Alinghi Red Bull Racing were docked-out early into a chilly Barcelona that barely registered above 5 degrees all morning for a three-and-a-half-hour session, keen to capitalise on a brilliant shakedown sail yesterday but with a check-list as usual, as long as their arms. The most obvious technique concentration was on tacking co-ordination so with relatively flat water and a breeze that built and faded around the 10-knot mark, it was nigh on perfect for Maxime Bachelin and Arnaud Psarofaghis to take everything out of last night’s debrief and put it into action on the water.
Smooth as silk was the result and a big foil-to-foil tacking manoeuvre percentage (91%) was posted as the helms just clicked beautifully with Yves Detrey and Bryan Mettraux who looked like easy riders, full of confidence with the team’s AC75 in these conditions whatever mode they selected. Pretty much it was a day of dialling low to the water surface with a modicum of windward heel whilst concentrating heavily on minimal mainsail traveller trim and power-on.
Lucien Cujean, however, a spare body behind Arnaud on the starboard pod, slightly gave the testing game away with repeated moves to the back of the mainsail looking at the leeward skin trim that looked today, quite tight at times. It’s an area that all the teams are trying to understand better as it appears to give accurate micro-trim to the mid-section of the mainsail and then on up to the head of the sail in alignment with mainsail sheet pressure through the advanced double-yoke mainsheet system that the Swiss appear to have nailed.
Today, Alinghi Red Bull Racing looked more than good, and the sail trim was on point – was that a co-ordinated pre-set main and jib release we can see in the video on the bear-away or just great trimmer/helm co-ordination? We will never know the truth but the Swiss are certainly well into the evaluation of co-ordinated pre-sets with the mast rotation, cunningham, forestay, jib halyard etc etc…Building up those playbooks of settings is the big game in town and today was perfect for that kind of testing and data gathering.
On the boat today and yesterday was Joseph Ozanne, the Simulation and Artificial Intelligence Lead for Alinghi Red Bull Racing and after sailing he can usually be seen deep in conversation downloading the day with the sailors – particularly yesterday with the Flight Control Team. Many commentators believe that AI and SIM work could be the key to winning the 37th America’s Cup so the Recon Team caught up with him for a fascinating insight into what’s really going on. Joseph began by saying: “It’s a huge field, it’s not very new and it’s something that everybody is using and it’s a bit of a toolbox that we use everywhere so to model the boat, to model the sails, to analyse the data, to get some kind of intelligence that can help find the right settings.”
“The most important thing is to get the physics right. You need to get the boat models right, the physics right and all the data needs to be good. If you have wrong data, you will have wrong answers, so making sure that what you use to feed the AI needs to be correct and then you can get something meaningful out of it…We cannot model everything and some of the physics are still not super accurate so we need to spend time onboard with the sailing team just to make sure that we are doing the right job and they are understanding what we try to provide so there is a bit of back and forth between them and us, so for us it’s quite important to spend a bit of time out there on the water just to make sure that we grab the physics correctly and the behaviour correctly and then we can get better discussion and better feedback from everyone.”
And Joseph continued: “There are things that are hard model you know like the instabilities in the wind or the things like the filament with the water that are pretty hard to capture like ventilation…we do our best to model it and we do a very good job doing it but it can always be different and then whatever we provide as designer settings we always need to validate it on the water anyway to make sure it matches our expectation. Also, when we’ve got feedback from the sailing team that is not really expected we have to understand, so it always goes down to the physics, how you model it, and how you transmit it on the computer and that’s the way you get a better and faster design at the end.”
The Swiss are certainly more than committed to success in this America’s Cup cycle – all eyes on what will come out of the team’s build base in Ecublens in a few months’ time. Fascinating.
INEOS Britannia were solo AC40 one-design sailing in Barcelona today, so no recon was following their progress. Luna Rossa Prada Pirelli called off their planned session today due to the weather forecast in Cagliari. NYYC American Magic scheduled a maintenance day today and Orient Express Racing were launched early this morning with their sails on the lock but again were still in one-design mode so no recon following their progress. (Magnus Wheatley)
On-Water Recon Report – Alinghi Red Bull Racing: Alinghi Red Bull Racing rolled out their AC75 at 08:00, followed by crane-in 30 minutes later. Routine systems checks were conducted, with a particular focus noted on mast rotation linked with mainsail skin clew actuators. The M1-1R mainsail and J1-2R jib were prepared on deck ahead of a 10:00 dock-out.
The mainsail was hoisted in the port, and the yacht was towed south, 3NM off the airport, where the J2-2L was hoisted. The day’s sailing was characterized by long stretches of aero testing on each tack at varying angles, with long and relatively flat residual swell.
Stint 1 (10:55 – 11:20, 9-12.5kn 335° @ 10:55)
The team started with long upwind and downwind stretches. Lucien Cujean was notably observed several times at the aft, watching the mainsail.
Stint 2 (11:30 – 12:05, 8-10.5kn 340° @ 11:25)
Similar tests were repeated with long stretches both upwind and downwind. A few tack-and-bear-aways, along with JK manoeuvres, were performed. More tacks than gybes were performed today, possibly to improve on the previous day’s tacking performance.
Stint 3 (12:20 – 12:45, 7-10kn 350-0° @ 12:10, 9-11kn 335-345° @ 12:20)
Further testing was conducted in a similar fashion. However, 10 minutes into the stint, the recon vessel encountered an issue with a snapped propeller blade. The team was observed from a distance, but not all manoeuvres were counted. The team concluded sailing at 12:45, with sails dropped by 13:00.
The team spent three and a half hours on the water, with 85 minutes of sailing time. A total of 18 manoeuvres were observed, 89% of which were fully foiling.
