Author Topic: Americas Cup (Read 4542 times))

rsterne · « **Reply #80 on:** March 14, 2021, 03:59:21 PM »

How long will they delay racing if that is true?.... Any talk of shortening the Match?.... I sure hope not....

Bob

Novagun · « **Reply #81 on:** March 14, 2021, 05:26:27 PM »

No talk of shortening the contest. The word is that it will go as long as it needs to. Some are saying better wind today but the Metservice forecaste doesn't confirm that. There is a front on the way coming from the west but won't be here very soon. There is a change in the weather coming. Cloudy and breezy down here in Wellington.
They do have the option of other courses now that the covid restriction is lifted and they may get some wind further out. The Waitemata is a sheltered area especially where they have been sailing. This afternoon will tell.

rsterne · « **Reply #82 on:** March 14, 2021, 08:25:46 PM »

The "Morning Briefing" posted online says they are expecting 11-15 knots this afternoon.... Let's hope so!!!!

We just changed to Daylight Time here in BC, so the races are an hour later for us.... the first race is now at 8:12 PM....

Bob

Stinger177 · « **Reply #83 on:** March 14, 2021, 11:42:35 PM »

Quote from: Novagun on March 14, 2021, 03:50:54 PM

Forecaste for Waitemata Harbour up to and including Thursday. Variable 5 knots and up to 10 knots.

If they have deep snow foils, and want 25mph winds, they can come to Denver, Colorado, LOL.

I'll be watching again tonight.

Thanks again for the updates.

Stinger177 · « **Reply #84 on:** March 15, 2021, 12:53:25 AM »

WOW!

Spoiler alert for Race #7 - Don't read further if you haven't seen it!!

I got caught off guard watching the start and the first leg (I was busy posting elsewhere here in GTA) but it's nice to finally see some true closer match racing, and finally a change of lead within a race.

Let's see what a jib change will produce for Race #8.

I LOVE this stuff!!

Stinger177 · « **Reply #85 on:** March 15, 2021, 01:59:24 AM »

Race #8

Wow, again.

And then WOW, AGAIN!!

Within one race!! This one is worthy of some analysis.

What a race!!

Thanks for sharing with you guys!! We few band of Three Brothers!!

rsterne · « **Reply #86 on:** March 15, 2021, 02:01:57 AM »

WOW, just WOW!.... Spoiler alert if you haven't seen Race #8....

Race #7 was a great race.... but who would have thought that Race #8 would prove that light air sailing could be exciting.... From over 4 minutes behind at 2 marks to winning by almost 4 minutes in a shortened race, with both boats falling off their foils.... I won't tell you which way it went.... but you're in for some exciting stuff....

Bob

rsterne · « **Reply #87 on:** March 15, 2021, 02:02:50 AM »

We think too much alike....

Bob

Stinger177 · « **Reply #88 on:** March 15, 2021, 02:14:22 AM »

Quote from: rsterne on March 15, 2021, 02:02:50 AM

We think too much alike....

Bob

I see no problem with that. (Yoouse gotta problem wid dat?).

That Race 8 was just way too cool (or not). Bit of a nail biter, for either team supporter.

I wished for '80's style racing. I guess it's back, at least to some degree.

People make mistakes, and technology still cannot make up for it. I can't believe that NZ jibed over instead of just shifting up a few degrees and staying on the same tack, but then again, they don't pay me for my opinion, and I'm not on the boat.

Funky winds do not help either.

All the same, today was great fun to watch.

Happy that you guys are there to share this with.

Novagun · « **Reply #89 on:** March 15, 2021, 06:58:36 AM »

A pleasing result for Team New Zealand but it is not over yet. Jimmy Spittal is a crack helmsman and he has a slick team on Luna Rossa. Oh for 20knots plus of breeze. I just want to see if Ben Ainslie was right in his prediction that these monohulls could get to 60 knots. That would be something if not unsafe.
I don't know if you can hear it on the USA/ Canada video feed but Te Rehutai makes quite a loud buzzing noise as she sails. I think Luna Rossa does it as well. It is different from the noise of sheets groaning as they are clutched on winches. These boats probably do not have that system. They seem to have a traveller that does the trimming and a sheet that is really a boom or clew down haul. James thinks it is a hydraulic relief valve working. I think he is right.

I saw at the end of the second race one of the NZ crew with his head down. Not between his knees but hung low. One of the other blokes gave him a pat on the helmet. I thought the chap was either weeping or exhausted from grinding or just plain relieved.

rsterne · « **Reply #90 on:** March 15, 2021, 08:09:04 PM »

I have my own opinion for the reason the boats are falling off the foils.... I think in light winds they are retracting the (previously loaded) now windward foil too soon.... before the boat is back up to speed after a tack or gybe.... The Kiwi boat didn't touch down until they lifted the windward foil after the gybe.... The lift a foil (wing) creates is proportional to the area times the square of the speed through the water.... The drag of having two foils in the water is MUCH less than having the hull touch down.... For light conditions, drop the new foil, complete the maneuver, get the boat back up to speed, and THEN withdraw the unneeded foil....

Don't tell me this can't be done, Luna Rossa does it frequently when rounding the Leeward mark.... ever since they had the leeward foil stall and the boat skid many yards sideways during one of the races against the Yanks.... They learned that lesson from just making that mistake ONCE.... I think both teams have gotten so used to pulling the windward foil up immediately after a maneuver, when they are blasting along at 30 knots.... Do it at 15 knots, and you only have a quarter of the force to lift (or keep) the boat out of the water.... With both foils down, you only lose half the lift at 15 knots (compared to 30) and in all probability you stay foilborne.... JMO....

Bob

Stinger177 · « **Reply #91 on:** March 15, 2021, 09:17:02 PM »

This is too weird Bob.

I was thinking EXACTLY the same thing this morning while in the shower (it's where I do my best thinking).

Why are they not keeping both foils in the water until during a tack or jibe UNTIL they have established foiling speed, especially in lighter winds?

At the top of leg three, where Luna dropped into the water, they did lift their port wing way too early I think. The hull was already touching when they lifted that port foil. Wetted area, as we all know, is not a good thing.

It also appeared to me that NZ, upon approaching Gate 3, was on more of a reach (over-standing the mark) in order to stay foiling. Or maybe it's just me, or a luckier fluke in the wind in favor of NZ.

That's sailing for ya!!

I do wish they would have completed all six legs, but perhaps the Committee wanted to stop the pain and bleeding.

As for the buzzing sound, I haven't quite picked up on that. It's over-ridden by the sound of hydraulics controlling the traveler/clew (or whatever they call it these days on an AC75).

rsterne · « **Reply #92 on:** March 15, 2021, 10:31:12 PM »

There is a 45 min. maximum time limit for each race!.... I don't know if you heard it, but when Luna Rossa had just got back up on its foils, the race committee warned them there was only 7 minutes remaining....and they had nearly 2 legs yet to go....

Bob

Stinger177 · « **Reply #93 on:** March 15, 2021, 10:40:38 PM »

I did miss that part.

Thanks for the info.

Stinger177 · « **Reply #94 on:** March 16, 2021, 12:49:39 AM »

I'm obviously still learning about this foiling system, but do they actually angle the "outboard" foil a bit upward in a turn, sort of like pushing your hand against a wall to push yourself off in another direction?

I know that's a bad description, so let's call it the leward foil, or the one carrying the load on the turn.

The TV coverage is finally starting to show some great graphics in the form of wing wash!!

rsterne · « **Reply #95 on:** March 16, 2021, 01:15:49 AM »

Yeah, it's about time the TV coverage started showing the wing wash....

Yes, they have "flaps" on the foils so they can control the amount of lift.... In addition they can cant the rudder stock fore and aft, to control the attitude of the boat and also the angle of attack of the main foils.... bow high, more lift....

I'm going to assume you are watching live, but spoiler alert if you're not....

Spithill lost that race by not covering on the last weather leg.... The Kiwi's sailed great, but that mistake cost the Italians dearly, and they are now down by 3....

God I love Match racing....

Bob

Stinger177 · « **Reply #96 on:** March 16, 2021, 01:32:23 AM »

Yeah, I'm watching live right now. I'll be late for work tomorrow, LOL.

I wondered about the bow attitude. I was wondering why they didn't place the foils more forward to allow a higher angle of attack, but now that you've told me that, they can adjust that.

I'm an amateur aerodynamic engineer BTW. I also fly R/C sail planes, but underwater hydraulics are the same thing, right? It's all Fluid.

I did not know that they had flaps on the sail. So many new things.

Are they still controlling the tension of the mast stays? They must be, in order to control the luft?

Thanks for the info. I love this stuff!!

rsterne · « **Reply #97 on:** March 16, 2021, 01:39:40 AM »

They can bend the mast more to flatten the sail, or less to power it up.... No flaps on the sail, that's on the main foils.... It's the silver part on the back of the Luna Rossa foils, the trailing edge can move up and down to change the camber of the foil, and therefore the amount of lift.... They add camber to get the boat out of the water, then trim out the curvature to get rid of drag at higher speeds.... The main foils are placed pretty much at the CG of the yacht, and do 80-90% of the lifting, with the rest done by the foil on the bottom of the rudder....

I have designed and built a lot of my own R/C sailplanes as well.... so we have quite a lot in common....

Bob

rsterne · « **Reply #98 on:** March 16, 2021, 01:53:21 AM »

Race 10 Abandoned, see you back here tomorrow....

Bob

Stinger177 · « **Reply #99 on:** March 16, 2021, 02:00:11 AM »

Very cool info. Thanks.

Do these AC75 yachts actually carry spare (or alternative) sails onboard like in the old days. I can't imagine that they would even attempt a sail change these days. it's not like they can do a pit stop as in F1.

BTW, F1 racing starts this year in Bahrain, NOT Australia.

https://www.formula1.com/en/latest/article.f1-schedule-2021-bahrain-to-host-season-opener-as-australia-moves-later.4GpFlW2pc8sK9snFaVSHYg.html

GO VETTEL!! He found a ride!!

https://www.formula1.com/en/latest/article.f1-schedule-2021-bahrain-to-host-season-opener-as-australia-moves-later.4GpFlW2pc8sK9snFaVSHYg.html

So they abandoned racing for the rest of the day.

Guess that means I'll have to be to work on time tomorrow.

Or perhaps not.

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Americas Cup

Author Topic: Americas Cup (Read 4542 times))