A system failure occurred in my ship.
She was a Korean built ship, 3 to 4 years old.
Contamination of crankshaft L.O had occurred which was becoming black frequently. We checked for Possible causes of Contamination and finally we came to know that the contamination is due to the venting system of the pipe lines.
The vents of the scavenge drain camshaft L.O. tank are connected above the exhaust boiler platform. Since we have the scavenge pressure of more than 2 kg/cm2 none of the scavenge waste entered into the camshaft L.O. TK.
So finally a separate vent was provided for the scavenge drain tank and the contamination problem was rectified.