On 21 March 2003 the port main engine of the Australian cargo ship Searoad Mersey failed catastrophically leaving the vessel disabled in Bass Strait. The Australian Transport Safety Bureau (ATSB) has released its investigation report into the incident.

At 1612 on 21 March 2003, the roll-on/roll-off cargo vessel Searoad Mersey departed from Melbourne on a scheduled service to Devonport in Tasmania. By 1924 the ship had cleared Point Lonsdale and was heading in a south-easterly direction in Bass Strait.

At about 2118, the duty engineer received an engine room alarm and made his way to the engine room. During his subsequent inspection of the engine room, he found a main engine connecting rod lying on the deck on the inboard side of the port main engine. The port main engine had stopped and it was evident that there had been a catastrophic failure of one of the engine's piston assemblies.

A short time later the running main generator overheated and shutdown which caused the ship to black out. The generator had stopped as a result of the damage to the main engine which had caused a large loss of cooling water from the common cooling system.

By 2230, the ship's systems had been stabilised and the starboard main engine had been restarted. Searoad Mersey then proceeded back to Melbourne under its own power to arrive at Webb Dock in the morning of 22 March 2003.

The ATSB's report makes conclusions relating to the failure of Searoad Mersey's port main engine including:

  • A casting flaw found in the piston skirt which failed initiated a fatigue crack which eventually caused the piston to fail in service.
  • The vessel's maintenance system did not include a system for tracking the total operating hours of the main engine piston assemblies.
  • The vessel's maintenance system did not include a procedure for crack testing the piston skirts in the areas stipulated by the manufacturer in a service bulletin.
  • There was evidence to suggest that the engine type have had a history of piston skirt failures similar to that which occurred on Searoad Mersey.

The report also makes recommendations to the operators of Wartsila Vasa 32 engines and to Wartsila NSD in relation to the servicing of piston assemblies and the distribution of engine service bulletins.

Copies of the report may be downloaded from the website or obtained from the ATSB by telephoning (02) 6274 6478 or 1800 020 61.

Media contact: 1800 020 616
Last update 01 April 2011