UK MAIB’s latest Safety Digest informs of an incident regarding a tanker, which made contact with an adjacent berthed workboat and ground, after breaking from its mooring lines.
The incident
The pre-departure checks for a berthed tanker required the OOW to transfer propulsion control from the ECR to the bridge. At the first attempt the bridge engine controls appeared to be demanding ahead pitch, with the levers set to zero, resulting in an unsuccessful transfer of control.
The C/E went to the bridge to investigate and, having confirmed that all the bridge engine control levers were set to zero, a second attempt at transfer of control was made. Soon after, the OOW noticed that the vessel had started moving ahead and immediately pressed the main engine emergency stop button.
The forward movement was sufficient to break mooring lines and for the vessel’s bow to make contact with an adjacent berthed workboat and ground (Figure 2). The workboat sustained minor damage and the tanker was refloated at high water with the assistance of tugs
Lessons learned
Procedure: Standard operating procedures exist for a reason. A post-accident investigation determined that a defective circuit board in the propulsion control system had caused the demanded ahead pitch. However, the procedure for transferring control had been incorrectly followed and the first failed attempt had been a warning that something was wrong. This failure should have been thoroughly investigated before any further attempt was made to transfer control. The company has since updated its procedure to ensure that the bridge has control of propeller pitch before the engine is clutched in.
Qualified: The deck and engineering officers were unfamiliar with the main engine emergency and back-up controls. These essential skills are now included in the mandatory induction training that all officers must complete before their first watch.
