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 Post subject: 15' sail catamaran
PostPosted: Tue Mar 01, 2011 7:07 pm 
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Joined: Sun Jul 27, 2008 6:57 am
Posts: 90
Hi Morten, although I am not new to jem i have just recently discovered this part of the forum.I am very interested to know if the 15' sail cat can be modified and reduced down to an approx.
length of 12' .in my mind i would like to maintain the same width etc.just reduce the length .
Is there a formula to apply ? or could the reduced size be offered when purchasing the plans
Kind regards
Cridgie down under (Ray)


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 Post subject: Re: 15' sail catamaran
PostPosted: Tue Mar 01, 2011 10:32 pm 
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Joined: Mon Nov 12, 2007 8:12 am
Posts: 192
Location: S.E. Queensland
I don't know if it would work but cannot see why not. I would try marking out the reference lines. The ones that are usually 12 inches apart, to less than 12 inches ie minus 1/5th of of 12". Should not affect vertical measurement (as you look at the sheet) of the offsets . I could be off the mark but I reckon it would be a starting point. You would have to consider lessening the height of a mast in the case of a sailing craft. Any tight bends would become tighter still. Drag and all sorts of other stuff would be affected.
Cheers John.


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 Post subject: Re: 15' sail catamaran
PostPosted: Wed Mar 02, 2011 3:46 am 
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Joined: Sun Jul 27, 2008 6:57 am
Posts: 90
Thanks John for your input that was the way i was thinking too however i will anxiously wait for either Matts reply or mortens reply (hopefully both ) before i proceed
thanks once again for your prompt response
regards Cridgie down under . (ray)


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 Post subject: Re: 15' sail catamaran
PostPosted: Wed Mar 02, 2011 6:43 am 
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Joined: Fri Jun 18, 2004 8:14 pm
Posts: 4855
Location: Greensboro, NC
It should be possible. Morten drew that one up. He should be along to comment on it shortly.

_________________
-Matt. Designer.


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 Post subject: Re: 15' sail catamaran
PostPosted: Sun Mar 06, 2011 9:48 am 
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Design Reviewer
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Joined: Tue Dec 21, 2004 7:55 am
Posts: 141
Location: Denmark
Hi Ray,

I am sorry for the late answer, I just returned from a trip to UK and had a very poor internet connection there.

The catamaran is a fine balance between load and buoyancy. If you load it too much the hulls can't carry all the load which means that you loose the low drag the catamaran design offers.

I am afraid that what will happen if you scale down hull is that there will not be enough buoyancy, and therefore you will not be able to benefit from the catamaran design when rowing. The boat will float all right, but the waterline will be higher than the bottom between the two hulls.

If you are going to make the cat shorter you will also have to lift the bottom between the hulls. It will of course also be possible but require some more customization.

Please let me know if you have more questions and I will be happy to answer you, next time quicker I promise :)

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Morten Olesen - Boatplans.dk
Website: http://www.boatplans.dk/
Blog: http://BoatBuildingArticles.com/

Check out my author page at Amazon and browse for boat building books: http://www.boatplans.dk/news.asp?news=amazon


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