| Australia. Volvo Ocean Race: “movistar” goes for heavy metal |
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; "“movistar” in Melbourne: © “movistar” sailing")
| Sunday, 29 January 2006 | |
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Melendy Britt:The “movistar” shore crew is finalising the changes that the Spanish boat is to undergo before returning to the water. As it announced in the daily reports during the Cape Town to Melbourne leg, the most important thing is to change the hydraulics that move the Spanish VO 70’s canting keel, which have given the crew a headache since the twelfth day of competition in the waters of the Southern Ocean. “It is a drastic decision, but we are in no doubt that it is the right one –remarks Bouwe Bekking, skipper of the “movistar”–. We are going to discard the titanium hydraulics and go back to the stainless steel ones that we used in training before setting off from Vigo. They gave us no problems at all in over 20,000 miles of sailing. That way we can go all out without having to worry about their reliability”. But, if they worked so well then, why were they changed? “What led us to change the hydraulics was a simple search for more speed –explains Pedro Campos, team manager–, another turn of the screw for the boat’s performance, but we now know that we were not forced to make the decision as everyone was pushing the limits”. The hydraulics used by the “movistar” for the second leg of the Volvo Ocean Race are made of titanium, a very light material that allowed the team to save over 100 kilos of weight. Olympic gold medallist Xabi Fernandez explains why it is so important to save weight: “When you manage to reduce the weight of something in the hull, those kilos can be diverted to the bulb and stay below the minimum authorised weight; the heavier the bulb, the more sail area you can deploy and the faster the boat goes”. Steel versus titanium “The hydraulics have failed us because they are made from titanium; it is a very valid material –remarks Greg Waters, expert in hydraulic systems for canting keels–. The problem arose because they were too light, even for titanium. In my opinion, they should have been about 50% heavier, and even then, they would have saved a lot of weight in comparison with the ones we are going to mount now. Titanium has peculiarities that have to be taken into account when working with it, and it is better to make them a bit heavy rather than the ideal weight”. Waters works in the specialist company Central Coast, and he has been involved in the “movistar” project from the beginning. He has developed hydraulics for the canting keel systems of leading boats like “Morning Glory”, “Pyewacket”, “Wild Oats X” and “Wild Oats XI” –winner of the Rolex Sydney-Hobart 2005–. “These boats are examples that the canting keel system as such is not a problem if it is designed and built properly”. The Central Coast specialist is the father of the hydraulics mounted in the “movistar” on its initial crossing from Australia to Spain. “Initially, the idea was to mount carbon hydraulics. While the team was waiting for them to be ready, we made the stainless steel ones, which were the hydraulics used by the boat, without incident, when it sailed from Newcastle (Australia) to Vigo. The carbon ones were mounted in Sanxenxo and they scarcely lasted 20 minutes, so we went back to the stainless steel ones. We were later asked to make a second steel set, just in case they were needed, and just a few weeks before the start, the team opted for the titanium ones, which we do not manufacture”. The hydraulics work all the time the boat is sailing - over 470 hours on the second leg of the Volvo Ocean Race–, even when the keel remains in a set position. The titanium ones used by the “movistar” to reach Melbourne could not stand up to the demands of the race from Cape Town. “Their safety margin was insufficient. This variable measures the number of times that can resist the theoretical pressure they work at, which, under normal sailing conditions is 35 tonnes for each hydraulic arm, 70 tonnes in all. But, on occasions, this figure is exceeded, for example when you fall over a wave, and that is when they are under the most stress. So: the titanium ones had a margin of between 1.5 and 2, while the ones we are going to mount now have a margin of between 5 and 6, so you could say that with the stainless steel hydraulic arms, we will triple the safety margin”. Greg Waters talks from inside the “movistar”, where he is working on preparing the system to mount the steel hydraulics. “We are emptying all the oil from the emergency device tank and replacing it with new oil. When the arm broke, we had an oil leak, the boys added olive oil, the only thing available to preserve the system. The truth is that it was a very good idea and it worked”. The steel hydraulics will be mounted over the weekend. “The only thing we have to change is the system pressure, because as the new hydraulic arms are bigger, they work at a lower pressure than the old ones. Everything else remains unchanged”. |
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| Last Updated ( Tuesday, 31 January 2006 ) |
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