At 1612 on 21 March 2003, the Australian flag roll-on/roll-off cargo vessel Searoad Mersey departed from Melbourne on a scheduled service to Devonport in Tasmania. By 1924 the vessel had cleared Point Lonsdale, at the entrance to Port Phillip and was en route to Devonport.
At 2118:50 the engine room alarm sounded in the duty engineer's cabin, followed shortly after by the fire alarm. During his subsequent inspection of the engine room the duty engineer 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. There was oil lying all over the floor plates, on and around the engine, and on the deck head above the engine. It was apparent that there had been a catastrophic failure of the number one piston assembly, cylinder liner and cylinder cover.
A short time later the port main generator overheated and shut down which caused the ship to black out. The port generator had stopped as a result of the damage to the port main engine which had caused a large loss of cooling water from the common cooling system.
By about 2215 the various engine room systems had been stabilised and checked by the engineers. The decision was made to return the ship to Melbourne and by 2230 the starboard main engine had been started and the vessel was proceeding under its own power. Searoad Mersey arrived alongside Webb Dock in Melbourne at 0715 on 22 March 2003 where repairs to the damaged port main engine commenced.
The report makes the following conclusions relating to the failure of Searoad Mersey's port main engine:
- A casting flaw found in the piston skirt fitted to number one unit 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 their service bulletin Piston overhaul of VASA 32 engines after 24 000 running hours and later overhauls.
- The critical manufacturer's Main Components maintenance intervals for VASA 32, 32LN and 32GD bulletin had not been provided to the vessel or its technical manager.
- The evidence strongly suggests that Wartsila Vasa 32 engines have had a history of piston skirt failures similar to that experienced by Searoad Mersey.
The report 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.
Related Documents: | Media Release |
|Date:||21 March 2003||Investigation status:||Completed|
|Location:||Bass Strait||Investigation type:||Occurrence Investigation|
|Release date:||24 December 2004|
|Report status:||Final||Occurrence category:||Incident|
|Highest injury level:||None|
|Type of operation||Roll-on/roll-off container vessel|
|Damage to vessel||Nil|
|Departure point||Melbourne, Vic|