Tuesday, January 15, 2013

Americas Cup 2013

Anybody who has even the slightest interest in the Americas Cup competition has seen the video of Team Oracle's spectacular crash last October.  It is amazing that there was no serious damage to the boat except for the carbon wing, which was demolished. Until the crash, no one truly knew where the edge of the envelope was for these extremely powerful boats, so it was a learning experience for the crew of Oracle 17. The question now is whether they will overcome this setback in time to mount a competitive defense of the cup. The crash was certainly a serious bump in the road for them, but now they have a real, rather than theoretical understanding of how hard to push and, probably more importantly, that feeling in the collective gut of the crew of where the edge is. Anyone who has pushed a high performance boat, whether it's a 49er or TP52 beyond the edge of control, knows that feeling. Ironically, that experience, and the experience of quickly putting a broken AC72 back together, could turn out to be a winning edge when the big boats race on the bay.

Yesterday I visited the Oracle compound at Pier 80 in San Francisco and had a chance to see the nearly completely repaired 17 as well as the newest boat, which is still under construction in the same building. While there I also got a look at the newly delivered wing mast whose basic structure was built in New Zealand for completion in San Francisco. Here are some observations:
1. It wasn't until I was right up close to both the wing and the hulls that I could truly appreciate the power to weight ratio of this boat.
2. The hulls are beautifully sculpted shapes that hardly appear to be up to the task of supporting the vast size of the rig, until you realize that the wing, which towers about 130 feet above the deck, weighs only about 3,000 pounds.
3. I was impressed by the fineness of the bows of the hulls. These are almost delicate shapes that will be extremely fast in light air, but will be more challenging in a breeze. I say that because they are very fine, with commensurately little reserve buoyancy. When you consider that the center of effort in the wing is some 65 feet or so above the waterplane, with its center of gravity likely a few feet down from there, it's easy to understand that if the boat is at speed and sticks a bow or two into a wave, the chances of pitchpoling are significant. It's interesting to note that the boat that crashed didn't flip, that is, it didn't fall over sideways, it pitchpoled, or sailed over its bows. Clearly, sailing these boats will be more about power management than power generation in the conditions they are likely to encounter on San Francisco Bay.
4. The wing mast is a fairly simple shape in the profile view. It is a two-element structure, that is, a main element and a flap, and it appears to me that the real technology is in its structural design and control system.
5. Clearly the trick will be in knowing how to control the power in this rig. If there is much breeze at all during the actual races, the winner may well be the crew that has learned how to allow the rig to generate enough power without overpowering the boat and capsizing. As we have already seen, bearing off  an AC72 in a breeze will be tricky. The trimmers will have to be in perfect sync with the helmsman to ease the throttle as the boat turns away from the wind.
6. The course seems awfully short for these 72 foot boats. The marks appear to be set fairly close inshore so there will be little room on the left side of the course. The venue along the city front will make for spectacular viewing but the legs are only about 3 miles long, so these boats that are easily capable of 30 knots might take 15 minutes to get from the leeward mark to the windward mark. That doesn't leave much time for tactics, so I think the key will be to win the start and then don't crash.

1 comment:

  1. It is nice to join this competition. It is a great adventure for sailor.