34th America's Cup: multihulls!

Oracle Images

Hi Doug,
Yes all the stills look good but the videos show it to be wobbly. The latest vids of ETNZ and Luna Rossa show they are really trucking! Soon they will be all in San Fran. Can't wait. On something different... Theres a lot of discussion about T rudders around the traps. Especially about Tees or Cross forms. Seems to me theres no difference except the designer has placed the winglet at a certain height for a good reason? The AClass are going for cross' whereas others are T's. Any hydro people out there can comment? Peter S

 

Hi - There are 60,000 registered sailors in US Sailing but there are 61,000 in Yachting Australia. NZ would probably be more!! There must be more sailors in USA?? Peter S

 

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Where you put it is an ongoing discussion. Steve Clark(I think) said the bottom mounted foil slapped the water a lot on a C Class-he thought that was slow. I-14's "recover" energy from the wake(?) and so on as you know.
Here John Elways take on it:

 

34th AC ----Artemis--big News!

From Scuttlebutt tonight:

PAUL CAYARD: FULL COURT PRESS

Following their recent tuning sessions with America's Cup defender Oracle Team USA, Swedish challenger Artemis Racing announced they had halted their AC72 sailing program and would be proceeding with modifications to the boat. Considering that Artemis Racing is the only team that does not have a fully foiling boat, it was time to check in with team CEO Paul Cayard. Here's what Paul shared with Scuttlebutt's Craig Leweck:
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Sailing against Oracle was a full-scale verification that we needed to make some pretty big changes, and that's what we are doing. We are taking it on. The good news is that we learned this in February and not in July. So we have some time to react. But we need to commit more to foiling.

When discussing foiling, it is important to understand that it is not black and white. It is a spectrum, and what we are really saying when we say 'foiling' is that we are reducing displacement of the boat. The lifting occurs through the foils on the rudder and the daggerboard design. On a spectrum between zero and the full weight of the boat, a fully foiling boat is lifting the full weight of the boat.

Our boat had J boards, and while they lift a percentage of our displacement, they do not lift all of it. The game of foiling is trading off the drag associated with the boards. The fully foiling boats use L boards, but both the surface area of these boards, and the tightness of the L board angle, create more drag than the J board. However, they also cause more lift.

So each team's design tools predicted what the cost of the drag would be, and what the benefit of the lift would be, and it is fair to say that we got it wrong. So now we are reacting. Our team has come together, and is fully committed to tackling this issue full on.

Some of the aspects of the L boards that we will need to discover is their impact on maneuverability and downspeed acceleration. This had been a concern of ours, but our experience training with Oracle Team USA is that their L boards didn't' seem to be much of a hindrance, if any. This factored in our decision to make the modifications to our boats.

In parallel, we are converting an AC45 to begin training sooner on a fully foiling boat. This will help fill the gap as our second boat is still a few months away, so this will give us a training platform for March. The end game is to be race ready by the start of the challenger trials in July and that's where we are headed.

As for our changes, it is fair to say that we are going to be building a fully foiling boat. This will require a redesign of our boards and board cases, and rudders. It is a complete package once you go down that road. Boat #1 is now in the shed for three weeks, but we are doing work in some other areas, and are eager to get back on the water. It will not be a fully foiling boat when we re-launch. To fully convert this boat would keep us off the water for too long.

However, our second boat will now have a fully foiling package. The boat was already designed with greater foiling lift, and was very close to having full foiling ability. We called it skimming, wherein it was expected to lift roughly 80% of the hull's displacement, meaning the hull is barely touching the water. But now that boat will have full foiling ability, though we will retain both full foil and skimming options to test. The changes will slightly delay the boat's schedule, but we still expect to be sailing it by the end of May.

Obviously we are a little behind the eight ball on the foiling aspect of the AC72, but we have a sailing team that is suited as well as any other team to take on the challenge. I have been so impressed with our helm Nathan Outteridge, who mastered the foiling Moth to win their Worlds, and then to win the gold medal in the 49er skiff at the 2012 Games. In all the discussions we've had, he has been exceedingly confident in addressing these design needs now rather than use the time on the water. He believes the sailing team will figure it all out when the boat is ready.
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Part 2 of this interview will be in the Monday edition of Scuttlebutt.

Artemis video: http://www.youtube.com/watch?v=fiKvoTwWg04&feature=share&list=PL-Zq52g_28B8BXdxZ-TpC10lYPOzG-aZT

 

Exciting times indeed !
This next AC is going to be a stunning spectacle, I do hope it is a close series unlike the previous which although featured two very interesting boats was a total anti-climax. imho.

What is happening with the courses, are they being extended to cater for the massive increase in boat speed ?

 

Looking at the latest video posted on xssailing.com, it seems a real pity that NZ and Prada have to duel it out to see who gets to spend the next few races trying to avoid a careening all over the place totally out of control Oracle.
It would be so much more interesting if they had fleet racing for a week, and the top two went to the finals. I don't think Oracle would be in it.

 

The race was an anticlimax but BMW Oracle USA17 sailing on one float with the wing rig tuned in powering to windward is etched in my memory. Oh yeah there was that other boat there what was it called again?

 

34th AC

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Dissing Oracle is last year-she is foiling extremely well and is likely to win the America's Cup!

 

Stop the exaggeration doug. She is foiling yes, fast yes, and may well win the cup. But is there anyone out there who honestly think oracle is foiling as well as etnz right now?
Oracle is foiling and foiling well, and fast.
Etnz is foiling extremely well, as one would hope from all their time on the water. Oracle is not.
I understand your bias/support for the home team, but don't let it cloud common sense.

 

34th AC

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Oracle is at least as good as TNZ now! I spoke highly of TNZ as the first AC boat in history to foil and I meant what I said then and mean what I say now-it's not just "support for the home team" it's my realistic assesment based on what I've seen and read. I think Oracle will win the Cup because of all the adversity they've overcome and the excellent foil system that they have. Not to mention the tech team they have on the wing...

 

Doug, me old mate, you need to check the recent video of O trying to bear away.
What a debacle, couldn't do it, tried a number of times then almost went arse backwards and sideways when she cranked way over to WINDWARD.
Those needle-like bows are a disaster and Spit (and crew too, I guess) is/are defecating and high pitched farting and whimpering each time the helm goes up.

 

34th AC

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G'day mate-your Kiwi eyes distort your perceptions-they're testing and trying different things-you know- not the same old same old(soso). 17ers can pull the "wool" over the most astute Kiwi making them think the most absurd things, and all the time the 17ers are planning the Great Kiwi Whoosh Off-the ultimate 17er catflying experience.......

 

If etnz and oracle raced today, oracle would not win.
Maybe in 2 more weeks yes. They are a skilled and fast team for sure, and probably odds on favourites to win the cup.
But doug, right now, their foiling is nowhere near as controlled and stable as etnz. Open your eyes and stop behaving like a 12 year girl at a one direction concert

 

Further to the barking mad Black dog, check out these videos. Seems interesting that the most valuable and raw footage comes from amateurs.
http://www.sail-world.com/NZ/index.cfm?SEID=2&Nid=107056&SRCID=0&ntid=118&tickeruid=0&tickerCID=0

 

34th AC

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Looked pretty good to me. It's flat out impossible to draw any serious concludions from those videos other than what they were testing which is obvious. They were testing and the one way you know that for sure is that the had the leefoil up 2-3' or more. Obviously checking the advantage/disadvantage of keeping the boat closer to the surface. I thought it was particullarly cool how they lowered the windward foil during the one bearaway-something I suggested after the pitchpole video. Thats one major change to their procedure and a damn good one since it gives twice the lift when they need it. But thats all speculation-its all about testing and more testing and trying to ascribe other kinds of negative performance to them at this stage is just silly.
Thanks for the vid!