Development not innovation

Alinghi chief designer Rolf Vrolijk gives his views on America's Cup design in 2005

Being part of the America's Cup winning design team at Alinghi, Rolf Vrolijk for this Cup has continued his role as the Swiss defender's Principle Designer.

Since 2003, Vrolijk says, they have taken on three new personnel, including Kurt Jordan (ex Young America, America True and One World) who is taking care of all the finite element analysis from the mast, hull and appendages and Michel Richelson, the team CFD Manager, who's Cup experience dates back to 1983 and Cup veteran and sail designer Mike Schreider (ex-Team Dennis Conner, One Australia, America True) who's Cup experience dates back even further - to 1977...

This is in addition to the core of the Alinghi design team - Spanish designer Manolo Ruiz de Elvira, engineer Dirk Kramers, CFD man Jim Bungener - a team that comprises 15 in total. "In every area we just have one guy, so everyone has responsibility in their area," says Vrolijk.

As ever the design team have been continuing the endless process of perfecting the tools of their trade: the better their CAD, FEA and CFD modelling tools, then the more precisely they will be able design and engineer the boats. The team are using a wind tunnel facility in Ottawa Canada as well as the commercial tank test facility in St John's, Newfoundland also this time being used by BMW Oracle and Mascalzone Latino-Capitalia Team. Here they obviously test models of appendages, etc but do so at a scale larger than 1:1 to achieve more accurate results.

They have also been hard at work putting their Cup boats into version 5 mode. So is there much difference the performance of version 4 and version 5 boats? "On paper they are very similar," says Vrolijk. "Between version 4 to 5 there is no performance difference. It is more in acceleration rather than straight line performance. There you are talking 1/100th of a knot, not 1/10th. But you can choose better angles and you can have more freedom to pass and I think that was the idea: to make it more lively downwind."

And how will they develop? "They will get closer and closer together. Unfortunately!" continues Vrolijk. "That is the game, because of the changes you are sure that your competitors will have more or less the same length and displacement and sail area. There are no trades off in this new rule."

If the rule has now got so tight that boats will be virtually indistinguishable save for their paintjobs come 2007 - why not go one design? "What you are trying to sell to the rest of the world is just the technology, the research, development and all those things would be cut off," says Vrolijk. "So I think this still leaves enough freedom for the technical team and sailors to put a lot of effort in."

Looking at where the America's Cup Class boat should go, there is a faction - Russell Coutts included - who want a new boat that is more performance orientated, exciting to sail and more visually exciting in the same way as a 49er is more entertaining to watch than a Yngling. Yet at the same time there is another school which feels that a displacement boat like the present type of vessel is better suited to match racing. Rolf Vrolijk explains why: "There is 'what makes the best match race boat' and I think we are very close to that now. So in the future maybe we can work on this rule and try to refine it. But in terms of freedom and development we’d like something completely different with more performance and everything. But that would cut down the match race aspect of it, because the differences will be much bigger. The gaps will be very big and catching up and staying close will be very different because if you will have performance differences and you get differences on the water too. With these boats on paper you are talking about a difference of 1-2 seconds a mile, so less than half a boat length. Everything else you see on the water is not the basic performance, it is the sailors, sailmakers, mast builders, which is quite nice of course. Otherwise the jump would be just in the performance of the boats and if the boat is really fast the game would be over because the teams are too professional: We have seen it in the past - if someone knows what your performance profile is and if they have an option, then they have an advantage and as a professional sailor you will always use it and then the game is over."

While it could be argued that the present generation of Cup boats are becoming long in the tooth, they have developed considerably since they were first introduced. While hull shapes have become more slab sided and narrow, the biggest performance improvements over the last years have come from the rig and sails. The new Version 5 masts for example are both lighter (as allowed under the new rule) but because they can be made from a higher modulus carbon they are also much stiffer. "Much of it is due to the development in rigs and sails and because of that you can make different hull shapes. It is linked to the development above the water," says Vrolijk. "The optimisation and the details in the rig, will be the biggest jumps between a good team and a not so good team this time."

Other interesting developments include inflatable batten pockets to support the leech in headsails. These obviously aim to maintain sail shape while having the ability to be tacked without terminally clouting anything on the foredeck as solid headsail battens can. They are also lighter than solid battens. "The basic principle is that you have a sock and you fill it with a certain pressure and it is held by the pocket. It is just a soft pocket with a soft bladder but because of the pressure it is stiff and it is down to the pressure you can have and the shape it has and the transitions in the sail. There is a lot of stuff you can do there. It is an interest development because it might be help normal boats in the future."

In terms of the square topped mainsail, Vrolijk feels that they have already hit the limit size-wise. Now it is case of working on the twist behaviour at the head of the sail to make it more controllable.

As ever with top Cup teams there is tendency to bring everything to do with the design and build in-house. Vrolijk admits that at Alinghi they have moved further in this direction, but there are still items that are better outsourced. "Really it is better to put your resources into areas where you think you can develop something," he says. "The advantage of manufacturing an in-house mast won’t make any difference in winning the race so why would you do it? It is the same with [the manufacturing of] sails. There are things you can do with the finish of the sails but not the basic materials. So there is no big advantage to doing everything yourself. You have to quantify it. The most difficult thing this time is where do you put your energy and your money? Which areas are gains possible compared to the competition? You can try to cover the whole thing, but if the gains are so small you’re better off concentrating on other areas."

In the past Cup teams have had a tendency to hang on to their technical development only revealing them at the final moment. With the introduction of the Acts for this Cup cycle and for them counting towards the Louis Vuitton Cup challenger series, it is probable that any new technical developments will reveal themselves much earlier in the Cup cycle. "This year you won’t see a lot because people will be in testing programs but next year for sure you will see some ideas and new work," says Vrolijk. "But the options are not big and there is a restriction rule in Version 5 which says that if the measurer or somebody else comes across something which is exceptional or unusual, then they have to put up their finger and then they have to get an interpretation which becomes public and then it is a known thing."

This is the anti-hula clause. "Last time that was a big problem. Now if you can come up with an idea but you are not sure how it will be handled you are better off going to the measurement committee before you do it, because you might be stopped when you build it. So it is better controlled this time. That was a wish not just from us but it was also a big wish from BMW Oracle. The BMW Oracle intention is that they think they want to win on the water."

Despite results in the Acts now counting towards the Louis Vuitton Cup Vrolijk warns that there is still the likelihood of teams sandbagging. "This time it will be a lot easier to find exactly where you are and you will get a lot of ideas. And people will start sandbagging and they will use boats as reference. Probably by the end you will get lost a little bit and you won’t know exactly what people are doing. People can decide what they do for each event. But next year people will start to do things and will then decide to show things or keep them in house."