MAINSAIL_ISSUE 9 FULL

America’s Cup: ETNZ Monohull
AC75Emirates Team New Zealand
Continued from pg.16
design was always going to be a monohull because that is what ETNZ had
agreed Luna Rossa in exchange for funding and design tools that assisted their
victory in Bermuda.
“We are really proud to present the concept of the AC75…Our analysis of
the performance of the foiling monohulls tells us that once the boat is up and
foiling, the boat has the potential to be faster than an AC50 both upwind
and downwind. Auckland is in for a highly competitive summer of racing in
2020/2021,” said ETNZ’s CEO, Grant Dalton.
The only other fully funded and confirmed team for 2021, Ben Ainslie’s Land
Rover BAR, was not consulted about the design choice, but were given a
heads-up in recent weeks. The team’s new CEO, Grant Simmer, who most
recently worked with Oracle Team USA, says: “I think we were surprised that
they went for such a bold solution, but we applaud it. It’s a strong technical
challenge but a good call and in the spirit of the Cup.” But he says that
campaigns will not be less expensive. “We anticipate that they will actually
be more expensive,” comments Simmer. With most of the money being spent
on development and salaries, and the sailing teams increasing to supply a race
crew of 12 people, Cup teams might spent even more than the €100 millionplus
that they each laid out for Bermuda.
But one-design elements of the class have been promised, which might make it
easier for new and first-time teams to form for the next America’s Cup and still
be competitive. ETNZ is to announce the full class rule details next March
but has already indicated that the hydraulics, batteries and control hardware
AC75Emirates Team New Zealand
for the foils, for example, could be one-design, with scope for development of
control system software.
ETNZ has also said specifically that fully autonomous autopilot systems for
controlling the position of the foils will not be allowed. Key controls such
as the flaps of the T foils and their cant position will have to be adjusted
manually by crews. The foils will enter the hull topsides and go through a wet
box area, where they will be operated by hydraulic rams that move then in
and out and from vertical to horizontal position. On a traditional monohull
the keel attachment is the area of highest load, but here it will be these foil
attachments.
Choosing a rotating wingmast and soft sails rather than a wingsail that needs
to be craned on board each time the yacht races is pointed to as having more
‘trickledown’ potential for other areas of sailing. But the decision has also been
taken because once these boats are foiling, the restrictions on speed come from
either foil cavitation or aero drag, and designers believe that it will be easier to
manipulate a soft wingsail to reduce drag.
Although not offshore yachts, they will also be able to race in a wider variety
of sea conditions, including the choppy wind over tide conditions seen in the
Takapuna area of the Hauraki Gulf. Experts believe that it might be possible
to control ride height sufficiently to race, fully foiling, in waves of around 1m.
If designing and building such futuristic boats is a huge set of challenges,
so will racing these beasts. “We are in the early days of modelling, but there
will be big changes in righting moment so manoeuvring will be incredibly
challenging,” observes Grant Simmer. The new design promises to open up
another immense new chapter in foil development and sailing technique. MS
AC75Emirates Team New Zealand
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