Raising the Skirts

Team New Zealand's radical hull design concept revealed

17th January 2003.
By Staff

Team New Zealand - Photo credit Daniel Forster

Team New Zealand - Photo credit Daniel Forster

On perhaps the most exciting unveiling day since a victorious Australia II
revealed its wing-keel in 1983, the two remaining challengers in the Louis
Vuitton Cup, Alinghi and Oracle BMW Racing, and the Defender, Team New
Zealand, showed the result of three years of design work and effort in the
public ‘Unveiling’ ceremony on Tuesday.

The Swiss Alinghi Team was the first to drop its skirt, after a brief press
conference with designers Rolf Vrolik and Grant Simmer.

Team New Zealand - Photo credit Daniel Forster

Team New Zealand - Photo credit Daniel Forster

Alinghi’s SUI-64 is the same boat it has used throughout the Louis Vuitton
Cup, and is distinctive for its small, narrow and deep rudder. The keel strut
on the boat was very wide in comparison to the other boats revealed today and
the mast was further forward relative to the keel than the other boats. The
keel bulb itself appeared to be similar to that used by Team New Zealand in
2000, with winglets attached at the back third of the bulb.

Team New Zealand - Photo credit Daniel Forster

Team New Zealand - Photo credit Daniel Forster

“Our goal was to come out fast in Round Robin One and just keep moving
forward,” Simmer said. “Today people will focus on appendages and hull
shapes, but you shouldn’t underestimate the effect of small detail changes
and the tuning of these boats. This can result in big differences on the race
courses. We’ve spent over 1100 hours on testing and in-house racing and
SUI-64 is product of that work.”

“The boat is very narrow, very U-shaped compared to the last generation,”
designer Rolf Vrolijk explained. “This works together with the sail and mast
development programme. The appendages aren’t very different from what you saw
in 2000, but in the details we have worked very hard and made many subtle
refinements. We also developed the square headed mainsail that you see on all
of the boats now. I think it’s clear we have tried to push the engine of the
boat as much as possible and all of the other teams are trying to catch up.”

Oracle - Photo credit Carlo Borlenghi

Oracle - Photo credit Carlo Borlenghi

In comparison, the Oracle BMW Racing team’s USA-76 had a relatively large
rudder, and the keel bulb winglets were positioned right at the back of the
bulb. The keel strut itself was tapered and shaped.

“We’ve done a lot of work in the last few months, improving the boat and
appendages, the sails and the rig, and we’re hoping that we’re peaking now in
time to beat Alinghi and then Team New Zealand,” said Oracle BMW designer
Bruce Farr. “In comparison to SUI-64 we have a slightly smaller keel fin and
it’s tapered. Our bulb is shorter and higher and we have our wings at the
back of the bulb, rather than the centre of the bulb. We’re quite a bit
narrower than them, especially at the waterline.”

Farr went on to say that although all three boats are quite different, that
doesn’t necessarily mean we’ll see big speed differences.

“You would think that if you all worked hard enough you’d end up with similar
designs,” Farr said. “But there’s a combination of features that go together
to make a successful boat and a lot of them are fairly flat trade-offs, in
other words you can be in different places but have pretty much the same
result. So I think the designs get driven by biases in the experiments and
even biases in the designer’s beliefs. The fact that they look quite
different, well the performance could still be fairly similar.”

Team New Zealand followed the Challenger unveilings and stole the show when
both of its declared boats, NZL-81 and NZL-82 were slowly raised out of the
water to a cheering crowd. It was the first public showing of what had been
dubbed the ‘Kiwi Clip-On’, an elegant appendage incorporated into the hull
design that has the effect of lengthening the boat without a rating penalty.

Team New Zealand syndicate head Tom Schnackenberg quickly corrected the name
for the appendage, telling the assembled media that his team called it the
‘Hula’ – an abbreviation of ‘hull appendage’.

On both New Zealand boats the ‘hula’ is an appendage that is separated from
the rest of the hull by just a few millimetres. It begins about a metre
behind the keel, and runs back behind the rudder, effectively adding length
and volume to the aft section of the boat. Designer Clay Oliver went on to
say the ‘hula’ was an integral part of the boat’s design.

“The idea starts with the concept that you want to draw a boat that is long,
elegant and fast,” Oliver explained. “It’s not a matter of adding something
to a boat that you already envisioned. It’s actually imagining a boat that
you want to have and saying how can we get that shape? This is a solution to
that. It’s not a clip-on. It’s a hull that’s been drawn the way we want it
and that’s the solution.”

The other immediately remarkable feature on the Team New Zealand boats were
the keel bulbs, both much, much longer than either of the challengers.

Team New Zealand says the ‘hula’ has been approved by the America’s Cup Class
measurers and says it doesn’t expect to have any problems with protests over
the design. Although both challengers, particularly Alinghi have admitted to
exploring the use of a similar appendage, neither was sporting a ‘clip-on’ on
unveiling day.

The winner of the Louis Vuitton Cup goes on to meet Team New Zealand in the
America’s Cup on February 15th. There is another public unveiling before the
Cup match on February 11th.

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