The introduction of the AC75 for the 36th America’s Cup accomplished three things: the return to monohulls, the pursuit of high performance, and the guarantee there’d only be a few teams which would submit entry.
A new class of boat always comes with apprehension, but when it is an other-worldly foiling, single-hulled 75-footer that no one had seen before, lest even imagined, the pool of people to design, sail, and fund such a project has limits.
But here we are, now having seen on the water the AC75 is much more than just a mushroom-induced dream, we return to what is always true, which is the fastest boat will win the America’s Cup, but to win you must also finish. Mark Chisnell reports for Sailing World on the critical challenge of weight versus reliability.
Every racing sailboat needs to be both strong and light, but only a handful of them need to be strong enough to cope with a crash landing, coming off the hydrofoils at 50-plus knots. Images of the first-generation AC75s, in some spectacular touchdowns have already hit the internet—and those are the wipeouts teams have been willing to share. There will be a lot more before the Cup is won and lost.
It’s an interesting time to be a structural engineer with an America’s Cup team. It would be hard enough if the challenge was to simply build the AC75 with sufficient strength to handle the big crashes. However, the AC75 is a difficult boat to keep under the maximum weight allowed by the rule, and the need to keep it light puts additional pressure on the structural engineers.
“We start by hiring the best engineers we can possibly find, that’s a big part of it… a big structural failure at the wrong time could end the campaign, so they are absolutely critical people to a successful Cup campaign,” says INEOS Team UK skipper and team principal Ben Ainslie.
Building a safe but light structure starts with having a deep understanding of the loads and the stresses the boat will experience. The teams get this by modelling the boat in structural analysis software, which is a challenge unto itself because the AC75 is a completely new concept, a new type of boat. The team can apply experience from other similar boats, but there is no direct knowledge of what’s worked before. Full report.