Taking wing

This is a new inflatable wingsail (IWS) concept being trialled on the Swiss lakes. The man behind it is banker and former hang-gliding champion Laurent de Kalbermatten who, in the 1980s, created the first industrial paraglider.

This experience and the subsequent development of the ‘Woopy wing’ for ski gliders and ultralight aircraft led him and co-inventor Edouard Kessi to try the inflatable wing vertically on a mast.

The IWS wing, which is inflated and set on a telescopic mast, is being trialled on a 5.5m keelboat. It is a double-sided symmetrical sail with fans inside the leading edge that keep the compartments inflated and stable in a range of wind conditions. Its benefits are that it is freestanding and can operate without standing rigging or winches. No battens are used – sail fabric is used to create the ribs and fairing.

Check out a video of the IWS being inflated and sailing on Youtube. We will report in more detail on the concept in a future issue.