Aire Sawtooth Inflatable Trimaran
Sailor, do-it-yourselfer and small trimaran enthusiast Jeff Singer sent me the following information and pictures. I personally think this concept would be a great application for interior lakes … especially when camping.
Imagine how nicely things can be packed and tucked away for use during a camp out? But I’m sure there are many more water venues one could enjoy some fun sailing with this tri. Many Thanks for sharing it with us Jeff!
— Small Tri Guy
I’ve been trying out a number of different ideas for small sailing trimarans over the last five years or so. This year, I decided to see what an inflatable hull had to offer such a rig. Attached is a picture of the result “Anna’s Bananas”.
The Aire (and Tributary) kayaks (this one is a “Sawtooth” model) make the project much easier than it would otherwise be since all their hulls have lots of strong (17 pair in this case) cargo loops sewn into the seam between the bottom and the side tubes. This makes attaching rigid structures to the hull pretty straightforward.
This prototype sails quite well with a 52 sq. ft. sail and amas from Folbot. The rudder is my design and the leeboard uses Mark Balogh’s clever leeboard clutch. The raised seat allows for some hiking as opposed to being “stuck” in the bottom of the boat all the time. The mast is telescoping aluminum sections that are each about four feet long. The rig can be disassembled and packed into a bag about the same size as the hull.
Like all these projects that I talk myself into, it was more work that planned, but I guess that’s part of the fun.
More Details about Anna’s Bananas
The sail is a sail that goes on a “Bevin’s Skiff” out of the Alexandria Seaport Foundation. It’s incredibly cheap at $125.00, and decent quality (Neil Pryde out of Hong Kong). About 4 oz. Dacron. I like sails without battens because the sail can be wrapped around the mast while it’s still in the boat and then just tied off and bungeed to the roof rack. No battens to remove/install. There are some inexpensive alternatives if one like battens, such as the Laser 4.7 sail here: http://www.intensitysails.com/prsaforla47.html. $150.00 is pretty unbeatable.
The mast is sections of aluminum tube that have .058″ walls so the top section is 1.25″ O.D., the middle is 1.375″ and the base is 1.50″. With the .058″ wall thickness, the 1.25″ fits into the 1.375″ and the 1.375″ fits into the 1.50″. There is .009″ of difference between the O.D. of one section and the I.D. of the section below it. This is just what one needs to make a tapered mast that goes together and pulls apart with no effort but is still strong enough. I put a couple of pop rivets near the top of each section so that the tube above it stops about 6″ into the bottom tube. The tubing can be bought at onlinemetals.com or at www.texastowers.com. Both 6061-T6 and the 6063-T832 work fine, strengthwise.
The amas are from Folbot and are listed in their online store here under “Part-n- Pieces” “Show All” on the third page in. Folbot will also sell you the flat plastic piece that the amas buckle onto. That piece bolts to the aka cross tube (same aluminum as the mast) and can easily be made from a piece of plywood. The shape of the Folbot amas is not as good as some others since they make a little wake off their stern that travels in and hits the main hull on the side that may splash into the cockpit.
The Mark Balogh teardrop amas (at http://baloghsaildesigns.com/) don’t have this problem – they don’t leave any wake, but Mark’s stuff is often a bit pricier. Anyway the Folbot amas work well and if the wake is a problem they can be mounted aft of the cockpit so the wake just passes astern of the main hull. Hobie’s “Sidekicks” are mounted this way.
This second picture is of another rig I did two years ago on a Pakboats Puffin II hull.
It sailed well but I wasn’t entirely happy with the Puffin hull for this application as it is pretty bendy, especially with just one person in the center of it.
The sail in this rig was a Walker Bay 39 sq. ft. which was about right. The rudder was off to one side since there was no way to mount it on the center stern without modifying the boat. The tiller ended up being a “push/pull” style which worked fine since you were always sitting in the same place.
— Jeff Singer