The National Transportation Safety Board has released a marine investigation report detailing the June 2, 2024 collapse of an emissions control barge boom at the Port of Los Angeles.
The federal agency stated that the incident involving the vessel Stax 1 resulted in one minor injury and caused an estimated $3.2 million in property damage.
According to the federal report, the containership Erving, operated by Zodiac Maritime, arrived at the Fenix Marine Services container terminal at 03:46 and moored along the berth. The control barge Stax 1, owned by Stax Engineering, subsequently arrived at 04:08 to begin capturing emissions from the ship.
The vessel operations proceeded without incident for 11 hours until a night-shift supervisor noticed a tear in the exhaust ducting five feet (1.5 metres) above the stack.
While four barge crewmembers boarded the Erving to make repairs, terminal personnel discussed the need to raise the boom of ship-to-shore crane 16 to clear the barge's equipment.
At 16:38, the first-shift crane operator finished unloading cargo and attempted to raise the crane's boom, but the system failed to respond because the trolley cab was not fully parked. The operator informed the ship boss of the malfunction before departing the area, leaving the crane boom in its lowered position.
Shortly before the scheduled flex shift, a second-shift crane operator began moving crane 16 from the ground station with its selector switch wedged open and walked 35 feet (11 metres) away to monitor the alignment.
At 16:49, the moving crane struck the Stax 1 boom, sending sections of the metal structure crashing onto the barge, onto the Erving, and into the water.
The collision released approximately 10 gallons (38 litres) of hydraulic oil onto the deck of the containership and into the water, producing a visible sheen.
The NTSB reported that the impact sheared the barge's boom at its base, resulting in $3.1 million in damages to the Stax 1 and $175,000 in damages to the Erving.
Investigators determined that the second-shift operator moved the crane from the ground control station without a dock signal person or direct line of sight to the barge.
The report noted that the operator had not received formal container gantry crane training since January 1998, instead learning to operate newer models informally.
The safety manual from the Pacific Maritime Association warns operators to ensure the crane boom is in the full upright position before moving if obstacles are present. According to the Pacific Coast Marine Safety Code, "Crane operators shall not operate cranes when visibility cannot be maintained to assure a safe operation."
The NTSB concluded that the probable cause of the collapse was the shoreside operator moving the crane without verifying that its lowered boom had ample clearance over nearby structures. The federal agency also attributed the accident to the container terminal's inadequate guidance for moving cranes from ground stations.
Following the accident, Fenix Marine Services installed locks on ground control stations and programmed the cranes to prevent ground movement when booms are lowered.
Stax Engineering also implemented safety policies, including installing dockside warning signs and strengthening control rooms on its fleet of barges.