The top gig

We speak to Team Shosholoza's Jason Ker about America's Cup design

For those fortunate enough to get the job, working as a designer in the America’s Cup is the equivalent of taking a PhD in yacht design, a unique opportunity to delve into the minutae of what makes a boat go fast to a degree that is impossible for other jobbing naval architects.

A man who’s knowledge has rocketed thanks to his work as Chief Designer for South Africa’s Team Shosholoza is British yacht designer Jason Ker. “In any other type of yacht design, you never get the chance to really get into the level of detail, nor the chance to do as much learning in the way that you can with America’s Cup,” he says. “When you look back, you wonder how you managed without the tools and the knowledge that you pick up in doing an America’s Cup…”

While there was talk at the outset of building a second boat for the South African team, this was cancelled back in April last year. As Ker puts it, they were tight on budget and unless they could find ways to gain extra minutes of performance out of a new boat, it would have been hard to justify the extra cost. “We are pretty happy with what we ended up with,” says Ker. “It was never intended to be a boat to go all the way through, but it is not by any means a disaster that we haven’t got a second boat.”

Instead the South African team decided to make wholescale modifications to their existing Version 5 Cup boat, RSA 83. This took place during a six week period over the Christmas break and included replacing the bow and modifying the stern. “We prepared those while the guys were sailing at the end of last year and then when it was time for a Christmas holiday, the boat builders swapped over the parts,” recounts Ker.





Since then the sailing team has been back out on the water in their revamped RSA 83 training and racing with other teams – principally Areva Challenge, Mascalzone Latino-Capitalia Team and the Germans.

RSA 83 was the first new boat built to Version 5 of the rule. To recap this rule was introduced for this America’s Cup and principally sheds one tonne of displacement and increases spinnaker size. After RSA 83 was launched Ker and his team continued their work in preparation for the second boat, but once this was canned, their work was channelled into upgrading RSA 83. Under class rules up to 50% of the hull surface area can be altered after a boat is launched and Ker says ‘a good chunk’ of RSA 83 was replaced.

In addition to the design team’s development work carried out in house, the modifications also came about through lessons learned sailing against other teams.

Ker’s design team at Shosholoza is smaller than those of the ‘big’ teams like Alinghi, BMW Oracle, Emirates Team New Zealand and Luna Rossa. While big teams can dedicate huge resource to research the minutae of different areas of the boat and trying out new ideas, with a smaller resource Ker says they have had to compartmentalise what areas they have focussed on, be it rigs, appendages, hulls, etc. “We haven’t had a hull team and a rig team and a sails team - it has been slightly overlapped, which makes it more interesting, but it means we can’t have a three year hull design program or a rig design program,” he says.

For hull and appendages the design team take the input from the sailing team on areas to improve like the handling characteristics, while they work closely with the trimmers on sail design. The sailing team as a whole contribute when it comes to developing deck layout and ergonomics.

Within the America’s Cup Marina, all the boats are skirted at present as teams do their utmost to keep any new developments secret. As a result there is inevitable curtain twitching between the team bases and out on the water to check out any new developments competitors might be investigating (hence one reason why some teams disappear to Dubai and New Zealand). While the present style of Cup boat is getting long in the tooth, despite being more than 15 years old now developments are still being made. These tend to be relatively small with the top teams who have been in the game for years, and more wholescale with the newer or smaller teams who are striving to reach to the same level as their larger rivals by the time racing commences this April.

Already in this Cup cycle there have been several interesting developments. For example Alinghi and Oracle tried out a jumper-less topmast almost simultaneously and at least one other team followed suit to investigate if there was any benefit in this. “I personally don’t think there is a lot in it either way,” says Ker of the jumper-less rigs. “The biggest advantage of getting rid of your jumpers is that you don’t hook your spinnaker on them! So fundamentally that can be a race winning advantage, otherwise it balances out quite well. It is not a race winning thing.” Generally Ker reckons that when it comes to the rigs it will be a case merely of refinement for the teams.

Batwings – the flippers that are seen on the end of the top spreaders to stabilise the large roach on the overlapping headsails – have become standardised since they were introduced by Alinghi during the last Cup cycle. Basically they either hinge up or hinge out. Ker reckons this is not a development we are likely to see filtering down to other classes of yacht simply because most modern boats don’t use overlapping headsails any more. Now if you were to design a 21st century IOR boat….

When it comes to hulls it tends to be the bows and sterns that significantly differ between boats. Emirates Team NZ’s brutal looking bow on NZL 84, which they have repeated on their new NZL 92, has been a departure. “They are still on their own,” says Ker. “No one has copied them exactly. People have done different things but they are still the most unique in what they have done.” Luna Rossa have gone in that direction with their new ITA 94 while BMW Oracle Racing’s new USA 98 is “a flattery of NZL 84” as Ker delicately puts it.

Other teams have been trying out bowsprits as was first seen on BMW Oracle Racing’s USA 87 when it was launched last year. Ker describes the decision making process with this: “The bowsprit is just a function of how long your J measurement is compared to where you put your rig and how short your bow is. Everyone wants to have their spinnaker tack as far forward as they are allowed to have, so teams, if their boat has a short bow and the rig is quite far forwards, put bowsprits on or in some cases they are choosing to give up a little bit of tack distance for the convenience of not having a bowsprit. So I think Team NZ last time chose not to have a bowsprit and that is a valid choice.”



Deck layouts are becoming quite standardised. One of the few innovations this time round was with Alinghi who came up with a new mainsheet system last year. “We liked it a lot, but we decided it wasn’t something we should spend money on copying, although Oracle has copied it,” says Ker. The idea is that if you can shed friction from the mainsheet system it enables faster bear aways during the pre-start manoeuvring. With the Alinghi system the sheet goes straight from the car to the winch, but this means they have to mount their aft grinder pedestal on an A-frame rather than attaching it directly to the cockpit sole, in order for the sheet to run beneath it.

There was some talk last year of BMW Oracle Racing’s new USA 87 having a special rudder system – maybe a forward canard? - that improved her turning circle, even enabling her to move sideways. Ker doesn’t believe this. “My personal view is that they didn’t have anything going on there. I think they had a reasonable size rudder and it was down to the way their balance was configured. I think that helping them turning fast or bearing away fast at least. Looking at Oracle and Team NZ they both turn pretty nicely. I think we are seeing some of the new boats turning well and some of them not.”

An area of development that tends not to receive too much attention outside of the teams is what goes on down below on a Cup boat. Although they have shed a tonne of displacement with Version 5, Cup boats still weigh in at 24 tonnes around 23 of which is lead in the bulb. As a result the keel fin to hull attachment presents quite an exciting area in terms of loads.

Ker says there tends to be several ways keels are held on. ‘Keel towers’ have been around since the first generation of these boats but there are variations. “Traditionally Prada have always had a slot-in type keel, that pegs in, but most teams go for a bolt-on system. People are generally trying to make sure their structures are as light and as stiff as possible.” In addition to the slot-in style with bolts going through sideways, other keels are bolted in from the top, others from the bottom.

If the loads generated by the keel are exciting, the 70 tonnes or so of compression seen at the mast step are even more so. “People’s rig solutions are more dramatic,” says Ker. “People are holding the rigs on in Cup boats in quite different ways to how they are doing it in other boats now in terms of the way it is stepped.” Again there are a number of different ways of doing this, essentially having a conventional mast step, while others attempt to structurally link the mast step with the chainplates in various different ways. “People are trying to make the load path as direct as possible,” says Ker.

To accommodate the vast loads from the rig step and fin attachment, a huge amount of longitudinal stiffening is required within the hull and again the length and size of the stringers varies from team to team depending upon what their research work tells them.

For the likes of Shosholoza, Ker reckons that the hardest area of development to get up to speed with is the sails. “For the small teams it is massively difficult just to get to the level where Alinghi were in 2003. Some small teams won’t get there I’d say. Although the top teams won’t have moved very far beyond where they were, they will have moved on a little for sure, but not nearly as far as the smaller teams will have moved to get to there.” To achieve this it is vital to have the top sail designers working well with experienced trimmers. “For us we have always been working on the basis of trying to be on the pace by the time we get to the races in 2007, but we knew it was going to be long road. Hopefully we will be there,” says Ker.

On the sail team within Shosholoza they have Steve Collie in charge of the aerodynamics, Chris Williams who is in charge of design and who drives the North membrain Finite Element Analysis software, while ex-Oracle trimmer Brett Jones provides the main input from the sailing team.

One of the key developments for this America’s Cup, as we have mentioned in the past, is that the designer’s virtual modelling software has improved to such a degree of accuracy that they can now recreate very accurately what goes on in the real world. For smaller teams such as Shosholoza this has been a massive benefit as it is much cheaper and less time consuming to test items in the computer than in the real world.

“CFD has come on a long way and I think that is the biggest single difference, from a design team point of view, between this Cup and the last,” says Ker. “From a small team it is even more important because you just can’t go out and test sail A against sail B for two days to find out which is faster because first of all you haven’t got two boats and they aren’t equally sailed if you have. So you end up then relying on really good software tools and skills to work it out. Before you even put a sail on the boat you should know whether it has got the potential to be faster or not. Then the work on the boat is to do with trying to adjust the tools to match reality better, so that the next one you put up behaves exactly as you think it should rather than something like you think it should.”

The same is happening with tank testing where teams instead of using the tank as a primary source of testing are instead using it merely to validate their CFD results. At Team Shosholoza Ker and his team tested 10 models in a tank in Bulgaria, the last run taking place in April last year. “We got to the stage where we were able to predict with a combination of Flowlogic and Fluent whether the model was going to be successful or not, to the point where it wasn’t good value any more for us to carry on doing any tank testing,” says Ker.

Ker doesn’t think this will spell the end of tank testing though as it will always been needed for verification. “The more money you have, the more luxury you can have on relying on tank testing. We couldn’t afford to rely too heavily on the tank so we had to make sure our tools were good enough to not use the tank so much.” With the degree of accuracy ever increasing, so the scale of models used in the tank has increased in size. For example Shosholoza’s models were 1:3.6 scale, hulls roughly 7m long.

Shosholoza’s design team use many software programs to carry out modelling. CFX is used for developing sails and appendages (Ker believes both Alinghi and Team NZ use this too), while they use FlowLogic and Fluent for hull modelling primarily and also for appendages. “I think Prada and Oracle use slightly different code for hulls, but it comes down to the preference of the user. We tried everything and decided what we wanted to use.”

A huge benefit of this software is that it can be used to assess quickly any new avenues of development that they might spot other teams trying or that they come up with themselves. “We can look at almost anything that comes out and go ‘is that worth spending some time on or not’ quite quickly in the virtual world,” says Ker. “That is the key thing: You need the technology to be able to sift out stuff.” Once the numbers have been run in the computer for whatever the new widget might be, they can then assess whether the potential gain to be made by developing it fully can be achieved efficiently in terms of both time and cost.

Obviously it is all too easy for a team to lose focus and in Cup gamesmanship some of the larger teams have been known to throw up deliberate technological curved balls in an attempt to distract other teams. “We just have to keep coming back to what is the potential gain of succeeding in doing a solution like that, versus what time we would have to put in to achieve it and the cost,” says Ker. If something is relatively fast and cheap to implement they are more likely to go ahead with it rather than if it is likely to prove expensive and time consuming.



AOB:

Elsewhere at Ker Design, their production 39 footer is soon to start production. A yard in Croatia was chosen as builder shortly before Christmas. The moulds for the boat are in the process of being delivered there from Spain.

To date Ker says they have five boats under construction with boats set to go to the Med, to France while another is going to Colm Barrington, Irish owner of Magic Glove. Barrington’s existing 50 footer recently won its class against stiff competition at Acura Key West Race Week and this has sparked off several enquiries for IRC boats from the US.

Origin

While it is too early for him to be thinking about such things, clearly Ker would be under consideration to be one of the chief recruits for Keith Mills’ new design team. Having seen the South African team set themselves up from scratch he has some interesting observations to make about how to do this.

“The way Origin has been set up it looks like it is on the right track. They have publicly said they are looking for a CEO to start with and I think that is the right thing. If you can pick the right guy at the top and he can get the chain right, then you have a good chance of winning. If you start with the wrong one or two people you then end up with a team of the wrong people. Probably the first five people you hire will dictate the success or failure of a Cup team more than anything else, assuming you have enough money. I’m talking beyond the management group - the designers, sailors, trimmers, etc.

“When Russell Coutts joined Alinghi in 2003 he made sure he picked a good designer in Rolf Vrolijk and Rolf picked his core guys. They brought in Grant Simmer to manage it and picked a bunch of really good trimmers. With his first five decisions he had the whole thing set up right.”

One wonders who we shall see fill these key spots at Origin.