All things AC40 with Dan Bernasconi
An exclusive deep dive look at the new 40-foot one-design foiling monohull concept with Emirates Team New Zealand’s head of design.
One of the most exciting new aspects of the 37th America’s Cup cycle is the introduction of a new America’s Cup class – a scaled down 40-foot foiling monohull version of the AC75 class, known as the AC40.
Sailed by a crew of four, the teams can utilise the AC40 as a training boat for honing match racing skills, and/or a development mule for testing new rig or foil designs.
After being returned to full one design configuration the AC40 fleet will also be used for any preliminary regattas prior to the Challenger Selection Series and the 37thAmerica’s Cup Match – such as America’s Cup World Series events – as well as for the Youth America’s Cup and Women’s America’s Cup.
To find out more about how the AC40 concept came to fruition I booked some time with the man at the centre of it all – Emirates Team New Zealand designer Dan Bernasconi.
Bernasconi told me that the idea of a class of a class of scaled down AC75s that were simpler and easier to sail than the full-size boats was triggered by outside interest in the team’s one off half-scale training boat, the 38-foot Te Kahu, which the Team New Zealand sailors trained on whenever their AC75 was in the shed or in transit.
“Towards the end of the last campaign, in the last two or three months before racing, we were all thinking about what happens next – win or lose,” Bernasconi said.
“We had a few people casually ask about whether we were make the small boat that we had, Te Kahu, into a class. It's a really cool little boat and the sailors loved sailing it and there was quite a lot of interest from from local sailors here [in New Zealand].”
Encouraged by the interest, the team created a mock up of what a potential one design version of Te Kahu might look like, and even got as far as producing a draft marketing brochure.
Then, when work began on the Protocol for the 37th America’s Cup, Bernasconi and his designers revisited the idea.
“I guess it gradually turned into something more concrete and more of a reality as sort of a multipurpose boat for the for teams to use as a training/development boat for the pre-regattas – where it's easier and more practical to transport AC40s around the world to different venues,” Bernasconi said.
“But also to use it as a training boat both match racing and for development when you can swap out components, put your own foils and sails and rig.
“Then for the Youth America's Cup and the Women's America's Cup, it seemed like a great platform for that – and potentially for private owners as well.”
In terms of a design brief for the AC40 Bernasconi said the overriding principle was to make the smaller boat as similar as possible to the AC75.
“It's based on the the new generation of AC 75, rather than the old generation,” he points out.
“So the AC40 is scaled down from an AC75 with a wider span on the foil wings, and without the burden of the largely impractical Code Zero headsail and bow sprit.”
The AC40 is very, very, close to a scaled down AC75 in all respects, Bernasconi told me.
“The geometry is just scaled down,” he said. “The only thing that is really different is that the bow is shorter. That’s because the AC75 is quite a long boat and the forestay is a fair way back from the stem.
“If you take the AC 75 and scale it down not all the way to 40 feet and then shrink the bow so that the forestay comes almost to the stem. [With the AC40,] effectively, we've got a bigger boat into a smaller length. That's really about trying to fit it into a 40-foot container length.
To simplify shipping and reduce costs the AC40 is designed to be transported on its side in an open top 40-foot container or 40-foot a flat rack.
But the task of creating a new design based on the Kiwi’s full-sized America’s Cup-winning boat is a much complicated process than simply scaling back the hull and rig dimensions.
Much of the AC75’s scintillating performance came from the boat’s myriad complex proprietary control systems. Surely the team would want these to remain a closely kept secret from their rivals?
It’s hard not to see the AC40 concept as a sort of reverse Trojan Horse – a gift wrapped package of ETNZ intellectual property delivered directly into the hands of the challenging teams.
“We have had quite dilemmas about how much IP to give away in the boat,” Bernasconi confessed.
Despite understandable nervousness about the risk of giving away too much Bernasconi said the design team had not held back or compromised the potential of the AC40.
The primary goal, he told me, was for the AC40 to be a really cool boat that would take off well and deliver high performance across the wind speed range.”
Bernasconi said there had been some unease about putting all the teams secrets into the new boat. In the end the decision was made to trust that the team would stay ahead of its rivals by continuing to innovate throughout the AC37 cycle.
“As a design team, we are all really excited about the AC40 and we want it to be a success,” he said. “So we are giving it our best shot based on what we know at the moment and we hope that whatever we do give away we are going to improve upon over the next two three years of our with our R&D programme for the next edition to go into our next race boat.”
The AC40 hull shape is based on the Defender’s second AC75 race boat Te Rehutai.
“It’s even moved forward a bit from there,” Bernasconi hinted.
“It’s a really cool hull shape and the foils, which we're just getting into designing now, are going to be really good in terms of section shapes and flap mechanisms.
Meanwhile, above deck, the AC40 mast – supplied by Southern Spars – is going to be runner-less, like the next generation of AC75s.
Wind ranges for the AC40 are expected to be similar to the A75, but Bernasconi expects the AC40 to be slightly later to take off than the new generation full size AC75s.
“I think we're looking at takeoff wind speeds of seven to seven and a half knots,” he said.
“We are going to be pretty close to the scaled weight of an AC 75,” he said. “But it's difficult to scale the weight exactly. As you get smaller it gets harder and harder with weight.
“If you're going from 75-foot to 40-foot you the weights should scale by the the root of the length. But not everything on the boat scales down. For example, the electronics still weighs the same whether you put instrumentation on on a 75-footer or a 40-footer.”
At the top end of the wind range Bernasconi believes the AC40 will be “limited more by sea state than than by wind speed”.
With a crew of just four, by necessity, the AC40 needs to be a much simpler and more straightforward boat to sail. Hence the introduction of autopilot functionality to manage the the boat in flight.
“On the AC75s there were very strict rules about what sort of automation you were allowed in ride height control to control the flaps and keeps the boat in trim and at the right right height at a different wind conditions and speeds,” Bernasconi told me.
“In the AC 40 we will be providing an autopilot to make it more straightforward to sail. I think that's really important for the Youth and Women's America's Cup where the crews will need to be able to get in them and sail them well without the chance to do massive amounts of practice.”
Bernasconi believes that the introduction of an autopilot will speed up these sailors’ learning curve and make it less likely to have big crash downs during manoeuvres.
“We are going to do what we can to make boat as straightforward to sail as possible so the sailors can concentrate on maximising performance and match racing rather than on keeping the boat flying.”
Nevertheless let’s not pretend this new AC40 will be anything but challenging to learn to sail – particularly for the uninitiated.
Bernasconi agrees. “In terms of the actual physical components on the boat – the rig, rotation, traveller, mainsheet, Cunningham control, the flap control and the rudder rake – that's all basically the same as the AC75,” he points out.
Designing an autopilot system slick and responsive enough for the AC40 is no small task.
“It is a significant challenge for us,” Bernasconi said.
“We've got one guy who's going to be working full time for the next few months developing that autopilot, along with another couple of the electronics engineers.”
Might perhaps this autopilot technology turn out to be one of the mythical trickle-down products that find a more mainstream use outside the rarefied atmosphere of the America’s Cup, I wondered?
Bernasconi believes it could.
“I think there's there are a few large foilers, superyachts, or private offshore racing yachts that will be looking at autopilot systems,” he said. “It is going to be a growth area, for sure.”
Although the AC40 concept was born out of the Kiwi’s Te Kahu test boat, the hull shape will be much more refined – as Bernasconi explained.
“For cost reasons mainly, we deliberately came up with a pretty simple hull construction for Te Kahu, mostly using flat panels,” he said. “We haven't held back this time, so the AC40 hull shape is much more curvy [like the full-size AC75].
On deck the four person crew will be split two per side in distinct cockpits. No-one will be changing sides during racing.
“There will be a wheel at the front of either cockpit, so you'll have one helmsmen on either side – taking turns from tack to tack – and a trimmer in the seat behind them,” Bernasconi told me.
Exactly how the crew roles will work, Bernasconi expects, will be left to the teams to decide.
“We would imagine that on any particular tack you would have a helmsmen up front with a mainsail trimmer behind them.
“Whether the the jib trimmer is on the leeward side and they swap roles [with the main trimmer], or whether you always have the same person do the main and the jib is up to the teams. Then the other helmsman would probably fill the role of tactician when they're not helming.”
The final call on all this will be left to the teams to decide on how they want to arrange things.
“We will be fairly flexible in terms of the controls – the sort of joysticks and keypads we're putting in the boat – so that teams will be able to choose themselves how to how to arrange that,” Bernasconi said.
Standard on all AC40s however – given that the class is a grinder-free zone – will be the batteries that power the boats’ systems.
“There are no no jib winches, everything is controlled hydraulically,” Bernasconi confirms. “That hydraulic power comes from a pump driven by electric motor, which is powered by battery.”
No decision has yet been made on the type of battery technology to be deployed but Bernasconi and his team are constantly monitoring the market for the best options.
“We are always researching what the best options are. It is a really difficult area at the moment with global supply issues and batteries have really long lead times at the moment.
“We are obviously they driven by minimising weight so we do put a lot of effort into looking for the best options. There are always new products coming on the market so we haven't made the final call on that.
When it comes to the sail wardrobe for the AC40, North is the chosen manufacturer, and they will kit the boats out with a double skin mainsail – flown from a rotating D-section mast like the AC75s – and a choice of three jibs: J1, J2 and J3.
The AC40 hulls will be constructed by Australian builder McConaghy Boats at its China facility.
“We are doing all of the design work within Team New Zealand but it’s not a Team New Zealand supplied boat,” Bernasconi told me. “McConaghys will be supplying everything but the rig and sails and you would place your order with them.
When we spoke midway through December Bernasconi described the AC40 design process as “pretty advanced” although he said there were still some aspects yet to be fully locked down.
The hull and deck is completely locked down and they are building tooling for that already,” he said. “We have the hydraulic circuit close to final and a lot of the electronic components are locked down.
“We are currently working through all the detailed structural engineering of the bulkheads and skin and deck laminates, and the mechanical systems to all the steering systems and deck systems and so on.”
Team New Zealand may subcontract back to McConaghy for some individual parts, Bernasconi said.
“For instance we are quite likely to be building the foil arms and the rudders at Team New Zealand. Then we would supply those to McConaghys and they would do the complete fit out of all the hydraulics and electrical systems and commissioning.”
The one design foil wings, will either be built by McConaghy or outsourced to local machine shops in China. Then McConaghy will supply those fully commissioned boats – minus the mast and sails which the teams and other customers would order separately from Southern Spars and North respectively.
Emirates Team New Zealand will be the recipients of the first ever AC40. Boat one is expected to be rolled out of the McConaghy facility in China some time in July 2022 to be shipped straight to New Zealand for commissioning by the team during August of that year.
“That’s a bit of a different approach for us,” Bernasconi admitted. “We are used to getting a boat, fitting it out here and starting to debug it here.
“Whereas, with the AC40 being a production boat, we are having to do a lot more work up front because the deliveries will be staggered by five weeks.That means by the time boat one first touches the water in New Zealand the second one will be leaving the yard at McConaghys.
“We have got to get it right first time and so we're we're sort of doing a lot more work up front on the hydraulics, electronics and getting all that 100 per cent designed early on in the process.”
Bernasconi said the team planned to test those hydraulic and electronic systems in house on the bench in New Zealand.
“I'm sure there's going to be tweaks that we'll need to do the autopilot software, but we'll have a bit of a head start on that because we'll be getting our boat a month or so before anybody else.
“There will be full full team commissioning, checking and doing any debugging necessary on that on that boat,” Bernasconi explained.
“Over the years we have built a pretty stable team and built up our in house experience in electronics and hydraulics. [At the last Cup] with our race boat, we deliberately launched that pretty late and we were up and running with very few issues at the beginning.
“That’s given us some confidence that, even though the AC40 is a complicated boat, we've we've gone through the commissioning process with two AC75.
“The systems are all pretty much the same kinds of systems from the 75, so whilst I'm sure there will be some teething issues, we are confident that we will have the boats up and running pretty quickly.”
Bernasconi believes the performance of the new AC40 could could be close to that of the AC75 – a scary prospect for a 40-foot boat.
“Small boats are always a little bit lower in performance, but there's not going to be a huge differential there,” he said.
“We're going to get speeds approaching 50 knots in top end wind conditions and we are also concentrating on the low speed end and takeoff. Overall, I'd say just just a click under the AC 75.”
Aside from the America’s Cup teams and their associated Youth and Women’s Teams, the AC40 will eventually be made available to private owners.
According to Bernasconi, that target market would include GC32 and TF35 teams and even maybe even some TP52 owners looking to upgrade the thrill factor in their racing.
“It would be great if a circuit formed – maybe a Mediterranean circuit – and I think there is probably a group out there who would be interested in forming that,” he said. “We have had interest from private owners – both in New Zealand and and from overseas.”
“Obviously, a boat of this complexity and quality is not super cheap,” Bernasconi said. [Ed note – The Protocol specifies a price of 1.85 million US Dollars for the hull, excluding mast and sails.]
“I think, for what you're getting, the price is going to be really competitive. It is a complex boat but I think I think there is a lot of interest out there for sure.”
These days no self-respecting America’s Cup boat comes without an associated simulator and so it comes as no surprise that Bernasconi has a team of his people working on developing one for the AC40.
“It will be based on the technology that we have used for the last few Cups, and we will make available to purchasers – or perhaps prospective purchasers – of the AC40,” he said.
“Going forward maybe it’s something that we even provide for people that are dreaming of owning an AC40 and want to sail the simulator. We haven't worked through all that yet but I think there is some pretty exciting potential.”