Inflated Wing Sails
They call it “IWS”—Inflated Wing Sails. The wing sail has been around for a long time, but it became famous after it was first used in the America’s cup by BMW Oracle on their trimaran (which won the cup) in 2010. Wing sails are generally rigid, and can’t change shape like an aircraft wing. They also provide more lift and have a better lift-to-drag-ratio than traditional sails.
Now, a team of three in Switzerland has come up with an inflatable wing sail. One of the three, Edouard Kessi, developed the first paragliders, has a history of sail technology and is a known Swiss sailor. He has been working on inflated wing sails for the last two years.
Another me mber of the team, Laurent de Kalbermatten, came from the world of flying, hanggliding and paragliding, and is considered the father of paragliding. He developed inflatable paragliding wings. It was Kessi and Kalbermatten who did the original development of the system.
The third member, Stephane Fauve, has expertise in sail design and sail materials.
The original testing of the IWS was done on a laser in 2015.
The website describes the system: “IWS is stable in every wind condition. There is no pressure on the boat‘s structure. IWS offers a smooth balanced new way of sailing. No more winches, halyards, shrouds or complex deck equipments.”
Videos of sailing with the IWS are on the website, but details of how it all works are not explained. The inflated sail has a retractable mast inside the wing that telescopes up and down. Raising and lowering the sails is done by raising and retracting the mast and inflating and deflating the sails. The sail has an opening on the forward (luff) end of the wing with fans that propel the air in. It is not explained, but I assume it means that mechanical power of some sort must control the telescoping of the mast and the fans. There is fixed-length boom on the bottom made of lightweight material.
It appears that the sail works quite well in the videos in both calm and high-wind conditions. The mast is free-standing and there is only a main sheet. No other controls are on the rig. In the videos, gybing can be accomplished by rotating the sail across the bow. That means that something must be done with the mainsheet, although that is not explained. It can be treated like a standard jib sheet, but you’d have to gybe it back the opposite way to gybe a second time.
For more on the IWS, go to inflatedwingsails.com.
Inflatable Windsurfing Sail
During research on the IWS, I found an inflatable windsurfing sail that was quite interesting. The sail, know as an iRIG is different from the IWS. It was really the mast and boom that were inflatable, and the sail area attached to them. It was all one piece and the real advantage was that it all fit deflated in one bag. Quite ingenious, really. Having been a diehard windsurfer for many years, I understand the attraction. The company says you can inflate it in minutes and mount it on a standard windsurfer. One of the real hassles of windsurfing was setup and break down of mast, boom, and miscellaneous connection pieces and lines. You had to have a big bag to carry all that stuff, along with spares, besides carrying the mast, boom and usually several sets of sails for different wind conditions. With the inflatable sail system, you just need the sail, the bag and a hand pump. I saw only one size, though, which means it’s good for a limited range of wind speeds, although they do have different sizes, but they promote them for different size people.
The rig is also promoted to mount on a standup paddleboard. Since inflatable SUPs are out there on the market, the two systems together can be quite convenient in terms of transport and ease of use. All you need is an inflator.
The company does offer a strap that goes around an SUP with a fitting to mount the mast on a board that doesn’t have a mast base like a windsurfer.
For more on the iRIG, go to irig.com.