A-Cat based trimaran from Lunada Design
GALLERY | Click images to enlarge
Long time Proa File contributor Chris Ostlind is working up a new ultra-light, hybrid human/wind powered tri based on an A-Class cat hull. Now that’s what we call recycling. Chris says:
I’ve been pretty much out of the design arena for a little over two years now, so I was excited when I was asked to develop a set of amas for a fast hybrid function boat being built by my friend and multihull guru, Mike Leneman. Mike’s boat is based on a hull from an A-Class catamaran, making use of a Hobie Mirage drive, as well as a snappy sailing rig for propulsion and the whole idea of a super skinny, and quick main hull pretty much lit my slumbering creativity.
The new boat features a modular aka/ama modular unit with mounting technology directly from the high performance Seacart 30 racing trimaran:
The aka beam ends are tapered, four sided conical shapes with matching receiver sockets in the vaka hull to accept the aka ends when being assembled. This set of shapes prevents any binding of the akas in their pockets and ensures that they will slide home firmly. The assembly is then kept in place with discreet water stays, which not only hold the thing together, but they redirect the loadings away from tensioned beams to forms that are now in compression… allowing for lighter fabrication and an overall lighter boat.
Another design approach in use for this boat are the strongly shaped asymmetric amas. We haven’t tested this solution in the water yet, but we anticipate that the wetted shapes will provide enough leeway prevention to preclude the use of a keel appendage.
The great news is that even if you don’t have a spare A-cat hull lying around, Chris has developed a plywood/epoxy home builder version of the boat. Follow the development here on facebook.
From Chris Ostlind | Lunada Design
Thanks, Michael, for publishing the brief material on the new boat design. I’d like to emphasize that Mike Leneman originally developed the idea to use the A-Cat hull for this prototype project and that I was asked to create a lightweight design solution for the amas. After things were rolling along, Mike suggested that we create a complete boat for the homebuilders who might be interested in crafting one of these bad boys for themselves. With A-Class cat hulls hard to find on the used boat market, I drew a new hull that could easily be built and would function in the same capacity. The modularity aspect came from my desire to extend sailiong and boating through the use of a component solution so that small craft owners could really spread their boat bucks a long way. The successful XCR sailing canoe design makes use of the same philosophical design idiom and it has proven itself as extremely functional for coastal exploration.