Interesting article about design..

Posted by another swaylokian, What do you guys think? In the early 1980s, Ben Lexcen transformed 12-metre yacht design, using science where others had relied on gut feel. A combination of his free-thinking design, high-tech tools and a great crew as well as loads of Alan Bond's money tore the America's Cup from the grasp of the New York Yacht Club for the first time in the race's 132-year history. Six years later, Bond signed another designer, American naval architect Andy Dovell, now 45, to help with his bid for the 1992 cup challenge. Things unravelled for Bond, the bid came to nothing, but Dovell stayed, forming a design partnership with skipper Iain Murray and engineer Ian Burns. Their design roster, long and storied, includes 2001 Sydney-to-Hobart overall winner Bumblebee 5. Surfboard design has a lot in common with pre-Lexcen 12-metre yachts. Since World War II and the invention of foam and glass fibre, design breakthroughs have come from trial and error as well as some lateral thinking by surfers. But the last major innovation came two years before Australia II's victory when Sydney board rider Simon Anderson refined a three-fin design and proved its worth in professional competition. Little has happened since. Six years ago, Bill McCausland, a director of Surf Hardware International, met Dovell through a skiff racing acquaintance. Surf Hardware makes the Fin Control System, a removable fin design used in an estimated 85% of all surfboards made around the world. Before the FCS, surfboard fins were mostly hacked from resin-impregnated glass fibre mats then foiled using an angle grinder before being permanently attached to the bottom of the board using more glass fibre and resin. A surfboard fin is basically a wing. On a modern three-fin "thruster", the two outside fins are foiled on the outside and flat on the inside. This generates lift as the board moves along the wave, just like an aeroplane wing creates lift as it moves through the air. The centre fin is foiled both sides and acts as a rudder or stabiliser. Most riders don't realise that the board's hull, which they study obsessively, has less to do with critical surfing than the fins. After their initial meeting, Dovell and McCausland worked together on a friendly basis. The naval architect offered suggestions, and some were incorporated into the FCS roster. SHI then won $1m under the federal government's research and development Start program, matching the company's contribution dollar for dollar. A contract with Murray, Burns and Dovell was signed and goals put in place: better fins, better surfing, patentable intellectual property. This last factor is important because the original FCS patents won't last forever. New IP is needed to ensure a consistent revenue stream. In the 1960s, NASA spent a lot of time and money categorising airfoil types. Dovell started out assuming that the basic surfboard architecture, the three fins and their toe angles, was OK. "We took the basic fin area, profile, depth and chord and made subtle modifications," he says. The first modification simply took a NASA foil with a broad performance envelope and applied it to the fins. Accuracy is important, so McCausland had special moulds constructed. In tandem, efforts were underway at the Australian Maritime College's cavitation tank in Tasmania to figure out how to mount a fin so that its performance could be studied under scientific conditions. Field trials were held, with surfers given test fins to surf blind. On the beach, judges objectively ranked the performance of the riders, who filled out questionnaires when they returned to shore. That was 12 months ago. Surfers are still testing new versions of Dovell's designs, and more prototyping is underway. Some of the early discoveries, including the NASA foil, have already been applied to some of SHI's existing fin product. But the real advances, Dovell says, are still to come. The next phase involves building an electronic surfboard to measure flex and drive while on the water. If it works, surfboard riding may never be the same again. http://www.geocities.com/wunderboyi/ninetysixpercent.html