hot rod yacht

[jwboatdesigns]

Originally Posted by ned

hi ive read the book on chris and iv woundered how he kept the boat on its feet. I sail on the Shaw 30 cainting keeler Deep Throttle and we are always powered up with the 120sm kite.

In comparison to other Minis Navman had about 30% more sail area, but also a wider waterline beam and more ballast in the end of the canting keel. She was a pretty relaxed boat to sail, relatively that is, any 21 footer that can better 200 miles a day for 7 consecutive days is not really a holiday camp but she was fairly easy to drive. One of the things that helped her to carry all that downwind sail is that dynamic stability increases dramatically as speed increases so your ability to carry sail at 20 knots water speed ( S/l ratio 4) will be considerably better than it would be in the same relative wind speed at 10 knots ) S/l ratio 2) .
This was the first canting keel boat that I'd done, and I near scratched my head bald working out some of the more esoteric issues. I did the rigging load figures about five times before I reluctantly accepted that they were about what I'd have expected from a seriously powerful 30 footer.

Have fun with your project, I'd like to hear about it.

John Welsford

[ned]

i should be starting to build in 3 years or so as i am only 13

[jwboatdesigns]

Originally Posted by ned

i should be starting to build in 3 years or so as i am only 13

Good goal to have, in the meantime, join your local library, ask them to get some of the specialist magazines on high performance yachts, get a book called High Performance Sailing by Frank Bethwaite and read it from cover to cover, ( you need to do that about once a year as you will not understand all of it the first time through, and will get more from it each time you read it) and some of the boat design books which will teach you the basic calculations and how to draw a hull.
Its very likely that one of the Universities in Auckland will be starting a comprehensive marine technology course in 2012, two years after that you should be about ready.
You'll need maths and physics, english and art! Do your homework!

See you in 2014.

John Welsford

[ned]

i am thinking of getting someone like Rob Shaw to design the hull with a sipmle sail pan and then i have a boat builder as a father so we might take up the project together

[jwboatdesigns]

Originally Posted by ned

i am thinking of getting someone like Rob Shaw to design the hull with a sipmle sail pan and then i have a boat builder as a father so we might take up the project together

I'd still do the study Ned, if he two of you are that interested in sailing then a detailed knowlege of the design and engineering of performance sailing boats will be a big help to your career on the water.

John Welsford

[ned]

hi
I want some advice on these statistics 110 m gennaker, 40m main, 13m jib, 60m frac gennaker, 40m code 0 and 250 kg canting keel and 4 85kg crew on 50cm wings on a flat bottomed 3m wide down wind planing 650