Adjustable-Shape wing sails

[556Geoff]

I'm interested in anyones experience with the Chinese Dragon Wing type of adjustable wing sails. I'm planning on building a concept rig for some small ice boats this winter. The concept is attractive because of the large wind ranges these boats operate under (four to six times the true wind). Ice and land sailors don't have the dynamics of waves kicking the rig around and these boats would be a stable flatform for some interesting trials.

[Petros]

I do not have any direct experience with these rigs, but I have been reading about them and have been doodling something to build along these lines. I want to build one to put on my 14 foot sloop or to build a cat to put it on to try it out.

Are you referring to what they call a modified junk rig? They appear to have the advantage to be able to control the twist since each "batten" has its own sheetlet. They also do not have a main boom and I suspect the stress on the fabric is less since you do not have to pull so hard on the corners to control the shape. Also with the battens there are no larger areas of fabric to flap and flutter in the wind.

I am thinking of a modified junk that I can control both the twist and the camber of the sail at every point along the full height of the mast. I suspect it should work well for land sailing.

[556Geoff]

Info on this rig is at: http://www.trikini.com/Cheapwingsail/cambercontrol.htm --The rig is double sided and thus a foil. The battens are adjustable to change the shape of the foil.