The U.S. Coast Guard has issued its report from its investigation into a fatal lifeboat accident on Shell’s Auger tension leg platform in the U.S. Gulf of Mexico in 2019.
The case
The incident took place during a routine lifeboat launch and retrieval drill on June 30, 2019. Two people inside the lifeboat were killed when it fell 80 feet, landing upside down in the water. Another person, who was exiting the lifeboat when it released, was seriously injured.
According to the report, the aft hook on the Auger platform’s Lifeboat No. 6 inadvertently opened as the lifeboat was being winched into the davit following the drill. “The lifeboat, still hanging from the forward hook, swung in a pendulum motion away from the facility. A few seconds later, the forward hook separated from the lifeboat and opened, and the lifeboat fell approximately 80 feet, landing inverted in the water,” investigators said in the executive summary.
“Based on the evidence collected and evaluated, it is probable that on the morning of June 30, 2019, the crew cycled (open to closed position) the hooks two times while in the water. The cable conduit, already compromised, was exposed to additional stresses, including compression and stretching. It is probable that during the second cycling event, the conduit, already weakened and damaged, separated during the closing action.
As a result, when the system was reset, the locking shaft on the aft hook did not return to the fully closed position, but rather, came to rest in an “almost open” position. In this position, the hook could support the weight of the lifeboat and its occupants,” the report stated.
Lessons learned
- The primary causal factor that directly contributed to the casualty was the complete separation of the aft hook control cable conduit surrounding the inner member.
- The operator and/or OEM’s failed to replace the aft hook control cable after it was identified as damaged.
- Contributing factors of the incident include the lack of systems, policies or regulations in existence to ensure that control cables are properly monitored and changed out in accordance with the OEM’s recommendations and/or best industry practices.
- The final report calls for instituting regular inspection and replacement schedules for lifeboat hook control cables, along with a requirement for the Coast Guard to review the entire lifeboat / release mechanism system during the design approval phase.