Ship main engine failure investigation

I was recently called to a 130m, 5000 tonne ship to investigate the events leading to, and the cause, of an engine failure. The engine failed only a few months after being refurbished, so the ship owners wanted to know what had happened, how it had happened and what could be done to repair the engine. The only clue from engine data was a header tank alarm. The engine itself was so badly damaged that it was initially hard to determine what had failed. After removing a few more cylinder heads, the clues eventually led to a cracked liner causing hydraulic lock which broke a rod and filled the sump with coolant.

As you can see, the piston and liner on cylinder 9 of this V16 quad-turbo Mitsubishi diesel have disintegrated. Piston 10 was in tact with the bores scored but no signs of excessive heat.