Sail Drive Scares

[John Casey]

Newbie here doing some reading on sail drives as I have never been around them much.

I'm sure the Lagoon guys here are all familiar with this case: Lagoon Litigation » The facts, the litigation, the arbitration and issues. and have covered it in much detail.

My questions is whether any sail drives have the equivalent of a prop-shaft coupler that would have saved the day in this case?

Thanks.

[Andrew Troup]

By "prop shaft coupler": do you mean a shear-pin arrangement of the type found on outboard motors?

[HappyMdRSailor]

Originally Posted by John Casey

Newbie here doing some reading on sail drives as I have never been around them much.

I'm sure the Lagoon guys here are all familiar with this case: Lagoon Litigation » The facts, the litigation, the arbitration and issues. and have covered it in much detail.

My questions is whether any sail drives have the equivalent of a prop-shaft coupler that would have saved the day in this case?

Thanks.

John,

Not tons of experience with them, nor a Lagoon owner... BUT I have worked on them, know the construction... what do you mean by "Prop-shaft coupler" and saving the day....

[boatpoker]

Originally Posted by Andrew Troup

By "prop shaft coupler": do you mean a shear-pin arrangement of the type found on outboard motors?

Wow ! absolutely stunning that someone would fork over that kind of money on the "Terms & Conditions" that basically state .... give your money then piss off !

[Pete7]

Originally Posted by John Casey

Newbie here doing some reading on sail drives as I have never been around them much.

My questions is whether any sail drives have the equivalent of a prop-shaft coupler that would have saved the day in this case?

Thanks.

John, I think if you picked up a lobster pot with a shaft drive mono then if the rope cutter fails you could do an equal amount of damage to the p bracket and shaft seal.

Pete

[boatpoker]

Originally Posted by Pete7

John, I think if you picked up a lobster pot with a shaft drive mono then if the rope cutter fails you could do an equal amount of damage to the p bracket and shaft seal.

Pete

You are right about that. I saw a 36' mono sink after a similar episode. The strut was torn off the boat leaving a 12" hole.

Thats why I have a polyurethane drive saver on my boat.

[Captain Bill]

I have autostream feathering props on my saildrives and they have pressed in rubber hubs like outboard props. Not many outboards still use shear pins. They are supposed to slip should the prop lock up under power. I have wrapped up a couple of Lobster pots under cruise power in Maine with no damage, but the engine did stall. This feature is a function of the prop design, not the saildrive. I have no idea if the Lagoon was equipped with these kind of props, but given what happened to the Lagoon, it might be a really good idea.

[colemj]

Our Volvo folding props also have pressed in rubber hubs that will slip/shear in that situation. In addition, the saildrive drive shaft spline itself connects to the Volvo engine flywheel through a rubber-hubbed damper plate that will slip/shear with overspec torque.

Our first line of defense is line cutters.

I don't know about the design of Yanmar drive/engine connections or their standard props.

Mark

[John Casey]

Originally Posted by Andrew Troup

By "prop shaft coupler": do you mean a shear-pin arrangement of the type found on outboard motors?

Andrew, not a shear-pin arrangement, but something like the "rubber-hubbed damper plate that will slip/shear" that Mark refers to.

I have even recently helped a boat owner put one back together after a careless passenger let a line foul the prop while he was reversing on a motor sailor. It was a v-drive, but I was thinking there must be a setup that will perform a similar protect function on sail drives.

The situation described on that site, kind of surprised me as actual able to occur, whether operator carelessness or not.

I'm seen/heard outboard props slip as Captain Bill describes with his pressed in rubber hubs. Perhaps an option box that this unfortunate owner did not tick.

Definitely something to be aware of.