America's Cup declining?

The comet was about materials science, particulalry understanding of airframe fatigue. The initial design had stress risers that lead to catastrophic failure. Once the stress risers were ironed out the vehicle was fit for service since the fundamental design was not flawed.

That's nothing like the AC72. The AC 72 are extreme in their very SOR, their level of structural safety (FOS) is always a gamble in a racing ULDB. Large sailing foilers can have no useful application they are just extreme sport platforms.

Even Le HYdroptere which is a tougher foiler than the AC72's is very extreme and quite prone to catastrophic failure. And they might sit for another year waiting for a weather window to smash the Transpac record and they still have an 'extreme' risk of foundering while doing it.

They are extreme alright.

For reference officially the safest form of transport ever invented is the lift not the airliner.

 

Hardly Doug. Taberly and friends did the ground work in the 90's and the Hydroptere concept has been continually researched funded and refined for how many decades now ? And it's still extreme and severely limited by ocean conditions and always will be.

Force 10 in a seaway would completely trash any of these types of boats.

 

America's Cup Ascending!

================
"Hardly, Doug."
Really? Who cares about Force 10 in a seaway in reference to the AC 72?
It's an Americas Cup boat suitable only for the anticipated conditions on the race course-just as it should be.
Your condescending attitude toward hydrofoils is really amazing and completely devalues your contribution. Keipers foiler sailed over 20,000 miles at sea -all around the Pacific. But we're not talking about cruising boats -we're talking about the most amazing America's Cup race boats ever designed.
Sailboats that do what no America's Cup boats in history have ever done-faster upwind and downwind by three or four times compared to other AC boats. Incredible vision of the highest degree of sailing technology from their air wings to their water wings- testaments to a vision for a state of the art + America's Cup raceboat!
They are spectacular boats and part of a vision to change the AC forever-and they will, I hope.

===============
Originally posted by Doug Lord>>
"The apparent wind on an AC boat will be between Force 8 and Force 10. Your "real" sailboat definition ignores that ,it seems to me. These boats are specifically designed as race boats and therefore,in my opinion, it is ludicrous to attempt to hold them to the same criteria you might hold an ocean cruising boat to.
These boats are highly engineered ,state of the art sailboats the likes of which have never been seen on this planet-to fault them for being new and state of the art + is shortsighted because you're faulting progress and new development at the same time............"

 

Doug I was referring to this:

So apparently you do !

The point is that Force 8 and Force 10 are a weather conditions and nothing to do with the apparent wind.

 

But they didn’t suit the course did they ! Two boats wrecked and numerous capsizes before the weather restrictions were introduced. And the carnage would have continued if everyone hadn’t happily agreed to reduce the weather to ideal benign conditions. Because the flying machines didn’t like rough conditions.

I know one foiler voyaged in the Pacific but that's the exception isn't it ? If people travel across Australia or continental Europe by hang glider or canoe to NZ from Tasmania does that make it a sensible form of transport for anyone but an extreme sportsman ?

I'd be intererested from a practical naval architecture approach as to how a ULDB foiler could match any sensible SOR for cruising, and that includes safety as well ? One down side of any multihull is their weight sensitivity, for a foiler that's going to be not just a downside but a total anathema. Anyway perhaps another thread .

As for it being a pinnacle of racing that's a matter of opinion, and you hold quite a different opinion to mine. That's OK with me but apparently you don't like the idea that anyone could diverge from the one true path.

Your posts sound more and more like fundamentalist religious zeal rather than an interested amateur designer discussing design on a boat design forum, for example:

If you turn that comment around and apply it to yourself ; Your emotional zeal is making you condescending in this case isn't it.........

These AC72's are extreme in every regard, it's a different argument as to whether they are good for the sport, so far it doesn't appear that it will be.

I watched the last race and I saw a team of skilled pilots keeping a giant flying machine in the air being followed by another giant flying machine. It looked as interesting as aircraft taxiing on a runway, ah there’s a deHaviland comet…

You think that’s the pinnacle of yacht racing, I don’t see it myself. I miss the real ongoing tactical battle that was so enjoyable.
The announcers try hard to inject some excitement but even they struggle at times ….until there’s some broken equipment that bit was interesting. I hope some of the following races are a bit closer for the viwers sake otherwise its just the starts that are exciting to most of us.

I know for you it’s the bestest thing you’ve ever seen ever. As Ad Hoc said to you it’s as though the Messiah has arrived on Foils for Doug.

And I said before and say again this is not new technology as you keep claiming; Taberly and co developed these platforms decades ago and have been refining them to the current form of “le Hydroptere” which is the pinnacle of large ocean foiler technology. She’s sitting in CA right now having failed this season to find the right conditions to cross the Pacific.

It’s all great engineering from very professional engineers and hydrodynamicists and I take my hat off to them all. But The pinnacle of sailing……………..come off it, it’s the pinnacle of speed.

 

America's Cup Ascending!

-------------------
Beaufort WIND Scale:
"A system of estimating and reporting WIND SPEED devised by British Rear Admiral, Sir Francis Beaufort(1774-1857) in 1805 based on observations 0f the effects of the wind. "
http://www.stormfax.com/beaufort.htm
----------
Since it was originally conceived of to allow estimates of WIND SPEED, I think its perfectly ok to use it as a reference for the WIND SPEED across the deck of a boat in order to emphasize the nature of such wind.

 

Jeez Mike. Your long winded statement in post 136 just repeated what I said in one line.

"It was a whole technical leap ahead of the "C 47". but suffered from structural failure. The lessons learnt from that failure enabled the successful development of---

 

America's Cup Ascending!

===================
Wrong, again. The foil system on the AC 72 is NEW-never having been used on any sailboat anywhere in the history of hydrofoils.
The three foil configuration with a single main foil is a NEW development foiler design, as is the main foil itself, pioneered by TNZ: a curved foil for a specific range of altitude control plus a "bent up" "L" foil-used in conjunction with manual adjustment of the foils' AOI.
------
Bull! You assume you know why the first boat crashed and presume to know what happened to Artemis(before anyone else).
The Oracle crash had absolutely nothing to due with it being "rough"-just not true. It was a crew error and happens all the time on smaller catamarans. With better systems controlling the foils AND with no crew error that could have been prevented.
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.
-------------------
I'm not interested in a foiler for cruising, but Tom Speer, an aerohydrodynamisist ,familiar to these pages, has designed a boat similar to Keipers boat-maybe we'll see it one of these days.
===============
You and your buddy, Hoc, make a point of dissing my enthusiasm for the new AC boats and for foilers in general and thats you're right. But you use it as a weapon to try to denigrate the value of what I say about foilers, hydrofoils and the AC 72 in particular and I think that simply shows a lack of ability on your part to translate your obvious bias against foilers and multihulls in general to a well reasoned argument.And as above, if you can't rationally explain it you will make up "facts" out of thin air. Too bad...
Not that I'd pay any attention to either of you at this point.....
I'm too enthusiastic about the most significant developments in sailboat design taking place with the 72's ,45's, Mirabaud, the Moth, and last but not least DSS-probably the most significant use of "foil assist' yet on monohulls. There's a lot to be enthusiastic about and there are many very accomplished designers and engineers that "feel" the same way I do and would surely react negatively to your assesment of multihulls, foilers in general and the AC 72 in particular.

Pictures: L to R- 1) Aussie 18, 2) AC 45,3) Rush Randle foilboard, 4) AC 72, 5) Moth, 6) Williwaw-"cruising" foiler, 7) Mirabaud, 8) Quant 28 DSS

 

No it doesn't.

When I said Force 2 to force 7, I meant force 2 to force 7 conditions, which include, not only actual wind speeds, but resulting sea conditions as well.

Apparent wind speeds would, of course, have too be added to that.

I made this statement to counter someone else's suggestion the the races be held under a very limited range of wind conditions.

 

I hate to say it, but your comparison seems ridiculous.

The 'Comet' was far from the first pressurized airframe and it traveled at sub sonic speeds. It did fly higher than other pressurized planes of its time, but nowhere near three times as high.

The Boeing 377, which my dad flew to Europe in the early '50's, for example, was pressurized.

The Comet failed due to a bad engineering choice of its of its designers, who chose more esthetically pleasing rectangular windows over the more structurally sound round ones.

Being of British extraction myself, I feel free to say that kind of mistake is typical of the British.

If we were to make a suitable comparison between these boats and more normal catamarans, in the aircraft world, we would have to compare a normal jet airliner to a scram jet, hypersonic, sub space one which, due to its high performance, could only carry, say, 20 passengers.

 

That's the whole point, imo.

Foiling cats are good for just a certain type of racing. They don't appear to be suitable for close-quarters tactical battle made of fast tacks and false tacks, which are a real delicacy when it happens. Why are they not suitable for that type of races? Because of their primary characteristics - high speed. Can you imagine two boats coming in contact or crashing at each other due to a wrongly evaluated distance or timing, at a speed of 30 kts (boat 1) + 30 kts (boat 2), followed by a violent capsize due to a sudden dead-stop? It would be a massacre of the crews, literally.

So, each boat to it's own purpose. Foilers for super-speed lovers, other boats for people with other preferences.

And the above reasoning could be extended in a similar manner to other boating or shipping activities. You won't see a foiling cat transport 2,000,000 barrels of crude oil. It just cannot do it in an efficient and economically viable manner. Just as it cannot do many other things which other boat types can.

Cheers

 

See comments in text.

 

"The Prejudiced Brigade" - good title for a book? ... but I'll not write it; hardly riveting reading I would imagine.
Seems certain arch-conservative Australians gravitate to this type.
Why don't you soapbox negative-ists ... find something else to do instead of decrying breakthrough, experimental yachting craft.
You're not compelled to watch. Instead you fill up this site with your biased nonsense. No one is listening to you ... enthusiasts of fast sailing will ignore, skim and dismiss your rants ... and turn to the enjoyment of observing the peak of modern technological yacht design - and the skill of the crews sailing them.

 

...under a well-defined set of rules, aimed at obtaining a goal of high speeds.

But they are admirable sailing machines indeed.

 

The crews are skilled the engineering is terrific and no one has ever said otherwise.
I look at these craft on two quite separate levels, one is the excitement of refined technology and the achievement of modern materials. The other is looking for the racing tactical skills. That might….. maybe come with a much closer match.

The head on was quite close in the last race and NZ were a bit wobbly without the headsail, that has probably raised a few concerns.

I think it’s better if a certain amount of skill and a bit of luck can make up for the technological edge. But I think the class is doomed and the future of the AC depends on some more suitable designs. No matter what the small number of very vocal posters may opine.