Tornado-Cat

The winning foils

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The winning foil ? (from a photo posted by nav in another thread)

 

attachicon.gifFoil.PNG

While TNZ is bringing the focus on their cyclists, no comments here ?

 

If the picture is right and not PS, this foil has a trailing edge like the wing of a plane going down.

 

What if their trailing edge is flexible and preformed that way ? The foil would have a natural tendency to go down with no load and to go up under load.

 

Basically the foil would act like to one of a moth without the need of a wand, thus providing better natural stability, without the need of an uptip.

 

With the 10% and 30% rules, teams who did not use their allowance could still copy it.

 

Not a poisson d'avril. What do you think Doug, and others ?

It's not a PS and its not the most radical shape one either, I'd suggest.

 

I don't know if it is the most radical shape or not but it is the only foil I have seen channelling the water that way at the bottom of the shaft.

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^ Here:

 

www.sail-world.com/152751

 

Also interesting that they would seem to consider swapping 10% tips as routine. So the choice is not simply low / fresh wind boards, there might be a palette of options in between thanks to different 10% tips

Thanks Xlot.

Long time that I think, and said here, that the 10% and 30% will make the difference.

 

As they have to put it for 9am for measurement and they need 2 hours to set it, the winning foils will be those properly set and the precision of the meteoroligical forecast.

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Team France made it clear earlier I thought that it was 30% that was being swapped by teams. Did I miss something in that SW article. Where is a swappable 10% tip mentioned?

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This answers at least some of the speculation as to why extra power helps. Straight from Dan Bernasconi himself

http://www.stuff.co.nz/sport/other-sports/91004250/performance-beats-reliability-as-team-new-zealand-change-tack

Just stating the facts that most people here knew but a few continue to believe can't possibly exist!

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Team France made it clear earlier I thought that it was 30% that was being swapped by teams. Did I miss something in that SW article. Where is a swappable 10% tip mentioned?

FC was clear that they could use the foil tips with the 30%, and Martin F explained they could not change the foil itself now but could still tweak the foil section. If not the 10%, what could it be ?

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For you Doug, the AC winning foil will be as horizontal as possible, but the new generation of trimarans will have an uptip and no foil under the central hull.

 

Gitana 17

 

GitanaMaxiTrimaran2017_13.jpg

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TC, don't be too sure about the daggerboard foil. When this picture was released recently they stressed that it was not an accurate portrayal of the foils. And their designer is Guillaume Verdier, who designed Maserati's daggerboard foil and their whole foil system. He believes strongly that the daggerboard foil is a real advantage for an ocean going tri.......

All the big tri's will be using UptiP ama foils because of the automatic altitude control for the ama.

Did you see Darth Reapius's sketch of the AC 49.2 foils? Almost every single foil was an UptiP in it's "normal" position-not even considering cant or foil loading. It's in the Light Air Foiling thread..... http://forums.sailinganarchy.com/index.php?showtopic=175623&page=2#entry5693382

 

 

 

Martin of catsailingnews said this morning that Macif is also testing a daggerboard foil(probably on this boat dl)

 

picture by Alexis Courcoux:

 

 

wko7rt.jpg

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Team France made it clear earlier I thought that it was 30% that was being swapped by teams. Did I miss something in that SW article. Where is a swappable 10% tip mentioned?

FC was clear that they could use the foil tips with the 30%, and Martin F explained they could not change the foil itself now but could still tweak the foil section. If not the 10%, what could it be ?

 

 

If you want to clarify your first unclear post don't use words like tweak!

We know they can reshape the boards as often as they like if it's a less than 10% change by weight.

GTF suggested the swappable tips (for all teams) were taking advantage of the up to 30% clause of the rule. (Although I was pretty sure there was a finite limit on how often you could swap 30%!?)

 

So are you talking about reshaping, or are you suggesting that they are swapping a tip (less than 10% of total foil weight) on the end of a swappable lower foil section (that is up to 30% of the total foil weight)?

 

All teams or just specific ones?

 

I guess it's also possible that what was said before the rule changes is all irrelevant now...

 

New foils (for GTF anyway) arrive about today IIRC

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Thoughts on AC foil design:

1) It seems to me like common sense that during the past year or so foil designers would have experimented with foil geometry enough that they may have found the golden key that unlocks a foil shape/implementation that creates an optimised highspeed foil with ,at least, a degree of heave stability without the drag associated with a "traditional" UptiP foil.

-

2) Also, they have no doubt worked on foil design and implementation solutions that will allow a foil theoretically optimized for one range of wind to be reconfigured in a situation where those conditions change in the middle of a race day. The idea that any Team would piss away the Americas Cup because the conditions changed is unthinkable to me. In my opinion, that means that they will use every means at their disposal from cant to changing foil tips to new types of foil design to allow a foil to work well in a much wider range of conditions than possible until now. That may be the most significant aspect of foil development in 35........

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In case you have any kids looking for "the Winning Foils" you might look at this: http://forums.sailinganarchy.com/index.php?showtopic=183182

The first really good foiling OPTIMIST! Video is not the best but the boat really flies.....

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Clearly what Ernesto originally had in mind with his hip pocket challenge running an optimist regatta.

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^ I used the word "tweak" the foil section because that is the word that MF used.

 

Do you understand what he meant though?

 

Do you want to clarify what you think is going on with changeable parts to the foils - or just act as if it's all perfectly clear, at least to you.

 

Your latest claims seem to be in conflict with what has been stated by at least one team.

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Thoughts on AC foil design:

1) It seems to me like common sense that during the past year or so foil designers would have experimented with foil geometry enough that they may have found the golden key that unlocks a foil shape/implementation that creates an optimised highspeed foil with ,at least, a degree of heave stability without the drag associated with a "traditional" UptiP foil.

-

2) Also, they have no doubt worked on foil design and implementation solutions that will allow a foil theoretically optimized for one range of wind to be reconfigured in a situation where those conditions change in the middle of a race day. The idea that any Team would piss away the Americas Cup because the conditions changed is unthinkable to me. In my opinion, that means that they will use every means at their disposal from cant to changing foil tips to new types of foil design to allow a foil to work well in a much wider range of conditions than possible until now. That may be the most significant aspect of foil development in 35........

 

I think you will find that the foil cannot be changed during a days racing, tuned maybe, that was what ETNZ seemed to indicate in a recent explanation, but I am pretty sure you can't be 'swapping bits out', that's why they put so much emphasis on the weather forcasting.

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^

That's what I read also, not so much from a protocol point of view but a logistics point of view.

They said they would need to set the foils up, get the measurement certificate and then spend two hours tuning things.

 

This also means they would need to set it up on the dock and nothing I have seen suggests that ETNZ are remotely as efficient as BAR as getting their boat onto the dock :D

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Would efficient be quite the right word?

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Thoughts on AC foil design:

1) It seems to me like common sense that during the past year or so foil designers would have experimented with foil geometry enough that they may have found the golden key that unlocks a foil shape/implementation that creates an optimised highspeed foil with ,at least, a degree of heave stability without the drag associated with a "traditional" UptiP foil.

Agreed

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^

@Nutta

 

Questionable I admit. Dictionary.com has two definitions:

 

1. (of a machine or system or machine) achieving maximum productivity with minimum wasted effort or expense.

 

2. (of a person) working in a well-organised and competent way.

 

So, I guess it comes down to the definition of the objective. If your objective is to get the boat onto the dock, then #1 clearly applies IMO.

#2 not so much given the need for competency.

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Thoughts on AC foil design:

1) It seems to me like common sense that during the past year or so foil designers would have experimented with foil geometry enough that they may have found the golden key that unlocks a foil shape/implementation that creates an optimised highspeed foil with ,at least, a degree of heave stability without the drag associated with a "traditional" UptiP foil.

-

2) Also, they have no doubt worked on foil design and implementation solutions that will allow a foil theoretically optimized for one range of wind to be reconfigured in a situation where those conditions change in the middle of a race day. The idea that any Team would piss away the Americas Cup because the conditions changed is unthinkable to me. In my opinion, that means that they will use every means at their disposal from cant to changing foil tips to new types of foil design to allow a foil to work well in a much wider range of conditions than possible until now. That may be the most significant aspect of foil development in 35........

 

I think you will find that the foil cannot be changed during a days racing, tuned maybe, that was what ETNZ seemed to indicate in a recent explanation, but I am pretty sure you can't be 'swapping bits out', that's why they put so much emphasis on the weather forcasting.

 

You don't have anything against it in the prot or the rule

 

1) less than 10% change is authorized as many times as desired

2) it has to be declared

From December 8, 2015, a Competitor shall obtain prior written

approval from the Measurement Committee for any modification

including the changes as detailed in Article 35.10(d)(iii)

3) coming back to a previous agreed foil is not a change

 

So it only relies on the necessity of measurement and when the MC does it.

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Thoughts on AC foil design:

1) It seems to me like common sense that during the past year or so foil designers would have experimented with foil geometry enough that they may have found the golden key that unlocks a foil shape/implementation that creates an optimised highspeed foil with ,at least, a degree of heave stability without the drag associated with a "traditional" UptiP foil.

-

2) Also, they have no doubt worked on foil design and implementation solutions that will allow a foil theoretically optimized for one range of wind to be reconfigured in a situation where those conditions change in the middle of a race day. The idea that any Team would piss away the Americas Cup because the conditions changed is unthinkable to me. In my opinion, that means that they will use every means at their disposal from cant to changing foil tips to new types of foil design to allow a foil to work well in a much wider range of conditions than possible until now. That may be the most significant aspect of foil development in 35........

 

I think you will find that the foil cannot be changed during a days racing, tuned maybe, that was what ETNZ seemed to indicate in a recent explanation, but I am pretty sure you can't be 'swapping bits out', that's why they put so much emphasis on the weather forcasting.

 

You don't have anything against it in the prot or the rule

 

1) less than 10% change is authorized as many times as desired

2) it has to be declared

From December 8, 2015, a Competitor shall obtain prior written

approval from the Measurement Committee for any modification

including the changes as detailed in Article 35.10(d)(iii)

3) coming back to a previous agreed foil is not a change

 

So it only relies on the necessity of measurement and when the MC does it.

 

 

You just have to muddy the waters don't you.

I, and I presume Doug, were talking about what can be done during a days racing, after the foils to be used for that day has been made clear.

Read ETNZ on that if you want more info. Or find the rule that clarifies what changes if any can be made to foils during the day - after measurement.

And if you would state once and for all which bits of the foils you believe are actually going to be exchangeable instead of dodging the question (it's ok to say you are unsure) we might have a basis to work from in discussing % changes.

(The section of rule you quote has been well known for the last 2 years - but is meaningless without a clear understanding of implementation)

For all we know the 'mana from heaven foils' the teams all seem to suddenly be expecting may not even have exchangeable sections

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http://softbank-team-japan.americascup.com/en/news/327_HOLROYD-THE-WAR-OF-THE-FOILS.html


m517_crop169014_1024x576_proportional_14HOW STABILITY, STRUCTURES, AND DAMAGE WILL IMPACT AMERICA'S CUP




The battle that is the America’s Cup may start in 52 days, but make no mistake; the war of the foils has been raging for years.


As teams begin to line up with their America’s Cup Class race yachts in Bermuda, the dagger board shapes deployed are coming under increased scrutiny – what may look like similar designs to an untrained eye, actually yield multitudes of differences when matched against one another.


You might say Nick Holroyd, Technical Director for SoftBank Team Japan - who led the design of the first foiling America’s Cup yacht four years ago - has some expertise in this field and took the time to share his perspective on what he’s been seeing in the daily recon reports.


“How are they spending their allocation strategically? That’s what I’m asking”, said Holroyd.


“Can you perceive from their designs that they’re an upwind, downwind, or a maneuvering boat – where do they see the race being won? Once you’ve picked that strategic approach then you can look at the details of how they got there.


“For sure we’re seeing a real split in the fleet in terms of the stability that’s inherently designed into the boards. That may well reflect how far advanced those teams are with their control systems. The overall stability is the inherent stability in the board plus the quality of control system – how fast you can get boards to target – plus how good the human interface is for the helmsman.”


Yet wrapped in the stability equation, Holroyd is keenly watching for board failures on other teams as he dissects the structural engineering that other designers have gambled on in an effort to solve as many of the performance tradeoffs as possible.


“To make these boats efficient you’re forced into making some extreme structures”, said Holroyd.


“There’s an incentive in light air boards to have a lot of span – which is structurally difficult – and for heavy air boards you’re trying to design them to not cavitate, and that’s also structurally difficult.”


Asked how a team might fair if they had broken a foil during practice at this point in the competition, he was quick to assert that the time to build a new dagger board has long since passed.


“You’re well inside the timeframe to built a new board in time so if you have a major structural issue at this point that warrants ‘open heart surgery’, that can take you off the water for 3-4 weeks. These patients take a while to recover.


“If you were having structural issues in your boards at this stage of your campaign you would be nervous.”


As for the question of whether the Cup will be decided by foil design or control systems, Holroyd explained it’s still a game that’s decided by a multitude of factors.


“In the America’s Cup you’ve always had a whole bunch of things you’ve got to do right – you’ve got to raise the money, get the team going, sail well, have a fast boat, be reliable, have good meteorology – and frankly screwing up any one of those things could loose you the race. You have to have the complete package"












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C8fAqfNUwAAR26o.jpg

At long last, but the picture isn't clear: looks like T-rudders with a substantial acorn, in any case not similar to OR's Y stabilizers

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In case you have any kids looking for "the Winning Foils" you might look at this: http://forums.sailinganarchy.com/index.php?showtopic=183182

The first really good foiling OPTIMIST! Video is not the best but the boat really flies.....

 

Much better video:

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http://softbank-team-japan.americascup.com/en/news/327_HOLROYD-THE-WAR-OF-THE-FOILS.html

m517_crop169014_1024x576_proportional_14HOW STABILITY, STRUCTURES, AND DAMAGE WILL IMPACT AMERICA'S CUP

The battle that is the America’s Cup may start in 52 days, but make no mistake; the war of the foils has been raging for years.

As teams begin to line up with their America’s Cup Class race yachts in Bermuda, the dagger board shapes deployed are coming under increased scrutiny – what may look like similar designs to an untrained eye, actually yield multitudes of differences when matched against one another.

You might say Nick Holroyd, Technical Director for SoftBank Team Japan - who led the design of the first foiling America’s Cup yacht four years ago - has some expertise in this field and took the time to share his perspective on what he’s been seeing in the daily recon reports.

“How are they spending their allocation strategically? That’s what I’m asking”, said Holroyd.

“Can you perceive from their designs that they’re an upwind, downwind, or a maneuvering boat – where do they see the race being won? Once you’ve picked that strategic approach then you can look at the details of how they got there.

“For sure we’re seeing a real split in the fleet in terms of the stability that’s inherently designed into the boards. That may well reflect how far advanced those teams are with their control systems. The overall stability is the inherent stability in the board plus the quality of control system – how fast you can get boards to target – plus how good the human interface is for the helmsman.”

Yet wrapped in the stability equation, Holroyd is keenly watching for board failures on other teams as he dissects the structural engineering that other designers have gambled on in an effort to solve as many of the performance tradeoffs as possible.

“To make these boats efficient you’re forced into making some extreme structures”, said Holroyd.

“There’s an incentive in light air boards to have a lot of span – which is structurally difficult – and for heavy air boards you’re trying to design them to not cavitate, and that’s also structurally difficult.”

Asked how a team might fair if they had broken a foil during practice at this point in the competition, he was quick to assert that the time to build a new dagger board has long since passed.

“You’re well inside the timeframe to built a new board in time so if you have a major structural issue at this point that warrants ‘open heart surgery’, that can take you off the water for 3-4 weeks. These patients take a while to recover.

“If you were having structural issues in your boards at this stage of your campaign you would be nervous.”

As for the question of whether the Cup will be decided by foil design or control systems, Holroyd explained it’s still a game that’s decided by a multitude of factors.

“In the America’s Cup you’ve always had a whole bunch of things you’ve got to do right – you’ve got to raise the money, get the team going, sail well, have a fast boat, be reliable, have good meteorology – and frankly screwing up any one of those things could loose you the race. You have to have the complete package"

 

Nice analysis - hadn't seen this, thanks for posting.

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Funny how cavitation is mentioned by Holy roid as a big problem, Yet all the so called experts here, poo poo'ed me when i said ETNZ boards were cavitating at speed.

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Funny how cavitation is mentioned by Holy roid as a big problem, Yet all the so called experts here, poo poo'ed me when i said ETNZ boards were cavitating at speed.

 

There's a big difference between knowing that the heavy air foils are going to be up against the cavitation limit and actually witnessing the cavitation itself. There's no way for you to know from watching from above water if the boards are hitting the cavitation limit, the bubbles produced are tiny. It has very little to do with how much spray is coming up. In fact ventilating foils like on the sailrocket produce a ton of spray because they're sucking air from the surface down to the foil to surpass the cavitation limit.

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Cavitation was a HUGE issue for OR on their rudder T-foils during AC34. A very clever seat-of-the-pants fairing solution by Paul Bieker was part of their comeback success.

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C8fAqfNUwAAR26o.jpg

At long last, but the picture isn't clear: looks like T-rudders with a substantial acorn, in any case not similar to OR's Y stabilizers

 

m517_crop169014_1024x576_proportional_14

 

Uh-oh: so they're Y-rudders after all, although I'd say the Y is less pronounced than on OR and AR.

 

Also, note the extreme advancement of the stabilizer over the rudder blade, the Paul Bieker concept

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I thought you had it right the first time, confirmed by the photo of the orange-red rudders above.

 

What exactly are we seeing in the next photo?

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I thought you had it right the first time, confirmed by the photo of the orange-red rudders above.

What exactly are we seeing in the next photo?

Well, it seems to me there's a Y indentation on the stabilizer leading edge, no? On a T-rudder, it would be perfectly straight

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I thought you had it right the first time, confirmed by the photo of the orange-red rudders above.

What exactly are we seeing in the next photo?

Well, it seems to me there's a Y indentation on the stabilizer leading edge, no?
it's not obvious to me but you are probably right

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Funny how cavitation is mentioned by Holy roid as a big problem, Yet all the so called experts here, poo poo'ed me when i said ETNZ boards were cavitating at speed.

Cavitation does progressive damage, sort of like pitting on the suction surfaces - but damage is slow and progressive - likely only a big problem after running for hours, and can likely fill and sand every night to deal with it. They won't be running at the problematic 40kt+ speeds that often given lighter airs of Bermuda. The bigger issue is that to reduce onset of cavitation you need thinner foils - that don't have the bending strength of thicker lower speed optimised boards. Hence low speed (thick long) and high speed (thinner shorter) boards.

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Funny how cavitation is mentioned by Holy roid as a big problem, Yet all the so called experts here, poo poo'ed me when i said ETNZ boards were cavitating at speed.

Cavitation does progressive damage, sort of like pitting on the suction surfaces - but damage is slow and progressive - likely only a big problem after running for hours, and can likely fill and sand every night to deal with it. They won't be running at the problematic 40kt+ speeds that often given lighter airs of Bermuda. The bigger issue is that to reduce onset of cavitation you need thinner foils - that don't have the bending strength of thicker lower speed optimised boards. Hence low speed (thick long) and high speed (thinner shorter) boards.

 

Seems that most teams have long and thin, at least in low wind

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^ According to JS recently, maybe in the Holroyd article too, teams have only shown their first pair of foils so far. They didn't specify if they are the pairs for heavy or light conditions, am curious which it is or if it varies by team.

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I always thought and said here that teams would present their best foils when it is late and difficult for others to copy, even with the 30% and 10% rule.

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I always thought and said here that teams would present their best foils when it is late and difficult for others to copy, even with the 30% and 10% rule.

Do you think the late shown foils will be the heavy or light air ones?

 

Some articles have suggested the crossover will be between about 9 - 12 knots.

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I always thought and said here that teams would present their best foils when it is late and difficult for others to copy, even with the 30% and 10% rule.

Do you think the late shown foils will be the heavy or light air ones?

 

Some articles have suggested the crossover will be between about 9 - 12 knots.

 

Until now I thought, as everybody, that they were lightwind. However most photos show pretty good wind for BDA, and the fit the description of fin for speed and long for low wind. So, could they be both at the same time ? or intermediary before more specialized foils ?

Difficult to know.

Also, they can still modify the section of the foil with the 10%, perhaps by adding some extra thickness for light wind races. It is not forbidden if presented to the MC with IGES files, accepted, and measured.

I know nav is going to challenge that, but...

Anyway, the real speed test will be with the new foils, and all surprises are possible.

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I tend towards these foils we are seeing so far as the ones designed more for the top of the wind range too. That strategy also better-suits what Bermuda has had for the past few months.

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Right, iirc now is the period of stronger winds.

Yep. We have seen very, very fast straight lines and also sudden turns in the MIH videos, they must surely be the high-speed foils.

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Thoughts on AC foil design:

1) It seems to me like common sense that during the past year or so foil designers would have experimented with foil geometry enough that they may have found the golden key that unlocks a foil shape/implementation that creates an optimised highspeed foil with ,at least, a degree of heave stability without the drag associated with a "traditional" UptiP foil.

-

2) Also, they have no doubt worked on foil design and implementation solutions that will allow a foil theoretically optimized for one range of wind to be reconfigured in a situation where those conditions change in the middle of a race day. The idea that any Team would piss away the Americas Cup because the conditions changed is unthinkable to me. In my opinion, that means that they will use every means at their disposal from cant to changing foil tips to new types of foil design to allow a foil to work well in a much wider range of conditions than possible until now. That may be the most significant aspect of foil development in 35........

 

I think you will find that the foil cannot be changed during a days racing, tuned maybe, that was what ETNZ seemed to indicate in a recent explanation, but I am pretty sure you can't be 'swapping bits out', that's why they put so much emphasis on the weather forcasting.

 

You don't have anything against it in the prot or the rule

 

1) less than 10% change is authorized as many times as desired

2) it has to be declared

From December 8, 2015, a Competitor shall obtain prior written

approval from the Measurement Committee for any modification

including the changes as detailed in Article 35.10(d)(iii)

3) coming back to a previous agreed foil is not a change

 

So it only relies on the necessity of measurement and when the MC does it.

 

 

You just have to muddy the waters don't you.

1) I, and I presume Doug, were talking about what can be done during a days racing, after the foils to be used for that day has been made clear.

2) Read ETNZ on that if you want more info. Or find the rule that clarifies what changes if any can be made to foils during the day - after measurement.

3) And if you would state once and for all which bits of the foils you believe are actually going to be exchangeable instead of dodging the question (it's ok to say you are unsure) we might have a basis to work from in discussing % changes.

(The section of rule you quote has been well known for the last 2 years - but is meaningless without a clear understanding of implementation)

4) For all we know the 'mana from heaven foils' the teams all seem to suddenly be expecting may not even have exchangeable sections

 

1) Yes, I was speaking of the possibility to change foils during the race. I don't know, I think they have to be measured first

2) TNZ article seems to confirm that foils have to be measured in the morning at 9am before racing

3) I always said that theoretically both the tip and the 10% could be exchangeable. However:

- there is a limit of changes for the 30%, which means teams can only have a limited number of tips

- if teams break their foils they will limit this possibility and possibly have no exchangeable tips

- the 10% is about a modification. There is no possibiity, IMO, to stratify a new section during the race, so the only possibility is a small piece that can be fixed on the foil to make it thicker, or longer, for low winds

4) the fact is that TF told us they would have more tips than foils, so, unless a mistake from them, it is a proof. If they break some foils now it might be a different story. Even if they find the miracle foil, why would they give up the possibility to have extra material if the are allowed to ?

 

Back to TNZ, I am 100% sure that their bicycle is a smoke screen to hide something more serious about foil. If it was not the case, why would OR and TJ spy them so much ?

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clik17635215_1757325314597100_23453585359170

 

Maybe not interesting. Seemed to be missed in the Y or not-Y over the rudders, (not, with a torpedo, IMO)

 

Posting again as per the discussion above.

 

TC my only challenge for you is to delineate your various suppositions about foil use and adaption clearly enough for others to follow. It is so vague up until now that it could mean anything - but then maybe that is the effect you are hoping for? The old uptip methodology :(

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Look at all those non-aero rabble. Why bother with good foils if you have that lot in the crew pods? I wonder if they've considered a nice aero cycling configuration?

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Are there any good shots of foils from boats in BDA?

 

Weta got some great ones here.

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Are there any good shots of foils from boats in BDA?

 

Weta got some great ones here.

ETNZ spent the past six weeks training with the wrong foils, right?

 

Perhaps they removed them after the second sailing day just to hide them but that seems, umm, unlikely at this late stage.

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They spent time training on foils here.

 

Your guess is as good as mine on whether they were the foils that they'll use in BDA.

 

But one set was seen here only once that I'm aware of. Not saying that they were not used more than once, but it was towards the end of their time here and quite a short outing.

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Thoughts on AC foil design:

1) It seems to me like common sense that during the past year or so foil designers would have experimented with foil geometry enough that they may have found the golden key that unlocks a foil shape/implementation that creates an optimised highspeed foil with ,at least, a degree of heave stability without the drag associated with a "traditional" UptiP foil.

-

2) Also, they have no doubt worked on foil design and implementation solutions that will allow a foil theoretically optimized for one range of wind to be reconfigured in a situation where those conditions change in the middle of a race day. The idea that any Team would piss away the Americas Cup because the conditions changed is unthinkable to me. In my opinion, that means that they will use every means at their disposal from cant to changing foil tips to new types of foil design to allow a foil to work well in a much wider range of conditions than possible until now. That may be the most significant aspect of foil development in 35........

I think you will find that the foil cannot be changed during a days racing, tuned maybe, that was what ETNZ seemed to indicate in a recent explanation, but I am pretty sure you can't be 'swapping bits out', that's why they put so much emphasis on the weather forcasting.

You don't have anything against it in the prot or the rule

 

1) less than 10% change is authorized as many times as desired

2) it has to be declared

From December 8, 2015, a Competitor shall obtain prior written

approval from the Measurement Committee for any modification

including the changes as detailed in Article 35.10(d)(iii)

3) coming back to a previous agreed foil is not a change

 

So it only relies on the necessity of measurement and when the MC does it.

You just have to muddy the waters don't you.

1) I, and I presume Doug, were talking about what can be done during a days racing, after the foils to be used for that day has been made clear.

2) Read ETNZ on that if you want more info. Or find the rule that clarifies what changes if any can be made to foils during the day - after measurement.

3) And if you would state once and for all which bits of the foils you believe are actually going to be exchangeable instead of dodging the question (it's ok to say you are unsure) we might have a basis to work from in discussing % changes.

(The section of rule you quote has been well known for the last 2 years - but is meaningless without a clear understanding of implementation)

4) For all we know the 'mana from heaven foils' the teams all seem to suddenly be expecting may not even have exchangeable sections

1) Yes, I was speaking of the possibility to change foils during the race. I don't know, I think they have to be measured first

2) TNZ article seems to confirm that foils have to be measured in the morning at 9am before racing

3) I always said that theoretically both the tip and the 10% could be exchangeable. However:

- there is a limit of changes for the 30%, which means teams can only have a limited number of tips

- if teams break their foils they will limit this possibility and possibly have no exchangeable tips

- the 10% is about a modification. There is no possibiity, IMO, to stratify a new section during the race, so the only possibility is a small piece that can be fixed on the foil to make it thicker, or longer, for low winds

4) the fact is that TF told us they would have more tips than foils, so, unless a mistake from them, it is a proof. If they break some foils now it might be a different story. Even if they find the miracle foil, why would they give up the possibility to have extra material if the are allowed to ?

 

Back to TNZ, I am 100% sure that their bicycle is a smoke screen to hide something more serious about foil. If it was not the case, why would OR and TJ spy them so much ?

Same reason that dogs lick their balls. Because they can.

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I agree Stingray, ETNZ might be hiding these foils as they just wanted to test them and then cover them up from the competition!

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clik

 

Maybe not interesting. Seemed to be missed in the Y or not-Y over the rudders, (not, with a torpedo, IMO)

 

Posting again as per the discussion above.

 

TC my only challenge for you is to delineate your various suppositions about foil use and adaption clearly enough for others to follow. It is so vague up until now that it could mean anything - but then maybe that is the effect you are hoping for? The old uptip methodology :(

 

I think I responded you pretty politely and will all possible explanations. Now your turn, can you give us your point of view and how you can sustain it ?

Up to now you have just been criticising, complaining, whining, without any serious basis. Don't make a Dana of yourself :mellow:

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I hadn't seen this before-seems pretty good-mentions rudder differential and using cant to reconfigure a board:

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You're welcome-the best video on foils by any team so far! It's the first confirmation by any team of my theory of using cant to reconfigure foils-something I've said for a long time. Pretty cool!

 

 

The difference shown below is just cant:

 

2em39si.png

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TC, in keeping with the America's Cup axiom - "Never tell the whole truth before the Cup"-- I think when Team Japan showed the take off of the boat at 7.5 knots of wind they were fudging it. The reason I say that is the recent story by Team France of taking off in 6 knots of wind and doing 18 knots(corrected for misprint).


The stuff about cant and rudder differential are things every team is doing ,but they're not going to give other teams exact data on light air take off. I have doubts about the Team France info as well....


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Excellent video, thanks Doug.

 

+1

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Yep, not bad.

 

Clever editing at the beginning.

 

Beautiful smooth wing surface at the start, maybe only because it's in the shed?

 

No BS Kiwi engineer mode - didn't hear him mention F1 or a sponsor name a single time :D

 

Lots of switching between 45s and acc in the video and graphics.

 

Boards outside max beam in some diagrams.

 

Cant as adjustment or change of mode of course not 'reconfiguration'.

 

Only one 30% change allowed to any board?

 

No mention of exchangeable parts

 

Most radical shape now looks like ETNZ's original 'S' boards from the the AC34 tractor!

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Cant as adjustment or change of mode of course not 'reconfiguration'.

 

 

 

Damn "nav" what a pissy comment!

 

Merriam Webster----- reconfigure: to change the way (something) is arranged or prepared for a particular purpose

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confirmation by any team of my theory of using cant to reconfigure foils-something I've said for a long time.

 

Take my comment any way you like, but the foils are not being reconfigured in any sense.

Cant is simply one of three main foil adjustments that can be made while racing, but of course you cling to it as justification of ......something.

 

Also your drawings and annotations above do not represent the comments made in the video. But carry on....

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confirmation by any team of my theory of using cant to reconfigure foils-something I've said for a long time.

 

Take my comment any way you like, but the foils are not being reconfigured in any sense.

Cant is simply one of three main foil adjustments that can be made while racing, but of course you cling to it as justification of ......something.

 

Also your drawings and annotations above do not represent the comments made in the video. But carry on....

Say what you want, but you have been WRONG from the beginning about cant, which allows the uptip configuration from more stability.

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:lol: Gimme a 'U', gimme a 'p'...

I'm thinking you want to follow that with: Y.o.u.r.A.r.s.e! 😂

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Love the foil fairing in the dark with a laser beam to pick out the centreline! So that's how the pros do it. Will be setting that up in my garage tonight.

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Love the foil fairing in the dark with a laser beam to pick out the centreline! So that's how the pros do it. Will be setting that up in my garage tonight.

^ that was coool..wear your sunnies

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confirmation by any team of my theory of using cant to reconfigure foils-something I've said for a long time.

 

Take my comment any way you like, but the foils are not being reconfigured in any sense.

Cant is simply one of three main foil adjustments that can be made while racing, but of course you cling to it as justification of ......something.

 

Also your drawings and annotations above do not represent the comments made in the video. But carry on....

 

You know I think you really don't get it! The illustration in the video of cant showed exactly what I show in the sketch that I did in January-precisely....And the wording backed that up by describing a highspeed foil canted(bottom in*) for greater stability as I've been saying and saying for months.

It allows a foil to have a much wider effective range and allows foils to be built that can work well in any condition.

* when a foil is canted it can be the whole 15 degrees or just two or three degrees-whatever is called for by the change they're addressing.

The "S"foil allows the foil to start out max outboard to leeward and be adjusted from there by cant as necessary.....

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Doug

 

You are so full of shit. Your diagrams above regarding cant are BS. Watch the video again, Watch every single video of boats sailing and every singe photo. Nobody is using cant like you show and the video does not show what you are showing in your diagrams. They do not reconfigure the boards to become uptip. You really do not have a clue what you are talking about.

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3:40 in watch it several times and you might get it.

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Most radical shape now looks like ETNZ's original 'S' boards from the the AC34 tractor!

Forgive for the question, but why was ETNZ AC72 B1 nicknamed the Tractor here? Was it a dog?

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It was designed to plow a furrow through ORs rule change shit...

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I forget how 'Tractor' came to be (something to do with Massey Ferguson or some such after somebody called it 'agricultural'?) but it did start here at SAAC and extended even to T shirts worn by Kiwi fans in SF.

 

Both DogZilla and CheeseZilla were coined here too, 'DogZilla' making it into even the New York Times.

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Most radical shape now looks like ETNZ's original 'S' boards from the the AC34 tractor!

Forgive for the question, but why was ETNZ AC72 B1 nicknamed the Tractor here? Was it a dog?

 

Someone wrote that she looked "agricultural" compared to Oracle's elegant AC72.

Then the next poster came up with the nickname "Tractor". ETNZ fans used it in an affectionate way, others followed.

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Most radical shape now looks like ETNZ's original 'S' boards from the the AC34 tractor!

Forgive for the question, but why was ETNZ AC72 B1 nicknamed the Tractor here? Was it a dog?

 

Someone wrote that she looked "agricultural" compared to Oracle's elegant AC72.

Then the next poster came up with the nickname "Tractor". ETNZ fans used it in an affectionate way, others followed.

 

 

and then it foiled!

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Do these AC50's ever - ever foil with the tip of the foil out of the water like the 72s?

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Yes, they all sport the patented system widely known in the industry by the name UptiP.

 

How much time they get that tip out of the water during a race is read real-time off the boat and displayed in graphics during the broadcasts by a BMW developed system called TiptimE.

 

It's truly brilliant..

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Do these AC50's ever - ever foil with the tip of the foil out of the water like the 72s?

 

No

 

 

sketches by Darth Reapius from "the winning foils" :

 

Almost all are some degree of UptiP and are shown with no cant. Cant can change how a foil works and can allow the reconfiguration of a "specialist" foil into one more suitable for the conditions actually encountered on the race course as opposed to the nutty idea of gambling the whole shebang on specialist foils that can't be reconfigured. See the video in post 1975......

 

e7lz5e.png

 

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^^

LOL. In fact, the foil tip is nearly horizontal (except on BAR) - zero or very small dihedral - and they don't appear to be canted (!!). There's a meaningful picture by Weta27 showing ETNZ in one of its initial outings, carrying out a foiling gybe. The boat is exceedingly high over the water, yet neither tip breaks the surface

 

This reminds me I cannot find any more darth reapius' beutiful summary, hoping for an update soon

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Am praying for an update too, especially once we see the second pairs that teams sport here soon. By that 'Art of the Foils' video SBTJ could be that first reveal.

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D's sketchs show very little "up" to the foil tip of Team Japan and none of the sketches show cant. However, the video specifically shows an animation of a Team Japan foil canting from horizontal to uptip specifically to enhance stability. Cant can be use on every single teams foils to enhance stability as required......

It is a simple and basic method to allow the enhanced control systems for these boards to be used to reconfigure a foil for different conditions that might be encountered while racing. The so-called solution of light air and heavy air foils can be completely altered by designing a foil that can be optimized for different conditions with cant without leaving the team stuck with light air foils in heavy air conditions or heavy air foils in light conditions. Cant allows an instant reconfiguration of a foil to adapt to changing conditions with very little to no downside.

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What people here get confused by is they 'cant' understand the confusing definition that you are using for 'configure' or 'reconfigure.' There is a disconnect somewhere.

 

Reconfiguring the overall force vectors through cant and rake and depth is of course different from 'reconfiguring' just the foil shape - which quite obviously doesn't happen during a race.

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D's sketchs show very little "up" to the foil tip of Team Japan and none of the sketches show cant. However, the video specifically shows an animation of a Team Japan foil canting from horizontal to uptip specifically to enhance stability. Cant can be use on every single teams foils to enhance stability as required......

It is a simple and basic method to allow the enhanced control systems for these boards to be used to reconfigure a foil for different conditions that might be encountered while racing. The so-called solution of light air and heavy air foils can be completely altered by designing a foil that can be optimized for different conditions with cant without leaving the team stuck with light air foils in heavy air conditions or heavy air foils in light conditions. Cant allows an instant reconfiguration of a foil to adapt to changing conditions with very little to no downside. wrong

 

"For each board once it's deployed we're allowed to rotate it about two axis, the secondary axis of cant we can use to modify the the orientation of the board in a way that perhaps gives us more stability so if we can go from perhaps a mode which is very fast but unstable to a mode more stable easier to sail kind of mode and can the guy when he's driving the boat look around and get his head out of the boat and see the gusts coming or is the board so tricky to sail that it requires the complete focus" - Nick Holroyd

 

Absolutely no mention of high wind or low wind speeds, he specifically mentions cant slows the boat down and makes it a more stable foil, simple as that.

 

Downside - cant = slow.

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^^

LOL. In fact, the foil tip is nearly horizontal (except on BAR) - zero or very small dihedral - and they don't appear to be canted (!!). There's a meaningful picture by Weta27 showing ETNZ in one of its initial outings, carrying out a foiling gybe. The boat is exceedingly high over the water, yet neither tip breaks the surface

 

This reminds me I cannot find any more darth reapius' beutiful summary, hoping for an update soon

 

Been in a remote town with no internet spearfishing. Back to civilization now, I notice there's some new things out there! France sailing with their new boards sounds pretty interesting (instead of noticeably asymmetric boards) so I'd expect to see them really picking up.

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It was designed to plow a furrow through ORs rule change shit...

 

Ha, ha. Classic.

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"Absolutely no mention of high wind or low wind speeds, he specifically mentions cant slows the boat down and makes it a more stable foil, simple as that.



Downside - cant = slow." quoted Darth.



This is so on point, Thanks.



So for years Lord Dog has spewed his crap on about how this cycle is still using uptip technology as per AC72's whilst those more enlightened have known that the game has moved on significantly into a different phase and style of foil shape and importantly control, that has little relevance to the past.


He has railed against this tidal shift as he has clearly lagged in his comprehension and his increasing irrelevance.



We saw another recent climb down during his post #1931 and now we have the Nic Holroyd Video to drive the point home that no longer in the world of active controlled foils does anyone still use the dihedral as created by the ororiginal M&M uptips, unless of course you want a passive foil system - which is not the case in AC world.



BUT, still we have him clinging to the last vestiges of his knowledge by claiming that ANY amount of foil tip that operates above Horizontal is uptip, and now he compounds that by claiming it "reconfigures" the foil.


So semantics on angle of tip and poor choice of words is what keeps our fLoriDa iDiot in the game......



Thankfully we are 50 days away from seeing actual foil shapes, how they will be flown, and the performance that results.


Then we will see a deluge of opinions on why one foil was faster than another with a thousand extenuating circumstances of "But" or "Shoulda, woulda, coulda" & "Its never normally like this....."


But that's sailboat racing....



As Oracle just showed, you are only one luff away from nearly capsizing (the whole show)....... And that mistake was caused without the presence or pressure of another competing boat. Food for thought.



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Do these AC50's ever - ever foil with the tip of the foil out of the water like the 72s?

DON'T FEED DOUG LORD

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