The fatal capsizing of the tug came after a ‘failure’ of safety systems, the report shows

A tugboat capsized in less than 10 seconds, killing two lives due to a “malfunction of the systems that were supposed to keep them safe”, marine researchers have discovered.

The Biter capsized while towing the passenger ship Hebridean Princess towards James Watt Dock in Greenock on February 24, 2023.

Tugmaster George Taft, 65, and sailor Ian Catterson, 73, were unable to escape and their bodies were recovered from the ship’s wheelhouse by Police Scotland divers the following day.

A Marine Accident Investigation Branch (MAIB) investigation found that Biter was struck by ‘belt’ forces and capsized as it was unable to change direction to operate directly behind the passenger vessel before the weight of the tugboat came onto the towing rig.

When this happened, a rope on the tug, called the ‘goo rope’, did not prevent it from being towed sideways and the rope being loosened.

Investigators also found that an open accommodation hatch compromised the tugboat’s watertight integrity and limited the crew’s chances of survival, as it was highly unlikely that there was air in the wheelhouse when the vessel overturned.

The MAIB investigation found that the training of the Clydeport naval pilots had not prepared them to operate conventional tugboats such as Biter.

It also found that the exchanges between captain/pilot and pilot/tug were incomplete and that, in the absence of a shared understanding of the plan, the passenger ship captain and tug masters could not dispute the pilot’s intentions.

Andrew Moll, Chief Marine Accident Inspector, said: “The Tug Biter accident was another cruel lesson in how quickly things can go terribly wrong.

“In less than ten seconds, the tug capsized and two experienced seafarers died due to a failure in the systems that were supposed to keep them safe.

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

“Port authorities, ship captains, tugboats and pilots must jointly bear this risk. Pilots and tug crews must be adequately trained and experienced for their role, and they must share a detailed understanding of the towing plan before starting work.

“The speed, which has an exponential effect on the drag forces, must be carefully controlled and the lines laid out correctly.

“Everyone involved must then monitor the implementation of the plan and, if necessary, take action to keep everyone safe.”

The research also found that Hebridean Princess’s speed of 4.6 knots (kts) meant the load on Biter’s tow lines was between two and five times higher than at the recommended lower speed of 2-3 knots.

Given the rapid capsizing of the tug, it was unlikely that the crew had sufficient time to operate the emergency release mechanism.

The MAIB has recommended that Clyde Marine Services Limited, the tug’s owners, review its safety management system and risk assessments to provide clear guidance on rigging the blob; the safe speed to carry out important maneuvers, and that it has a recognized training program for its tugboat captains.

Recommendations have also been made for Clydeport Operations Limited to commission an independent review of marine pilot training and to assess risks and review pilot quality limits and the tug matrix.

A spokesperson for Clyde Marine Services said: “We acknowledge the publication of the Marine Accident Investigation Branch report. We will take the time to review and consider it.

“Our thoughts remain with the affected families and Clyde Marine Services will continue to cooperate fully with the ongoing official investigations.”

Clydeport Operations Limited has been contacted for comment.

The MAIB has also made recommendations to professional associations representing pilots, harbor masters and tugboat owners to develop appropriate guidance on the safety issues raised in the report.