I think that the main thrust bearing has been faulty for a while now so instead of the propeller pushing against that it has been pushing against the universal joint that was used to cope with any small misalignment between the prop and the engine. It isn't designed to take the main thrust of the boat! Last month's engine mount failure probably stressed the joints and bearings and so this weekend it finally gave up the ghost and went bang in a very spectacular way. It also bent some of the engine mounts so the engine is definitely no longer in line!
Unfortunately I was in the middle of a three point turn just below a weir with very strong river flows when we found ourselves with no power. Well, lots of power in the engine but none getting into the water!
Fortunately I managed to get a rope around a bollard on the bank and stop Relativity from crashing her way through the main shopping centre in Reading. A particularly narrow and twisty bit of the river Kennet.
After a Friday night spent in the town centre where I woke with a start every time another drunk staggered past the boat. I really didn't want to find myself cut loose and drifting down river in the dark.
Pete came over on Saturday and we managed to get the broken bits out. Later in the afternoon the nice man from Reading Marine came and made the time honoured whistling sound that means "that's going to be expensive." I'm expecting a quote tomorrow.
As we arrived back in to our moorings we found that the rest of our neighbours has got BBQs going and a gentle party was had.
Thank you all for your help.