thanks for the info. i'll book mark it. seems similar to omer's wing sail:
http://www.omerwingsail.com/
ben
> The swing-wing is a soft wing sail, essentially a junk rig supported
> by snowshoe-like wishbone frames to give the sail a double-skinned
> airfoil surface for its leading edge.
>
> Because it works like a junk rig, it's easy to reef -- just let the
> halyard down another segment, pull on the new downhaul, and you're
> there. With a portion of the "wing" in front of the mast, it's at least
> partially balanced. Because it has a great leading edge that naturally
> orients to windward, it doesn't suffer the questionable upwind
> performance of a junk.
>
> The design is by Bertrand Fercot, implemented on his Wharram Tiki 30.
> He reports that his boat tacks easily and sails faster than a standard
> Wharram Tiki 30. Details are at:
>
>
> http://wharrambuilders.ning.com/profiles/blogs/sailing-with-pha-tiki-30-n119-1
>
> Kim and Rudolph aren't really related to the design. I just like to
> mention them because they're the ones who convinced me it's a great
> idea. Kim is the person who first mentioned the design in this forum,
> and Rudolph is the person who pointed out a lot of benefits that I
> wouldn't have noticed otherwise.
>
> The original discussion can be found here:
>
> http://au.groups.yahoo.com/group/harryproa/message/7314
>
> ---
>
> For a quick summary, it's the only soft wing sail I've seen that:
>
> - Can be raised and reefed with a single halyard,
>
> - Can be reefed or stowed simply by letting out on the halyard and
> tugging on one of the downhauls,
>
> - Can use soft heavy-duty sailcloth because the wishbones, not the
> sail, create the shape,
>
> - Automatically shapes itself to the wind without hydraulics or
> additional control lines,
>
> - Has the added benefit of the low sail/sheet stresses of a junk rig,
>
> - Delivers the partially-balanced forces of an easy rig,
>
> - Reduces those forces further by creating a double-skinned airfoil,
>
> - Eliminates both the boom and sail track, which are noticeable
> expenses once you include all the attendant hardware, and
>
> - Uses a fixed mast (no bearings!) and thus: an easier mast to build,
> erect, and remove.
>
>
> Cons:
>
> - Not as efficient as a solid wing,
>
> - Definitely requires some labor for the creation of those wishbone
> frames,
>
> - Not as established as other designs that have been tested for years,
>
> - Will therefore likely require some experimentation, and
>
> - May be tough to use as a schooner rig; it looks like those
> mainsheets need to be lead aft, and not just to the windward cockpit.
>
> ---
>
> Personally, I'm largely sold on this design if I go for a single
> mast. I love the efficient shape, lack of many moving parts, and lower
> cost (if you don't count labor and experimentation).