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Does anyone know why the Volvo instruction book states that ‘the (engine) control lever must be in the neutral position when sailing’?(MD2020 – 2 bladed prop on B34). If left in neutral when sailing I experience vibration and prop noise, so I engage astern and the noise and vibration stop. Is that doing any damage? I can’t think how…. (Clearly the answer is to fit a folding prop I know!)
Bluejay
This is an age old debate I have often had!
I always used to engage gear to stop the spinning of the prop and hence noise, but then read it like you and thought I should follow instructions!I can’t think of any reason why it should need to spin freely, surely you are not causing much more drag if its stopped compared to spinning and surely if engaged in a fixed position you are saving a small amount of running wear on the gearing? I cannot think that it is causing any harm whatsoever if fixed.
Wish I knew the best answer too!
Steve.
I have a Bruntons Autoprop fitted to my B40 Ocean. I always stop the engine in the ahead position to feather the blades and prevent the propeller from rotating, saving wear on any gearbox rotating parts.
When we collected our B34 in Feb2001, we were told at the handover that
if you put the gearbox in reverse when sailing you may not be able to engage neutral when you want to start it. I havent experienced this, but I have had the gearbox jam twice when overenthusiastic crew go from ahead to astern too quickly, so I think it is a possibility. If it does jam, you need a very large wrench on the front of the crankshaft and a good heave to unlock it. I let it freewheel and you learn to ignore the small amount of noise.Graham
I was always told that if the propellor is spinning it is taking power to spin it and that this will effectively cause more drag than if the prop is stopped, so I always select reverse.
Also, if the prop is spinning then it whines, vibrates etc. and I would expect that this may increase slightly the wear on the gearbox and also effectively the gearbox hours will be more than the engine hours.
However I have found that it can sometimes be difficult to get the gearbox out of reverse when sailing quickly; slowing down makes it easier to do.When we were on our Easter break, we had a fantastic 7.6k through the water sail, glorious. I decided to engage the prop into forward gear to stop the spinning noise….I lost half a knot!
I was quite suprised at how it made such a differance to the speed, so I was more than happy with the noise seeing as i was getting some of the best sailing you could wish for!!
Steve.
I had the same problem with whinning when sailing with drive in neutral.
Contacted Opal and they recommended gear in reverse.
This seems to be OK, as a chartered engineer I would prefer to see the drive stationary rather than than being driven in reverse as is the case when in neutral.
Have also contacted Volvo Penta, suprised to hear there was an issue with noise and the resultant backdriving. Confirmed their literature statements from handbook and asked how to stop noise and will there be damage to drive with time, and would this invalidate any warranty?
Awaiting reply.
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