Cincinnati, Ohio, on the Ohio River.
The towboat Capt. Kirby Dupuis was upbound on the Ohio River with 13 barges in tow when its captain saw a flash on the engine room video display. The towboat’s fire detection system triggered seconds later.
The captain sounded the general alarm and instructed the crew to begin firefighting operations. They ultimately tried, and failed, to activate the Novec 1230 fixed fire suppression system in the engine room, which allowed the blaze to burn for longer.
The fire started at about 0708 on Nov. 9, 2021, at Ohio River mile 501 near Belleview, Ky. It was fully extinguished at about 1300 with help from several fire departments. Nobody was hurt and the tow remained intact throughout the incident, but the 120-foot towboat sustained nearly $1.8 million in damage.
National Transportation Safety Board (NTSB) investigators said the fire started after pressurized lube oil sprayed from the port main engine onto a hot surface and ignited. They attributed this to a missing retaining ring and mounting bracket on a lube oil tube that had vibrated out of a joint.
The investigation also identified crucial training gaps that left the Capt. Kirby Dupuis crew unprepared to effectively fight the fire.
“Although the crew drilled regularly in the months preceding the fire, including simulated fires … that included the upper engine room, they did not include scenarios or exercises that simulated activation and operation of the fixed fire-extinguishing system,” the NTSB said in its report.
“Had the crew been more familiar with the system and activated it properly,” the report continued, “the system would have shut down the engines and ventilation fans before a complete release of both cylinders of suppression fluid into the engine room and may have quickly extinguished the fire.”
Florida Marine Transporters of Mandeville, La., operated the vessel. The company did not respond to an inquiry about the NTSB findings.
Capt. Kirby Dupuis was heading upriver from Paducah, Ky., to Steubenville, Ohio, with 13 dry barges carrying sand, stone and steel when the fire started some 35 river miles from Cincinnati. There were six crewmembers on board at the time.
The captain was on watch in the wheelhouse when he saw the engine room flash on the closed-circuit TV display. He mobilized the deck hand-engineer on watch to alert fellow crewmembers and begin firefighting operations.
Heat and smoke kept the deck hand-engineer from accessing the engine space. He then joined other crewmembers attempting to fight the flames from the starboard side of the main deck. Heat damaged electrical panels, making the fire pump inoperable, the report said.
The captain gave the firefighting team permission to activate the Novec 1230 fire suppression system. They shut engine room windows, doors and ventilation in preparation for activating the system. The deck hand-engineer believed he discharged one canister of Novec 1230 and soon afterward received permission to “hit the second fire suppression system,” the report said. Neither system activated.
Novec 1230 is a liquid fire suppression chemical made by 3M. It is designed to extinguish the fire without causing any damage to engine room equipment. The fire suppression system on Capt. Kirby Dupuis consisted of two storage tanks and a nitrogen tank that pressurized the chemical.
Activating the system took multiple steps. Both the cylinder release and valve release levers needed to be engaged for the system to deploy. After the incident, investigators determined the Novec 1230 tanks were still full.
“When investigators inspected the fire-extinguishing system, they observed that the ‘valve release’ remote pull lever was pulled out as per the instructions, and its corresponding globe valve was open,” the report said. “However, the ‘cylinder release’ remote pull lever was not fully extended, and its corresponding nitrogen cylinder’s actuating lever remained in the ‘set’ position.”
Florida Marine Transporters is working to update its training programs to address the activation of fixed fire suppression systems. As of fall 2022, the company was creating a fixed fire suppression training guide video that will be mandatory for its crews.
Capt. Kirby Dupuis, built in 2011, was powered by two 2,000-hp Caterpillar 3512 main engines. The port main had 73,135 running hours, and its most recent overhaul occurred in May 2018. The engine had not been serviced during the year that the deck hand-engineer had worked aboard the vessel.
Investigators found a sheared bolt on that engine that previously held supporting clips for the midsection of the lube oil tube. The retaining ring that was supposed to be behind an O-ring on the tube was also missing.
“The wear found on the seal O-ring groove lip of the lube oil tube indicates that there was movement of the tube in the joint due to natural vibration of the operating engine,” the NTSB found. “It is likely that at some installation, after maintenance that required removal of the tube, the retaining ring was not reinstalled on the tube.”
It isn’t clear how long the engine had operated in that condition. Florida Marine inspected its fleet after the Capt. Kirby Dupuis fire and found 10% of engines had similar issues. All issues have since been corrected.