It was a top end overhaul, but the report states they removed one single main bearing for inspection. This is pretty common on overhauls I’ve done. You choose one main bearing as a representative health check.
It also said their policy was to replace any bearing inspected with a new one, which I’ve see vary by manufacturer and technician whether they replace or reuse. Where they screwed up was not checking the part number on the bearing shell they removed, which seems a crazy oversight, and making the assumption that since the con-rod journals were normal size that so should the mains.
I’m curious about this statement:
The Ocean Guardian’s local service managers and technicians stated that their normal practice when machining main bearing journals of a crankshaft was to also machine the connecting rod bearing journals throughout the engine at the same time, and vice versa when machining the connecting rod bearing journal surfaces.
I’ve only experienced an in-situ machining of a con-rod journal so can’t imagine doing all of the journals just because you are doing one. Is this common practice for engines where you can pull the crankshaft? To just go ahead and do all of the journals? Is that sort of “since it’s here…” and just to ensure uniform bearing shell sizes?