An incorrect steering setting was selected on a cement carrier ship when it unexpectedly sped up and collided with two tugboats in Tasmania's north-west, causing millions of dollars' worth of damage.
The Australian Transport Safety Bureau (ATSB) has released a preliminary report from its ongoing investigation into the collision between commercial cement carrier Goliath and two stationary TasPorts tugs, York Cove and Campbell Cove, in January at the Port of Devonport.
Goliath was travelling from Melbourne on a routine trip with 17 crew on board when the master of the ship felt it "was not swinging as expected" as it manoeuvred a tight turn in the Mersey River.
In a dramatic few seconds, the master attempted to stop the ship from moving forward by changing the steering setting, while being informed of the "rapidly decreasing clearances" between the ship and the tugs.
According to the report, "as the ship's speed continued increasing, the master checked the rudder angle indicator located in front of the port wing console and found that both rudders were still amidships and not at the angles corresponding to the VecTwin joystick setting as expected".
In a space of fewer than five minutes, the ship's speed increased from 1.4 knots to 4.7 knots at the moment of impact.
No crew members were on board the tugs, and no-one was injured.
Moments after the collision, it was determined the steering mode selector switch on the steering console was in manual mode when it should not have been.
Just five minutes after the crash, TasPorts activated the port's crisis management and incident management teams while port personnel began to deploy oil spill response equipment and oil containment booms around the two tugs.
ATSB chief commissioner Angus Mitchell said the investigation was ongoing.
"The ATSB will review and assess the ship's safety management system and navigation procedures, the effectiveness of bridge resource management on board, and review past incidents involving Goliath," Mr Mitchell said.
The tugs had a combined 69,000 litres of diesel fuel and other oil on board.
While much of the oil and diesel was contained, people and their pets were urged to stay out of the water between Devonport and Latrobe.
The Environmental Protection Authority (EPA) launched a response and found at least one oil affected bird, a cormorant, in the days following the collision.
The Goliath sustained minor damage and returned to service just under two weeks after the incident.
Recovery of tugs ongoing
The total cost of the bungle is unknown, but TasPorts said replacing the tugs, repairing the wharf, which was also damaged, and salvaging the tugs would go well into the millions of dollars.
The salvage operation to remove the sunken tugs from the river, described as one of the most complex undertaken in Australia in recent years, is in its final stages.
Specialist salvage divers and barges from the mainland were brought in to help remove the wrecks.
Both are expected to be lifted from the river by a crane and transported to Bell Bay later this month.
A number of restrictions, including on speed, have been in place for large commercial vessels operating close to the wreck site, including the Spirit of Tasmania ferries.
A final report from the ATSB, which will include detailed analysis and findings, will likely be handed down later this year.
The ATSB said relevant parties will be notified if any critical safety issues are identified.
