15' sail catamaran

Forum for www.boatplans.dk. Guests welcome to post!
Post Reply
cridgie down under
Posts: 90
Joined: Sun Jul 27, 2008 6:57 am

15' sail catamaran

Post by cridgie down under » Tue Mar 01, 2011 7:07 pm

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)

john the pom
Posts: 192
Joined: Mon Nov 12, 2007 8:12 am
Type of boat I like: <-- Please read instructions to the left and delete this text. Then, tell us what type boat you like! :-)
Location: S.E. Queensland

Re: 15' sail catamaran

Post by john the pom » Tue Mar 01, 2011 10:32 pm

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.

cridgie down under
Posts: 90
Joined: Sun Jul 27, 2008 6:57 am

Re: 15' sail catamaran

Post by cridgie down under » Wed Mar 02, 2011 3:46 am

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)

User avatar
jem
Site Admin
Posts: 4864
Joined: Fri Jun 18, 2004 8:14 pm
Type of boat I like: Wooden
Location: Greensboro, NC
Contact:

Re: 15' sail catamaran

Post by jem » Wed Mar 02, 2011 6:43 am

It should be possible. Morten drew that one up. He should be along to comment on it shortly.
-Matt. Designer.

User avatar
Boatplans.dk
Design Reviewer
Posts: 141
Joined: Tue Dec 21, 2004 7:55 am
Type of boat I like: <-- Please read instructions to the left and delete this text. Then, tell us what type boat you like! :-)
Location: Denmark
Contact:

Re: 15' sail catamaran

Post by Boatplans.dk » Sun Mar 06, 2011 9:48 am

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 :)
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

Post Reply