Peter Worsley  - Wingsail Experiments -

Attempting to control a sailing wing directly with sheets (ropes) as in a normal sail
is an inefficient method. Much more precise and automatic control can be achieved using
a tailvane (like a plane uses). Click here for explanation

There have been 3 methods I have tested to control the tailvane to obtain
optimum wing angle of attack.

This page describes Cable control and Radio control.
For the third method,
Auto-mechanical control go here.

"Twice Lucky" is a 13ft "Hawke Surfcat" grp catamaran that I have used for testing my wingsails.

On Barton Broad (Norfolk UK) testing cable control.

The symmetrical section wing  is 2.5ft x 8ft making 20sq ft. The tail is 1.5ft by 4ft
The tail pivots about one third back from the leading edge about 15 degrees either side.

The mast (which is from an Optimist dinghy) extends inside the lower portion of the wing and terminates
in a pin which pivots on a plate in the wing (diagram below)

This makes it easy to fit and the wing simply rests over the mast.

Cable Control

The tail was adjusted by a tube and cycle cable system "Bowden cable" to a single lever with neutral,
 wind from left, wind from right positions. With this system a disadvantage is that the rig cannot rotate
more than about 180 degrees, it has to be constrained from full rotation using a rope or sheet. and
there is a "gybe" when going downwind when passing through the wind.

The next system I tried was
"Remote Control" - A control box is mounted within reach of the rider
with a simple control which adjusts the wing for right or left tack.
The box transmits a radio signal to a servo in the wing unit which controls the angle of the tail.
This system allows control of the tail angle wirelessly, eliminates the need for cables or pulleys, and also allows the rig to rotate the full 360 degrees.
So when travelling downwind passing from the wind on one side to the other,
 where before there would have been a gybe with the rig slamming over 180 degrees.
The rig can now pass across the bow
of the boat smoothly to the other tack.

No more rope-pulling to control the sail.
Fingertip control is used and the sail finds the wind without any human intervention!


In use, the system worked like this. To sail the boat, all you need to do is move the lever in the direction
the wind is coming from. If you want to reduce the drive to zero, you just centralise the lever. You can go
in reverse also, just move the lever away from the direction the wind is coming from.
In this way the whole assembly is free to weathercock and it may be left that way safely in any wind if the control is left in neutral.
(For long-term "parking" the radio system is switched off and a pin inserted to keep the tail in neutral)

The system would be particularly suitable for the disabled, as it is much simpler
than present systems used for disabled sailing.

Next - the latest system. Auto mechanical control


1st Wingsail model 2nd Wingsail model Fullsize Boat Electric Power What are Wingsails? Contact
"Twice Lucky" wingsail construction Method Windmill boat tests (Sailing directly into the wind)

Any Questions? click here