34th America's Cup: multihulls!

34th AC

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You sure got that right. A video of the the two together would be most enlightening!

 

It means that the fastest boat is out of the frame, way to the left, and is painted orange. The sad part is that while it can sail at 68knots on starboard tack, it has to lower it's rig and be unceremoniously dragged back upwind on port by a RIB, but that's the price you pay for ultimate speed. What was the question again ?

 

34th AC

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True........for now.

 

34th AC

Exquisite Chris Cameron photo showing TNZ's surface piercing main foil(note angle) :
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34th AC

Rudder foils have appeared on Artemis in a rather different(I-14ish)location:
about 51 seconds in....

http://www.youtube.com/watch?feature=player_embedded&v=a_pGGxmSHyM

 

34th AC

A bit here about Artemis' new rudder foils: http://www.catsailingnews.com/

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pitchpole event

Besides additional weight and structure, what is the downside
of a large hydrofoil above the water line that would submerge
as the hull noses down. This would provide lift and time to allow
the skipper to react.

dlawson

 

Going back to the very beginnings of catamaran sailing large plates were put at deck level on the bows of the hulls at some angle of attack.
Worked for some, but if the nose dug deeply into the back of a wave for instance that could cause the bows to be pushed deeper into the water and actually cause a pitchpole.

 

ETNZ have been pushing thier AC72 pretty hard in some tough conditions.

 

Like

http://crew.org.nz/forum/download/file.php?id=19713

Any next shots.

 

Hello, My name is Evan Stufflebeam and I go to high school in the desert of Arizona in the US. I stumbled upon the Volvo last year at about this time and have fallen in love with sailing of any kind since. Over the summer I was in San Francisco and sailed about 30 feet behind Jimmy's AC45 on a sailboat tour around the bay. Over the past week I read through most of the pages on this blog as I think about AC72's all the time, and you guys answered any questions I had throguhout all of it. I look forward to talking with you guys about the great boats and much more!

 

34th AC

Welcome to the forum, Evan! Sounds like you had a pretty exciting summer and sounds like lots of fun. Looking forward to further contributions from you.

 

I was wondering if anyone knows how quickly ETNZ can get the boat up foiling? Does it take quite a distance at speed or are they able to get it up in a short span like what it will be on the race course? That is an area where I thought Oracle may have an advantage if they do have a "guy on the joystick" you talked about earlier to rise create lift faster if they can constantly control the pitch.

 

34th AC

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I think both TNZ and OR can change the angle of incidence of the foil under sail. The difference is that foil adjustments on OR are likely to be more frequent. Both could start foiling fairly quickly given the right conditions.
Here is a pix of TNZ and Luna Rosa(which uses a mainfoil system closer to Oracle than to TNZ). In this picture LR is ahead but the rumor is that TNZ caught up and finished a minute ahead:

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Interview/translation of Franck Cammas from Prada by Voiles et Voiliers:

"At the moment steering Prada/LR there is quite a lot of friction but the boat reacts very quickly. It is very rigid. I have never sailed such a rigid boat in terms of lack of distortion of the platform. Suddenly the slightest helm movement really creates an instant reaction. There is no movement absorbed such as in a supple platform. Everything, as a result, is very nervous. But at the same time, everything is controllable. The boat has no parasitic elements; everything works, no flexibility, no angles change.
Also a wing compared to a normal soft sail gives more stability in aero power and in control, it does not move similarly in bending or twist to a flexible sail.
Actually it is more impressive to view the winged AC72 from a distance because on board, you have the impression that everything controls itself.
Even bearing away (doubtful translation) in 14 knots for the very first time, there was no slaughtering; the feeling of security was a pleasant surprise.
I have only sailed with a wing once before on an Oracle AC45; it is in no way the same size. You cannot say I have really sailed with a wing - but it is rather easy. You can play with the sail/wing plan, can invert the camber, which is not possible with a soft sail; can produce a negative camber at certain heights, and many other combinations, shapes not achievable with conventional sails."