Saturday 21 January 2017

Saturday,work day.

Decided to bite the bullet and pull out the port drive shaft.
I have had an annoying vibration under way for a few years now,it seems to be worse just where the helm position is situated.
We had a few of these on the Incat vessels and the experts put it down to the natural frequencey of the structure of the vessel being excited by something like an engine .
The source is usually quite small but enough to set it off.
In my case it seems to be the port engine set up.It only occurs when both engines are running at cruising speed together.

Son James has returned from Western Australia to start his own business so wa available to  do the hard part and pull out the flexible shaft between the engine and gearbox.
To transmit the engines 420 hp the shaft is substantial and there not being much room in there he was very welcome when offered to help.
We dismantled the shaft and were going to check the alignment but found there was considerable wear in the torsional vibration coupling on the flywheel.
We have taken it home and disassembled and need to replace the center bush and some large washers which ensure it guides the flexible shaft,hopefully this will make a considerable improvement .
I will have to get some advice on a suitable plastic material to replace the parts,not much use trying to get replacements as the obviously were not good enough .
A bit of a job for next week,unbelievable how many parts in the coupling made in Germany for me by the Vulcan company as a gift,the sales people organized it for me when they heard I was building my own boat.We used their products on the Incat vessels.
There was great competition from another German company Gieslinger who now supply Incat with a fiberglass part which weighs about one tenth the weight and should be cheaper than the massive rubber ones ,such is progress I see.
Mine has done 15 years but only 2500 hours so should still be ok.
Better make some parts for the other side too then,could be a winter project after the circumnavigation.

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