What about the crab claw rig?

[moderncrabclaw]

Hello, new to the forum here. I am 33 yrs old in Seattle, WA. I Have aquired the sailing bug, this happened a few years ago when i wanted to do more than just paddle around in my canoe. I have a 17 foot aluminum canoe built by grumman, and have tried several sail rigs on it (lateen, batwing gunter, steve mannings sticks and string sprit rig, simple bermudan rig) I have enjoyed each, then i came to a website one day trying to expand my knowledge of sailing. This website discussed crabclaw sails, their theory and i wanted one. How ever i decided that if i was going to build one, i would try my best to bring the design "up to date" . So armed with my understanding of delta wings lift, i re-disigned the sail for the smallest leading edge possible, and for the flattest surface possible. The resulting theory seem promising, and I have the sail frame built. I will be covering getting my sail material this weekend, and hopefully adding the new "mast" next weekend. With the winter storm season going here now i may not get to test it until spring... I have not really told many people of the design of this sail yet, as I am applying for a patent for this new rig, but I have no problem talking theory, and potential for this rig with you fine folks here.

You guys may find this link interesting...


http://potter-yachters.org/members/P...terMar2002.pdf


Will

[Trevlyns]

Welcome to the forum Will! Interesting reply and a useful link too, Be sure and keep us informed of your progress

All the best

[safewalrus]

Crabby,

Welcome to the forum, now don't get me wrong but the idea as I see it is to get it to drive you forward not upward, so whilst the flat bit may have some use (depends) the slimline leading edge seems out to me! surely the best drive is to cross the wind as near perpendicular as possible to get every ounce of drive out of the thing - a streamlined leading edge appears rather like a lightweight steamroller - not a lot of good!

[moderncrabclaw]

CRABBY,

Yes this sail when built right will let you tack into the wind , but will also sail on most points very well. it does provide a bit of bow lift, has a tendancy to reduce drag and a low healing moment. The two things that affect the performance of this sail are leading edge size and the ability to keep the surface as flat as possible. when the wind passes over the leading edge (when positioned correctly) it will curl into a vortex on the back side of the sail. this vortex is a low pressure area....like the top of a wing surface...just gets the low pressure differently thats all. This is all theory so far (until i get my boat wet with it on), will hopefully get field test soon...the weather in Seattle is not co-operating with my days off .



Will

[safewalrus]

I'd have a word with your local reverend and get him to explain to God that some things are more important than going to church on the Sabbath - and this is one of them! Also tell him because of this you need all the help he can get from the Big Man! I know he'll understand and help (so to will the Big Man once told, after all if the bible is to believed most of his senior staff used to be sailors and the like!!!)

[yipster]

came across some more pretty pics

[Trevlyns]

Very pretty indeed, Yipster! Thanks for the great link - I've book-marked it.

Best!

[safewalrus]

Yipster, I agree with Trev, bookmarked, fantastic thank'ee