Asymmetric outrigger hulls or amas

Designs (and general discussion) about catamarans, proas, trimarans, and other craft that do not need ballast to stay upright
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Asymmetric outrigger hulls or amas

Post by george_dimsdale »

I'm planning to build a drop in outrigger assembly to convert a canoe or similar small boat to a trimaran for sailing. I've looked at the designs offered by Chesapeake Light Craft and Storer and want to learn some more before I start cutting wood. I understand, with my limited knowledge, that asymmetric outrigger hulls may control leeway, rather than using a daggerboard. Can anyone direct me to information on asymmetric hull design and construction, especially as applied to plywood construction?

I live in southern Yukon in Canada, where our long lakes have long fetches for the frequent winds, so I will be sailing in chop up to 2 ft most of the time.

Thanks in advance for any help.

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Re: Asymmetric outrigger hulls or amas

Post by AlexQ23 »

Hi Georges,
There are few things to be aware of: Construction: I thing foldable plywood would be great for an outrigger. The principle is fully describe in the Gougeon brothers book and could be design by folding some hard paper as template.
Profile design: A good start will be to get inspiration by the Proa dagger board profile known as Proa 1 to 3 noted P20110, P20212 or P30212.
Lateral area: Normally 4% of the sail area would be sufficient but in the case of a canoe I will go a little bit further and take 6 or 7%.
This surely will help to go up wind but I'm really not sure that will be enough to make it through! Good luck !

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