I'll add an interesting story here.
Many years ago I considered myself lucky to be sailing on the last Doxford ever to go into service. Doxford had pushed the envelope as far as they could to produce an engine that they hoped would compete with the likes of Sulzer and Wartsilsa and so to try to drag the opposed piston idea kicking and screaming into the competition they built a three cylinder medium speed opposed piston engine. Fascinating to watch and an unbeleivable crankcase abd turned upside down everything I knew about engines up to that point. It took about 10 minmutes to remove the top piston and get into the liner but about 2 hours to change a dam injector!! Anyway the big problem was ring wear due to the increased speed and subsequent loss of compression. The answer was to pour buckets of oil around the top piston during manoeuvring and seal the rings to ensure reliable starting.
One morning at about 02.00 hrs we were manoeuvring in to Eastham Lock at the start of the ship canal and the Second Engineer was in the ECR. I had gone out onto the aft deck for a smoke and watch us go into the lock before going down to relieve the second again, I was a fiver at the time. The old man had been warned time and time again by the Chief that starting was not as reliable as it should be and this wouldn't improve until we could re-ring the engine so allow plenty of time for manoeuvres. As we went into the lock and the rear gate flew past me on the aft end I thought "That's a bit brisk", then I heard the "chuff, chuff, cafuff, cafuff" from the funnel door as it tried to start. Nothing. Then again chuff, chuff, chuff, cafuff. Again nothing. By this time I was taking the Board of Trade appropriate steps in the circumstances, i.e. very large ones! As I reached the tops she went again, chuff, chuff, chuff, carumble, rumble, rumble. How we missed the forward gate I have no idea but someone was on our side that night!
When we explained how close it had been to the old man he didn't seem in the slightest bit phased out by it all!! He was Lithuanian so probably didn't realise anyway!!