Prop blocked or idling?

[sailfreak]

One of my sailing friends and I had a lively discussion on the advantages and disadvantages of sailing with the prop blocked or idling. Both our boats have fixed props, his has a conventional stern gear, mine a saildrive. I always put the gear in reverse immediately after switching off the engine. Although the difference in speed is only about a tenth of a knot and can hardly be noticed I feel more comfortable without the wear on gear and bearings and the noise of a turning shaft and gear. He keeps his prop idling as he fears standstill damage if it's blocked, and he likes to guess the speed from the whirring of the gear box. What do other people think or know?

<hr width=100% size=1>sailfreak

 

[A_7]

Oh no, not again! Oh well, I'll play. Always put in in astern and in gear once the engine is off.

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[Althorne]

Oh No let it run! I live in London and can't stand it when there's no noise.

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[A_7]

Good reason. OK, let it turn.

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[Althorne]

Yee Gods. They go sailing and want to sit there listening to props turning to guess the speed. Wish I'd thought of that, just think how much fuller my life would have been with something else to dom instead of just sailing........oh dear how much I've missed. /forums/images/icons/frown.gif Must be this London way of life.

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[isha]

some make use of the rotating shaft and connect a generator to it providing a charge for the batteries whilst sailing and the engine off.

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[Sailfree]

If its a Volvo gearbox some are specific that it should NOT be locked in gear. Someting to do with the way the clutches work.

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[tugboat]

This subject was dealt with very recently - have a look at page 2 on the Reader to Reader threads. Always a good idea to do a search before asking a question - saves a lot of repetition and irritation.

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[duke]

Hi All,

I have a hydraulic gearbox so putting into reverse doesn't work.
Any suggestions as to how I can stop shaft revolving ( I have an autoprop prop.).

Regards,

Duke.

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[john_morris_uk]

Yep, get yourself a shaft brake. There are various makes look through the small ads in the yachting press.

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[oldharry]

<...Put it in astern and in gear once the engine is off.>

And pay for a new gearbox when the clutch wears out.... like has happened on my boat.

This time I plan to fit a shaft brake.

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[Ships_Cat]

What engine/gearbox do you have?

John

<hr width=100% size=1>I am the cat but I am only 6.

 

[Twister_Ken]

Scientific advice

It has been scientifically proven, after extensive theoretical and emprirical work, that one is faster than the other. 48% of scientists have proven that it is faster to lock the prop, 47% that it is faster to let it rotate. 3% are looking for funding before publishing their results and being damned, while the remaining 2% are still conducting long-term in-water testing and are now somewhere between the Maldives and Zanzibar.

<hr width=100% size=1><A target="_blank" HREF=http://www.writeforweb.com/twister1>Let's Twist Again</A>

 

[Ships_Cat]

Re: Scientific advice

And others of us just make sure that prop drag is minimised by running the engine in gear with the throttle wide open.

John

<hr width=100% size=1>I am the cat but I am only 6.

 

[duke]

O. K.

Thanks.

Duke.

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[Magic_Sailor]

Funding advice

I have it on good authority that funding is available from the National Lottery for this type of study.

Magic

<hr width=100% size=1><A target="_blank" HREF=http://practical-business.co.uk>Click for website!</A>