The PhDs on Alinghi 5


Alinghi 5Alinghi 5
We speak to Chief Designer Rolf Vrolijk and structural guru Dirk Kramers
While the BMW Oracle Racing trimaran is now effectively in its third iteration, with the solid wing its fourth rig, considerably fewer significant changes have been made to its counterpart, Alinghi 5. This is partly due to the Swiss cat having only been launched in July 2009, some 11 months after the American tri, but also, Alinghi point out, pointedly, because they haven’t had the same seemingly limitless resources of Ellison’s team. "The boat, here in the water, is as it was launched in Switzerland. The only changes have been the appendages, foils and rig," claims Chief Designer, Rolf Vrolijk. While Alinghi were late starting - the ‘go’ button pressed, but then released and pressed once again, in timing with NY Supreme Court cases being won and Appeal Court decisions overturning them - at least they had the advantage of having a good idea of what BMW Oracle were conjuring up thanks initially to the vital statistics in their original Notice of Challenge specifying a 90 x 90ft platform and thus a trimaran. "By knowing that it is a boat that wide, you know also it is a boat with quite high stability, because they can’t build it very light as they have to keep the beam [at 90ft]. So you basically know what your starting stability and righting moment are," explains Vrolijk as to their design process. "To match that with a catamaran is not that easy, because the catamaran has a different beam to length ratio - with a narrower beam and lower stability, flying earlier - all those things." So part of their design process, once they had decided upon effectively creating a 2.5x version of Ernesto Bertarelli’s 41ft Jo Richards-Sebastien Schmidt designed Le Black, with fore and aft rig tension provided by its unique Y-shaped fore and aft spines/dolphin strikers,

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