The Birds and the Boats

siimat writes: "Wow, a bat-winged sailboat! Richard Dryden has produced "a variable geometry mast and sail that can adapt intelligently to changing wind conditions, and fold away conveniently after use without the need to dismantle. The inspiration has come from the remarkable wings of bats and birds." Too bad you won't be able to buy one until later this year..."

Comments

Currious

[CaptTrips]

I found that design uncannyingly similar to a da Vinci drawing. Does anyone else notice the similarities?

It'll never Fly

[Anonymous Coward]

Given how much "stretch" the fabric would have to have in order for the sail to keep half decent shape... this one is "not going to fly".... A far better example of efficiency are the wing sails used in Little America's Cup Catamarans.

Sail fabric needs to have minimal "give" in order to effectively translate the force derived from the wind... into a thrust vector. I see no way to adjust how much sag/bag is in this sail... and if it's a stretchable fabric... then you're going to loose much of your efficiency...

Looks cute... but the new focus for sailboards are kites... (Robby Naish is now only playing with kites)... the wind vector is both stronger and more consistent as you get off the surface and get the sail higher up... as to multihulls... the sails are getting to have higher and higher aspect ratio sails... more like the wing sails of the previously mentioned Little Americas Cup boats... and the vast monohull community... they're still so in love with wood... no .. I'll be nice.. by and large their efforts are along the lines of hull materials and shapes... as well as trying to get the least stretch in sail cloth by new materials... roller reefing is about to catch on big time for the mainsail (on the boom please and pray not in the mast)...

This is a cute experiment... but it is a evolutional dead end....

Why a bat, when a Star is just a good

[theEd]

I sail a Star boat(www.starclass.org) and this one-design class has used a flexible rig since the 1930s. The mast is extremly long and thin and tapers at the tip. The running backstays have both an upper and lower attachment and each is a adjustable so that one can change the shape of the mast changing the tension of the stays. There is also a rammer which allows one to move the mast fore/aft in the step.

Another thing is the sail needs to be cut correctly because in a situation in which one increases the bend of the mast during a heavy air condition could lead to increased fullness, which is the opposite of what one wants in heavy air. The Star main is shaped such that when the mast is bent back, most/all tension on the upper backstay. the main is "flat". As one shifts the tension from the upper to the lower, the sail is pulled in a way that increase the fullness of the main, which is better in light wind conditions. But I'm sure Mr. Dryden has thought of this.