Blast off for Ainslie’s America’s Cup
DESIGN WORK CONTINUES IN THE STRICTEST SECRECY. ELAINE BUNTING TALKED TO INEOS TEAM UK’S NICK HOLROYD
Two more America’s Cup teams launched their first AC75 foiling monohull designs in October, illustrating the varying design approaches of each of the four teams. Sir Ben Ainslie’s INEOS Team UK named its new boat Britannia and revealed a design with a distinctive cutaway bow. It was preceded two days earlier by Challenger of Record Luna Rossa Prada Pirelli Team’s design, which some say shares design thinking with Defender Emirates Team New Zealand.
The British challenger represents a colossal expenditure of time and specialist expertise – 90,000 hours of design time and 50,000 hours of build time, according to Ainslie.
All four teams – Emirates Team New Zealand, American Magic, Luna Rossa and INEOS Team UK – are now trialling their first AC75S, and rapidly accruing the data and knowledge they need ahead of the first World Series event in Sardinia next April, and a tight timeline for building their subsequent versions in 2020.
All the teams are watching each other very closely and being highly guarded about their design approach. There are important differences between the four designs that are apparent even to the most untrained eye, but no one involved in the teams is keen to talk in detail about how. For example, the British boat seems wider, with foil rotating points inside the hull, and pronounced slab sides, while Luna Rossa’s has a more conventional bow shape, reverse sheerline and a knuckle or ridge along the bottom that has echoes of Emirates Team New Zealand’s ‘bustle’.
Obvious differences
Nick Holroyd (pictured right) is INEOS Team UK’S principal designer. He was the former technical director of Softbank Team Japan for the last Cup and, before that, technical director of Emirates Team New Zealand, and was a key hire in 2018.
“Certainly there are differences between boats designed for pure foiling and boats designed to have a displacement sailing window at the bottom of the range, but in terms of understanding what the wind limits might be, none of that stuff is published yet,” he says. “Some boats are designed purely around take-off and launch, and some purely for aerodynamics once in flight.”
There are some big challenges with designing for the new rule, he explains. “We’ve come out of a paradigm with the foiling boats from the AC72S and AC50S where we could reconfigure the boat with different foils and rudders for each day based on the forecast, etc. But the big difficulty with these boats is that the measurement certificate for the match will be defined five days before the match, which is the maximum forecastable in Auckland.
“And then you are fixed with that certificate for the duration of the event. So the ability to mode the boat on a day-by-day basis is effectively gone. That makes designing the boat across a very broad wind spectrum a difficult thing to do.
“Where the focus is right now is looking at race modelling and the weather statistics we have, and trying to address the problem of how you design a boat that’s capable of winning a series across a couple of weekends.”
How each crew intends to sail their boat and the work already done on smaller test boats and simulators has shaped the thinking of the new designs. Britannia’s pared back bow but full and rounded shape appears to contrast with American Magic’s bottlenose shape, but both have twin trench cockpits separated by a central
aerodynamic corridor.
The AC75S have a one-design mast and supplied rigging, but the design of the soft wingsail is open to interpretation (see more on this from Ben Ainslie on page 84). While INEOS Team UK’S boat and Luna Rossa’s have both been seen with boomless mainsails, Emirates Team New Zealand and American Magic have been using booms, pointing to some fundamental sail control differences.
Designed to experiment
Hull shapes illustrate some differences in thinking about how quickly these boats will fly and how stable they are.
“Our boat is close to American Magic – much, much closer than styling would suggest, the two of us being challengers,” Nick Holroyd concedes. “The Challenger of Record [Luna Rossa] and the Defender are probably, or perhaps, dealing from the same hand.”
Talking more about how these boats are going to be sailed, Holroyd comments: “The boats are broadly similar. Most of the boats come down to some kind of split port and starboard cockpit. There are variations across the fleet about how much you might move crew around during the race. The Kiwis have all their grinders fixed, whereas we have the option to split the grinders side to side and the option to add pedestals – so if the racing opens up with longer tacks we can bring weight up and move onto pedestals on the weather side to increase righting moment.
“I would argue that some of the boats have been designed more specifically, and some have been designed to give options to experiment and to give the sailing team an ability to sail in different styles and see what works. In some respects our boat is in the latter camp. We have a few more options to try – different sailing
‘WE HAVE A FEW MORE OPTIONS TO TRY’
styles, moving crew up and so on.”
Pressed on whether this boat will be the more radical of the two allowed, as the New Zealanders have implied regarding theirs, Holroyd says that’s not the case.
“It’s not more radical but the first boat has the flexibility to fit sailing style to the crew – we can let them have the flexibility to try different methods and the sailors can experiment. The first boat is, in a way, more general purpose. As we understand more about sailing these boats, we will work towards a more focused solution.”
A close eye on rivals
But figuring out what other teams are doing with their designs, and where they have decided to concentrate a necessarily finite amount of design time, is also vital.
“The Kiwis inherently know most about the event and the style of boat that they’ve drawn perhaps gives you some insight into what they foresee the event being.
“And the other thing to remember is these boats may be freshly launched, but they are a year old already because of the lag between production time and build. The sign-off date for this boat was in September 2018. So in a way it’s a fairly early version of our thinking on the class.”
In that time, the modelling tools have advanced, and there is much more data available from the earlier scale test boats.
One of the most important areas is entirely
unseen: the control systems. The time and expertise devoted to this aspect of the designs has exploded. “It’s a key area, scarily so,” admits Nick Holroyd.
“There is an inordinate amount of complexity in the control systems and distribution of power round the boat from the grinders. Our design team has about 40 people and a good number of those are consultants or specialists. That includes everything from naval architecture, performance production, structures, mechanical guys, performance data analysts, hydraulics and the mechanical and electrical side.
“These boats are controlled using automotive engine control units so we are writing all our own control software to run all that, so then there’s coding and programmers. And there’s a design group for these boats with mechatronics, and, and, and...”
Complex systems
The requirement for these complex systems has, in itself, transformed Cup designs and teams.
“In a way, that’s been the huge growth in my time. When I started with the Cup at Team New Zealand many years ago it was just a few naval architects, a couple of structural engineers, a rig designer and a sail designer,” recalls Holroyd.
“Now you have software engineers, control system designers, you have hydraulic specialists as well as all the CFD experts – and the basic naval architecture. So yes, the breadth and size and complexity of where Cup design has gone to is fascinating.
“Then when you’re building, you need every one of those parts to arrive on time and work. So there’s also a huge amount of bench testing work, of every sub-system you can think of on the boat, from the mainsheet to the foil cant mechanism, the foil actuators, break controls, all those things.”
It does, however, get easier as the design cycle advances into its next phase, he adds. The
No 2 designs each team is working on now will be much more refined.
“Life gets a little bit easier. With the first boat you have to design a wingsail, a pair of foils, rudders, the hull, all the systems and you have to deliver that all on time. There is a huge crush on both design time and all your suppliers.
“Going forward we get a second hull, four more foils, several more rudders, two more rigs etc – but they come in staggered, in a more manageable process. And, in every teams’s case, we will see the quality and innovation creep up on all these features because you have a bit more time and a more manageable timeline to work through the process.”
Meanwhile, everyone involved is being ultracautious about what they divulge. Holroyd explains why: “As an example, take the 2013 America’s Cup and look at what each team had chosen to work on. Emirates Team New Zealand had pushed the foiling concept very hard. Oracle put a lot of time into aerodynamic analysis.
“With a new class of boat where nobody has defined what the key performance criteria are and where you need to work on, I think people are guarded [about revealing] where they are investing their time. There are very key decisions to be made, and [design] resources are finite. We try not to reveal those key decisions.”
Other teams are wrestling with these problems and trade-offs just as much as INEOS Team UK. Everyone is looking hard at each other, trying to work out what they are doing, and why.
“Yes,” agrees Holroyd, “and that’s an area we’ve worked on as well: looking at the other teams and asking do we agree with them?
“The first thing I look for is where are they expending their effort and what has it produced for them? We will take anything we can learn from them – and quickly. It’s a very short process for the next boat.”