[Public-List] Prop while sailing, locked or free to spin ?

Jonathan Bresler via Public-List public-list at lists.alberg30.org
Fri Apr 22 15:46:48 PDT 2016


Folks,

In a separate email thread, Daniel Swords provided the following information

"Several years ago Yanmar issued a document stating that the engine should
be left in neutral while sailing. The reason, with the boat moving and the
shaft locked in gear by the drag against the prop (especially three bladed
props) owners were damaging their gear boxes trying to force them back into
neutral so they could start their engines. Of course another solution would
be to drop the sails before starting the engine but many people like to
know the engine is running before dropping their sails. When I bought my
boat it came with a Yanmar diesel and a three bladed prop and the previous
owner suggested keeping the engine in gear while sailing and since I am
always single handed I often started the engine before dropping the sails
and it sometimes took a lot of effort to get the engine out of gear, enough
that I could understand possibly damaging the gearbox doing so. I hated the
three bladed prop and changed back to a two bladed prop and I  leave the
engine in neutral while sailing. I  have not noticed the two bladed prop
turning (the three bladed prop certainly did) so perhaps it is just parking
its self behind the keel."

Google "Yanmar Advisory Notice # MSA08-003" dated 02/08/2008, which
definitely states the engine shifter should be left in neutral while
sailing with the engine off.

Sounds definitive.  Leave a Yanmar in neutral.  Do not use the transmission
to "lock" the shaft.

Guessing that the other methods of preventing the shaft from turning remain
available even with a Yanmar diesel.

Jonathan

On Fri, Apr 22, 2016 at 4:51 PM, Michael Grosh via Public-List <
public-list at lists.alberg30.org> wrote:

> That is interesting. I'm always amazed at engineering details that emerge
> when the rock is lifted to see what"s underneath.
> So the act of basically screwing itself through the water wouldn't negate
> the circular drag factor?
> Michael Grosh
> #220
> On Apr 22, 2016 12:03 PM, "Gordon Laco via Public-List" <
> public-list at lists.alberg30.org> wrote:
>
> > But of course it should be kept in mind that a windmilling prop generates
> > drag which is calculated as a function of the swept circle... Whereas a
> > locked prop generates drag calculated as a function of the blade area
> > alone.
> > A locked prop is significatly better with regard to sailing
> performance...
> >
> > Gord #426 Surprise (hard at it preparing PICTON CASTLE for sea here in
> > Lunenburg)
> >
> >
> > On 2016-04-22, 10:54 AM, "Wes Gardner via Public-List"
> > <public-list at lists.alberg30.org> wrote:
> >
> > > I just heard from Chris, for my motor/trans, he says I can let it
> turn...
> > >
> > > Wes
> > > Griffin's Faith #196
> > >
> > > On Fri, Apr 22, 2016 at 10:30 AM, Wes Gardner <
> wesgardner1952 at gmail.com>
> > > wrote:
> > >
> > >> From what I can tell, some transmissions don't like being turned while
> > the
> > >> motor is not running and some don't care.  Mine, from what I can tell
> > from
> > >> Chris Oliver is a "splash type" trans.  I will hazzard a guess that
> mine
> > >> wouldn't care (as long as the fluid is at the correct level).  Chris
> > >> commented on this while we were reinstalling my motor - he says that
> > these
> > >> types of transmissions are fairly sensitive to both "too high" and
> "too
> > >> low"  fluid levels...I have a Vetus 3.10.
> > >>
> > >> Hopefully others will have more...
> > >>
> > >> Wes
> > >> Griffin's Faith #196
> > >>
> > >> On Fri, Apr 22, 2016 at 10:23 AM, Jonathan Bresler via Public-List <
> > >> public-list at lists.alberg30.org> wrote:
> > >>
> > >>> Folks,
> > >>>
> > >>> Have heard from list members to lock the prop while while.  Several
> of
> > our
> > >>> racing members do so by putting the A-4 into gear after rotating the
> > shaft
> > >>> to "hide" the two blade prop behind the deadwood.   Some folks use a
> > >>> vise-grip on the shaft with the handle against the hull to stop the
> > shaft
> > >>> and prop from spinning.
> > >>>
> > >>> While sailing last night, I came up with a slightl different way to
> > lock
> > >>> the prop.  Wrapped the rubber strap from a rubber strap oil filter
> > wrench
> > >>> around the shaft till the handle was held against the hull.   Worked
> > >>> great.  Getting it off, required a good steady pull on the handle to
> > spin
> > >>> the shaft backwards a few rotations.  Had picked up a pair of these
> > strap
> > >>> wrench at Advance Auto in their discount bin for $5.00, I seem to
> > >>> remember.  Useful for removing the oil filter, as well.
> > >>>
> > >>> So what do you do ?
> > >>> Lock the shaft or not?
> > >>> If you lock the shaft, how ?
> > >>>
> > >>> Sample:
> > >>>
> > >>>
> >
> https://www.buysend.com/en-US/Product/Details/20985?U=2pc-silverline-500mm-6
> > >>>
> >
> 00mm-mechanics-plumber-rubber-strap-wrenches/&gclid=Cj0KEQjwl-e4BRCwqeWkv8TW
> > >>> qOoBEiQAMocbP9E1Gluu36O8RLAr6XhNvZTNK4zs6HU8NoPloic7aY8aAs0c8P8HAQ
> > >>>
> > >>> --
> > >>> Jonathan M Bresler
> > >>> S/V Constance Alberg 30 #262
> > >>> Annapolis/Eastport MD
> > >>> _______________________________________________
> > >>> These businesses support your Association:
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> > >>>
> > >>
> > >>
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-- 
Jonathan M Bresler
S/V Constance Alberg 30 #262
Annapolis/Eastport MD


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