34th America's Cup: multihulls!

The fairings look rigid and not movable in the video.

 

I agree that they are beautiful. No point in comparing apples with oranges.

I wonder how the cost of the boat design and manufacture compares with all other costs. I'm picking the latter would be more.

m

 

^^^

Certainly the rear fairing looks fixed, but there are adjustable panels on the main fairing perhaps? I like the idea!

 

Corley, the GB team.

Sir Keith Mills was quite vocal on the unsuitability of the class and their inherent dangers and cited that as one of the significant factors in the decision to pull out.

There were several press releases along the same line.

"I pulled the GB team out because it wasn't viable on a number of fronts but safety was one of them,…." He called the class “….dangerous boats to sail with minimal control, hit a big wave and that is it…..”

I’m surprised no one remembers them. But then that was well before two boats were wrecked not to mention all the capsizes to date as the people tried to learn to control these platforms.
Also giant ULDB foiling multihulls aren’t very conducive to being pressed into service for some financial return after the event either, and I think Sir Keith was also considering his 10’s of millions going into a very fragile craft that could be so easily turned into landfill.

I wonder what he would have said if he'd known that safety has been improved with severe restrictions on the weather they are to be allowed to race in. But then I suspect the design would have been scrapped from the inception and a different class would have been sailed instead.

A lot of people were expecting the debacles that have occurred with these boats. Amazing technology and a great achievement but they didn't safely meet the initial SOR they were supposedly designed for. It was just going to be a lottery as to whether or not they got through the series.

I hope they can keep enough control to keep the boats apart when racing, that will be the big concern now, a collision will be catastrophic.

 

34th AC

I wonder what experience in sailing large very fast multihulls Sir Keith has? I've googled him and all I can find is experience ocean racing lead keels. Does anyone know anymore about him-particularly why his opinion on these state of the art vessel's is worth more than say,Larry Ellison, Russel Coutts or any of the many, many other supporters of the new boats. To me, the fact that he controlled the purse strings of the UK team is not a qualification to speak authoritatively on the matter in the manner that he was quoted as doing.
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Extensive experience sailing big multihulls would surely lend a degree more credibility than what I have found so far.

 

I'd say experience has shown us that large multihull racing is a complete folly
how many parked boats and classes?
40'ish seems to be the only sustainable size
Any designer could have worked out the Oracle 90 was folly, you dont have to make one and race it to work that out. 40+tonnes on main sheet, 90+ on mast ball is crazy
Did Boeing make a supersonic passenger plane No, because they worked out it was folly before they built one

 

34th AC

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Mr. Mills is not Boeing and I seriously doubt he studied anything technical about the new AC boats but I would like to know more. The big ocean racing multi's(100'+) have proven time and again that fast sailing multies are seaworthy in the ocean with proper design ,engineering and crewing. The big multies are here to stay in the AC I would think-representing, as they do, the state of the art+ in sailboat design.

 

Doug are you seriously saying you would say yes and enter the Cup not knowing what it takes to build the boat?
What do you think those guys did had a few beers around the pre preg pile and just made one?

PS I think a Moth is the state of the art race boat and a successful class to boot

here ya go the holy grail of AC
everybody is doing it in a Moth
http://www.youtube.com/watch?v=ssx0Rmiznlo

 

The concord delivered lots of passengers, still complete folly, spectacular, an engineering achievement yes but its parked today like most large multi's
Cant you see the difference?

 

Powerabout,

Physics is what it is.

For open water boats, bigger is better.

BP5 is the king of the hill at the moment. It is not a "folly", the builders just followed the formula to get the boat they needed for the performance they were after.

Work out how to make a tri just as efficient but bigger than BP5 and it would be the new king of the hill.

IDEC will be setting a new record soon. 97' is not a small boat. Francis Joyon has kept his boat more along the "simple is better" philosophy, but again big.

Before too long, the open water types will figure out how to use foils to handle rough conditions without backing off so much. This has the opportunity for a new generation to up the performance without going bigger (for now). However, eventually offshore foilers will then be faced with scaling up as the only choice for going faster.

I will admit that the current AC has an element of "folly" from an engineering perspective. They really did not want this to be a foiling race. However, now that it is, something in the 55' - 60' range would have been plenty "spectacular" yet less expensive and more manageable in terms of things like crew safety.

However, this is all in the context of "now that it a foiling race". This was not planned. The 72' size is well withing the "state of the art" when compared to the big offshore boats.

I will agree that most big expensive multihull boats do not stay "state of the art" for long and may not see decades of service.

The pace of development is what it is.

I think the big boats are neat and cool and awesome and outrageously expensive. Only the rich or well sponsored should even consider trying for a big world class multi.

BP5, IDEC & the 72' AC boats are not mass transit passenger vehicles. They are all about being the fastest in their chosen venue.

Your are probably right that trying to be the fastest is "folly" when you think of the money spent vs. any immediate tangible return. However, where would the world be if everyone gave the pursuit of betting better or faster or more efficient.

And by the way, I have said before that scaling up the moth some (say a crew of anything from three to five) would make for an interesting diversion in the world of AC. Anything with real room for advancing some form of high speed boat sailing just seems like a good place for these rich guys to spend their money.

Just please do not go back to boats that would be hard pressed to keep up with an A Cat.

 

Yes, physics is what it is. But, I cannot think of another extreme sport where the forces influencing the physics are so variable and influential. These forces can naturally increase by a factor of 4 within seconds. This is all fine, but get it wrong these craft capsize. Capsize is clearly dangerous.

What sort of TV coverage will the finals draw and how much is being paid for this coverage? Europe or Asia won’t pay much, for sure. NZ cannot afford to pay much. Australia is only ever interested in Australian sport. It does not leave much does it?

m

 

unfortunately the Cup is a technology race so thats the criteria
F1 cars are a spectator sport and it wouldn't exist without that so many rules to ensure its good for spectators.
AC just has to work out where it wants to be.
I personally like match racing and the best ones I can remember are in slow boats in light winds, thats not where the Cup came from but was for 30 years.
Rich men building the biggest and fastest ( follies) was where the Cup came from.
So we cant really complain about that.

I do enjoy the Cup and its money to allow very fast hardware innovation and we have all (sailors) benefited from that over the years.
AC is a development class kind of but that only goes for 4 years. To call it state of the art with tight rules is a bit difficult in my opinion.
They cant have auto foil adjustment nor moveable foil surfaces, so does that make the Moth light years a head?

 

I love match racing too, especially if it is well televised with all the techno on position angles, velocities etc. But people also love test cricket or cooking programs. The question is what % of viewers?

I don't think that AC will ever decide where it wants to be. Controversy has always driven its attraction. Skulduggery with rules has won a goodly number of titles. Remember the farce of multi against mono? Thats what these guys will do to win. Its hardly cricket.

m

 

Ac

Possibly good book about America's Cup crews: http://www.theridgefieldpress.com/18752/gabrielson-tells-1890s-story-of-fishermen-and-americas-cup/

 

OK, I have a question for the foiling/wave piercing experts here:

It is my understanding that the initial designs were made under the assumption that foiling would be (de facto) prohibited by the rules. ETNZ made a successful appeal against the relevant rule and foiling was now (de facto) legal.

So ... the Oracle hulls were presumably designed under the "no foiling" assumption. As an old control systems guy, my conjecture is that the hydrodynamic analysis assumed that when the windward hull lifted and then returned to the water it would do so under a fairly narrow range of angles of attack, which in turn would be constrained by the hydrodynamic characteristics of the leeward hull.

But when we foil we have a craft which looks more like a seaplane than a boat, that is, it lifts off and touches down. AOA at touchdown is unconstrained by hydrodynamics because the hulls aren't in the water yet. So why should we assume that the bow design for non-foiling would be suitable for takeoffs and touchdowns? If it isn't, did Oracle get snookered by ETNZ deciding to design a foiler from the git-go and roll the dice on the judges' decision? A lot of the Oracle touchdowns look far from elegant, which is what got me thinking.

Cheers,

Earl