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Unorthodox Genny


Roger Morrison

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Pasted from the other forum--no response:

First thanks to all for yer wonerful advice re my chopped mast and Gaff innovation! I got it ALL working, and am the envy of every--well some--bridge-locked sailers on the Trent Water-way!

Now, i wanna pick up sail area with a new genny to fit the shortened mast & main stay:

Luff...........18 ft (Total area about 120 sq. ft)

Leach........16 ft

Foot...........16 ft

Any obvious reason why this won't work?

Some have suggested the 'foot' is too long??

Existing jib is about 70 sq. ft on the same stay, but with luff of 16.5 ft.

ANY advice will be greatly appreciated! Roger

Any thoughts?? Roger

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Roger what are the overall measurements of the deck to fore stay attachment measuring up the the mast, Lower fore stay mount to the mast horizontally , And the over all length of the forestay from mast mount to lower mount. Also what kind of boat is this? LOA, LOD, LWL, and beam. Does she have a center board or fixed keel?

The measurements you provided will not make a very effective sail, other than a real big stay sail. (Keeps the boat into the wind while ar anchor)

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Thanks Craig,

Roger what are the overall measurements of the deck to fore stay attachment measuring up the the mast, Lower fore stay mount to the mast horizontally , And the over all length of the forestay from mast mount to lower mount. Also what kind of boat is this? LOA, LOD, LWL, and beam. Does she have a center board or fixed keel?

Mast is 17 ft (9ft cut off top) Stay attached to mast head.

Horizontal distance from forestay mount to mast: aprox 9 ft. (Boat is under snow...)

Foresay length: aprox 19 ft

Boat is: "Grampian 23" LOA: 23' 7"; LWL: Aprox 21' 6" LOD:??? Beam 8'

Fixed keel with a center board; Draft 28" Up; 5' down.

I lost 15 sq. ft. of sail with the chop job...not much really... So i want to recoup it with this larger Genny.

Current jib is about 70 sq ft. This one will be about 120 sq ft...

Thanks for your interest.... Roger

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  • 2 weeks later...

The trick with non-boomed headsails is a good sheet lead fall. The approximate location of this is found on a line running directly through the clew to a point about half way up the luff. An overly long foot will cause the lead to fall much farther aft then you have beam or even boat to sheet into.

Your fore triangle dimensions provide for 76 sq. ft. of area with the lead at 63 degrees to the LWL, intersecting the clew cringle. This places the sheet lead just aft of the base of the mast on a 100% jib and a pretty normal location.

Your jenny dimensions provide 113 sq. ft. of area (no foot or leech round calculated in either sail) and the lead for this shaped sail will fall about 7' 6" behind the clew cringle on the 100% jib, with it's lead about a 30 degree angle from the LWL. Also because of these dimensions the clew will be nearly 2' higher off the deck then the 100%. This means the sheet will need to fall around the middle of the cockpit side deck, where the boat narrows toward the stern. You should have enough boat left to place a track or pad eye where you need a block, but you will likely have to reverse the sheet's direction to get back to a winch.

My data about your little yacht shows a husky (heavily built, chopper gun with poly) 23' 3" (LOD) boat displacing 3,200 pounds about 35% of which was ballast. They didn't build many but do have a small following.

For your proposed new sail, I'd recommend the most hoist you can get, even if it touches the deck close hauled. This will get the sheeting angle forward some and provide the most drive and area, the deck acting like an end plate. Have the sail cut as flat as they dare so you can carry it over a wider range of conditions and points.

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  • 5 weeks later...

Playing with a few scale (they don't have to be perfectly accurate) drawings of your sail plan will reveal a genoa shape that you can get a good sheeting angle on. Maximum luff height is always a goal on headsails, as long as they don't foul something or permit the head to get to pointy (generally not a problem on a genoa). From your previous measurements you should try to adjust the leach (lengthen it) and foot (shorten it) dimensions to move the clew down, which will also move the sheet fall (where the deck pad eye or track lives) forward, to a handier location.

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