America's Cup: Emirates Team New Zealand pushes the wind limits
by Richard Gladwell Sail-World NZ 23 Sep 2019 20:16 NZST
Emirates Team New Zealand takes a dive - Waitemata Harbour - September 22, 2019 © Richard Gladwell
The new America's Cup class AC75 answered many questions as to how the type would handle fresh breezes with the Defenders sailing for the second successive day in fresh winds off Auckland East Coast Bays, to the north of the designated America's Cup courses.
Emirates Team New Zealand started the third week since her launch with a training session in conditions that were reported at both the top and bottom end of the course as being 18-20kts, gusting over 25kts. The wind shifted from SW to W during the afternoon.
The Kiwi team left the dock just after noon, returning around five hours later.
There was a lot of downtime adjusting what is believed to be wing control systems - which are designed and installed by the teams, while the carbon foil arm and lifting mechanism are standard supplied one design parts.
The wind conditions were the most severe yet for the AC75 - which is also believed to be fitted with different wing designs on each foil arm for testing purposes, as was done with the AC50 testing (providing a comparative test from one wing to the other).
Most notable concession to the conditions was the use of a short hoist jib, with its chunky profile being dictated by the girth measurement requirements of the AC75 rule.
The first run for Te Aihe was not pretty with the boat falling in to windward and then rolling to a lesser angle leeward. It was not clear if this was due to the AC75 control systems and crew responses, or it was a function of the puffy squally offshore winds. Or both.
After a lengthy further period of adjustment, Te Aihe started another run down the Bays - with this being much better and she began hitting good speeds with a relatively low and level flight.
The run ended abruptly with a slight nose dive accompanied by a big splash, which the boat sailed through and recovered, following which the crew appeared to call a time-out to reflect on what had happened.
The final runs of the day proceeded largely without incident and with the AC75 sailing fast on what was now a beam to broad reach (in terms of true and not apparent wind direction).
Although the AC75 sailed briefly on Sunday, today's session could be the last until Friday with winds gusting over 40kts predicted for the rest of the week.