cat design

[barry71]

hello

i am currently working on a 16 foot tri hull and am getting close to finish. i hope to sell this year. however i am considering a double hull for my next project. i have been wondering how to figure the design of the joining structure. i would very much like to hear your considerations on the subject of design, material, and expansion stress relief. i am thinking of a sail boat of close to 50 feet with an over all width of 20. thank you for your reply barry

 

[gwolf]

Don't make the front hull sections too long unless you use an additional forward cross brace. The side loads when turning are large for large boats - see the Philips sponsored composite boat disaster in the UK about 2 years ago.