Steering discrepancy seen as factor in Tasmania collision

In its preliminary report on the collision of the cement carrier Goliath (IMO 9036430) with two moored tugboats, the York Cove and Campbell Cove, at the port of Devonport, Tasmania in January, the Australian Transport Safety Bureau (ATSB) has said that the facts of the incident included a steering mode discrepancy during harbour manoeuvring.

The initial report lays out the evidence collected in the ATSB’s fact-finding investigation, but it does not include a root-cause analysis.

On the morning of January 28th the Goliath approached the port of Devonport to call at the bulk cement terminal. It entered the port at about 11:30 local time, with the master on the bridge, and slowed as it approached the swing basin opposite the terminal (IMN, January 31st 2022).

At about 11:45 the master had the second mate transfer engine and rudder control to the port bridge wing manoeuvring station and set the controls in joystick mode. His practice was to manoeuvre using the main engine telegraph for power control; the bow thruster control; and the joystick for the specialized VecTwin rudder angle control, the ATSB said.

ATSB Chief Commissioner Angus Mitchell said that “ships fitted with the VecTwin twin-rudder steering system can be manoeuvred at low speed with thrust from the propeller redirected as required by the two rudders, controlled by a joystick. The system allows astern thrust to be generated using ahead inputs on the main engine without the need to stop the engine and engaging astern propulsion, as would be required for conventional ship manoeuvring.”

As the ship moved into the basin, the master took the helm at the bridge wing station and moved the VecTwin joystick to the “astern to port” setting. However, he determined that the ship was not turning as quickly as he had expected. He put the joystick to the “astern” rudder angle setting, then put the engine telegraph to half ahead, then quickly to full ahead. Under the joystick setting and rudder orientation selected, “full ahead” would be expected to produce astern thrust and slow the ship. However, shortly after the vessel had picked up speed to four knots and was still accelerating.

As the ship closed in on the wharf, the master looked at the rudder angle indicator and determined that both rudders were amidships – not the rudder angle set on the VecTwin joystick. He called out to the second mate to tell him that the vessel was not in joystick steering mode (it was in manual mode) and he put the telegraph to all stop. Shortly after this  the Goliath struck two moored harbour tugs at a speed of 4.7 knots. The tugs York Cove and Campbell Cove were badly damaged and began flooding.

The second mate had by now switched the bridge console’s steering mode selector to joystick mode. The master put the engines astern and maneuverer the ship to its berth, and the crew carried out tank soundings.

No injuries were reported, but both of the tugs eventually sank in about 20ft of water. First responders put out a containment boom to reduce the spread of fuel; salvors ultimately pumped out about 18,000 gallons of diesel from the two vessels.

The tugs were both declared a constructive total loss.

The Goliath suffered damage to its bulbous bow and some of its hull plating on the starboard side. By February 10th it had been repaired and returned to service.

1993-built, Australia-flagged, 11,754 gt Goliath is owned and managed by CSL Australia Pty Ltd of Sydney, NSW, Australia. It is entered with Standard Club (International Division) on behalf of CSL Australia Pty Ltd.

https://www.atsb.gov.au/media/news-items/2022/devonport-ship-collision/

https://www.atsb.gov.au/publications/investigation_reports/2022/mair/mo-2022-002/