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Wing Sails have been around for a while, and exemplary development
work has been led by Messrs. Clark, Hubbard and others in the "C" Class Catamarans. There seems little doubt that
these are now the fastest sails - a fact validated by the selection of 72 ft. Wing Sail Catamarans for the next America's
Cup contest. But the evident speed advantage of Wing Sails is somewhat conditioned by their considerable complexity, fragility,
and expense. This would seem to create an opportunity for "wings" that are simple, sturdy and less expensive. That
is the challenge that I seek to explore with the Hoyt 2 Tier Wing Sail.
Instead of being
a one piece foil, my Wing Sail idea employs 2 foils - one vertically stacked on top of the other, with each foil capable of
separate angular adjustment. As shown, both of these foils share a common free standing leading edge foil, which also houses
the structural mast. The 2 stacked foils are each separately and rotationally attached to the rearward edge of the common
leading edge foil, whose angle to the wind is controlled by the mainsheet. The camber controls that create the aerodynamic
curve that provides forward drive, are located in two horizontal "trays" which separate the 2 rearward "flaps"
or foils.
The advantage of having two separate stacked foils is that the upper foil, whose higher
leverage position most affects heeling, may be separately de-powered or completely neutralized while the lower foil retains
full aerodynamic camber for maximum forward power and pointing ability. Contrast this with the conventional cloth sail attached
to the rear of a mast, which to control heeling in a puff, must wastefully be luffed along its entire leading edge, thereby
sacrificing forward drive and pointing ability.
It is my belief that this 2 tier foil system
(Patent Pending) will provide easy and precise heeling control, leading directly to more speed, safety and comfort under sail.
Note also that the forward position and semi-balanced nature of this rig will significantly soften the swing of the boom during jibes, thereby reducing the dangerous
potential for head injury that conventional rigs must face. Adelante!
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Wing Sails Filled With Helium
In
pursuit of the light weight that is key to their efficiency, present day Wing Sails tend to be fragile, complex to build,
and expensive. But by utilizing the interior volume that is inherent in wing construction to be filled with helium, heated
air, or other lighter than air material, the same overall light weight wings can be achieved in simpler more robust construction.
Moreover the upward lift that is provided by lighter than air material can be harnessed to counter heeling and completely
avoid rig inversion in the case of capsize.
So, while conventional sails must accept the
adverse effects of heeling as a concomitant force that will always accompany the forward drive force of the sail, my idea
is to enlist the inherent vertical lift force of lighter than air material like Helium to reduce or counter the adverse effects
of heeling. The harnessing of lighter than air elements can be achieved with bladders or other means, but the net effect will
be a new found stability for sail craft, new ease in handling and new safety in the avoidance of rig inversion. Employing
black surfaces to maximize heat absorption from solar power in order to gain levitation from hot air chambers within the Wing
is another area worth exploring.
Anytime a sail craft is forced by the wind to heel, the efficiency of its
sail, hull, keel, centerboard and rudders is automatically decreased. In small sail craft this heeling decrease in efficiency
is controlled by crew weight "hiking out" to counter heeling. A more effective and more comfortable means of heeling
control would be to develop stability control within the sail itself - which my invention will facilitate.
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