Bi-Plane rig on a 20m cat

[scape]

hiya. this thread caught my attention because I'd like to see bi rigs take off for cats, they just make more sense to me; but i think a bi rig in a 20m cat would be tough to do, beyond designing some seriously awesome masts, i'd be curious how you'd tack-- i suppose you could depower one of the mains to assist with some sort of pivot.

here's a slick schionning radical bay 8000 bi rig with two jibs; looks like he rolls one jib up (towards the end) to help with a tack/not obstruct airflow.
http://www.youtube.com/watch?v=ciP_xuZHih0

[Skint For Life]

Originally Posted by Corley

I have a friend who is building a 12m biplane schionning cat with freestanding carbon rotating rigs It's not my cup of tea but it will be interesting to see how it goes he should be launching in 2012.

Thanks for the pictures. I am also interested in how this goes. Please keep us updated

[Corley]

I was down at the yard the other day to have a chat to the owner about building space for my next project. Mike has his boat closer to finished but is still waiting on his rigs to arrive.

[Becaris]

Originally Posted by Corley

I have a friend who is building a 12m biplane schionning cat with freestanding carbon rotating rigs It's not my cup of tea but it will be interesting to see how it goes he should be launching in 2012.

So, could you ask your friend the planned height of his masts off the water? I'm curious as to how much shorter he is going than a single stick. Also, what kind of boom setup is he planning? And... what is the name of the boat? Thanks!

[Corley]

I'll ask next time I see him.

[Whimsical]

Name is Bi-Polar
Mast height is about 17.2 mtrs above W/L. About the same height as the conventional rig
Boom is 4.5 Mtr???, don't have the drawing in front of me, rigid vang
Originally it was shorter but a longer boom, pushed the height up a bit to compensate for the shortened boom
Flexibility is to be 8% at a wind strength to lift the hull with 1 sail up, but i can't remember that either sorry advanced alzheimers i think
Aiming for about 50 Mtrs of rag including the mast area each stick. Big flat top main
The wing is 720mm at the base and 390mm at the top

Mike

[brian eiland]

Originally Posted by Becaris

That does seem to be my biggest problem. I have talked to a lot of people with single stick experience, but very few have ever sailed a bi-plane rig on anything the size of which I'm considering (about 20 m (60') length, cruiser).

The advice to go sail one, is good advice. I plan to charter Coolchange and try their biplane rig, and then immediately charter a single mast cat of about the same size for comparison.

Did you ever get that charter of Coolchange in??...seems if you were really interested in that rig you should do that.

Meanwhile there are some interesting discussions of Derek Kelsall's rig going on over in the forum at 'multihulls@steamradio.com'
http://www.steamradio.com/mailman/listinfo/multihulls

http://www.kelsall.com/TechnicalArticles/TheCatRig.pdf
(a stayed bi-plane rig)