10/13/2004 - I've been building this car-toppable trimaran using a 17' aluminum Gruman canoe since last spring. Early incarnations involved using a plastic kayak as an outrigger to make a proa, but in the interest of stability I changed the design to a trimaran. The outer hulls are of "stitch and glue" construction using thin plywood with epoxy/fiberglass at the seams to reinforce and protect them.
A sketch of the original proa design using a windsurfer sail, with child in flying outrigger hull.
View from above. |
And the side. The hulls are stitch and glue mahagony plywood with fiberglass on the seams. |
Me included for scale. |
Sitting on the crossbar seat. Max and Evan will ride here, or a heavy adult on a windy day. |
The seat at the end of the crossbar. |
A close-up of the retractable leeboards. Both leeboards are made of laminated marine plywood coated in fiberglass and epoxy. |
The junction between the crossbar and the amas. |
A detail of the crossbar-ama junction. Clevis pins shown. |
Crossbar attachment to the canoe gunwale. Clevis pins again. One side has a hinged arm for removal, the other side is fixed. |
Strut used for the base of the mast. Uses a windsurf mast foot. |
Back end of ama showing drain made from 2-liter pop bottle nozzle. Also used with water rockets |