Raising the BAR

If you have the best sailor in the Olympic history, sailing the best boat available, then the long wait for a British victory in the America's Cup will be over. Easier said than done of course

Sailing competitions are all about the best sailors? Not so says Andy Claughton, technical director of Ben Ainslie Racing (BAR). "One disappointing thing for naval architects about the America's Cup is that is actually turned into a mechanical engineering contest," said Claughton. "We have to think about things like the electromechanical actuators for the wing flaps, we have to control the dagger boards coming up and down - it is all about power consumption and getting the systems light."

In fact Claughton is leading a team of 20 or so designers. Their initial focus is to develop the technologies that will be deployed on AC45 yachts test boats (which are 45ft long) over the course of the next two years, before being included in the 62ft AC62, which is the boat that will actually challenge for the America's Cup.

The rules are complex and are set by the defending champion, in this case Oracle Racing from America. The defender can thus contrive rules, timings and location to suit their own purposes – an accepted quirk of the competition.

"The rules are just about fixed now," observed Claughton. "What they have done is configure the rules so it is very hard for a challenger to come up with something from left-field that will beat them. The boats are going to look very similar but the devil will be in the detail of the control system, and the hydrodynamic design and the aerodynamic control of the wing and so on. To the layman's eye they will be quite similar but to the engineers eye they will be quite different."

Among the details for the 2017 America's Cup is that AC 62 boats are not allowed to have been in the water for more than 150 days prior to the start of the completion. Also, the World Series of Challenger events in 2015 and 2016, will use AC45-F boats. These are 'one class' boats that are all of the same design and therefore virtually identical. The good thing about this is that it becomes a true test of seamanship, but it means that the technologies and designs that Claughton and his team are working on cannot be tested in a racing capacity until 2017. In a bid to control costs, only one America's Cup class boat is allowed to be built.

"It is part of our strategy to look beyond what rules allow us to do, and try and work out exactly what the physics of the problem are," claimed Claughton. "Then we have to come back behind the fence of what the rules will allow and work out best how to tackle the problem. We are doing a lot of our development work on the test-bed 45ft catamarans, so we have to design smaller scale versions of what we want to do on the big boat."

The boats themselves are spectacular, seemingly flying above the surface at up to 60mph. Claughton said: "They are fully foil supported, so the whole seven ton boat is actually supported in a hydrofoil that is no bigger than a regular surfboard - the structural problems are quite severe. There are little wings at the end of the rudders, where the rudder pitch is controlled so the helmsman can control the way the boat flies."

One of the features of the America's Cup boats is that all of the power used in moving the control systems, the control for the wing for example, has to be created by the crew – the grinders. They turn grinding handles that shifts hydraulic fluid which moves the actuators. Claughton commented: "It's a fairly heart in the mouth operation for the helmsman because he will press a control button and hope that the crew has actually generated enough power to move the control surfaces. It's a really strange combination of human power and technology. And a lot of energy is expended in saving energy!"

BAR will be based in the purpose built HQ in Portsmouth harbour that is due for completion in May 2015. It will house design team that Claughton has assembled and they have a very specific deadline. It is a different mindset from that in Formula 1, who demand a new car that is up and running for the start of the season. "But actually," said Claughton, "if they don't go so well in Melbourne you know you have got a race two or three weeks later and there is time for an upgrade. We can't. On 24th June 2017 an upgrade in four weeks is completely useless to us. It is quite a different mindset."

The parallel with Formula 1 is relevant as BAR is working with Red Bull Advanced Technologies as consultants for performance prediction based on simulation. The logic is that there are similarities between the two forms of racing. The fastest car down a straight will not necessarily win a Grand Prix as the crucial areas concern deceleration and acceleration round corners. Equally the America's Cup now has a constrained track – there are more twists and turns and a boat will rarely be going in the same direction for more than a couple of minutes.

BAR is therefore looking to use the simulation techniques developed in Formula 1 to find out how to get the best out of the boat, and that is new territory. Claughton said: "We are just in the process of working out what is the best way of getting our data to them. They are relying on us to give them a very accurate picture of how the boat performs. They are not doing any work that says how this boat will behave. We are telling them how the boat behaves and they are helping us create methodologies that will simulate the performance bit. So it is just about finding the right approach for the sailing simulator."

The actual design platform is Siemens NX, which was selected partly by default. Claughton had identified who he wanted to work on his design team and the platform of choice for those individuals was Siemens NX. Siemens PLM is now a partner of the team, who also use the company's Team Centre software.

Claughton explained why the BAR designers have gone down this route: "I think two reasons are apparent to me. The NX CAD is very good with surfaces and we have quite complex surfaces in terms of aerodynamic shapes. It is very important that these surfaces are well behaved when you get right to the edges of them and that is what NX does. It is very reliable with shapes. If you do an offset inside or outside it to make a mould it will do it. It won't crash.

"And the other thing is that we live in an environment where we are very quick to parameterise a problem, because we want to create geometries for CFD. Also if you have got the problem correctly parameterised you can do all the work in the 2D CAD, which is the lingua franca for the construction side of things. You can start the 2D drawing process much earlier in the piece."

Jan Larsson, senior marketing director EMEA for Siemens PLM, added: "It needs to be fully integrated with all the traditional core modelling tools, but also be able to drive the models parametrically as well. So they can do very rough designs initially when they have all the ideas kicking around, but then they can drive the final design by tweaking the parameters they have attached to the models, saving them a lot of design time downstream."

With a large design team working on the same project it is important that the process is managed correctly. "That is why they have Team Centre in place," said Larsson. "All the revision control is managed by Team Centre. The project is split down. Normally engineers will be working on different parts of the boat, so you don't have people trying to change the shape of the hull at the same time. You are in a fully managed environment when you do this. It minimises the risk of people making changes they shouldn't and eliminates the risk of people working on outdated information."

Training and support has been provided by Majenta PLM, Siemens PLM's channel partner.

First test

The initial ACF45 test boat was in the water in October and its initial objectives were to try out control systems and hydrofoils. The second boat will move on to modelling the cockpits, the helm steering position, building a new wing with some different control systems and much more.

Assesing the first tests Claughton said: "We were not really looking for a performance advantage as such, these are test beds , they are just prototypes. Part of the experimentation with the first AC45 test boat was to explore some systems for adjusting the hydrofoils in terms of angle of attack and the angle of cant. We wanted to measure how much power it took it to move the various control surfaces because in the AC62 we are limited to human power only so it is really turning into a massive mechanical engineering problem. You are trying to find very efficient ways of moving these heavily loaded components because you know that you have to save the energy of the grinders. - it is no fun being a grinder on one of these boats!"

However, it clearly is a lot of fun being part of the BAR team at the moment, and they are open to engage with people who can provide useful technology, although given the time sensitivity there does need to be a disciplined approach to only progressing technologies that are likely to deliver performance for the AC62. Claughton concluded: "Who knows where the race winning widget or technique might come from? So our door is always open. We want to win the America's Cup. We want to win it well. We want to win it using British technology."





The America's Cup

Starting in 1851 with a 'round the Isle of Wight' race, the America's Cup is claimed to be the world's oldest sporting trophy. It was won by America from its inception through to 1983, when an Australian team triumphed. Since then American, Swiss and New Zealand teams have won. Britain has never won the Cup.

The next race will take place in 2017 in Bermuda, a venue determined by the holders. The event, as tradition dictates, is held between the defender and a challenger. In recent events the challenger has been determined by a challenger series.

Current holder is Oracle Racing, who race out of the Golden Gate Yacht Club and who retained the trophy in 2013 in San Francisco, having first won it three years earlier in Valencia.

Sir Ben Ainslie

Sir Ben Ainslie was knighted in 2013 for services to sailing. This came shortly after his gold medal at the London Olympics, his fourth consecutive gold to add to his silver won at his first Olympics in Atlanta 1996. It is a record that makes him the most successful sailing Olympian from any country, and he was selected to carry the flag for the host nation at the London 2012 closing ceremony.

His many other sailing achievements include 9 European titles and 11 World Championship titles, mostly at Laser and Finn classes.

Ainslie tasted victory in the 2013 Americas Cup after joining the Oracle team as tactician from race six. Up to that point the Oracle team has lost every race to the challengers from New Zealand, but won the last race by 44seconds to clinch the series 9-8.

Tim Fryer

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