Airbattens- New Solution for Roller Furling Mains

by Sail-World Cruising on 8 Aug 2007 Robert Henderson was a racing sailor before buying a 40-foot pilothouse cruising so that he could take off for ocean passagemaking . The boat came with an in-mast furling mainsail, which he liked from a safety point of view, but hated from a performance point of view. The sail had no shape and negative roach. All the sail's performance characteristics were traded away so that it would roll into the mast easily.

As a result he developed and patented the AirBatten system that has battens that can be individually inflated after the sail rolls out of the mast and deflated in order to roll the sail back into the mast. By being able to inflate and deflate the battens individually, the sail can be reefed by deflating some of the battens and keeping others stiff. The Airbattens are stiff enough to support a mainsail with enough roach to overlap the backstay, while keeping the leech of the sail straight.

Roach and a flat leech give a main sail great power when going to windward and increased sail area for sailing downwind. In fact, Henderson has won some singlehanded races with his boat after replacing his shapeless underpowered sail with a full-sized main equipped with Airbattens.

The system can work with a mainsail made out of any material and construction layout. Mark Wood's UK-Halsey loft in Miami works with Henderson and builds these sails on request.

Here below inventor Robert Henderson supplies answers to the many questions you might have about Airbattens:

• The system can be used any sailcloth, the first sail was Spectra and the current mainsail is Dacron.

• The air is contained in a bladder made of Desmopan which is thermoplastic polyurethane… Very tough stuff.

• The battens are inflated each time you sail, from a compressor. The fill time is 1-2 minutes. The battens are deflated before you furl the sail.

• The control panel is 6' by 7' by 4' and contains the compressor and the total air logic system for inflating and deflating the battens at the touch of a finger. It is a 12Volt system, weighs less then 5 pounds and uses less then 5 amps for the 2 minutes that it is used to fill the battens.

• Tubes, four millimeters in diameter run from each batten down the leech of the sail to the clew, where they are connected to a coiled tube which moves with the sail as it is furled and unfurled. The coiled tube then connects to straight tubing which goes through the deck at the base of the mast and runs to the air logic control panel. No assistance is required as the sail is furled and unfurled. The 4 mill tubes lie with the leech line in the hem of the sail and are unnoticeable.

• The control panel has an inflate/deflate button, a pressure gauge and toggle switches for each batten, these toggle switches are used when reefing the sail.

• I have a furling Airbatten genoa on Windswept but it is filled manually from a hand pump each time it is used. Fill time is 20 seconds. It could be accommodated in the mainsail control panel.

• A manual pump could inflate a racing sail and it would take less than 20 seconds.

• The pressure is fully adjustable with the push of a button. Ideal pressure is between 15 and 20 PSI.

• I had more than 300 tacks/gybes on my original sail with no appreciable wear. I re-cut the sail to fit inside the backstay when I started cruising the boat. An Airbatten sail can carry up to 25% more sail than an unbattened furling mainsail even when cut to fit inside the backstay.

• We have no plans for full battens at this time, but will certainly consider them in the future.

• The in-mast furling sail can be reefed to any point since air supply is controlled to each batten. If the sail is furled in 50%, the top 2 battens are empty and the bottom 2 battens are inflated, thus giving you a well-shaped reefed main.

• When the first Spectra sail delaminated, the battens and tubing were still in good shape and could have been used again. Some of the tubing on the boom has been in the cold and the sun for fourteen years and is only now showing signs of wear.

• Since each batten can be filled separately, if you lose one, you still have 3 left. I have not lost the use of an Airbatten in fourteen years of sailing.

• Airbattens will work with furling headsails and yes they must be deflated before furling them in.

• I would anticipate running the plumbing from the forestay, along the foot and then up the leech. No amount of tacking will hurt the plumbing.

• I have a furling headsail. At the clew I have 4 valves, one for each batten. It is easy to deflate the batten that is being reefed.

For more information, contact Mark UK-Halsey Sailmakers' Florida loft: ukhalseymiami@bellsouth.net


Here Robert Henderson tells the background, long history and issues of the development of this innovative concept:

I have been sailing with the use of Airbattens since 1992, and here's how it all started.

In 1991, I was looking for a 40’pilothouse with hopes of sailing from Lake Erie down the St. Lawrence, out and around Newfoundland and up iceberg alley as far as I could get insured. Beneteau was making such a sailboat as a special order for Australia. I managed to have them ship a modified one to Canada. It came with an in-mast furling system. From a safety point of view, I liked it; from a racing point of view, I hated it. The sail had no shape and negative roach.

I set about to resolve the problem by experimenting with an Airbatten system. It allowed the sail to carry enough roach such that the sail overlapped the backstay. I raced the boat in single handed events and found the system so successful and easy to use that I decided to apply for a U.S. patent on the system. The patent was granted in August 1994 and I then explored the possibility of marketing it in the U.S.

I came to realize that the market at that time for in-mast furling systems was quite small. At most boat shows very few sailboats carried in-mast furling systems. Realizing that I was ahead of the market, I looked for an industry ally. Over the next year, I developed a relationship with Hood Spars and shared a booth at the 1995 Newport boat show with them. They thought Airbattens were a great way to expand their in-mast furling spar business. The Hood Spar division was then sold to Europe and dashed my opportunity to work with a viable industry partner.

At that point, I decided to let the market develop further while I sailed my Airbatten main and put it to the test for the next few years. I sailed down the St.Lawrence in 1997, around Newfoundland and north up the coast of Labrador past many icebergs and hundreds of whales, often shrouded in fog and buffeted by 35+ knot winds. It sounds somewhat daunting, but it truly was a magnificent trip.

Instead of returning to Canada, I decided to sail south and spent the next few years sailing the east coast of the U.S. from Boston to Key West with lengthy stops in the various sailing meccas such as Newport and Annapolis. I then spent a year in the Bahamas and eventually wound up in Miami, where the boat Windswept is based today.

All the while I flew my Airbatten mainsail. I found out rather quickly that Spectra de-grades rapidly in the hot Florida sun and before long I was forced to look for a new mainsail.

In 2004 I received a letter from George Weber. I remembered that I had received an inquiry from him back in 1995 concerning Airbattens. He had ideas similar to my own on Airbattens and I had sent him a video which demonstrated how the system worked. In his 2004 letter he was wondering what had became of the product in the intervening years. I told him what I had been doing and after several conversations we concluded that the Airbatten market was ready to pursue and we agreed to set up a company in the U.S. and market the product.

The first order of