MAIB Report: capsize and sinking of the tug Biter, with the loss of two lives off Greenock, Scotland on 24 February 2023.

Summary

At about 1527 on 24 February 2023, the twin screw conventional tug Biter girted and capsized off Greenock, Scotland while attached to the stern of the passenger vessel Hebridean Princess, which was making its approach to James Watt Dock. Biter’s two crew were unable to escape from the capsized vessel and lost their lives.

 Safety issues

• The marine pilot’s training had not prepared them to work with conventional tugs.
• Master/pilot and pilot/tug exchanges were incomplete and, with no shared understanding of the plan, the passenger vessel’s master and the tug masters were unable to challenge the pilot’s intentions.
• The passenger vessel’s speed placed significant load on the tug’s lines and almost certainly caused the gob rope to render.
• The tug’s gob rope did not prevent it being girted.
• The tug’s rapid capsize meant the crew had insufficient time to release its towlines.
• An open hatch compromised the tug’s watertight integrity and limited the crew’s chance of survival.

Recommendations

Recommendations (2024/157 to 2024/166) have been made to Clyde Marine Services Limited, the tug’s owners, to: review its safety management system and risk assessments to provide clear guidance on the rigging of the gob rope; the safe speed to conduct key manoeuvres; and, to adopt a recognised training scheme for its tug masters.

Recommendations have also been made to: Clydeport Operations Limited to commission an independent review of its marine pilot training and to risk assess and review its pilot grade limits and tug matrix. Recommendations have also been made to professional associations representing pilots, harbourmasters, and tug owners to develop appropriate guidance on the safety issues raised in this report.

Andrew Moll OBE, Chief Inspector of Marine Accidents:

 “Tug Biter’s accident was another cruel lesson of how rapidly things can go dreadfully wrong. In less than 10 seconds the tug capsized, and two experienced seafarers lost their lives, because of a breakdown of the systems that should have kept them safe.  

 “Small conventional tugs remain an essential part of UK port operations. However, the vulnerabilities of these vessels must be understood by those that operate and control them.

 “Harbour authorities, ship and tug masters, and pilots should collectively own this risk. Pilots and tug crews must be suitably trained and experienced for their roles, and they must share a detailed understanding of the towage plan before they start the job. Speed, which has an exponential effect on towing forces, must be carefully controlled and the lines correctly set. Everyone involved must then monitor the execution of the plan and, if needed, act to keep everyone safe.”