Cup Spy: Video looks at what ETNZ are doing with their test wing foils program
by Richard Gladwell/Sail-World NZ 29 Jan 17:04 NZDT
26 January 2024
Emirates Team New Zealand - LEQ12 Prototype - Day 59, January 26, 2024 - Auckland © Sam Thom / America's Cup
An America's Cup commentator, with access to the Recon File System - the repository for all spy information collected by the individual recon teams, looks at what Emirates Team NZ are doing with their test wing foils program.
Tom Morris, a sailmaker and top UK sailor, has been a long-time follower of the America's Cup, particularly in technical analysis, and has produced a series of videos looking at various aspects of the Cup under under the banner of Mozzy Sails.
Last week, he released a video analysis which claims that the "new foil" being run by Emirates Team New Zealand is not a new foil at all, and gives quite a detailed explanation to back up his assertion.
Like Sail-World, Mozzy Sails has full access to the Recon File System which contains all the content gathered by the AC37 Joint Reconnaissance teams which follow each America's Cup team when they are sailing in other than One Design mode on an AC40.
To recap, Emirates Team New Zealand restarted sailing for 2024, on January 16 - with a new wing foil fitted, and did a towing test - covered by their AC37 Recon Team, and sailed the day afterward. On January 22, their assigned Recon team reported a new second wing foil on Emirates Team NZ - www.sail-world.com/news/270829/Cup-Spy-Jan-21-22-Kiwis-reveal-new-test-foil
At the time we looked at the "new" foil and couldn't see a lot of difference with the one from January 16. There was no declaration sheet, that we could see, and the Recon team commented to that effect. The Mozzy Sails video questions whether there is in fact a new foil, and says that if there was it would mean that the Kiwis had exceeded their permitted allocation of four new foils for the LEQ12, 40ft test boat. He also looks in detail at the two wing foils first revealed last week.
- On the first report from the Recon team on January 16, 2024 their report comment alongside Port and Starboard Wing read "New foils were being used" on both Port and Starboard foils. The port wing flap was recorded as 0391243_FF1207 and Starboard wing flap as 0391242_FF402
- The next sailing day, January 17, 2024, the Port Wing Foil was now identified as "0391233_FW1207" the starboard foil was blank - under "Changes" the comment read "New Starboard Foil again. Waiting for declarations.
- On January 18, 2024, the Port wing had the same Foil id and same Flap id. On the Starboard Arm the comment was made "Continuing to use the new Starboard foil (FW04).
- On January 19, 2024, the Port Wing Foil ids were unchanged, the Starboard Wing and Flap, were commented a continuing with the new Starboard Wing.
- Next sailing day on January 22, 2024, the port wing and flap had the same id as on January 16, 2024 but with the comment - "Day 1 New Port Wing", however the Starboard Wing and Flap now had identification data with the wing called "0391234_FW1208" and the Flap "0391244_FF1208"
- They didn't sail on January 25, but the Port wing changed to 0391233_FW1297 (and the Recon Team comment - "Day 2 New Port Wing"). The previously unnamed orphans on the Starboard side stayed the same as the previous sailing day.
- Same song next verse for the following day January 26, 2024 - all the same ids for Port and Starboard wings, with just the Port wing comment updated to "Day 3 new port wing".
We did query Emirates Team New Zealand as to where the Recon team got this detailed information - and received the reply that "Recon and the accuracy of it, is totally the responsibility of each recon team. The teams don't have any input into what goes into it [the Report].
Bottom line is there is clearly some movement of foils and flaps. What is new and what is being reused is a matter for the teams to know and others to find out.
For the record, on November 13, 2023, when ETNZ restarted their LEQ12 program, having sailed the AC75 for the final time, the Port Wing foil id was "0391233_FW1207", and on starboard, the Wing Foil id was recorded as "391232_FW402".
We've had a long standing policy of not commenting on foil shapes, going back to 1992 when they appeared on the then new IACC class. Our logic is that the design teams for each team usually number about 30 people with the median degree being at a Masters level - usually in hydrodynamics or aerodynamics. Multiply that by five or six teams and that is about a collective design group of 150 boffins. If wing foil design was that simple, or obvious, one would have thought that over the five America's Cup cycle in the IACC class, they would have been able to come to some common understanding as to what was the fastest wing foil shape. Instead they were all different.
In the last Cup the teams had two quite different styles of foils. Again amongst over a hundred designers, there was no real design consensus.
At this stage of a Cup cycle the focus often goes on the nuances of foil shapes, as they are an obvious point of difference between the teams, yet after each Cup pundits and critics point elsewhere as to the crucial design factors that contributed to a win or loss.
The exception was in the 2017 Cup in Bermuda, when the Kiwis All Purpose foils were effective at a lower windrange than the Kiwis expected, and despite needing to be scanned to monitor the growth of a hairline stress crack.
ETNZ's policy seem to have been to design the fastest possible foils and then the sailing team is responsible for working out how to sail with them. It would seem that is a big part of the current exercise.
But have a look at Mozzy Sails video - what do you think?
Go back into the previous editions of Cup Spy - off the bottom of this page - and see what the Kiwi team were saying about their new foils in the Interview video.