Safety Board Finds Probable Cause of 2013 Barge Fire
Failing to isolate tank-cleaning operations from ignition sources was the probable cause, with failure to provide adequate tank-cleaning training to employees a contributing factor.
The National Transportation Safety Board issued a marine accident brief detailing what investigators found after a fire and explosions damaged two barges that were docked in Mobile, Ala., on April 24, 2013, in order to have the barges' tanks cleaned. The brief says flammable vapors flowed from the tank hatches into the engine room of towing vessel Safety Runner and ignited, with the fire spreading to both barges alongside. Three people were seriously burned, and damage to the vessel and the barges was estimated at $5.7 million, according to the document.
The two steel barges, each 300 feet long and constructed in 2012, contained about 462 gallons of residual natural gasoline, a first-distillation of crude oil. The barges were docked at the Oil Recovery Company Gas-Freeing Marine Terminal in Mobile when the incident occurred. The brief says two ORC employees opened all of the cargo tanks and hatches on the barges and began to strip the tanks of residual gasoline. After they finished, they installed portable pneumatic fans to help ventilate the tanks.
An employee told investigators that an air hose disconnected from one of the fans, and the fan malfunctioned. The ORC person in charge shut down two dockside compressors that powered the fans, in order to check out the malfunction, and the Safety Runner pulled in alongside as the fan was being examined. The vessel docked in order to drop off a radio technician; the Safety Runner's captain told Coast Guard investigators he was unaware the tank-cleaning process was under way.
According to the brief, the Safety Runner's main engines then "started to run away" because tank vapors from the barges entered the air intakes for the main diesel engine, and this fueled the engines. "The captain tried to shut down the engines from the vessel's pilothouse but failed. Two deckhands then activated the engine's emergency shutdowns on the vessel's main deck; however, the engines still did not shut down. The concentration of the vapors from the tank barges was high enough that it introduced additional fuel to power the engines, even though the vessel's normal fuel supply had been shut off," it states.
The vapors ignited and the fire then spread to both barges, causing several explosions. The Safety Runner's crew had to abandon their ship. The people who sustained serious burn injuries were the ORC person in charge, who was standing on the deck of one of the barges; a Safety Runner deckhand; and the radio technician from a second towing vessel that had dropped off the barges at the terminal.
The barges burned for six hours, with several more explosions occurring during the night. The Coast Guard closed the mouth of the Mobile River to vessel traffic, and local fire and police departments ordered all persons and vessels within a 1-mile radius to evacuate.
The investigators found evidence of inadequate management oversight by ORC, including employing a person in charge without proper credentials and not having an operations manual that specifically addressed tank cleaning operations at the terminal. ORC's failure to isolate tank-clearing operations from ignition sources was the probable cause of the incident, and its failure to provide adequate tank-cleaning training to employees was a contributing factor, the safety board determined.