And here's some of the evidence to support my earlier piece on what Oracle was up to during the 34th America’s Cup

Judging by the number of emails and comments that are coming in a week after the America’s Cup was won, the issue of what Oracle Team USA did to make its boat blistering remains a hotly debated subject. Thanks to all who have sent in their views, keep them coming.

In the meantime, here are a few pictures that were sent to me by Bieker Boats, the brains behind some of the key modifications that were made. As you can see, fairings on the rudder T-foils and the hull interceptors were actually used.

The interceptor – small ridge running around the transom modifies the water flow like a boot spoiler on a car.

Rudder T-foil mods looking from forward to aft. The fairings were added.

Rudder T-foil looking from aft to forward. Note the filet from the middle to the trailing edge of the rudder.

You can see more of what Bieker Boat get up to on their website.

Also, in response to some of the issues that have been raised:

1)   There was a day that both teams could have sailed but chose not to: the 16th September (thanks to those that pointed out the typo that said October). With the event falling behind schedule, regatta director Iain Murray suggested to the teams that they might want to race on the reserve day 16th September in order to catch up. Both decided not to. This, in my opinion and of course with the benefit of hindsight, was the first day that the Cup slipped out of the Kiwis grasp. Had they have raced, Oracle would have been denied the opportunity to carry out big mods and the Kiwis could have carried on their roll.

2)   Oracle did not have an automatic control, system, they’re illegal. The buttons on the wheel control the angle and position of the daggerboard by opening and closing valves on the hydraulic rams that move the boards. Timing is crucial because no stored energy is allowed ie. the hydraulic system cannot be pressurised. Pressing the button needs to coincide with the grinders winding the pumps. It didn’t always go smoothly.

3)   Although Oracle had the TNZ data from the Louis Vuitton challenger series, the Kiwis were never pushed by either of their competitors. They knew Oracle was watching so why show your hand. Also, by their own admission they only discovered some of their performance later on during the Cup itself. Both teams freely admitted to learning new tricks every day during the event, that’s one of the aspects that made this Cup so different.

4)   The time limit is a particularly contentious issue and an interesting one. When the limit was agreed by the teams back in the latter end of 2012, no one was convinced that foiling would be a reality. However, six months later when foils became the norm, it turned out that the additional drag of the foils when the boats were not on them and sailing in displacement mode, meant that teams were unlikely to be able to get around the course in 40 minutes, simply because of the extra drag. As a result, conscious that the event was over running and aware of the risk of losing the first race to a time limit and then not being able to start a second race, regatta director Iain Murray decided that he would not start a race in under 10 knots of breeze if there was a chance that the wind would build later. That way at least he would stand a better chance of getting at least one race in rather than losing two.
This is not my assumption, it’s what he told us at a press briefing during the event.
   
And for those that are wondering what the context for all this is, here’s the article on what Oracle changed to make their boat go so much quicker…

WHAT WAS CHANGED ON ORACLE?

Having remained in San Francisco for a few days after the end of the event, I got to speak to a number of people about what was really going on. It didn’t take long for the real picture of what was behind the speed improvements to emerge.

Oracle’s jump in performance half way through the America’s Cup is still the subject of hot debate, particularly among the New Zealand press who are convinced that the black cat had some special device that allowed them to foil more effectively. Was the ‘Herbie’, as it became nicknamed, legal? Would Team New Zealand take legal action?

Continue reading: WHAT WAS CHANGED ON ORACLE?

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America’s Cup: How Oracle Won