Dumb Sheave for Sprits'l

[Dennis Marshall]

Does it matter if the dumb sheave for a sprits'l is drilled athwartships or fore and aft in the mast?

[NormMessinger]

Seems like if it is drilled fore and aft it will let your sail move to port or st'bd equally whereas if you drill it crosswise your sail will hoist on one side of the mast and have to wrap when you tack.

--Norm

[Todd Bradshaw]

Yep, fore-and-aft. Otherwise, every time you tack the luff will either tighten or loosen, depending on which side of the mast the halyard comes out. If you already drilled the hole crosswise, you can live with it as it isn't all that big of a deal, but front to back would be best. It also allows the tail of the halyard to be lead forward and secured to something at the bow if you want to rig a simple forestay to help stiffen the masthead.

[Mike Field]

On the other hand, if you're setting a jib as well (even flying) you'll have your forestay anyway, and you might want to consider taking one halyard to each side to act as shrouds. In that case you're probably better off running the sheave athwartships.

This is the way my fifteen-footer Aileen Louisa is rigged, and I've never had cause to want to change it.

[Dennis Marshall]

Thanks all for the reply to my query. Since I will not be setting a jib, I will drill the hole fore and aft.

Mike, thanks for the pic and email. I appreciate it very much.

Dennis

[skuthorp]

Aint this an amazing place! If you think about it long enough someone else will ask your question for you. Thanks from me too!

[pwilling]

You might think about a fairlead or dumb sheave made out of a shaped piece of hardwood, screwed to mast instead of hole through it which would weaken it unnecessarily. My 16' whitehall has a rig like this, the sheave on the fwd face of mast, snotter led through it with an eye splice on one end to go in slot on inboard end of sprit. Works fine. A sprit rig is inherently not going to perform the same on both tacks, because the sprit itself will upset the ideal shape of the sail when it is on the lee side. That will make more difference than how you lead the snotter I think.

[Todd Bradshaw]

I figured, maybe incorrectly, that we are talking about a dumb sheave through the masthead for the halyard. For the snotter, down lower on the mast, I would not drill a hole in the mast for anything except maybe mounting a thumb cleat for the snotter.

[Dave Hadfield]

I ran my dumbsheave fore and aft and brought the fall of the halyard foreward through a beehole in the stem (forward transom actually, since it's a pram).

It functions thus as a forestay even though I don't set a jib.

Gives me comfort when closehauled and the mast is ominously bent....