Thanks David :)
I enjoyed the "Weaverbirds new sail " thread, a lot of great info and Ideas there, and the pics, it's actually just what I needed to move forward on a Proa specific junk rig that has dedicated windward/leeward sides.
That's why I was asking about rise, glad to hear I had that one right, this just might be doable.
Funny part is, apparently I was trying to make it work on the bad shunt(s) :)
The concept is pretty basic at the moment and only covers parallel panels:
wishbone battens with one way batten hinges (See A Below) about 1/3 of the chord from each end on the lee side of the wishbones, hinges open to leeward making wishbone wider at that area, may need to use two at each end.
sailcloth on leeward side only similar to an aero-junk, OR, wingsail.
Sail hauled across mast from shunt to shunt, something like a Yard Hauling Parrel?
mast line just aft of luff side batten hinges or between if two batten hinges are used.
sheets for each shunt run through deadeyes in the windward batten and attach at the back of the batten hinges (In between batten hinges if two are used at each end), pull on the sheet is on the lee batton.
wind pressure forces the batten hinges at the mast line open giving camber at leading edge.
Sheets attached to batten hinges at leach close hinges leaving aft ~50% of the sail flat.
it could even tack :)
Headsail is problematic but,
Headsail Concept 1)
a pair of roller reefing headsails, one for each shunt on their own yard/halyard, 2 panels, cone shaped centre batten rolo-reefs both panels simultaneously, or a single panel rolo reefing from the lower edge.
Headsail Pipe dream, er, I mean concept 2)
wingsail, run fabric all the way around the wishbones and fabric extends over top wishbone/yard and back down inside the sail, wishbone tilts on each shunt fabric attached to mast so when the sail is hauled across the mast fabric pulled tight at the luff and released at the leach so the wishbone/yard can tilt, I suppose it could be flat topped but I'd like a bit of an angle even if only because it would look better
pretty barebones yet and i doubt it makes much sense except to me.
A) one way batten hinges would be similar to those that David developed, I'd make the battens themselves out of wood, rectangular, hinges would be rectangular aluminum tubing slid over the battens, the hinge would be hardwood to start off with, with taper on only one side and probably not much.
I don't think twisting in the batten pockets should be a problem with wishbones.
A few things that don't really fit in or need to be addressed:
Headsail concept 1 might be detachable for use as stormsail since it would have it's own yard and halyard anyway, let you drop the sail bundle on deck for least windage and lowest center of gravity.
weathercocking could be a real problem if one caught a gust at the wrong moment.
rope stops at the mast lines might be tightened/loosened to change camber of the rig, if not on the fly than fairly quickly.
The wingsail route would eliminate a lot of drag, the Aero_junk route could look pretty amazing though :) that's always important.
needs a lot more thought, not to mention a fair amount of luck and a couple minor miracles.
Bill