34th America's Cup: multihulls!

[cavalier mk2]

I'm thinking they did it to reduce bow lift and keep the nose slicing the water.....very much a raptor.

 

[Corley]

Quite enjoyed this ETNZ AC72 video linked from the attached sail world article. Looks like they have that 72' cranking along nicely.



and the article

http://www.sail-world.com/Australia/Americas-Cup:-Emirates-Team-NZ-claims-near-40kts-in-AC72-+-Video/101508

 

[Doug Lord]

34th AC

Geez! I saw the L foil on the stb side and the port hull was almost flying yet not one mention of foils in the article!! Yes, James this is a tremendous achievement-the FIRST foiling Americas Cup boat in the history of mankind.
Once again the Kiwis lead the world of sailing!
Gary, I didn't know you were working for TNZ- you must be.
I can't believe I missed this and that no one in the media understands what they are looking at. Fantastic!


Picture: The usual suspects claim this is a photoshopped picture including the so-called "editorial" staff on SA:
update: comment from Maganus(Canadian C Class team and former TNZ member) :
" Do you guys actually believe they would spend the time to PS this ****? really?
Does each team shadow the other guy with a chase boat when they are training? Of course they do, so how much is actually hidden? So you really think they spend all this time PSing to throw the other guy off the scent? I don't think so.
It is what it is, they're foiling!
B "

 

[Doug Lord]

34th AC-Oracles foiler

Interesting video. Good shots of the foils-she will be a foiler as well! Wonder what the significance of TNZ foils being curved and having "L" foils is compared to Oracle's straight daggerboard + "L" foil?
MoreOracle pictures here: http://forums.sailinganarchy.com/index.php?showtopic=138901&st=300#entry3845246

http://www.youtube.com/watch?v=WPDAf9jPjwQ&feature=player_embedded

 

[Corley]

Here is an article from Sail World has the same video plus some other photos.

http://www.sail-world.com/Australia...A-is-splashed-in-San-Francisco---Video/101543

 

[gypsy28]

Is the A frame on the bows of Oracle just to hold the prodder up whilst the rig is off or will that stay?

DAVE

 

[Silver Raven]

Interesting video. Good shots of the foils-she will be a foiler as well! Wonder what the significance of TNZ foils being curved and having "L" foils is compared to Oracle's straight daggerboard + "L" foil?
MoreOracle pictures here: http://forums.sailinganarchy.com/index.php?showtopic=138901&st=300#entry3845246

http://www.youtube.com/watch?v=WPDAf9jPjwQ&feature=player_embedded

Gooday Doug, Corley & Gary. Thanks for the video links Corley.
Doug - just ignor - 'wet-noodles' & 'mo-bike' following the lowest common denominator to - way below the bottom - has no gain - just ignor them. Regardless of Paul's opinion - he's at least honest enough about that it's his opinion & not trying to shove it down our throats. He's just making a statement. I respect his right without agreeing with him, allowed - I'm sure.

While I dissagree with his - evaluation of 'match racing' - - again he's not telling me that every other way is wrong - just not his evaluated way (sorry if the grammer is wrong) - that's fine - - I'm sure he'd be the first to agree that I'm allowed to have another view of 'match racing' which I've done for over 40 years now & in about 10 different classes - mono & multi. Just because one decides to cover tack or split tacks - doesn't make it not - match racing.

Wonder what 'Cav' would think of cruising a ORMA 60' - cruising version - up the 'Inland passage' & the whole of the coast of the Pacific NW ??? WOW - a pair of them 'cruising' in those waters - would just be a total blast - for sure. Would sure allow enough time to explore a lot of the wonderful areas ashore & say hello to all the great people & bears/beavers - eat salmon & have a few 'sundowners'.

Fun times guys - do enjoy & great sailing to all. ciao, james

Gary - what about that aft beam on the American AC - great foil shape - what about fitting a 'flap' into the middle of it - to controll the amount of lift or down force - sure might help balance the for & aft of the hulls - especially when the bows are being pressed - when going - off-the-wind ???

Very interesting times - for sure. Imagin - 72's out of the water - who'd-'ave-thunk-it ??? WOW.

 

[cavalier mk2]

I'm like everyone James, cruising a ORMA 60 in the PNW sounds like a blast. The often light airs of the inland passage would welcome the sail area. The challenge of course would be maneuvering through the tight spots at speed. The Nicol can get through some things that would definitely be tight with the 60. Now who's buying?

 

[Corley]

Is the A frame on the bows of Oracle just to hold the prodder up whilst the rig is off or will that stay?

DAVE

It looks temporary and just a means of resisting dolphin striker tension I guess we will find out soon once they step the rig. Seagull strikers do exist for cat front beams but would seem to be a draggy solution on such a high tech and otherwise clean platform.

 

[yves]

Wow, if enough winds to be on its foils, that will be a no race in case the others don't get some (but I guess they can still add them), what do the rules state exactly ? Only out dimensions and sail area ? Nothing about the appendages ?

Edit, quite precise in fact :

RUDDERS
7.1 Each hull shall have one rudder. The rudder or rudder stock shall penetrate the hull.
7.2 No part of a rudder, through its entire range of motion, shall be less than 1.000 m or greater than 3.000 m forward of the stern plane.
7.3 Rudders shall rotate about an axis within 10 degrees of perpendicular to MWP.
7.4 Rudders shall not translate in any direction.
7.5 Rudders (including rudder stocks) shall not exceed 5.000 m in any direction, measured along a straight line.
7.6 Rudders shall not have components such as trim tabs or moveable winglets that can be adjusted while racing; however, a movable or retractable device whose sole purpose is the removal of weed or debris is permitted.
7.7 While an AC72 Yacht is moored, rudders shall be capable of: (a) freely rotating through 360 degrees; or (b) being removed without the assistance of a shore-based or floating crane.
8. DAGGERBOARDS
8.1 Each hull shall have one daggerboard.
8.2 Daggerboards shall penetrate the hull forward of the rudder and aft of the forward watertight bulkhead under rule 5.10.
8.3 The maximum dimension of any daggerboard shall be 7.000 m in any direction, measured along a straight line.
8.4 The primary lower load bearing support of each daggerboard may rotate about a single axis and shall not translate in any direction.
8.5 A daggerboard shall not translate along the longitudinal axis more than 0.020 m within its primary lower load-bearing support.
AC72 Class Rule Draft 2.0 Page No. 11
8.6 Daggerboards shall not have components such as trim tabs or moveable winglets that can be adjusted while racing; however, a movable or retractable device whose sole purpose is the removal of weed or debris is permitted.
8.7 Daggerboards shall be capable of being raised (without the assistance of a shore-based or floating crane) so that, when the AC72 Yacht is moored, the daggerboards do not extend more than 0.300 m below the local hull surface.

Considering that on the hydroptere, the trimming of the horizontal plane on the rudder seems to be one or the key point, might be the critical aspect there (as it is forbidden in the AC72 rule)

 

[Doug Lord]

Wow, if enough winds to be on its foils, that will be a no race in case the others don't get some (but I guess they can still add them), what do the rules state exactly ? Only out dimensions and sail area ? Nothing about the appendages ?

Edit, quite precise in fact :

Considering that on the hydroptere, the trimming of the horizontal plane on the rudder seems to be one or the key point, might be the critical aspect there (as it is forbidden in the AC72 rule)

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But whats not prohibited is pivoting the daggerboard fore and aft in its lower bearing(primary load bearing support). Doing that manually would allow altitude control.
This picture illustrates that Oracles boards pivot-best illustration I've seen yet:

click-

 

[Doug Lord]

34th AC

Comment by Julian Bethwaite on DA in the "Flapper or gyber" thread regarding AC trickle down technology:

"None of us pay anywhere near enough attention to this arena. I look forward to the advent of foiling AC's and the wash down effect to all of us.Cant attached the photo, its too big. I will get one of my sons to reduce it and then post it, maybe a few, great stuff.

Julian
Sydney (mostly) "

 

[yves]

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But whats not prohibited is pivoting the daggerboard fore and aft in its lower bearing(primary load bearing support). Doing that manually would allow altitude control.
This picture illustrates that Oracles boards pivot-best illustration I've seen yet:

click-

Yes indeed, but I guess that will make it much more sensible for controlling the horizontal angle of the hull, will be interesting anyway !

 

[Doug Lord]

Yes indeed, but I guess that will make it much more sensible for controlling the horizontal angle of the hull, will be interesting anyway !

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With the main foil's angle of incidence being controlled manually(if at all) and the rudder foil fixed, pitch control will be good. They aren't allowed to use the windward foil to pull down and create more RM.

 

[groper]

Have a look at the ETNZ day 4 video, at 1:07 there is footage of the boat flying the windward hull, and the leeward hull is barely touching the water! they obviously have plenty of lift from that foil...