Shaft turning while sailing, Perkins PRIMA 50M

[BentP]

Originally Posted by chris95040

This seems to be a controversial issue for some (dumb) people.

Different transmissions, with dfferent designs, have different ideal operating conditions. Read your manual and do what it says.

Some folks should leave it spinning, or immobilize it externally. Some folks should put it in gear (maybe fwd, maybe reverse. RTFM.).

Some folks claim to know 'the answer' for you even if they don't know your transmission. Those folks should be ignored.

And then again, some people, like yourselve, should think twice before they throw themselves at the keyboard, calling other folks stupid and ignoring the fact that they might just have education and experience on that particular field. Just saying....

[bigdog5]

I have the same problem with a hydralic box.I was down the boat in the river and noticed the prop turning in the current,so after a bit of thought and a rummage through the odds and ends,I screwed an eye in adjacent to the prop.I then hooked a bungee cord to the eye and wrapped it around the prop until it stopped turning (3 times in my case)and clipped it to itself.Works a treat,cheap,and the worst thing that can happen if you forget it is breaking your cord!😀

[jreiter190]

Originally Posted by chris95040

This seems to be a controversial issue for some (dumb) people.

Different transmissions, with dfferent designs, have different ideal operating conditions. Read your manual and do what it says.

Some folks should leave it spinning, or immobilize it externally. Some folks should put it in gear (maybe fwd, maybe reverse. RTFM.).

Some folks claim to know 'the answer' for you even if they don't know your transmission. Those folks should be ignored.

So,us dumb people should be ignored, while smart people such as you should be heeded? Tell us dumb people what happens when you manipulate the controls of a hydraulic system that has no power to it. Example; car engine dies. What happens to the power steering?

[Mike OReilly]

Originally Posted by jreiter190

Mike, you must stop the shaft from spinning while the engine is off if you have a hydraulic Velvet Drive, due to the fact that the tranny only gets lubricant when the engine is running. So, install a shaft brake and remember to release it before putting the transmission in gear or run the engine for several minutes every four hours or so to lubricate the transmission. I've seen many velvet drives burned out because of freewheeling, though, to my knowledge, no one ever knew how long it takes to damage the transmission. Play it safe and have a shaft brake installed.when the engine is off, you have no hydraulic pressure, so it is useless putting into any gear.

Thanks jreiter. I've tried to get a definitive answer on this in the past. I always get conflicting answers, but it has always bothered my that I couldn't stop the turning. On previous boats I always put the transmission in reverse while sailing to halt the free-wheeling.

I've gone through two manuals that I have for velvet transmissions, and I can't find any directions (either way) as to whether I should stop the shaft from spinning while sailing. Do you have any links I could read? As I say, it has always made sense to me to stop the rotation under sail. But on the flip side, if this really is a problem, then why would anyone fit a hydraulic transmission to a sailboat without providing a way to lock the shaft?

[chris95040]

Originally Posted by BentP

And then again, some people, like yourselve, should think twice before they throw themselves at the keyboard, calling other folks stupid and ignoring the fact that they might just have education and experience on that particular field. Just saying....

Originally Posted by jreiter190

So,us dumb people should be ignored, while smart people such as you should be heeded? Tell us dumb people what happens when you manipulate the controls of a hydraulic system that has no power to it. Example; car engine dies. What happens to the power steering?

WOW!!! I don't know who you people are, nor were you in my thoughts when I wrote my post.



To the OP, please, trust your manual.

[Lepke]

When I was young and sailed, I'm 67, most transmissions were manual and could spin w/o damage. I knew of several offshore sail boats that drove a slow speed low amp generator off the spinning shaft.

[billgewater]

OK. Hydraulic gearboxes can come to serious grief if allowed to spin under sail. I speak from expensive experience.
Three possible solutions.
1. Put at least two SS hose clamps around the shaft so that the screw bodies perfectly align. Then provide a piece of soft wood that levers against the shaft from a lower pivot point. Cut a notch in the wood that accommodates the screw assemblies of the hose clamps.
When you sail, turn up into the wind so that the shaft stops rotating and then push the piece of wood onto the hose clamps. This will lock the shaft as the hose clamp screw assemblies will remain in the notch. On my boat (16 m ketch) this works for me. If someone inadvertently starts the engine and puts the boat into gear, the soft wood will just tear out. Does require access to the shaft and a place to put the piece of wood. On my tub the wood is 2 inch by 2 inch pine and is about 1.2 m (4 ft) long. The notch is about 30 cm (1 ft) from the top. The assembly is near the internal exit bearing. A bit agricultural but it works and is super cheap. I am sure there are variations on this.
e.g. the wood lies across the top of the shaft with its default position locking the shaft. Held up when motoring.
2. Insert a standard motor cycle disc brake assembly near the gear box in the coupling. This would shift the shaft aft by an insignificant amount. Recheck if you have PYI type seals. You would only need a single flat disc. Insert it at the gearbox side of the shaft coupling. You would need hydraulic callipers that are spring loaded to be closed when there is no pressure. Mount the callipers off the gear box or some other place stationary relative to the gearbox. Connect the hydraulic line to the gearbox hydraulic line via the gear box pressure gauge plug or the gearbox heat exchanger lines. When the engine stops, the callipers will automatically close stopping the shaft rotation. When the engine starts, the oil pressure will rise (usually to over 100psi) and open the callipers. I have not tried this but if installed, then a sensor to ensure the callipers are open would seem a very good idea. An obvious modification is to use manually controlled callipers. Maybe even push bike brakes with some locking mechanism.
3. Chat to an engineer. Pay well for success.

[svfraidknot]

for a cheap brake buy a small pipe wrench fit it or the shaft wedge it in but dont forget about it ...

[Fine Tolerance]

Hi Sea Scamp, We are just up the coast from you and have a Perkins Prima but that fact is actually besides the point. Your question is a function of the gearbox, not the engine and unless the gearbox make and type is known no-one can give you an answer to your question. If you do not know your gearbox make post a picture so-as it can be identified. Chris95040 is 100% right. Other posters, while giving good information have not answered your question because no one knows what gearbox is on your prima. Back when new Perkins standard original offering was a ZF Hurth gearbox but as the Perkins Prima engines are over 20 years old (the Volvo Penta 22's kept using this engine long after Perkins stop releasing them as their Prima range) any gearbox could now be coupled. All it could have taken was a different adaptor plate.

My suggestion to you is to find out your gearbox type and download the manual,(if available, most are) off the web. It will tell you what you can and can't do.

Like Chris I am surprised that it took 12 posts before the fact that the gearbox make and model needed to be know before your question could in any way be answered. This is not to say that many of these posts didn't offer insight into other drive systems nor to denigrate the time and thought that these posters had put into their reply. Without these people posting replies this would not be the forum it is.

[jreiter190]

Nicely put, Fine Tolerance, I,for one, got many chuckles out of the posts you could tell came from experience instead of opinion. I think we covered a lot of different gearbox types. My 28 horse power Kubota has a mechanical Hurth,which I'm grateful for, though I could swear the transmission manual said to put in forward when the engine is off and under sail. Of course, I can"tell put my hands on as things disappear regularly on KAREN and, a year or so later, resurface so I'll check if that's right next time I see it.

[Captain Bill 3]

Automatic shaft locks are made for hydraulic transmissions. When the engine is started the trans oil pressure unlocks the the shaft which is locked when there is no oil pressure.

[Sea Scamp]

Originally Posted by Chris151e

Hi Shane and Tracy,
My boat is a 36' Islander Freeport with a three-blade prop, Perkins 4-108 engine, and a Hurth transmission. These are the tags re the Hurth transmission that came with the boat in 1979.
windows print screen

Thanks heaps for all the response's

especially the one from Chris, as my engine and gear bow is pretty well all original. and after the 35 years she has been in the boat, and had several owners, although a lot of the documentation is there, I could not find anything on this subject. So thanks heaps Chris, for posting up the warning signs. a least I now have a good lead to carry on with.

Also I hope that others can benefit from all the good ideas and advice that has been posted up, on this thread.

Hi Bigdog5, the noise of the shaft turning while sailing is what got me going on this in the first place, one of the main reasons for sailing is for the peace and quiet, Cheers I hope there was something in here for you too.


Kind Regards


Shane & Tracey


p.s 14 days till we back out there for a month, heading South with the whales from Morten Bay to Lac Mac

[Sea Scamp]

Hi
Good news, considering I am just over 2699nm away from my boat, I have narrowed the gear box down to either the HURTH HBW 10 or the HBW 250, Reverse gearbox, also I am lead to believe it is a splash lubricating type of gearbox, so It dose not matter weather it is in or out of gear, while sailing. But can be locked into reverse, by using the control arm.

I will update this thread once I am onboard and have given it a go, and confirmed the gear box make and model, and weather or not it can be locked.

Thanks Heaps for all the input


Cheers


Shane & Tracey

[HappyMdRSailor]

Originally Posted by Sea Scamp

Hi
Good news, considering I am just over 2699nm away from my boat, I have narrowed the gear box down to either the HURTH HBW 10 or the HBW 250, Reverse gearbox, also I am lead to believe it is a splash lubricating type of gearbox, so It dose not matter weather it is in or out of gear, while sailing. But can be locked into reverse, by using the control arm.

I will update this thread once I am onboard and have given it a go, and confirmed the gear box make and model, and weather or not it can be locked.

Thanks Heaps for all the input


Cheers


Shane & Tracey

Boy Shane.... Your vision is spectacular!

I can't make out the big E from 20 feet away...

Thanks for the update, and we look forward to the next one!!!

(ps, sorry this thread got to the edge of proper posting for no reason)

[ctl411]

Originally Posted by Mike OReilly

Thanks jreiter. I've tried to get a definitive answer on this in the past. I always get conflicting answers, but it has always bothered my that I couldn't stop the turning. On previous boats I always put the transmission in reverse while sailing to halt the free-wheeling.

I've gone through two manuals that I have for velvet transmissions, and I can't find any directions (either way) as to whether I should stop the shaft from spinning while sailing. Do you have any links I could read? As I say, it has always made sense to me to stop the rotation under sail. But on the flip side, if this really is a problem, then why would anyone fit a hydraulic transmission to a sailboat without providing a way to lock the shaft?

Mike, I have a velvet drive also. I found a manual online for Chris Craft. It states "under sailing or slow trolling conditions one or both transmissions can be left spinning. The transmission was designed for this". That said my boat had a caliper disk brake with a starter lockout to prevent turning with the brake on. I used it because the noise from the shaft. Now I have a Max prop and took the brake caliper off.