Load on an on mast main halyard clutch?

[Scott T-Bird]

@Richard19068 , I assume your desire is to get the halyard out of the cockpit? I've seen plenty of boats with clutches mounted to the mast, so I doubt there is any issue with the loads, otherwise, there would be clutches designed specifically for masts and they might have additional screws. Also, there are pads that you can attach to the mast that can distribute loads.

If you have a block at the base of the mast that you can use, I would simply run the line through the block and up the mast to a cleat. Pulling up is half the load and far easier than pulling down through a clutch. You can use the clutch instead of the cleat, put I think I would just hitch the line to a horn cleat. That avoids all the issues with a clutch and is just as easy (and less expensive). That gets your line out of the cockpit! Either way, I don't think that the shear load on two 1/4" fasteners through the mast wall is really an issue. Tapping it is not difficult, either. Just make sure to get the drill bit that goes with the tapping size -that's key. I've done several and after the first, it's a piece of cake ... sort of like, well, you know ...

 

[Richard19068]

Thanks Scott.

The halyard is at the mast. The clutch was going to be used to temporarily hold the main halyard to free up the mast mounted winch so it could be used for the reef outhaul line when reefing.

Combined with my inexperience tapping holes, having an 1/8" wall thickness for 1/4" screws, the angst I go through drilling holes in my boat (especially the mast) and not really needing it that badly I just decided to forget it.

 

[JohnShannon]

Don't you have to factor in the righting moment of the boat? Windy enough and the boat is over on its ear somewhere in the curve from dead upright to 90 degrees there is a peak force. That is generated by the sails and effected by the halyard. Rope clutch manufacturers do suggest specific sizes for specific applications almost as if they have lots of experience with the problem

 

[Richard19068]

Don't you have to factor in the righting moment of the boat? Windy enough and the boat is over on its ear somewhere in the curve from dead upright to 90 degrees there is a peak force. That is generated by the sails and effected by the halyard.

I'm sure that's part of the equation.

Rope clutch manufacturers do suggest specific sizes for specific applications almost as if they have lots of experience with the problem

I couldn't find anywhere in Spinlock's information that specifically addresses mounting to a mast. Only decks. They do provide information about safe working loads at various line diameters but I think that's about what the clutch will take and doesn't address the mounting surface or method.