Catboat rig on a catamaran

Anyone seen or tried a catboat rig, ala Non-such , on a crusing catamaran?

[Laz]

Aren't most cats rigged with the mast near the center? I think this is due to the extra forward forces that get translated into downward pressure on the bows, but I don't know why.

-Dan

[tspeer]

There are beach cats that use a cat rig - the A class catamaran being a good example.

For cruising cats, I think the problem is structure and balance. If the center of effort of the rig is to be near the usual location, then the mast support must be further forward, and this means the main structural bulkhead must also be moved forward. This may restrict the size of the forward cabin and make for a (nearly) solid foredeck, whether you wanted it or not. If the mast is in the usual location, the lateral area of the hull must be moved aft. This could be done by changing the board location, but the lateral area may move forward as the boat is pressed and the bows depressed, with weather helm being the result. The boat will not lie ahull the same with the boards moved aft, either, and tacking may be affected.

Then there's the problem of supporting a cantilevered mast. John Shuttleworth covers this in connection with an Aero rig. See http://www.steamradio.com/JSYD/Articles/52AeroDesign.html

Not to say that you couldn't use a cat rig - but you'd have to engineer the whole boat to do it. There've also been biplane cat rigs, with Team Phillips being one of the most notable recent incarnations.

Thanks for your replies.

My idea was to have 2 Non-such masts, one on each hull. This would, I hope, reduce the stress. This would end up looking somewhat like the Hobie TriFoiler but on a much larger scale.

[SailDesign]

Your problem with two sticks, one on each hull, is that you will be hard pressed to find enough bury to keep the masts upright. Think of the depth of a Nopnsuch, and then see where you have that on your cat. If ya got it, fine, otherwise you _will_ break the boat, especially with the excess stability you have ;-)

Thanks I did not think about that. I will try to find out from existing cruising cats if I can have that height.

[Stephen Ditmore]

I think it can work, and I'll reiterate that you should look to the example of Team Phillips. The two masts can be stayed with wires from the partners of each to the hounds of the other, forming a big X, if there is a compression strut between the two masts at the hounds.

Tom Speer's concern about balance could be partially addressed by increasing rudder size.

[yipster]

whatever happens with team philips after al the mishaps? website gone also? will it try to race again?
http://www.ensta.fr/~dsim/cata1surfonbleupetit.gif
did find this high tec "ensta" at http://www.ensta.fr/~dsim/index.html

Thanks for the Team Philips references.

I missed it when it was first referenced in tspeer message. I went and look at some of the pictures and that's pretty scary.

[Polarity]

you can go an look at Pete Goss's site before it was shut doen using "the time machine" http://www.archive.org/

[grob]

Another way of supporting the masts with twin rigs is to use an A frame setup, see my we site www.fourhulls.com, for an example of how it might be done.

Also see http://www.mko.freesurf.fr/innovoile/historic_e.html for another a frame biplane rig.

Gareth

[Tad]

First they broke both bows off, fixed that, then pushed the mast steps through the bottom in early trials. Fixed that problem and went sailing. But Team Phillips was abandoned (breaking up in a gale) in the North Atlantic west of Ireland in February (February!!!) of 2001. Months later largish chunks of the boat washed ashore in Iceland.

A bit too big of a step forward?

Best, Tad.