In my 39 years in the business, probably 15% was spent chasing down and repairing junk in the garden spots of South America and West Africa. Most of my time was with EMDs. I’ve experienced many piston, liner, carrier, head failures but only one rod bearing failure.
Around '89, the company was rotating out the tugs from various divisions for overhauls. I reported aboard in Corpus to a recently dry docked and overhauled tug. 400 hrs on the overhaul. On the trip over to Tampa with a loaded barge, 900 RPM with floating .84 rack, the PME started lugging. I took the PME control and slowly lowered the throttle. As I was about to shut it down, the rod came through the hand hole cover. The scoring on the crankshaft had me highly concerned.
On arrival in Tampa, we were met by ABS, the company that overhauled, the engine parts supplier, VP of engineering and a machinist for the crankshaft repair.
It was quickly observed that the failure was caused by a mismatched bearing. They were all happy to find the simple cause. I was amazed the machinist declared the journal could be polished out and still use standard inserts. The VP of engineering declared “You highly talented professionals figured this out in short order. Has it occurred to you that if you have one mismatched bearing, you have at least one more?” The look on their faces was priceless.
I sailed on this tug for 12 years. The first 4 were challenging with the piss-poor rebuilt engine components.