Cup Spy April 15: Kiwis on a mission to work out their AC75 wrinkles before heading for Barcelona
by Richard Gladwell/Sail-World NZ 15 Apr 2024 10:15 EST
15 April 2024
Flat underbody and deep skeg - Emirates Team New Zealand- AC75 - Day 3 - April 15, 2024 - Auckland © Sam Thom/America's Cup
Emirates Team New Zealand sailed a three hour plus session today, Monday.
It was their third day of sailing, the first was the same day as the AC75 was launched, and the Kiwis appear to be on a tight schedule.
The word around the waterfront, is that they will be sailing for just two weeks, before packing up and heading for Barcelona where the serious workup will begin.
Currently the as yet unnamed AC75 - that will be remedied on Thursday afternoon - is sailing with legacy foil arms and wingfoils (ex Te Rehutai). That might take the edge off the sailing, for fans, however for the design teams this test/sailing block is useful to benchmark Boat 3 against Te Rehutai. The variables at this point are the new hull design and the new sails, and new systems.
The breeze started light and patchy, but filled in later in the three and a half hour session. Cup Spy watched from Narrow Neck at the start of the session, there was the usual (for Day 3 of a sailing program) man up the top of the mast sorting halyards and locks.
The session started with the J2 jib, and with a bit of assistance from the Catalyst chase boat, the team started doing their standard speed runs, off Takapuna - and sailing across the wind up and downwind.
The striking impression watching the new AC75 is the depth of the skeg, compared to Te Rehutai, and the flatness of the aft underbody. The hull and skeg almost has wineglass appearance. The new Class rules permit a greater foil arm depth, and the loger arms will be fitted in Barcelona.
From the Recon team video (66 video files posted today), the AC75 kicks up a lot of water in the rudder area, until the hull lifts off, and it pops effortlessly.
Burns Fallow, the lead sail designer was interviewed by Sam Thom of the AC37 Joint Recon Team after the session. Burns has been part of every New Zealand America's Cup Challenge (except 2017) starting with KZ-7 and Fremantle in 1986/87. He is one of a handful of current team members who were there at the beginning.
He made some interesting points.
"It's been a good day. It's been our longest day of the three so far. And each day, we're getting a little more adventurous with what we do—and as you saw, we did a few little laps at the end. So it's all good."
The sails being used on Boat 3 - are new, unlike the legacy sails that were mandatory when testing for the present campaign on Te Rehutai.
"We only get to build six main sails in total, so we've got to think about what the right main is for when we actually put the whole package (including foils) together", he explained.
"The learning curve is not quite as steep as the last campaign. That wasn't a curve. That was a mountain. But every boat is new. Every boat is different. We're always learning. And that's kind of cool."
Each team is restricted to six new mainsails. "We're only three days into this sail, and this main will obviously inform what we do with our next ones," Burns explained. "There's a reasonable cycle of design, manufacturing, and finishing each sail. And you've got to think about how you program all of that. For us, it's relatively simple because our target date is in October, later this year. It is tricky for the challengers because they've got to negotiate their way through a Challenger Series first."
The role of the sail designer has changed since that first Cup in Fremantle.
"We now only have one designer," he says. "We've got several other people doing specialist jobs in the aero department. And now, I'm just part of the aero department.
"That's changed over the years. We used to have a sail designer who was king of their own little domain, but now it doesn't work like that. We're involved in all sorts of stuff. So, as a rig designer, you're just involved in all sorts of things. And that's what's made doing these campaigns more and more interesting over the years."
AC37 Joint Recon Team Report:
Emirates Team New Zealand - AC75 - Boat 3 - Day 3 - April 15, 2024 - Auckland
Day 3 for ETNZ AC75 Boat 3 started with a very light southwesterly breeze. The boat rolled out of the shed at 8:40hrs, and the team started the now-standard setup procedure. However, having some problems maneuvering the boat under the crane as there had been some lifting equipment breakdown. Leaving the dock at 11:00hrs, the team towed down the harbour and out towards Rangitoto Lighthouse.
Hoisting M2 and J2 just south of Rangitoto Lighthouse around 11:15hrs, the team spent about 40 minutes rigging up on the water and getting all the systems tuned up and ready to start sailing.
In very light conditions, Chase 1 proceeded to tow AC75 B3 onto the foils, hoping to build some apparent wind and start sailing; however, as B3 sheeted on and dropped the tow, they quickly found themselves back in the water, not being able to sail under their own steam. A quick 5-minute break, and the team felt they had enough wind to pop without the tow. Successfully popping onto the foils and sailing out of the harbour down the northern side of Rangitoto Island.
The team spent 10 minutes sailing mainly on port while it could be seen that some of the sailors were walking around onboard the yacht, checking over systems. After a few maneuvers, the team came out of a tack and proceeded to touchdown and come to a stop. Chase 1 came alongside, and the shore crew boarded the yacht, spending about 20 minutes stopped.
The team then went for a 25-minute sailing session, completing working back towards Takapuna Beach and running down the northern side of Rangitoto Island. Spending time working through maneuvers. Coming out of a tack, they touched down and proceeded to stop. With Chase 1 alongside, a cyclor swap was completed as well as a change to the Jib head lashing. Stopping for 15 minutes.
Starting sailing around 13:00hrs after the crew change, the team went for another few windward-leeward laps. In the still down-range conditions, the team touched down out of a gybe; however, managing to quickly regain speed and pop onto foils. After roughly 24 minutes of sailing, the team stopped sailing again as they fell off the foils during a round-up. They then completed a Jib change, changing down to the J4, and while this seemed a strange call at the time as the team started sailing again, the wind was building from 6-8kts up to around 12 knots.
Sailing again well-powered on the J4, the team went for a longer downwind run then working back upwind towards Rangitoto Lighthouse, spending more time on each board and completing a few less maneuvers. Another 20-minute sailing session, the team stopped for about 15 minutes. Not seen making any changes to the yacht.
After this last break, the team started working on some practice starts using one of the permanently laid race marks as the pin and the rest vital marks. They completed two starts each with a short 2-lap windward-leeward. Sailing back into the harbor after the last upwind. Dropping sails just east of North Head and heading into the dock.
[AC37 Joint Recon team: Sam Thom and Andrew Burgess]
Crew: Sailing: Peter Burling, Nathan Outteridge, Andy Maloney, Blair Tuke. Cyclors: Hamish Bond, Louis Sinclair, Marius Van Der Pol, Simon Van Veltooven, Marcus Hansen, Dougal Allan
Session Statistics: Emirates Team New Zealand - AC75 - Boat 3 - Day 1 - April 12, 2024 - Auckland
- Weather: 17-20° Part cloud cover otherwise sunny.
- Wind Strength: 5-12kts
- Wind Direction: 230-240
- Sea State: 0.1mtrs
- Crane In: 0930hrs Dock Out: 1100hrs
- Dock In: 1540hrs Crane out:
- Total Tacks: 15 - Fully foiling: 11; Touch & Go: 3; Touch Down: 1
- Total Gybes: 12 - Fully foiling: 12; Touch & Go: 0; Touch Down: 0
Additional Images: