ATSB: Maintenance plan problem leads to grounding

The incident

On 19 August 2016 at 1458, a Port Phillip Sea Pilot boarded 'Bow Singapore' outside Port Phillip, Victoria. The pilot was to conduct the ship through The Rip and the South Channel to an anchorage in the northern part of Port Phillip.

At 1614, as the ship neared the eastern end of the South Channel, the rudder ceased responding to helm inputs and remained at 5° to port. The ship started swinging towards the edge of the channel. Steering was regained a short time later but, despite the efforts of the pilot, the ship grounded at 1617.

On 20 August at 0040, Bow Singapore was re-floated, with the assistance of the rising tide and a tug. The ship proceeded to anchor and, later, to the discharge berth in Geelong. After discharging cargo, the hull was inspected by divers and no damage was found.

Findings

• The ATSB found Bow Singapore’s steering gear ceased working and the rudder remained at 5° to port. A telemotor solenoid, controlling the rudder’s movement to starboard, had stopped responding to electrical signals. This initiated an uncontrolled turn towards the edge of the channel and shallow water.
• The company’s procedures for a steering gear failure required a change in operation from the bridge to local emergency operation from the steering gear room. However, the procedures did not include the steps to be taken on the bridge prior to that change, such as using non follow-up mode and changing to alternate telemotor and/or pump systems.
• The planned maintenance system for the steering gear did not include or contain any schedules for any detailed inspections or scheduled parts replacement. In addition, the hydraulic system port and starboard solenoids were painted green and red respectively, to match the side of the ship that each is on when mounted on the shuttle valve. However, this was opposite to the direction the rudder would move when they were operated.

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