More on Pre-fabricated “Fiberglass Pans” for Hull Construction
After reading about the L7 trimaran, Michael Waters offered some thoughts regarding the concept of using a pre-fabricated fiberglass base for simplified hull construction. He sent me the image of an early catamaran design … one he first sketched inside his design notebook 50 years ago. It included the idea of using what he then termed a pre-fabricated fiberglass solepiece (or “soul piece”) as he referred to it.
Mike said he wasn’t the only one to have this idea. In 1962, he read a report about a designer named Don Karmin. Don used what he termed fiberglass “shoes” for the bottoms of a new 30’ plywood catamaran hull he had designed. Since it usually takes a few years for a plan to move from design to construction, it’s possible Don and Mike came up with the concept around the same time.
Mike remembers reading about Don using this technique for the hulls of his very slim (and fast) “Karmin catamarans” in a Multihull Magazine. The boat design was called Cobra. Mike remembers the Cobra winning a lot of the races in the Long Island Sound area in the 60’s and 70’s. Other models — the Mark II and Mark III — came afterwards from the same design.
After some searching, Mike found pictures of one of those Karmin cats (click here for the photos that were available at the time of this writing). It looks like Don Karmin may have been the first to actually BUILD a boat using this concept — around 1960.
The plan is to revive this idea yet again, for a new 7-meter trimaran Mike is working on now (named the ‘W22’). I hope to write more about this boat in the future. One design feature of the W22 will be what Mike referred to as a “significant knuckle for spray deflection.” Mike’s former boat, “Magic Hempel,” had it. Even though Magic Hempel was fast, it was also remarkably “dry.”
What is really cool about this “pan” concept is that complex hull shapes necessary for high-performance would become available to home boat builders … without the complex building methods often reqired to attain such shapes.
Stay tuned. With the current L7 and coming W22, perhaps another chapter may soon be written in the history of multihull construction – regardless of whether or not they’re referred to as “fiberglass pans, souls, shoes … or solepieces.”