Transition Rig

The concept
Other ideas

Transition Rig

inspired by the wings of bats and birds:
shape-changing and foldable


Think of an umbrella: we carry it around folded until it rains, and then open it in a few seconds to give us shelter. When the rain stops, we fold it away again so that it doesn't get in the way. The Transition Rig follows a similar utilitarian logic - when you need a sail you can raise it quickly and gain power from the wind. When the voyage is over, or if a storm strikes while you are at sea, you can quickly fold the rig away.

The idea for the Transition Rig came 30 years ago, and I now have successful prototypes for smaller craft such as windsurfers, kayaks, canoes, and dinghies. I suggest that a similar approach can be applied to bigger ships too.

When you have a mast that is jointed to enable raising and lowering, other things become possible. You now have a variable-geometry rig with the potential to change its shape in use and according to conditions. No doubt you have watched birds soaring in thermals and along hillsides facing the wind and marvelled at the way they continuously adjust the shape of their wings in gusts and lulls. The Transition Rig gives the same possibilities for shape-changing in use.

My name is Richard Dryden, and you can contact me by e-mail at

The concept Versions Joints Sails Other ideas