Spin the bucket? (Reverse for Sailing?)

[Loren Beach]

My featherer is quite similar to the Max, and what we do on those light-air days is to make sure we are going at least 4 kts forward under power. Then shut down the engine and put the trans in reverse to lock the shaft.
Seems to work every time.
(Using reverse to lock the shaft is advice right out of the Universal manual.)
On any windy day, when we will be sailing at 4 kts or above, the movement thru the water should straighten out the blade pitch...

As stated in other threads here, be sure you have the less viscous grease that PYI advises (and sells).

Loren
M25XP, Martec Feathering two blade prop.

 

[Kim Schoedel]

Thanks to all! I appreciate the input.

 

[mherrcat]

This is probably not applicable to the feathering props, but the Universal Manual downloaded from this site seems to have somewhat contradictory statements regarding whether to leave the transmission in neutral or reverse when sailing under no power.

On page 40 it states, "Do not leave gear in forward when sailing. Gear must be in neutral for freewheeling or shifted into reverse to lock propeller while sailing."

On page 43 it states, "Caution: Transmission must be left in neutral when sailing, do not leave in forward gear when sailing without power as it will damage gear."

 

[Loren Beach]

Manual-wise, I see what you mean. FWIW, the several professional marine mechanics that I know all say to leave the Hurth trans in reverse to lock the shaft when under sail.
This would apply to reducing drag with a fixed prop, also.
Loren

 

[Mort Fligelman]

Proper gear

Everything I have read convinces me that reverse is correct.....

I have a mark on the top and bottom of my coupling.....if just out for a day sail I put it in reverse......if racing we shut down the engine in neutral.....align the shaft from the quarter berth, and then put it in reverse...

Pretty anal.....but it does seem to work....

FWIW

Mort Fligelman
Acapella 1987 E35-3
Boca Raton, FL

 

[WhiteNoise]

Reverse

I agree. Everything I have read and been told says reverse.

I also have the 2-blade feathering Max Prop and can attest that if left in neutral (which I have done once or twice unintentionally) the prop may not feather and will spin. I know this because, don't ask how, I heard it spinning. I put it in reverse and it stopped and feathered.

Hope that helps.

 

[u079721]

Hard on the tranny?

I agree. Everything I have read and been told says reverse.

I also have the 2-blade feathering Max Prop and can attest that if left in neutral (which I have done once or twice unintentionally) the prop may not feather and will spin. I know this because, don't ask how, I heard it spinning. I put it in reverse and it stopped and feathered.

Hope that helps.

A couple of times I too have forgotten to go into reverse right away, and later put the tranny into reverse to feather my Max Prop. But the "clunk" that I have heard always makes me wonder whether doing so is hard on the tranny? Maybe it is built to take it, but it sure sounds nasty.

 

[WhiteNoise]

Clunkidy Clunk, Clunk

That clunk happens when you go forward to reverse, etc. while motoring too. I would have to assume the prop is built to take it and as for the tranny, minus the noise, I wouldn't imagine the force made is any different than normal. Afterall, you're still moving a prop through the water, whether fixed or feathered.

I'm sure omeone out there has a more educated/calculated explanation than mine as I am making only an educated assumption. ... and you know what they say about assuming.

 

[Mike.Gritten]

We have a Westerbeke 4-92 (apparently equivalent to the newer W30) driving a Paragon SAOD transmission (1:1) which, in turn, spins a 3 blade feathering Max Prop. I have read this thread and was intrigued with the variety of responses. I vowed that I would do my own test and let you all know the results.
We were out for a great sail this weekend and I observed the following.
If I simply put the transmission in neutral and then shut the motor off, the prop remained spinning as attested by hearing a "swishing" noise. The noise instantly disappeared as I shifted into reverse. I followed the Max Prop directions and shut the motor off while still in gear and motoring along normally - no swishing noise so no rotation. I could put the transmission in neutral or reverse with the same lack of rotation noise, so I continued my old practice of sailing while the transmission is in reverse gear.
Incidentally, I noticed a speed gain of almost half of knot, from 4.0 to 4.4 knots while sailing a close reach in ~6-7 knots apparent, with fairly flat seas once the "swishing" noise stopped. Kind of cool!

 

[Kim Schoedel]

Thanks Mike,

I am going to try the test too. Don't believe I have been shutting down the motor while in gear with enough boat speed for the Max Prop to align for less drag. Next time out, I will give try the reverse method. I normally just make sure it is in forward and without a lot of speed. Sounds like you gained about a 10% increase in forward speed. That is a bunch in my book.

 

[Mike.Gritten]

Kim,

we see what we want to see sometimes and the conditions were a little fluky (not ideal, rock-steady wind speed/direction numbers). I could not "guarantee" the 10% improvement, but it was measurable and we certainly did record the 0.4 knot bump per my previous post.

 

[Loren Beach]

More locked-prop info

Some more (educated/expert) opinion on whether to keep the prop from turning while under sail.
This is from the current issue of Yachting Monthly, a very fine magazine.
This is the first time I recall having the mechanical logic explained so well.

LB

ps: now combined with earlier thread on this subject

 

[Team R]

Transmission in Neutral - Test It!

I have found that I lose about a knot with my E-29 in gear as opposed to letting it spin. A few things to note. 1. The transmition is hydraulic on my boat, so lubrication isn't an issue. 2. The packing will drip while sailing if the shaft spins. 3. There is more drag in turbulant flow versus laminar flow if the shaft is moving through the water then it is likely in laminar flow (at low speeds like when your sailing).
So if your transmission can deal with being in the neutral then you might be faster on the water. I recently switched from a 2 - blade epoxy prop that would not spin when the transmition was in neutral, which is a much better option.
Good Luck

 

[bayhoss]

Spin the Bucket?

In reading the info that came with my M12, the instruction state to leave the trans in neutral to prevent damage to the trans. Anyone else seen similar data?

Best,
Frank
E28 Valinor

 

[Seth]

Stop the spinning

We have a lot of posts on this, but a spinning prop produces much more drag than a stopped one, and for most tranny's a spinning prop will put you in a situation where the shaft is turning without the benefit of lubrication..2 good reasons to lock it in reverse when sailing!

Cheers,
S

 

[bayhoss]

Thanks Seth

Wow! Do I ever enjoy a swim in the information pool. Into reverse she goes!

Best,
Frank E28 Valinor

 

[Howard Keiper]

OK, I subscribe to the 'locked in gear' theory, but what makes reverse so special? If the tranny locks at all (as mine does), why shouldn't I just leave it in fwd?
Howard Keiper

 

[Loren Beach]

OK, I subscribe to the 'locked in gear' theory, but what makes reverse so special? If the tranny locks at all (as mine does), why shouldn't I just leave it in fwd?
Howard Keiper

Since this instruction is in my Universal M25XP manual and all (?) of these engines have a (stock?) Hurth trans..... you might have to contact Universal-Westerbeke or maybe ZF/Hurth for further information.
That's my best guess, anyhow.


Regards,
LB

 

[Emerald]

OK, I subscribe to the 'locked in gear' theory, but what makes reverse so special? If the tranny locks at all (as mine does), why shouldn't I just leave it in fwd?
Howard Keiper

My recollection on Yanmar transmissions (really we're talking a Kanzaki transmission most likely:

http://www.yanmarhelp.com/i_box2.htm )

is that they use a cone type clutch that can become stuck if put in forward instead of reverse to prevent prop spin. I believe if you scour the above yanmarhelp website, you can find a specific discussion of this, but not seeing it right off this morning).

 

[Howard Keiper]

I've got an Atomic-4 (direct drive)...I don't think it matters one iota whether it's in fwd or rev.
??

Howard keiper