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rbgarr
03-14-2011, 10:14 PM
Interesting! http://www.stadtdesign.com/swing_rig/swing_rig

Lucky Luke
03-15-2011, 03:48 AM
Thanks for the link! Very interesting!

These new unstayed masts, permitted by the performance of carbon fiber/ epoxy offer a whole new range of possibilities in rig design. In this case, I specially like the fact that in this one, like the rotating masts (limited rotation) of modern racing multihulls, the mast's aerodynamic profile, unlike round masts, can follow the sail shape. Very interesting too, and very new as far as I know, is this angle between the masts and it's rotation axis, well shown in this picture: http://www.stadtdesign.com/images/swing_rig.gif

We can also mention this rig (not very good looking to my eyes) that was developed years ago and had a whole sort of "boom+ bowsprit" huge assembly rotating the whole rig, jib an main together. I just can't recall the name they gave to that:o.

Question then is about the efficiency of a catboat compared with a two-sail rig...??? I know catboats have strong partisans, and "small America cup" catamarans have been single sail boats for years, just like last America cup r< winner, but the slot affect between main and jib has proven most efficient for both offshore racing and cruising.

The recent design by Nigel Irens of "Farfarer", also using 360deg. pivoting masts , but a couple of them in a (sort of) schooner configuration is also very interesting:
http://farm2.static.flickr.com/1224/5109341424_8c307e61a3.jpg.

This rig could be compared with a sloop whose fore stay has been replaced by...a mast, and whose jib's top has gone away from the mast.... Very special anyway. Main mast rotation is not a full 360 deg. because the boom hits the foremast, hence not allowing the jibe permitted by a catboat, but the foresail can.

There has been much discussion about it on Sailing Anarchy forum http://forums.sailinganarchy.com/index.php?showtopic=118399, with comments by Frank Blair, the owner of "Farfarer", and by Nigel Irens staff member.

Uncle Duke
03-15-2011, 06:33 AM
Eric Sponberg has done great work on freestanding, rotating masts. His modification of the Freedom 38 "Wobegone Daze" is particularly interesting (though expensive, I'm sure!)
http://www.sponbergyachtdesign.com/Wobegon.htm
http://www.sponbergyachtdesign.com/Masts/WOBEGON2.jpg
http://www.sponbergyachtdesign.com/Masts/WOBEGON3.jpg

Tangent: he also did a "false bow" for that boat, extending the waterline length and adding buoyancy - very interesting process:
http://www.sponbergyachtdesign.com/Wobegonbow.htm