Sailfeed
July 1st

Red Bull does a pretty good job here of making the America’s Cup look like it might be pretty exciting:

But Dean Barker also does a good job of explaining why there is turmoil beneath the surface and protests in the offing:

There has been a lot of discussion in the media centred mainly around the issue of the rudder and rudder elevators. In the AC72 Class Rule you are allowed to build rudder elevators which are not allowed to exceed the maximum beam of the yacht, nor extend aft of one metre forward of the stern plane of the yacht. The AC72 class was never envisioned to fully foil, however through 1000′s of hours of design and testing we made a decision that our first AC72 would be a fully foiling yacht. To do this we needed to increase the engineering of a number of components of the boat to accept the extra loading as a boat comes clear of the water. We also took design compromises to allow us to build a boat which would foil in a stable and reliable fashion. The compromise was often straight line speed, but a compromise we felt necessary for safety and the ability to push the boat hard.

The Safety Recommendations included a number of points regarding the rudders and rudder elevators. The main ones were imposing a minimum rudder length of 2.1m, introducing a minimum elevator area of 0.32m2, removing the maximum beam rule which effectively allows the elevators to extend outside the beam of the boat, and insisting the elevators must be symmetrical in plan view.

We agree with imposing a minimum length of rudder even though this made one of our set of rudders illegal. We also thought it was sensible to impose a minimum elevator area. However we are completely opposed to allowing elevators to extend outside of maximum beam and having to be symmetric.

Allowing the rudder elevators to extend outside of max beam is incredibly dangerous and introduces serious risk for the crew. If a crew member was to fall overboard from either hull while the boat is foiling there is a much greater chance they would be struck by the longer elevator and this would lead to a serious injury. As the rule is currently written, with the elevators limited to maximum beam, the chance of injury is greatly reduced.

The second point we are completely opposed to is having to make the elevators symmetric in plan view. We took a clear compromise when designing our boat to position our rudder bearings to allow us to build an elevator to the size we felt necessary. With the existing class rule it is possible to build an elevator well in excess of the imposed minimum area. From day one of sailing our AC72 yachts we have sailed with asymmetric elevators. We have now done well over 60 days with these elevators and have never had a structural issue with either rudders or elevators. It is completely unnecessary to impose the requirement for the elevators to be symmetric in plan form. There is no logical argument to say that asymmetric elevators are not safe….

The AC72 Class Rule is not an unsafe rule. There are choices each team needs to make and these are a balance between performance and safety. You can make an incredibly safe AC72 which would probably have a compromise on performance. So the rule encourages a certain amount of risk vs reward. The boats are incredibly powerful, complex and amazingly fast. The faster you go the more risk there is. This is the same as with motor racing. Imposing real safety measures have greatly reduced the chances of further crew injuries. However there is a line which needs to be drawn between safety improvements and class rule changes which have no bearing on safety.

Sounds pretty reasonable, no? As a result, Emirates Team New Zealand plans to file a protest with the America’s Cup jury.

Which means we may not be seeing this sort of foiling gybe in a race situation anytime soon:

It’s perfectly normal America’s Cup drama and legal maneuvering. Hopefully, it will sort itself out in time to take the competition out on the water. But sometimes things go pear-shaped, and the whole mess ends up before a judge. That would be the ultimate failure of Larry Ellison’s grand America’s Cup vision.

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