The back of the mainsil also flutters under tension (whipping sound). And canters vibrate like an alien noise

JaseNZ:

 

 

 

Yeah its the hydraulics its been mentioned on tv a couple of times. You would think they would be able to filter that noise out during broadcast.

 

I think Kenny said they included that intentionally, with the mic's that are on the boat. I dint mind, it adds to the atmosphere, you hear the boat, not just see it

American Magic had a permanent whistle, the sail and whatever hardware that was there, created the whistle

tdgeek:

 

American Magic had a permanent whistle, the sail and whatever hardware that was there, created the whistle

 

I also questioned their louder barking hydraulics. And if it was because the pumps were supplied by Airbus, the big sponsor. To me sounded like the ones in the A320 that bark when they are charging the primary and secondary systems using the PTU ready for flight :) 

3puttssuck: Bring back proper sail boats from days gone by. This is farcical and comes down to luck IMO.

I don't feel so. AC75 you drop off the foils, motor racing you have mechanical failure, or you get hit, rugby you get a card and lose a player.

The teams today used different sails, each for a reason, more gain = more risk. Light winds, thats a risk. They sail on the edge, just as F1 engines and chassis are built. Like any sport you get luck, but 13 races, that helps to average it out. There was a good amount of skill today, and some mistakes by the best sailors in the world. 

Thats sport

Oblivian:

 

jamesrt:

 

It may be a silly question, but here goes:

 

On the TV1 live coverage of the racing, there is the fairly loud hash buzzing or grinding sound very frequently - what actually is causing that?  It's probably coming over the radio feed; are the boats themselves actually that loud?

 

 

Straight line?

 

Strain forces on the carbon and mast stays I think. Accentuated when the mainsil is shifted under hydraulic ram.

 

When they are tacking, there is added noise of the hydros charging the Canter arms

 

I think that sound is the hydraulics tensioning the mainsheet and/or shifting the traveller, and it's probably a system using hammer action like a (pneumatic or electric) rattle gun to maximise peak torque and save effort from the grinders.  The maximum downforce on the mainsheet is 40 tonnes apparently. Tensioning up a sail is easy until you get to the hard bit if that makes sense, there's basically no stretch in anything, so not much effort to pull the sheets in 99% of the way, the last bit might only move the rope a tiny bit to get everything tensioned up, but will take almost all of the effort.  To put another way, you can turn a seized nut that you can't budge with all your weight behind a large breaker bar with a small hand tool that won't even twist out of your hands.

It's not a sound consistent with the usual creaks and groans of ropes on winches etc.

Fred99:

 

I think that sound is the hydraulics tensioning the mainsheet and/or shifting the traveller, and it's probably a system using hammer action like a (pneumatic or electric) rattle gun to maximise peak torque and save effort from the grinders.  The maximum downforce on the mainsheet is 40 tonnes apparently. Tensioning up a sail is easy until you get to the hard bit if that makes sense, there's basically no stretch in anything, so not much effort to pull the sheets in 99% of the way, the last bit might only move the rope a tiny bit to get everything tensioned up, but will take almost all of the effort.  To put another way, you can turn a seized nut that you can't budge with all your weight behind a large breaker bar with a small hand tool that won't even twist out of your hands.

 

It's not a sound consistent with the usual creaks and groans of ropes on winches etc.

 

They use hydraulic accumulators as well as live power. The boards go up and down on electric/hydraulic, everything else is man powered.

https://www.sailingworld.com/story/racing/mechatronics-in-the-americas-cup/ 

tdgeek:

3puttssuck: Bring back proper sail boats from days gone by. This is farcical and comes down to luck IMO.

I don't feel so. AC75 you drop off the foils, motor racing you have mechanical failure, or you get hit, rugby you get a card and lose a player.

The teams today used different sails, each for a reason, more gain = more risk. Light winds, thats a risk. They sail on the edge, just as F1 engines and chassis are built. Like any sport you get luck, but 13 races, that helps to average it out. There was a good amount of skill today, and some mistakes by the best sailors in the world. 

Thats sport

Batman: NZ boat is faster. Better sailors would be Luna Rossa as the always won the starts

mudguard:

I think I've watched most of the races and I get frustrated, what has the closest race been? 100m? There's next to no passing and even the most recent one was a farce. It is like watching F1 these days. Great from a technical point of view in terms of getting from point a to b quickly, but dreary to watch. And falling off the foils, I can't even think of a motorsport analogy, losing all but first in your gearbox?

I can think of a lot if F1 analogies that take you from a close second into the pits and lose track position. Then Lewis has a problem caused by himself or not and then you are both running together again

AC75 is man and machine and team, strategy, pick the windshift or avoid the lull, box TNZ in so your low wind advantage helps, sail the correct sails, or take a calculated risk that the slower to accelerate sails give you less drag once up to speed. Brains trust, skill.

Arguably the two foil drops are not bad luck. TNZ tacked in backwash from LR, should be ok, but their own backwash also played a part, you can call that a mistake. LR was in known light air when they tacked towards the gate, they could have done a wider turn to bleed less speed, but in sport if you are solid and reliable you run second. They made a mistake pushing the low wind a tad too far. That's sport, a game of inches

I like the technical aspects of sport, so to me at least, these nuances are part of it. From a "race", yes I can see it looks boring

Batman: Me no sailor but apparently the data says we've got a faster boat

https://www.google.co.nz/search?q=new+zealand+2+3+knots+quicker

That's from yesterday, same data for other days,

jamesrt:

 

It may be a silly question, but here goes:

 

On the TV1 live coverage of the racing, there is the fairly loud hash buzzing or grinding sound very frequently - what actually is causing that?  It's probably coming over the radio feed; are the boats themselves actually that loud?

 

I've discovered a better alternative coverage - the Official AC coverage streams live on youtube. They explained that it's the hydraulics. They explained a lot of stuff on that stream that you don't get on the TVNZ coverage.

Warning - I get the feeling that the American commentators on the Official channel supports Luna Rossa. Their voices were so upbeat and happy when TNZ dropped off the foils and then completely dejected when Luna Rossa got overtaken.