In my Tornado days in the 1970's I saw a 20-21' LOA with a beam about 16' folding tri that sailed quite well. It was kit made of some sort of wood and looked like a Shark finish. The problem was mounting on the trailer. The center section was basically a hull similar in size to the amas with no ****. The hinges required the center hull to be mounted pretty high. The amas folded almost underneath the centerhull completely. It took about two hours to put together. It had a daggerboard in the center hull and kickup rudder and about the same size as the sailplan as the Tornado. He made the boat from plans in Popular Science or Mechanics I believe. I haven't seen one since.

thommerrill