Derelict bollard causes multimillion-dollar drillship collision in Mississippi

Last year, a drillship collided with a cargo ship in Pascagoula, Mississippi, causing nearly $5 million in damage. The cause of the collision was found to be a damaged bollard that had become detached from its base in high winds, the National Transportation Safety Board (NTSB) has now determined certainly.

The incident happened on March 12, 2022 at ST Engineering Halter Marine and Offshore Shipyard (STEHMO), where the VALARIS DS-16 Drillship was stranded. During the passage of a cold front, the mobile offshore drilling unit detached from the dock and drifted into the Bayou Casotte Channel, where it collided with the cargo ship Akti. Fortunately, no injuries or contamination were reported.

Investigations revealed that the mooring lines of the VALARIS DS-16 were secured by six bollards on the pier of the STEHMO shipyard. In strong winds of 30 to 40 knots one of the bollards at its base broke loose and broke the bollard securing the drilling unit’s four bow lines and the two stern lines of a semi-submersible.

Ultrasonic thickness tests conducted after the incident showed the lower portion of several bollards was damaged, with some also showing signs of external corrosion and wasting. It was also noted that all bollards used by the VALARIS DS-16 has been modified from their original 1997 design, adding vertical components to accommodate more lines.

The NTSB concluded that the likely cause of the swerve and collision was the failure of one of the shipyard’s mooring bollards, which had been modified during a high-wind cold front to increase its height for more lines.

Since the incident, STEHMO shipyard has replaced 10 of the 14 bollards on the pier and plans to replace one more by the end of March 2023. Yard managers have also started evaluating the safe working load of the new bollards and are planning a tug pull test.

This incident is a reminder of the importance of regular maintenance and inspection of equipment to ensure its safe operation and prevent costly accidents.

“Due to continued increases in vessel size and sail area, previously adequate bollards may not have sufficient capacity to moor larger vessels,” the report said. “Currently, there are no regulatory requirements from the U.S. Coast Guard or Occupational Safety and Health Administration for facilities to inspect and verify the loading capacity of bollards at shore-based facilities. Bollards and associated mooring equipment on the pier are vital pieces of equipment that must be able to withstand the tremendous forces that large vessels exert on them. Exposed to seawater, bollards and associated pier mooring equipment are at high risk of corrosion, which can significantly reduce service life. The Coast Guard has recommended facility owners and operators develop a routine inspection program for bollards and other mooring equipment.”

Marine survey report 23-05 is available on the NTSBs website.

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