Trailing a prop.

Someone was looking for a shaft brake , so a prop cpould be trailed.

http://www.controlmastersinc.com/kobelt.htm

Makes small (but maybe big enough) for sail boats and BIG ones .

Genuine marine , not Yachtie , so priced accodingly.

Shaft brakes come up once in a while. I'm aware of Kobelt and there are others.

As FF points out they are pricey for most of us.

It just occured to me that if one didn't want an auto release/application unit you could simply rig a heavy clamp on collar to the shaft with a disc secured to the collar that had several holes drilled in the circumference and use an arm with a clevis and pin arrangement to a very solid point on the vessel structure, the stringer. That way if someone wanted a prop locked in a specific position for reduced drag it could be done.

Not all vessels of course have the shaft room to do so .
No, I've not done it, twas just an idea.

Go Karts use cheap disc brakes , should someone want to just build a custom disc and mounting setup.

We use a pro built prop brake on out 90/90 that locks into a notch so the prop (2 blade) is indexed properly behind the deadwood.

Std procedure is to hang the start key over the pulled prop brake handle.

What about a piece of chain and a large pair of vice grips.
Worked for me.

SD

Asking how to stop the propeller from turning?* Just put the transmission in-gear with the engine turned off.* Am I missing something?* This was standard practice when racing auxiliary-powered sailboats.

If you have a mechanical gearbox that would work. Those small gearboxes, Hurth and the like, are mechanical.

Most of the gearboxes here are hydraulic, so putting into gear will have no effect all. It takes hydraulic pressure to lock the clutches or bands. Without the engine running there is no hydraulic pressure. The propellor will freewheel.

Thanks for reducing my ignorance.

"Without the engine running there is no hydraulic pressure. The propellor will freewheel."

If you can't turn your props by hand when you are hauled out, it is unlikely your forward motion will turn them, so you won't have to put a brake on if you lose an engine, whatever transmission you have.

With regards to keeping a shaft from turning if the engine has to be shut down, we simply tie it off. A number or years ago I installed brackets cut from a length of heavy aluminum L-extrusion and mounted them on the underside of the heavy cabin floor beams directly over each shaft coupler. I drilled a hole through the extrusion and mounted a stout shackle in it. So if we have to tie off a shaft (we've had to do it three times in the 12 years we've had the boat) I simply wind a length of strong line around the shaft coupler a bunch of times and tie it off to itself and then run the line up to the shackle and tie it off there.

We then hang "remove before flight" red streamers on the power and shifter levers for that side to ensure we don't start the engine later and inadvertently put the transmission in gear.

Those vice grips that incorporate a bicycle type chain will work well.