America's Cup declining?

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I said this about Artemis:

"As to Artemis, it appears to have been crew error combined with an engineering fault, but since no "official" report has been released ,it is not possible to know for sure. But we do know that it was not "rough" on the day of her tragedy-thats just made up stuff, Mike."

 

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I'm not sure releasing the sheet at that speed and direction would have helped all that much-seems like the rig would be slammed by a whole lot of force from the wind coming more and more from behind as the boat slowed as opposed to from forward of the beam where it was before they started to slow. The foils have awesome power and could have -likely- prevented the pitchpole in the early stages if they could have jammed the windward foil down at max lift . Have you seen the last two TNZ finishes where they approach the line not foiling and all of a sudden punch it as they cross-fantastic display of foil power and very cool to watch.

 

All the loads come from the wind. Spill the wind, spill the power, reduce the loads.

Doug - "seems like" and "I'm not sure" are quibbling. The power of the main drove it under, nothing was done to get rid of the power. If they had of and it still went over you would have been correct. Watch it again.

When somebody shows the wing could not have been let out any more I'll accept all the other discussions. Speaking of Oracle.

Funny, no one ever comments. Except to call me an idiot. I watched one of the 45's do the same thing, at the end the jib was let loose, too late and too little with the size of the wing. Same result. It just didn't breakup.

Isn't it interesting just how slow the pitchpole happened? They slowly kept getting pushed over. A knife to the mainsheet would have given them a good chance to remove the wind pressure (if done early enough), possibly falling back to an upright position.

Don't you wonder if the designers could simulate the balance point where wind pressure and bouyancy would have made the crash inevitable due to gravity? Seems like the first thing an accident investigation would have checked.

 

Okay, you bear away in strong, hardening wind - but to dump power on a conventionally stayed, but full wing rig, like Oracle's, achieves nothing; actually makes situation worse because as the needle bows buried and the boat slowed, AW goes aft providing even more toppling moment on the massively powered wing.
Maybe with an unstayed rig where the wing could run out to and beyond 90 degrees abeam, to spill power - but such a free standing design is near impossible with this type of catamaran.
Oracle's major problem was the insufficient bow buoyancy.
Originally designed for a boat that wouldn't fly.
Also, as the cat slowed, the T rudders would have reduced their effectiveness, negative angles and less water speed passing over them, in keeping the sterns down.
But what they should have done, is not to have turned downhill in that wind strength and wave size, but kept jogging to windward ... and waited.
All 20/20 easy hindsight of course, different in the here and now..

 

Lets look at those facts:

Artemis wasn’t in rough conditions but she did experience a strong gust well over the average just as she was bearing away. That’s on record, I did read that she put her bow into a wave as well, and that’s just heresay, but likely. A bad combination , but importantly that was before she was broken in a pitchpole .

Oracle had both strong wind, and ran into a steep wave just as she was bearing away. Would it have made enough difference if the foil had been down? Very likely not, given the wave orbitals and the way the foils work in pitch control. And the professional crew surely made a call at the time they thought was on the ball and they certainly didn’t expect the result.

As for the failure of these boats to meet the initial SOR:

Wind energy was supposedly designed for up to 74% higher than that currently being allowed for in the finals ! 74% more wind energy driving these foiling platforms than is now allowed. It became very apparent that these non reducible rigid wings cannot consistently operate safely at anything like the 33 knot wind speed that was supposed to be the limit.

What do you think of Le Hydroptere? She at least was designed for ocean conditions and the concept has been successfully campaigning for several decades. A much better platform that the AC72’s in that regard. How would she fare against the ac72'S if the racing had been outside the bay or off Freemantle or Newport ..

 

Safety researchers learned decades ago that ascribing adverse outcomes to "crew error" is an intellectual dead end, as exemplified by this 70's-era aerospace industry joke:

NTSB to manufacturer: Why did your airplane fall out of the sky?

Manufacturer: The crew was operating outside the flight envelope.

NTSB: How do you know that?

Manufacturer: Because the airplane fell out of the sky.

A more contemporary and enlightened viewpoint is given by Nancy Leveson's observation that "human error is a symptom, not a cause." Analyses that dig below the symptom gain insights into subtle and complex factor that lead to progress -- the AF447 accident investigation is an excellent example of this.

Of course, if one's analysis is based on the premise that the technology is perfect, the venue is ideal, and the event management is above reproach, then the only conclusion left is that the people on board didn't know what they were doing.

Cheers,

Earl

 

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I think the reduction in the wind limit is a political overreaction to the Artemis crash. Team New Zealand sailed many times in winds at or above the old limit.
Any boat, properly engineered, should be able to. You still seem to have the tendency to try to tie the crashes to conditions when it wasn't or shouldn't have been a major factor-certainly not the "cause".
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Hydroptere is a great boat but given the reports from the Transpac I sure as hell wouldn't want to be aboard sailing through all that junk-not a good place for a speed record. UNLESS, they have the new radar/sonar they've been developing that would have the ability to see objects at the surface or just below in time for her to avoid them. I don't think they have that yet.
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Hydroptere has two surface piercing main foils and one rudder foil. The 72's have a single main fully submerged foil coupled to a curved foil that acts a bit like a surface piercing foil with a much smaller range than Hydropteres foils-so when the speed falls below or rises above a given speed range they adjust the AOI manually(electro-hydraulically). And two small rudder foils.
So in conditions suitable to both boats the AC 72 would have a real good chance.

 

And since the logical conclusion is that the people on board DID know what they were doing (they are the best of their generations, with the best of other generations aboard and onshore to add the benefit of their experience) then if there was nothing wrong with the boats then the only conclusion left is that none of these incidents really occurred.

I often wonder to what extent the "blame the sailors" idea, like other armchair quarterbacking, is simply a means by which people who have never been able to win a race can comfort themselves with the idea that despite all the evidence, they are actually better than the champions.

Just about every raceboat broach, capsize or other failure can be put down to crew error by some people. After all, if everbody was perfect in every way at every time no boat would ever capsize until the windforce on its fully-feathered sails was enough to blow it over. In the real world, of course, even the best humans are not always able to react and predict everything perfectly. Then the armchair quarterbacks criticise the sailors as if the fact that they were not superhuman means that they are to blame.

In all the talking to designers I have done and all I have read, one thing I have noticed is that the great designers are fine sailors and/or have very close relationships with very fine sailors. That grounds the designers in the real world where boats have to accelerate, get through nasty waves, bad air, gust response, and edge-of-control situations. Those who are more boffins, whether designers or commentators, seem to forget that sort of stuff and assume that boats are always in states of equilibrium and under perfect control in perfectly uniform conditions.

All the stuff I have ever read about human factors and accident analysis echoes the excellent points you have made. My wife's former boss was a vision scientist working in stuff like the ability of naval pilots to land choppers on small frigates, and the info he gave about the potential for the human nervous and visual systems to stuff up even the best pilots was fascinating - and scary. Add in "soft" psychological factors and accidents become much more understandable.

Cheers.

 

In an experimental development class Root cause failure analysis demands that the facts are established and not subverted..

Both Oracle and Artemis pitchpoled while bearing away in combinations of wind and or wave that were sufficient to cause a bow immersion at sufficient speed to drive the bow under.

Highly professional teams thoroughly briefed by the designers, engineers, and hydrodynamicists still were surprised to find themselves pitchpoled.
To blame the crews is neither helpful nor sensible. (I note Earl and Chris have just said the same).

The alternative, which the organisers themselves have adopted as fact (with very professional advice) is that fundamentally the designs themselves are flawed for the conditions they were supposed to be able to operate in. That is they failed their initial SOR.

If TNZ had so far avoided major incidents doesn't mean they wouldn't or couldn't. And the NZ team is very happy with the wind speed reduction and I guess a lot of people in that team too are breathing a sigh of relief. Some of the crew reported difficulty earlier in controlling the boat at speed in adverse conditions. If the craft are simply unsuitable then it's a lottery as to whether they founder or not.

Now with the huge reduction in allowable wind energy they are certainly a lot safer. The SOR has been adjusted sensibly to suit the boats by downgrading the conditions they can operate in but there were numerous capsizes and two boats wrecked before this occurred.

SO yes the experimental design is apparently at fault from any Root Cause Failure Analysis perspective and I'd like anyone to show otherwise.
What's concerning is that it appears a lot of people said the same before hand, that they would be a high risk, even a dangerous choice, but that was considered secondary to the corporate appeal of extreme sport.
A culture of deviance maybe?

I'm intererested in Le Hydroptere becasue her developers have ironed out the problems with foilers as best they can. And she is surely a much better foiling platform with decades of development and experience. She would suit the 33 knots semi sheltered admirably where the AC72's apparently don't.

 

They are using flat foils. And they are designing for too much lift at the operating speeds they are using.

You need an angled foil to control the amount of lift, or fancy computer control.

Like the old MU-2, once they told pilots NOT to cut flaps in an engine out on take off, the crash rate went way, way, way, down.

They need some aeronautical types (or them darned Ruskies) teaching them proper foil design and use.

IMHO.

 

Don't people like Tom Speer (Boeing), John Ronz (Rutan Voyager), Hal Youngren (Stealth fighters, Predator drone, Skunkworks, Project Daedelus) qualify as "aeronautical guys"?

 

Ive got a group of Swiss Sailors onboard this week. They are disappointed with the Americas Cup Circus

 

Chris. You forgot the, Late, Great Kelly Johnson.(Lockheed Lightning, F-104 Starfighter, U2, SR71, etc

 

The difference with Kelly Johnston is that he's not designing a current 2013 AC boat unlike the other aero gurus I mentioned, unless he's MUCH greater than we all thought.

 

Chris. Now I am confused.
Do you mean that Tom Speer, John Ronz and Hal Youngren were involved in the design of Oracle. :?: