On November 9, 2021, at about 7:00 am, a fire broke out on the Capt. Kirby Dupuis, a towing vessel that was pushing 13 loaded dry cargo barges up the Ohio River near Belleview, Kentucky. The six crew members fought the fire but could not put it out. Local firefighters from Indiana, Kentucky and Ohio finally beat back the flames, but not until the fire caused about $1,800,000 in damage.
A new NTSB investigation found that the likely cause of the engine room fire was a missing retaining ring and mounting bracket, which allowed a lube oil tube on the port main engine to vibrate out of joint and spray pressurized oil around the room. The oil hit a hot exhaust surface and ignited.
The vessel was powered by a pair of Caterpillar marine diesel engines. A senior technical service manager from Caterpillar reviewed a video from the engine room and inspected the damaged port engine.
During the inspection, the CAT manager also found a broken O-ring where the missing retaining ring would've connected a tube to the lube oil filter housing. The tube's supporting clips and mounting hardware were also missing, and the bolt that held the clips appeared to be sheared. The NTSB couldn't determine how long the clips and hardware were missing, but the last top-end overhaul on the engine was in May 2018.
Part of the problem, as far as the extent of the damage, was that the crew didn't know how to activate the vessel's fixed fire-extinguishing system, which could have released fire suppression fluid. The crew didn't miss by much as one of the two levers that had to be pulled to activate the system was not fully extended. While the crew conducted regular emergency drills, none of the work included training on the fire system.