Spinning Prop While Sailing

[fishsail18]

I have a Perkins 4-154, I'm not sure of the gear box? I thought I read it's not a great idea to let the shaft turn when the motor is off and to put the gear in Rev. to stop it from spinning. Is this a common practice?
Thoughts?
tnx

[a64pilot]

Depends entirely on the gearbox, some you are supposed to, some if you do, it will ruin the box.

[Stu Jackson]

a64 is right. Do a search on "transmission position" on this and any other boating website forum, and you'll get your answer.

[Calif.Ted]

Perkins normally use a Hurth transmission which specifies sailing in reverse to lock the prop. Yanmars with Kanzaki transmissions are sailed in neutral with prop spinning.

[a64pilot]

I think maybe some Kanzaki's are actually rebadged Hurth's? I believe mine is cause the boat owners manual says to place the transmission in reverse when sailing, but if you do that to a Kanzaki with cones, I believe that is not good for it?
Heck with it, get a folding / feathering prop, you know you want one

[Chalifour]

With our Yanmar 75hp, TD, once we kill our engine,we engage briefly in reverse and return to neutral position. Shaft and prop remains silent. Have done this since 2011 with no problem!

[Redpcx]

I have a Perkins with a VelvetDrive transmission. Engine instructions say to limit the time the prop freewheels the transmission.
I checked the VelvetDrive manual, and it says cooling and Lubrication will be maintained while sailing, freewheeling with the engine off.

Find out what YOUR transmission requires. Follow the TRANSMISSION manufacturers instructions. Most dont matter. If you have a folding or feathering prop, it DOES NOT matter, the shaft won't turn. I have heard many discussions. Not the big deal most folks love to argue about.

Stay Calm

[grae]

As others have said it depends very much on the make/model of gearbox.

The operation/maintenance manual for my Hurth ZF10 says:

3.5 Sailing or moving in tow

Rotation of the propeller while the boat is sailing, being towed, or anchored in a river, as well as operation of the engine with the propeller stopped (for charging the battery), will have no detrimental effects on the gearbox.

IMPORTANT
When the boat is sailing (engine stopped), the gear lever must be in zero pos-ition.
Never put the gear lever in the position corresponding to the direction of travel of the boat.
Locking the propeller shaft by an additional brake is not required: use the gear lever position opposite your direction of travel for this purpose.

So it would seem for mine the answer is either neutral and it'll spin of if you want to lock it then lock it in reverse.
Not going to get dragged (pun intended) into the discussion as to the merits of spin/nospin, I'm simply not smart enough calculate the drag of the prop spinning or not

[grantmc]

Originally Posted by grae

As others have said it depends very much on the make/model of gearbox.
The operation/maintenance manual for my Hurth ZF10 says ...

Exactly the same text/advice in the manual for the Hurth HBW range too.

[ur2slo]

I would venture to propose that the coefficient of drag depends upon the specific gravity of the said solution under effect of Coriolis parasitic induced drag at tip vortices affected by volumetric intake of C2H6O, along with a fair amount of ice!

[Mango51]

I have a Perkins 4236 with a hurth hbw 450-2R.
At the helm there's a plate that says keep in gear while under sail. except when running the prop alternator.

[Calif.Ted]

Originally Posted by a64pilot

I think maybe some Kanzaki's are actually rebadged Hurth's? I believe mine is cause the boat owners manual says to place the transmission in reverse when sailing, but if you do that to a Kanzaki with cones, I believe that is not good for it?
Heck with it, get a folding / feathering prop, you know you want one

It was my understanding that the "cones" would lock, the faster you are going the harder, and when an operator forced the shift to neutral it would cause damage. I did sail that trans in reverse before learning that Yanmar put out a TSB about always in neutral and when it wouldn't shift easily (think 5 kts. or so) I'd start in reverse then shift.

[transmitterdan]

Originally Posted by Chalifour

With our Yanmar 75hp, TD, once we kill our engine,we engage briefly in reverse and return to neutral position. Shaft and prop remains silent. Have done this since 2011 with no problem!

You probably have a folding or feathering prop.

[Don C L]

Do a search here, I believe there is at least one other thread about this topic.

[01kiwijohn]

shifting into reverse, with a Kanzaki, is not good for it; sailing at speed.
Shut off engine; luff up to slow below 2 knots, engage reverse,bear away and enjoy your sailing.
If you shift at, say, 4 knots or so, the cone clutch can engage with sufficient force that you may not be able to pull it into neutral when you go to start the engine next time.
I have a feathering prop and was instructed to just leave in neutral. But, I saw the shaft rotating while sailing. Many transmissions rely on the input shaft being driven, by the engine, to pump oil up to it and its bearing(s). The output shaft, spinning inside the gears, does not serve this function. For a few hours, maybe ok. For the 2500 NM from here to Hawaii, not so good.