Cup Spy - July 5: American Magic struggles in confused swells and sea state off Barcelona
by Richard Gladwell Sail-World NZ 7 Jul 2023 06:28 PDT
5 July 2023
American Magic - LEQ12 - Day 35 - July 5, 2023 - Barcelona © Paul Todd/America's Cup
What happened in the Cup - July 5, 2023:
- Alinghi Red Bull Racing sailed their two 40ftrs - out of Barcelona in an early morning session to avoid a lighter breeze later in the day, but encountered the same foiling issue as American Magic when the breeze lightened and the sea state did not.
- American Magic sailed their LEQ12 from Barcelona but in lighter winds and an awkward sea state had difficulty foiling on port tack. This can be seen in the Highlights video.
- Luna Rossa - no information on whether the Italian team sailed.
- Emirates Team New Zealand has arrived in Barcelona, and say they will be sailing in the middle of the month.
- INEOS Britannia is not sailing until August 1
- Orient Express Team (formerly K-Challenge) have announced their sailing squad.
Commentary:
Today was probably the most interesting yet, as we got the first look at multiple teams trying to handle the famed Barcelona confused seaway - in condition where the sea state over represented the wind-strength.
The two teams had very different days, but both had the same issue.
Alinghi Red Bull Racing caught the early breeze, before it was forecast to fade, and got in a good session with both AC40's using the supplied One Design foils. Alinghi Red Bull Racing removed their Tubercle foil, replacing it with a one-design wing foil.
American Magic picked up a fading breeze accompanied by a big swell running from South to North - not aligned with the breeze, and making it difficult to get foiling on port tack. American Magic co-helm, Paul Goodison reported it was impossible to take off on port tack directly into the 1 metre high southerly swell and an Easterly breeze.
The 2008 Olympic Gold medalist in the Mens Laser class, went on to explain that the sailing area was affected by a cross sea from two directions.
"There's one big wave swell going from south to north. And then there's a little bit of chop coming the other way where the wind and then as the day progressed, we were seeing 30-40 degree shifts around to the left. So what was a very favourable wind angle for taking off on starboard earlier on the day kind of got a little bit worse - port (tack) got a bit easier. But it was it was really good to test out the LEQ12 with with our own foils in' these conditions," he told the AC37 Joint Recon Team after the session.
Goodison believes the difficulty in lifting onto the foils would have happened regardless of what style of foils were fitted. The swell height and angle were the key factors.
"The wave angle played a massive part of it today, I think you could have probably had any foil on the boat and on starboard, you'd have had a significant gain and on port, it would have been almost impossible. It's never going to be easy when you when you go straight into a swell that's up to a metre in height. (The AC Recon team put the height at 1.5metres in their report, along with a swell from two different directions)
"Today is a little bit of a dark reality that maybe this is what's in store for us - a little bit bigger waves - a little bit lighter wind - and some some really tricky sailing conditions," he added.
Asked if their required take-off speed increased during the session as the wind lightened, Goodison responded: "I think a lot of it's just down to the waves and how you're surging."
"Obviously, as you as you're dropping down some waves, even if you're not going so fast, half the boat releases just naturally, depending on if you're in the peak or the trough. Sometimes you're able to take off quite early at some wind angles and wave angles. [Because of how the hull is sitting between swell peaks and troughs.]
"When the breeze shifts around, it suddenly it gets a bit harder to release the boat [as the angle of the boat to the swell changes]. So you've got to get a lot more speed to be able to get the hull out of the water, and onto its foils."
"It's all down to wave angle and height," he explained.
"At times the wind speed was hovering at around 5-6kts and none of the foils again are going to get the AC40 up on its foils, in that windstrength, no matter what the wind angle."
"You just have to be patient and wait for a bit more wind and then and then try and get some tests done."
Interestingly the minimum windspeed for America's Cup racing is around 6.5kts before the race start. It is believed that one goals of the rule changes made to the Version 2 of the AC75 Class Rule, is to lighten the boat to improve foiling ability at the bottom end of the wind range. The American Magic LEQ12 is an AC40 hull which is proportionately lighter than the AC75 - so the implications for teams racing AC75's in the Cup are quite serious if this issue is not resolved by the designers or sailing teams.
Given the conditions that prevailed Goodison explained that as the breeze shifted around the AC75 could "end up very square on to the swell."
"At some point, the whole structure falls out of the water, or the falls in the water and the hull is a long way out."
"We played around with different cant settings, different pitches, and then obviously setting the sails up to be a lot more forgiving than you would be for ultimate performance."
"We learned a lot today and we now have to review it all. Hopefully when we go out tomorrow, or the day after, we were in a better spot to learn something."
The as yet unanswered point, is the degree of cross-over from the AC40-OD (and the LEQ12 variants using AC40 hulls) to the AC75.
The foiling geometry between the two is quite different - and the AC40 performance will not be mirrored in the AC75, in the same sea-state. Another factor is the weight differential between the AC40 and AC75, with the 38fter weighing only about 36% of the larger 69ft AC75.
Hull weight (including crew) does affect foiling performance, and again it will be interesting to see the degree of co-relation between the two classes in the Barcelona conditions.
We will get a better handle on that once the two AC75's from the 2021 America's Cup - Patriot (American Magic) and Te Rehutai (ETNZ) start sailing in Barcelona.
From what we could see in Auckland the longer and heavier AC75 had relatively less trouble with an awkward sea-state in Auckland, than did ETNZ with their AC40. From what we could see on video on the rare occasion when American Patriot ventured out on to the Gulf of Mexico and copped an ocean sea-state, their AC75 seemed to cut through the sea-state with relative ease, and with less trouble than their chase-boats.
We are still of the view that being able to foil first at the bottom end of the wind-range (6.5kts) will be more crucial to winning the Cup than being able to hit 54-56kts at the top end. Time and time again in Auckland we saw races determined by light air foiling performance, and it will be the same in Barcelona.
Alinghi Red Bull Racing sailed both their AC40-One Design and their AC40 hull which serves as a LEQ12 development boat to test various wing foils, sails, controls and other custom design gear for the AC75 race boat.
Today the Swiss were wanting to test sails against the one-design benchmark, and removed the "Delta" or test foil, otherwise known as the 'tubercle' foil and replacing it with the standard wing foil. They were aware of the weather forecast for the breeze to ease later in the day and left earlier.
In the post-session interview Alinghi Red Bull Racing crew member Nicolas Rolaz said there will be more development foils to follow. Whether they will demonstrate the same lateral thinking as the 'Tubercle' foil remains to be seen.
Rolaz (22yrs) who eight years was still sailing Optimists, and won the World Championship, said that the Swiss also struggled with the seaway when the wind eased. "We didn't spend much time with both the J2 jibs up, because the waves were big and when the wind went down we struggled with takeoffs. But was good to test the J2 in this low-end breeze," he explained.
Weather conditions at Barcelona July 5, 2023:
Looking at the data below and comparing it with the Predictwind Observations, we can see that Alinghi Red Bull Racing left to begin training at 1000hrs and that for a period of about 90 minutes until just before 1200noon there was a good breeze of 12kts gusting 15kts from 060° to 070° before it eased back to be very patchy at 5-7kts, easing to about 3.5kts at 1800hrs, but holding a constant direction of 090°. American Magic didn't dock out until 1300hrs by which time the increased pressure had gone, and was long gone when they came in at 1730hrs. The lower limit for starting a race is 6.5kts average over a 30 second period until 4 minutes before the starting signal. So there is a good chance that in these conditions the race would not be started, but if it were then the racing is controlled by time limits and other requirements of the racing rules. In other words it would continue with the boats being unable to foil on one tack.
It would seem that the teams which have taken AC75s to Barcelona to test the seaway and design/sailing options will have an advantage over those who have not.
- The two Recon teams reported 5-12kt breeze from SE (Alinghi RBR) and 3-9kt SE (American Magic)
- Sea state: Beaufort 3 with Easterly Swell
- Conditions: 24 degreesC, Partly cloudy.
- Alinghi RBR Dock-out: 1000hrs Dock-in: 1355hrs
- American Magic (LEQ12): Dock-out: 1310hrs Dock-in: 1730hrs
- Luna Rossa Prada Pirelli: No AC37 Recon report available from teams sailing AC40s in One Design mode.
AC37 Joint Recon Team Reports:
American Magic - LEQ12 - Day 35 - July 5, 2023 - Barcelona
A two-boat session with pre-start manoeuvres was planned for the day and 2 buoys were dropped.
We rolled out 1015hrs with Magic (OD) first out but they changed plans once the mast was up, derigged, rolled her back in and got America (LEQ12) out on her own. Dock out was 1310hrs, crew on one tack was Slingsby with Menninger and Goodison with Campbell on the other.
Gibbs, suited up, was on stand-by on the chase boat along with Gulari and Calabrese, not on sailing gear.
After a long main hoist, again, plus some waiting due to an outbound GNV ferry at 1350rs we were out of the Port and upwind sailing on starboard tack at 24kts of boatspeed. Conditions were a SE wind at 6-8Kt and some confused seas (1m wind chop at 3.5 periods and 1.5metre combo swell at 6 sec periods from ESE and NNE). Take-off speed was 12kt but American Magic ventilated their foils seven times shortly after take-off, having to restart again on four occasions.
Then they held on take-off until hitting 18kts boatspeed and never ventilated again. The boat never sailed settled in these conditions, they were constantly over-correcting ride-height, windward heel and hull height (which fully touched the water regularly).
The wind dropped to 3-5Kt, after 30 minutes of sailing at 14kts of boatspeed in displacement mode sailing trying unsuccessfully to take-off, the team stopped we stopped at 1440hrs. Chase 4 pulled alongside and they had a 10 minute briefing and resumed sailing 1450hrs on port tack.
Again, they couldn't get America on the foils so they stopped 1452hrs for another briefing and what it looked like a crew change (in Gibbs, out Campbell).
The wind picked up a notch to 6kt and 1500hrs we resumed upwind sailing at 25kts boatspeed on starboard tack, with a 12kt take-off boatspeed.
Only one tack was completed all day - and was a "touch and go"
The team stopped sailing at 1510hrs and restarted sailing on port tack 1520hrs for six minutes - still not foiling as the windspeed dropped to 4kt.
The team stopped, had another briefing, and at 1535hrs attempted sailing again but couldn't get the LEQ12 onto its foils so they called it a day and towed back to Port.
Dock in was 1622hrs. When asked in the interview, Paul Goodison blamed the obvious port tack take-off difficulties on the wave angles and not on the different foils fitted to the port and starboard sides.
Report from: Lea Sitjà
Session Statistics: American Magic - LEQ12 - Day 35 - July 5, 2023 - Barcelona
- Total Tacks: 1 - Fully foiling: 0; Touch & Go: 1; Touch Down: 0
- Total Gybes: 0 - Fully foiling: 0; Touch & Go: 0; Touch Down: 0
Crew: Paul Goodison, Tom Slingsby, Lucas Calabrese, Andrew Campbell
Alinghi Red Bull Racing - AC75 - Day 74 - July 3, 2023 - Barcelona
From the AC37 Joint Recon team:
Alinghi Red Bull Racing rolled out their AC40-4 (YELLOW) and AC40-7 (RED) at 07:45 and 08:20 respectively, for a day of two boat sail testing. While the Red boat remains in One Design mode, the 'Delta Tubercle' foil on the Yellow boat has since been removed and replaced with the One Design foil.
The interview with Nico Rolaz, revealed there are more foils to come. The M1-1 LE mainsail
and J3-1 OD were prepared on the Yellow boat, the M1-2 OD and J2-2 OD on the Red boat, and both yachts docked out at 10:00.
The day's weather conditions were challenging, with dark clouds in the morning and squalls of heavy rain and gusts of 15+ knots. Wind conditions varied, with strong 'Llevant' winds offshore, the wind came through from the east, gradually shifting to 'Xaloc' (southeast) and decreasing throughout the session. Sea state was aggressively choppy, with an East Swell of 0.5m and 0.3-0.4s in period, increasing.
The teams started their session with upwind tacking. Yellow boat initially showed better performance, but the Red boat picked up pace in the lulls with its J2 sail. The second stint saw a series of tacks followed by a long downwind sail towards the course. A couple of roundups and bear-aways were also observed. The third stint involved a pre-start followed by a long upwind tacking duel, eventually leading to a long downwind return to the course start gate. As the wind strength decreased, the yellow boat higher angles out of gybes to maintain speed.
Post the third stint, the yellow boat swapped its J3 with the J2-1 OD sail. The fourth stint involved sailing upwind in light wind, with both boats struggling to maintain flight with their J2 sails.
The challenging sea state, in combination with decreasing wind, resulted in both boats practicing light wind takeoffs and manoeuvres. Light wind conditions and the rising sea state made manoeuvres more challenging towards the end, closing the session as both boats dropped their sails and were towed back to the base.
The new Catalyst 45 chase boat arrived the previous day and was on the forecourt today having its communications systems prepared. It is equipped with 4x Mercury Verado 450HP outboard engines.
Luna Rossa Prada Pirelli was still sailing when ARBR returned, while American Magic was exiting the port. Observing from a perch above the shop floor were Marcelino Botin, Adolfo Carrau, and members of the foil design and VPP team, indicating a focused attention on something new. Maybe related to Nico Rolaz' hint on upcoming foils.
The team spent four hours on the water, covering about 50NM. 51 maneuvers were performed at a rate of 18/hour (time measured in jib minutes), 88% fully foiling.
Session Statistics: Alinghi Red Bull Racing - AC75 - Day 74 - July 3, 2023 - Barcelona
- Total Tacks: 37; Fully foiling: 27; Touch & Go: 7; Touch Down: 3
- Total Gybes: 30; Fully foiling: 25; Touch & Go: 1; Touch Down: 4
Crew: Arnaud Psarofaghis, Maxime Bachelin, Yves Detrey, Bryan Mettraux; Nico Stahlberg; Théry Schir; Augustin Maillefer; Florian Trüb
Luna Rossa Prada Prada Pirelli - AC40-OD - Day 11 - July 35 2023 - Barcelona
No report available from the AC37 Joint Recon team:
This commentary was written and compiled from video, still images and statistical content extracted from the AC37 Joint Recon program and other material available to Sail-World NZ including photo files, and other on the water coverage from the 2010, 2013, 2017 and 2021 America's Cups. Its format is intended to give Sail-World readers a snapshot of all teams' progress on a given day or period.
The Last Word: