Boat Management, which happened to be three miles south of the Miss Dorothy, and who relayed the report to the Coast Guard.
By this time, the pilothouse was filling with smoke from the fire.
On deck, the crew used a 1.5-inch fire hose and handheld extinguishers to fight the fire. The vessel was equipped with two 50-pound ABC semiportable extinguishers and two 50-pound stationary carbon dioxide (CO2) cylinders that were connected to a hose reel. The crew attempted to operate the extinguishers and the CO2 hose reel system but were unable to do so because all were located in the same space as the fire and were inaccessible due to the intensity of the smoke and flames.
The engineroom was not equipped with a fixed fire-extinguishing system, nor was it required by regulation to be.
Both engines were still in operation. Because they could not be secured remotely from the pilothouse, the captain gave the order to pull the fuel oil shutoffs to stop the engines.
The emergency fuel oil shutoff pull station was located on the starboard-side main deck, on the external bulkhead of the engineroom. The shutoff pulls were connected to wires that were directly connected to the valve handles on the fuel supply valves for their respective engine or generator. The chief engineer told investigators that he was able to pull the shutoff for the starboard main engine, but the cable handles for the port main and the online generator were too hot for him to pull. Investigators later determined that all four shutoff valves were open, and the metal cables connected to the valves had been severed in the fire.
The fire continued to grow, and at about 12:52, the captain ordered the crew to abandon ship. The pilot and crew mustered on the forward end of the vessel before being joined by the captain from the pilothouse. By 1 a.m., the crew had evacuated the vessel to the tow’s barges.
The Christopher Wilson arrived about 45 minutes later, having tied off its tow further downriver. The Christopher Wilson picked up the Miss Dorothy’s crew and pushed its tow into the left descending bank at Mile 244. Both crews continued to fight the fire using the Christopher Wilson’s hoses.
The West Baton Rouge area 911 received notification of a vessel on fire at 1:45 a.m. and notified emergency personnel. The East Baton Rouge Sheriff’s Office Marine Division, the Baton Rouge Fire Department and the St. George Fire Department assembled and boarded the sheriff’s department’s 45-foot fire boat, which was located at Mile 240. The fire boat was launched and arrived on scene at 3:30 a.m. In addition, an ExxonMobil Refinery fire boat with suppression foam arrived. By 5:05 a.m., the superstructure fire was extinguished, and at 9:40 a.m., the engineroom fire was declared extinguished.
After the fire, the Miss Dorothy was towed to the company’s facility in Calvert City, Ky., where the vessel was determined to be a total loss.
No injuries or pollution were reported. The damage to the vessel was estimated at $2.4 million.
Crew members had not documented any issues with the 12-cylinder EMD 12-645E5 engines or fuel oil systems. The Miss Dorothy had a valid Certificate of Inspection issued in July 2019.
According to the NTSB report, post-casualty investigators found that the half-inch fuel-oil return line from the left bank of the starboard main engine had become displaced from its connection flange, but it was determined that this was a result of the fire, rather than an initial cause of it.
“Instead, the fuel likely came from another undetermined pressurized source (near the forward end of the starboard main engine) capable of spraying or atomizing the fuel, such as a faulty flange connection, gauge line, pressure gauge or pump seal,” the NTSB report said. The report noted that the starboard engine exhaust manifold was lagged with insulation, but the section of exhaust header between the engine block and the horizontal portions of the exhaust manifold were not shrouded, insulated, or lagged.
“It is likely that the uninsulated exhaust header acted as an ignition point for the atomized or spraying diesel fuel,” the report stated.
In the “Lessons Learned” portion of the report, the NTSB stated: “Enginerooms contain multiple fuel sources, making the spaces especially vulnerable to rapidly spreading fires. Regulations for towing vessels state that ‘piping and machinery components that exceed 220°C (428°F), including fittings, flanges, valves, exhaust manifolds, and turbochargers, must be insulated.’ Uninsulated engine exhaust surfaces can provide an ignition source for flammable liquids that can easily develop into fires that are difficult to contain. Towing vessel owners and operators, Coast Guard marine inspectors and third-party organization (TPO) towing vessel examiners should be aware of these dangers and fire risks and should regularly and thoroughly inspect equipment to ensure that measures are in place to prevent flammable liquids from coming into contact with hot surfaces.”