34th America's Cup: multihulls!

when you have a ton of clever people in your team that can think out of the box you need the lawyer to keep looking at the rules
Clever peoples thoughts come after the rules so hence they are always pushed as its rare day the smartest guy has written the rules.
There's one born every day, and in this case its the next genius

 

Sure, shoot the messenger, eh Doug - this piece is not mine but by Charles and Monsonnec (you may have heard of them? - like you know, they have a foiling site).
They ask some questions ... and the answers we've been fed by the convicted cheaters Oracle, are not convincing.
Not everyone has the gullible religiosity of yourself.
And yes, yes, shoot the doubters down with the tired old BS: conspiracy, tin hats, bla bla etc.

 

First Foiling Americas Cup-Property of the USA!

Its a real damn shame that you and others continue to impugn the character of Ellison, Spithill, the Crew, the Measurers, the Regatta Management and all those who have conclusively shown that there was no cheating. No excuse for it except that people just can't believe the Team Oracle did as well as they did. They flat crushed Team New Zealand-blew them right off the water-and you and these other conspiracy freaks just can't take it-and further, don't read or watch all the available information.
It is the most disgusting, pathetic demonstration of poor sportsmanship and sour grapes I have ever witnessed in my entire life!

 

"Component X" was a small spring, which was allowed under the rule. ("The use of stored energy and non-manual power is prohibited, except:
(a) for small springs, shockcord, and similar devices;") It was removed in later versions of the system. ETNZ tried to protest it on the basis that the spring force was resisted by the valve mounted to the trunk, and therefore the spring did work on the trunk. But even had their protest been timely, and even had the Measurement Committee ruled that the spring force contributed to moving the trunk (neither of which were the case), it was already OBE as the spring was dropped from the design before the regatta started.

The mechanical feedback was purely based on the position of the board trunk, and there was no measurement of the motion of the boat. So no stability augmentation system. It was a rules-compliant hydro-mechanical servoactuator that compensated for varying hydraulic supply pressure to give a consistent response to the controls. All it did was control the position of the valve - the position of the valve in space.

 

Now that's interesting! Thanks for the description.

That there isn't any electronic genie leveling the boat during those beautifully smooth foiling tacks and jibes, causes me to wonder all the more about what the crew who are controlling the foils are up to, during those maneuvers.

 

Okay, the truth slowly emerges - more to come I'm sure; this from over at SA posted by JohnMoon:

Posted Today, 10:11 PM
Clean totally missed it during his interview with Jimmy.
He asks Jimmy about the "little Herbie" and Jimmy flat out denies it. Then later, Jimmy spills the beans by mistake and goes on to explain how:

A. The foils are adjusted by only him using buttons on the steering wheel.

B. But then admits in the interview shortly thereafter that foiling upwind takes a massive amount of grinding upwind to stay on the foils upwind -"it just kills the grinders" Where would they be expending all that hydraulic pressure?
Jimmy can't be adjusting the foils accurately during this high speed (30 knots) mode. He's simply driving the boat. He has a gross adjustment on the wheel but I would think this type of mode would take super fast micro-adjustments powered by the hydraulics/grinders and a computer.

The hulls are about a 12" out of the water which would take major, rapid fine tuning, to control ride height, thus the huge, exhaustive amount of grinding going on during this mode.

To me, that would imply that some sort of automatic sensor is in the system is controling the foil angles - i.e. optimum ride height to reduce leeway. Super quick adjustments.... The guys just supply the oil pressure continuously.

From the video in the last 2 races where OR would just roll over the top of NZ on port tack at 30 knots, the grinders are grinding like mad, full time and it not for trimming wing sheet.

It seems like a lot of top OR people are {flat} out denying they had an automatic system but I think the facts show that that may not be the case. I think they installed it during the day off when they pulled the card. They didn't think they would need it but they were getting killed. Simply "sailing lower and faster" like Coutts is saying just doesn't make sense. They could have done that ealier in the regatta. And they would have discovered that from their two boat testing.

NZ wasn't grinding like mad when foliing upwind. Why? They only had the manual system adjusted by Dean on his wheel. They couldn't maintain it for very long or stay at a lower height (less leeway).

 

Problem with internet chat rooms is it's easy to take a desired conclusion and put together clips and details and make it sound like something, whether or not it's reality.

I don't see many facts in Gary's post. The only one I see is an observation that the grinders were working much harder. Good observation.

Now a yard trailer can lift the whole boat with 5 hp. A crane uses 150+ hp engine to lift the same weight and do it faster. No computer control necessary to put more power to a task. I know, apples, oranges. Point being, the theory a human can't control a system that consumes an {unknown} greater power put out by the grinders is a stretch.

 

Gary, here you have the claims written and signed by Tom Speer in person, against the suppositions based on guesses from somebody on the Sailing Anarchy forum.
If Tom Speer (not Oracle, but TSpeer in person) says that there was no automatic control system on board, then for me it is so and the thing is over.

Team Oracle is an entity created to move a lots of money involved in this (by now past) event, and hence it is not unimaginable that a lots of stuff has been going on in the shadows. But Tom Speer is a single person and a professional who has no reasons to write unsolicited false claims, so I believe him.

Cheers

 

First Foiling America's Cup: Property of the USA!

===============
Nuts! No truth whatsoever in that pile of horsemanure.

 

Since stored energy is not allowed Perhaps the grinders are simply pressurizing the system full time and a pressure relief vavle is bleeding off the excess.
The circuit is always fully charged and ready for response.

Doesnt sound illegal or technically advanced to me.

A normal engine driven pto is running full time...the grinders simply replace the diesel engine

 

Thanks very much for the clarification. I have one minor question: if the control and the board trunk was set to an angle of X (relative to the hull, not the water) and some outside force moved the board trunk to an angle of X prime, did the device move it back to X when power was available, or did it leave it alone until a new angle was commanded?

As a aside, did you ever work with Francis Reynolds at Boeing?

Cheers,

Earl

 

Yes. No. No.

One thing to think about is there was a LOT of friction opposing the board rake. The board had to react the side force from the sailing rig at a point one to two meters below the hull, and the vertical lift was inboard, adding still more to the moment on the board. Some pretty thick carbon was operating near the limit of its capability, and all that had to be reacted by the bearings of the board trunk. It's not like it was free to move under the influence of, say, varying drag due to speed or changing moment due to flying height. It was a pure position-command/position-hold system with no direct or indirect influence from the boat's flying height.

With regard to the height stability, the big lesson learned during the campaign was the natural coupling between side force from the sail rig and flying height, due to the coupling with leeway. It turns out that an L foil is in fact a surface-piercing foil even when the horizontal wing is well below the surface. That's because it is producing a lot of side force as well as vertical lift.

Due to the side force, the leeway varies a lot as the boat flies higher or lower. When the wing on the L board has dihedral, leeway will reduce the lift on the wing. That means that when the boat starts to fly higher, the leeway increases because there's less vertical board in the water, and the increased leeway reduces the lift on the wing. So you get a natural, stabilizing effect that's purely hydrodynamic with no change in the board rake.

Canting the board increased the dihedral of the wing and provided vertical lift from the rest of the board. This made the boats more stable when foiling downwind. Upwind, when the boards weren't canted as much so as to minimize the induced drag from side force, the boats weren't as stable.

The problem with dihedral is the vertical lift on the wing gets a leeward tilt. So it's like lee helm on a rudder - it adds to the side load that the vertical part of the board has to produce. So there's a drag penalty associated with increased stability. Getting the right balance of dihedral, wing area, and board immersion was a big part of what the teams were working on over the last year. To some extent, the teams started from different locations in the design space and arrived at a very similar point.

Say one team ended up with foils that were a little more stable and a little larger than the other team. That could make it easier for them to foil in marginal conditions, but it would also mean more drag that would hurt their upwind performance. But if they learned to use those small differences to their advantage, they could turn that upwind penalty around by foiling to windward with just enough natural stability to make it possible.

If they also had, oh, I don't know, maybe a center pod that caused the bottom trailing vortex to pass under their aft beam instead of over top of it, they'd have effectively extended the span of their wing by one or two meters, and that would have a big impact on their aerodynamic drag upwind. They could tune their wing to produce more power down low, but not suffer as big an increase in induced drag because of the span extension from the pod. Another team might try to recover a little bit of their induced drag by putting a box vane on top of their beam, but it wouldn't change the basic problem that their vortex rolled up above the beam instead of below it. With fundamentally better platform aerodynamics, a team could afford to trade off a little foil drag for more stability.

Maybe one team had a better appreciation of what was required for stable pitch-heave coupling, and realized that having the aft end of the boat in the water was destabilizing. That team might just trim their boat more bow-down so it was less likely to pivot about the stern when skimming. Which would, in turn, ensure that the boat came off the water in trim when skimming upwind and make it easier to make the transition to full foiling. A team that didn't understand pitch-heave coupling as well would have a tendency to rear up when trying to foil under those conditions. If they had flatter, fuller hulls, it wouldn't make it any easier for them, either.

All hypothetical, mind you, because I didn't have any insight into the other team's design. But this thread seems to be all about hypothetical supposition anyway.

 

Thank you very much. I didn't quote the additional material, but as an old control systems type I found it fascinating. Too bad you never met Francis, I think you guys would have had a lot to talk about.

Cheers,

Earl

 

Tom,

Thanks again.

You frequently provide reliable insight and enlightenment into things that the confound the rest of us.

Normally this has mostly been in reference to wings and foils, but our good fortune put you in a position to have real access to a certain amount of AC technical information.

I understand and respect the fact that there are probably limits to what information should be shared.

I am sure that a good bit of what was learned would be applicable to more mainstream boating. I hope at least some of it can eventually "trickle down" and become generally available.

 

I thought this cup did allow stored power if generated by the crew?
1st time in the AC history it was allowed as they knew they would need it