Pitch Lever Mismatch Led to Collision
The UK Marine Accident Investigation Branch (MAIB) has published its investigation report into the collision between the Kirkella and Shovette on June 24, 2022.
While alongside at King George Dock, Hull, England, the crew of the UK registered fishing vessel Kirkella lost control of its propulsion system, and the vessel collided with the unmanned tug Shovette, which was moored ahead of Kirkella.
During the collision Shovette’s hull and starboard fuel tank were breached by Kirkella’s bulbous bow. The tug partially sank, which resulted in pollution of about 7,000 liters of marine diesel oil being released into the dock. Kirkella was not significantly damaged and there were no injuries.
The investigation found that:
• the pitch levers for Kirkella’s propulsion control system were mismatched between the bridge and engine control room when control was transferred
• Kirkella’s engineer had not checked the pitch lever when control was passed between the bridge and engine room
• There was no procedure for control changeover
• The classification society’s rules for remote control of engines was not aligned with the international unified requirement.
Recommendations (2024/111 and 112) have been made to Det Norske Veritas to: propose to the International Association of Classification Societies that Unified Requirement M43.12 is reviewed to clarify its intent; and inform its customers that the Rolls-Royce Helicon-X3 system might allow remote control station changeover with mismatched levers and suggest that the manufacturer be contacted for advice.
A recommendation (2024/113) has been made to Kongsberg Maritime to issue a service letter to its customers advising that the Rolls-Royce Helicon-X3 system remote control changeover process can allow mismatching of levers resulting in the propelling thrust altering significantly, and advise them of methods of operation and/or rectification should these be requested.
A safety flyer to the shipping industry was produced with this report, highlighting the risk of mismatched propeller pitch levers during transfer of control together with potential mitigation of this risk.