A friend of mine from the late 50 / early 60's was a former enginemen on a USCG Wind-class (ex-navy) icebreaker. The icebreaker show on the History channel last week started me thinking about him and I just looked up that class ship. It has three 10,000 HP Diesel-electric power plants, according to Fahey.
Jim told me that they checked the the "big end" conrod bearing temperature like this.
Stand beside the engine, facing the hole in the base through which you can see the crankshaft revolving with a big-end bearing attached. Make a circular motion with your open hand near the rotating "big end" until you are in sync with it. Move your hand forward and hold the rod end through at least one rotation. Then check the rest (11?). All should be the same temp.
(If the engines shown on the ship in the show were the same, that means thery were opposed-piston and one of the crankshafts was way up in the air!)
Since it took me six years before I was sure I could tie a squareknot properly, I would not want to do that in a rolling sea, and boy, do icebreakers roll!
Karl