The NTSB issued its Marine Accident Brief 20/36 related to the Sept. 8, 2019 incident on Tuesday.
One crewmember was injured evacuating the vessel.
The accident resulted in the discharge of about 120 gallons of diesel fuel and the vessel was declared a constructive total loss.
The accident occurred in 35-feet of water about while the self-propelled, self-elevating, liftboat Kristin Faye was elevated to provide service to an oil production platform eight miles east of Venice, Louisiana. When the captain raised one of the extending/telescoping boom cranes on the vessel, the liftboat began tilting to port and overturned in less than one minute, according to the NTSB.
Marine Accident Brief 20/36 notes once the 22,500-pound port crane boom was moved from its cradle (horizontal position) to the vertical position, the boom’s center of gravity shifted about 17 feet.
The company’s manual did not include guidance for changes in the position of the crane booms once the vessel was elevated.
“The National Transportation Safety Board determines that the probable cause of the overturning of the liftboat Kristin Faye was the company’s inadequate preload procedure that did not account for crane movements or the planned loads (weights) to be lifted, resulting in a “punch through” of one of the vessel’s three legs,” the briefing said.