Help!!!! ( daggerboard construction or daggerboard design )

[01639770993]

I am really young and i am interested in catamaran deign. I've been gavering inforamation on catamarans for a while but i cant seem to find anything on daggerboard construction or daggerboard design. I would be extremly greatful if anyone could give me any websites relating to this or some advice. Also does anyone know how to workout the daggerboard area.

thankyou

[tspeer]

Probably the best approach is to look at successful designs, understand the princples, and work things out for yourself. I recommend Kurt Hughes' catalog, http://www.multihulldesigns.com/ , as a good collection of multihulls of all types. John Shuttleworth also has some excellent articles at http://www.steamradio.com/JSYD/Articles.html . Also see Alexander Simonis' paper, "Case Study for A Modern Charter Catamaran," Saling yacht Design - Practice, Longman publishers, 1998.

I'm not sure what you are specifically looking for. With a catamaran, a good approach to installing a daggerboard is to locate the trunk along the outer side of the boat, possibly angling it inward somewhat to reduce heeling moments, where it offers minimal intrusion into the cabin area. You might also be able to arrange the structure such that in a wost case collision the trailing edge of the board will break out through the outside skin and not result in any breach of the hull integrity itself. Cruising cats can also get by with just a board in one hull.

Hydrodynamically, the daggerboard should be as deep as possible to minimize the drag due to lift and as narrow as possible to minimize wetted area, but is limited by the considerations of strength, the ability to retract the board, and possibly class rules. For beach cats, Reino Urala has some interesting ideas on a daggerboards that are deep, but kick up like centerboards: http://personal.inet.fi/private/muu/boards.htm . These could probably be adapated for bigger cats, too.