CROSS HEAD BEARING FAILURE

White smoke was observed from number 3 unit crank case door, of an MAN KZ, 6 cylinder engine. Engine was stopped and on inspection, found the cross head bearing had completely wiped and the white metal has melted down, and the bearing keeps have cracked. The broken bearing was removed and found cross head pin was also damaged beyond repairable limits. The booster pump for lubrication also found damaged and it was also removed. Since cross head pin spare was not available, it was decided to blank the unit completely and to proceed towards Honkong, as the ship had just entered South China Sea. The weather was rough. The connecting rod was removed, the piston was removed, cross head was locked inside and the ship proceeded to Hongkong. At Hongkong, the spares arrived and with the help of workshop, the unit was reassembled and the voyage was proceeded.

It was due to the failure of booster pump such a drastic damage took place.

Lesson learnt :

it is imperative that the parameters are monitored and maintained properly. Also the alarm systems to be functional and same to be tried out every week.Cut outs also to be tested periodically. In this case when the pump failed, the low lub oil pressure for the bearings, should have stopped the engine. Had the cutout was functioning, such drastic damage could have been avoided.