How do you rig a Cunningham?

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Ernie Rogers

The addition of a Cunningham sail control has been suggested to me in this forum, but a search of the archives hasn't given me enough detail to rig one, and neither my big BOATUS nor West Marine catalogs give any info. What's needed to rig one? Thanks, Ernie Rogers

Cliff Ruckstuhl

cunning ham

The cunning ham is used as a sail control on the main. Any sail maker can install what you need on the main. What it does is it helps move the draft of the main. Forward for heavy air and back for light air. It works by pulling the luff of the main down which in turns stretches the sail cloth to move forward. You want the deepest part of the sail to be 50% aft of the luff line. The head sail will need to be about 40% back from the luff line. The main needs to be back 50% back for a few reasons one being the disturbed air flow from the mast section and the other it needs to work with the headsail like it's one big wing section. On my 23 I had come jam cleats on the mast and used a single line to pull down and jam it into place. The cunningham also takes out the wrinkles of the main sail.

Ernie Rogers

Thanks Cliff! Let me see if I have this straight:

There's already a cringle on the main between the tack and the reef. I assume this is for the cunningham. Correct? Then you either use a cunningham hook or just run a line thru this cringle to a jam cleat(s) on the mast? Do you need to run thru a block to get any purchase? Sounds like a downhaul, only you're pulling directly on the sail rather than a sliding gooseneck. Is that correct? Thanks for the help. Ernie Rogers

Greg Stebbins

That's it!

Ernie, You've got it in a nut shell. I did beef mine up to a 3:1 purchase with a hook to allow a secondary function. My cunningham can extend to the reef eye and be used to pull the sail down to the reefing horn in very brisk conditions. I attached an eye strap near the mast base and attached the conningham rig (2 single blocks, one with becket) to that. I cleat to a jamming horn cleat on the mast. Greg H23 Faster- S2 9.2C Impulsive

Ron Mehringer

Why not just uphaul?

My Prindle 16 catamaran had a 6:1 cunningham. It was needed because luff tension could not be adjusted via the main halyard. On most keel boats I would think that it would be most efficient to simply control luff tension (and thus draft) via the main halyard. On most boats the halyard already has the advantage of being run to a winch for lots of purchase. In one design racing, a cunningham is installed because there is a limit to how high the head of the sail can go up the mast (ususally marked by a black stripe near top of mast). Casual sailors don't have to worry about this. Those are my thoughts. If I'm missing something please chime in. I'm always willing to learn. Peace
Apr 19, 1999
Pearson Wanderer Titusville, Florida
Response to Ron re uphaul

On my H23, I can only increase halyard tension with the boat head to wind because the sail slugs tend to bind in the track otherwise (my sheaves are probably old too). You have to exert a lot of pull on the halyard to get the tension where you really need it, which is at the tack of the sail. The cunningham allows you to put the pull where it is most effective and it can be adjusted on the run regardless of the point of sail, without having to stop the boat. It really works. Peter S/V Raven
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