The vessel had a high-speed diesel generator engine upon which routine overhaul and maintenance was being done by the ship staff. While boxing up the big end bearing, the thin shell bearing was assembled in a wrong way.
It is well known that the top bearing shell has an oil lubrication passage (hole) such that the oil can cool the piston as it travels up the connecting rod. The bearing shell was misplaced whereby the top shell was placed in the big-end bottom and the bottom shell was placed on top part of the big-end. After about 2 to 4 hours of operation, the piston seized in the liner. The bottom end bolts failed as the crankshaft continued to rotate and the bottom end smashed through the crankcase causing an explosion.
Although a bad design feature allowed the shells to be wrongly fitted, The engineer responsible should have realized that the hole in the bearing shell now fitted in the lower half of the bottom end would not serve any function and investigated further.
