BMW Oracle has said that it cannot make compromises that would end the court case, since it cannot decide whether the new rule gives Alinghi an advantage, unless it sees the original version of the rule, which pre-supposes that there was an original version.

Was there?

BYM News thought that the best person to ask would be Tom Schnackenberg - affectionately known as Schnack - who chaired the committee that developed the new rule, to explain how that rule evolved.

The first news the public had about the new boat was very basic; it would be 90 foot long, have a bow sprit and the beam and draft would be tailored to fit the existing infrastructure. When you chaired the very first Competitor�s Commission to formulate the details of the new rule, how much more than that did you know?

Schnack: We knew that the boat would be 25 tonnes, with a max of 5.3m beam, and have about 510-530 sqm upwind sail area. We thought the foretriangle would be 33m by 11m, and that the mast height would be 39m. The mast was expected to be between 850 and 950 kg. We weren�t sure whether the boats would want one or two rudders and knew that it would take time to figure this out, so the rule then and now allows for both setups. We had decided that we didn�t need wings and so this was specified at the first meeting. This is partly because the teams may have to build pits for the keel/bulb and making them wide enough for the wings would be a real pain.

Can you explain what happened at the first meeting? Did people arrive with a host of different ideas?

Schnack: At the first meeting people arrived full of curiosity and questions. We talked about both the Class Rules and also the Competition Regulations and it seemed that people were impressed with the open-ness of the disclosure.

So, I assume they came back next time and each person had his own ideas. How did you reconcile these?

Schnack: Then what happened was a period of time in which designers called and emailed with a few questions and also some suggestions.

What was the atmosphere like in the committee? Did the challengers feel that having the defender present was a drawback, or an improvement on the old Challenger�s Commission?

Schnack: I can�t answer what the Challengers felt. We didn�t talk about the Challenger Commission. I understand that the Challengers, apart from BMWOracle didn�t have any voice or any information about the rule last time, until the rule was announced. I did have the feeling that the Challengers were comfortable having the Defender present at all times. Discussions were open and frank. I thought is was a great environment.

We have been told that, when the displacement was changed from 25 to 23 tons, any design advantage that Alinghi might have had was largely nullified. Is that how all the challengers felt?

Schnack: I can�t answer what the Challengers felt. However, the message Alinghi got was that if they were prepared to make a significant change to a key parameter, this would clearly require them to re-think the design going forward and hence would largely remove any perceived advantage. You may find Challengers on record as saying things about this.

Did it get more difficult to get consensus as you got deeper into details?

Schnack: Not always, the difficulty came with the difficult decisions, which involved protracted discussions. Some of these were almost peripheral, such as the keel lifting system, which is not even part of the racing equipment. The bowsprit went through a few iterations in concept and finally finished back where it started, not rotating or retracting. The choice of J dimension, which is a factor in mast position and balance, got a lot of attention and divergent opinions.

Speaking of detail, one thing that is puzzling a lot of people is how you are going to measure a 6.5 metre draft, when the travel lifts were block to block getting the V5 boats clear at 4.1 metres. Did you discuss this sort of practical detail, or was it all about theory?

Schnack: We talked a lot about practical questions and it was fascinating, that people were acting like �rule-makers� knowing that in a few months� time they are going to be trying to exploit any loopholes in the rules or procedures. The measurement of draft was a case in point and, in the end, we decided that we would measure it in the water; or at least the Measurers would.
Luckily, the Darsena is everywhere deeper than 6.5m, and so it is not difficult to find deep enough water.
Another key dimension was beam. Alinghi had looked at the travel lifts and imagined a beam of 5.7 and a weight of 25 tonnes as producing a nicely behaved boat.
About 6 days before our first meeting, a group went around the Darsena in a small boat and measured the distance between the steel piles. It was found that the distance between the piles was as small as 5.7m in some cases, and so the beam was reduced to 5.3m so that the boats could squeeze into the docks without having to move the steel piles.
In a similar fashion, the thought was that the boat would have a rig, which is about 39 metres above the deck. This grew to 39.4 metres after some rig studies. When you add on the 1.5m distance from the deck to the butt, it got to be nearly 41m in overall length.
Not long after this was decided, we learned that regular cargo planes can only handle 41m max length. Realising that this 41m would necessarily include protective crating and packaging, it was decided to reduce the mast height by 0.5m.
Later on, when the weight was reduced to 23 tonnes, the rig was reduced a further metre to help offset the reduced stability of the boat.

Is there anything at all in the new rule, as far as you can see, that might make anyone think that Alinghi has a design advantage?

Schnack: There is nothing in the rule itself to create a design advantage for anyone. If you want to figure out who might have a design advantage, you would need to look at which designers have the most experience over the longest time designing boats of around this size. That is probably the fairest measure. It is up to the others to catch up.

Did you get the impression that all the challengers were also happy that what had been achieved created a level playing field for everyone who wants to compete in the series leading up to the 33rd America�s Cup?

Schnack: Yes indeed. The AC90 rule is the same for all participants and because it is a �box rule� with all key dimensions either fixed or having simple maximum values, the rule doesn�t require a team to figure out how long or how heavy the boat should be, or how big the sails should be, as the old ACC rule versions 1 to 4 did.
This should ensure that the AC90 yachts all have very similar speed potential over a range of conditions and make for exciting racing.
In addition to stories in this 33rd America's Cup section, you can read stories from the 32nd America's Cup . You will also find some older stories and interviews, from the last event, HERE.
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