Wing Sail

[gonenil]

Edited...advertising. If you wish to promote your sailing products...you will need to take out an ad. Cam

[BigCat69]

No one has ever made any money with wingsails yet, so I doubt the viability of advertising one. I am an advocate of wingsails, and have a number of wingsail links, but I wouldn't bet a plugged nickel on paying to advertise one. Tim Dunn, BigCat, Inc. dunnanddunnrealtors.com/Catamaran.html

[davidpm]

I checked out his website. It looks like the design requires an unstayed mast.

[BigCat69]

Originally Posted by davidpm

I checked out his website. It looks like the design requires an unstayed mast.

Yes it does. The calculations and plans for the unstayed masts have been examined and approved by the US Coast Guard's engineers at the Marine Safety Office in Washington DC.

I sailed a boat across the Pacific that had unstayed masts. The next owner sailed that boat around the world, and the current owners are on a voyage from the Seattle area to (currently) South America. All with the original rig. I regard unstayed masts as being safer and more reliable than unstayed masts, because crevice corrosion and metal fatigue can't dismast you.

[Banshi]

The two big disadvantages of a wing sail would be weight and a fixed geometry both in size and shape, has a way to address the geometry problem been created?

[davidpm]

Originally Posted by Banshi

The two big disadvantages of a wing sail would be weight and a fixed geometry both in size and shape, has a way to address the geometry problem been created?

His website has a pretty good shot of what the wing looks like. Very clever solution. It would be great if someone could do independant testing.

Yes he has a way to change the shape of the sail.

[sailingdog]

I'm not a big fan of wing sails, especially for cruising boats. Wing sails have this one major disadvantage...they can not be reefed or furled.

[Banshi]

"Yes he has a way to change the shape of the sail."

Does this include sail area? As pointed out, this is also a important factor especially when cruising. I guess some research is in order.

[BigCat69]

My wing sail design is more easily reefed or furled than a marconi sail, because each batten set is a reef point, and the sail has lazy jacks. I have made no provision for light air sails, because since it is easily reefed, I gave the boat a large working sail area. You could fly a free standing sail like a spinnaker (or on a tandem rigged catamaran, a square sail with no yard needed.) I wouldn't flog the boat with extra sail, though - I'd take down any light air sails early.

The rig needen't weigh very much, if you use carbon / vinylester or carbon / epoxy for the battens. The masts are engineered for a catamaran, which does not heel. For 1200 sq. feet of sail per mast, they weigh about 1100 pounds each. I wouldn't put it on a tender boat. It is worth noting that the center of the weights is lower than a marconi sail, and that the aspect ratio is about 2 : 1.

You could have variable camber, if you wanted to. I don't intend to have variable camber on the boat I am building. The sail hinge could incorporate stops which were adjustable, which would have to be adjusted with the sail furled. With some additional complexity and a bit of extra weight, you could rig high-test small diameter lines which acted as stops, which could be led to the bottom batten inside the sail, where they could be adjusted while underway.