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Re: AC72 Oracle Team USA Spaceship has landed [Re: Timbo] #253617
10/17/12 11:42 PM
10/17/12 11:42 PM
Joined: Aug 2001
Posts: 917
Issaquah, WA, USA
H17cat Offline
old hand
H17cat  Offline
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Issaquah, WA, USA
Perhaps they should all go back to the AC45's. Plenty of action on the proven design. Also, would allow more teams to take part.

-- Have You Seen This? --
Re: AC72 Oracle Team USA Spaceship has landed [Re: samc99us] #253620
10/18/12 05:47 AM
10/18/12 05:47 AM
Joined: Feb 2005
Posts: 4,118
Northfield Mn
Karl_Brogger Offline
Carpal Tunnel
Karl_Brogger  Offline
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Northfield Mn
Originally Posted by samc99us
What are the bets on seeing this thing fly again?


ah, google Larry Ellison. He has almost more money than god. It'll be on the water again ricky-tick I'm sure.

Hell, a local company just spent $31m on an Oracle product, so that should help.


I'm boatless.
Re: AC72 Oracle Team USA Spaceship has landed [Re: P.M.] #253621
10/18/12 06:44 AM
10/18/12 06:44 AM
Joined: Sep 2004
Posts: 2,584
+31NL
Tony_F18 Offline
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+31NL
They are not allowed to launch the 2nd boat before February next year, and the 2nd wing wont be ready by Christmas apparently.

Re: AC72 Oracle Team USA Spaceship has landed [Re: Karl_Brogger] #253623
10/18/12 07:38 AM
10/18/12 07:38 AM
Joined: Jun 2001
Posts: 3,906
Clermont, FL, USA
David Ingram Offline
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David Ingram  Offline
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Posts: 3,906
Clermont, FL, USA
Originally Posted by Karl_Brogger



Your fascination with poo is disturbing.


David Ingram
F18 USA 242
http://www.solarwind.solar

"Do or do not. There is no try." - Yoda
"Excuses are the tools of the weak and incompetent" - Two sista's I overheard in the hall
"You don't have to be a brain surgeon to be a complete idiot, but it helps"
Re: AC72 Oracle Team USA Spaceship has landed [Re: P.M.] #253624
10/18/12 07:45 AM
10/18/12 07:45 AM
Joined: Feb 2005
Posts: 4,118
Northfield Mn
Karl_Brogger Offline
Carpal Tunnel
Karl_Brogger  Offline
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Posts: 4,118
Northfield Mn
BWAHAHAHAHA! That avatar is high-larious!


I'm boatless.
Re: AC72 Oracle Team USA Spaceship has landed [Re: P.M.] #253625
10/18/12 08:15 AM
10/18/12 08:15 AM
Joined: May 2007
Posts: 127
Rock Hill,SC
KevinRejda Offline
member
KevinRejda  Offline
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Posts: 127
Rock Hill,SC
Funniest one I've seen!


Kevin Rejda
Rock Hill, SC

Re: AC72 Oracle Team USA Spaceship has landed [Re: P.M.] #253627
10/18/12 08:29 AM
10/18/12 08:29 AM
Joined: Feb 2005
Posts: 4,118
Northfield Mn
Karl_Brogger Offline
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Karl_Brogger  Offline
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Posts: 4,118
Northfield Mn
I would watch that as an Olympic sport. Especially if they toilets were set up like hurdles.


I'm boatless.
Re: AC72 Oracle Team USA Spaceship has landed [Re: Team_Cat_Fever] #253631
10/18/12 10:24 AM
10/18/12 10:24 AM
Joined: Feb 2009
Posts: 43
where the wind never blows
Lockenfisch Offline
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Lockenfisch  Offline
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Posts: 43
where the wind never blows
Originally Posted by Team_Cat_Fever
...You can't push the development edge that hard without some consequences.


Sorry but multihulls pitchpole and break their riggs eversince... its just bad luck if you, me, Oracle or someone else will be the next one day ;-) Here it looks to me as if the recovery and the counteraction to not let the mast, wing go down was too slow. Maybe they had just no idea, never planned that?

Last edited by Lockenfisch; 10/18/12 10:25 AM.
Re: AC72 Oracle Team USA Spaceship has landed [Re: Lockenfisch] #253632
10/18/12 11:00 AM
10/18/12 11:00 AM
Joined: Dec 2001
Posts: 5,590
Naples, FL
waterbug_wpb Offline
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Posts: 5,590
Naples, FL
do you think the foils may have hurt the hull's ability to recover from the nose-dive during the turn down?

Since those things aren't adjustable, I would figure at some point the foils were actually trying to dive for lobster along with the bows...

And having 131 feet of wing pushing didn't help, either...


Jay

Re: AC72 Oracle Team USA Spaceship has landed [Re: waterbug_wpb] #253637
10/18/12 01:50 PM
10/18/12 01:50 PM
Joined: Jun 2001
Posts: 12,310
South Carolina
Jake Offline
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Jake  Offline
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Posts: 12,310
South Carolina
Originally Posted by waterbug_wpb
do you think the foils may have hurt the hull's ability to recover from the nose-dive during the turn down?

Since those things aren't adjustable, I would figure at some point the foils were actually trying to dive for lobster along with the bows...

And having 131 feet of wing pushing didn't help, either...


Those foils must have had incredible loads on them during that event...and you would think that when those lifting boards point to the bottom that they drive harder to the bottom. I heard mention that the foil loads tore up the hulls during that dive and they didn't even know if the hulls were repairable.


Jake Kohl
Re: AC72 Oracle Team USA Spaceship has landed [Re: Jake] #253638
10/18/12 03:12 PM
10/18/12 03:12 PM
Joined: Jan 2005
Posts: 105
Bloomington, IN
jbecker Offline
member
jbecker  Offline
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Joined: Jan 2005
Posts: 105
Bloomington, IN
Also, the main L-foils at that high negative angle of attack must have produced a lot of drag and contributed to slowing the boat, so in addition to pulling the whole boat down, they contributed to the torque loads that forced the bows down.

It will be interesting to see what design changes come out of this. I'm picturing main foils with super strong hinges so that the L-foil part swings to near vertical when top loaded, and back to horizontal under normal upward loads. I wonder if such a thing is possible with modern materials, and if the drag and weight of such a hinge would be acceptable. It would not be an angle of attack control per se, so it seems like it might be acceptable under the rules.


Jeff
Tiger 849
Re: AC72 Oracle Team USA Spaceship has landed [Re: P.M.] #253640
10/18/12 04:01 PM
10/18/12 04:01 PM
Joined: Jan 2005
Posts: 6,049
Sebring, Florida.
Timbo Offline
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Timbo  Offline
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Posts: 6,049
Sebring, Florida.
We all have had the same problem at every bear away, think A mark in a good blow, many times with the same results (pitchpole).

As you turn from going upwind to downwind, you've got several additional forces all happening at once, to include the centrifical force the rig exerts as it's being swung in the big arc, the added drive from the (momentarlily, until you accelerate) greater aparant wind which is now puhsing the bows down, not lifting the windward hull up, and the added drag of going faster, on the boards which also pulls the bows down, until they get into foiling mode.

From watching that video several times, it looked like a classic bear away nose dive. As they bear away and unroll the jib, the bows go down and never really come back up...they just keep going deeper and deeper as they accelerate, until it's too deep to recover. Use full screen to see this:

http://www.youtube.com/watch?v=drgglIebuQY

On our boats, we can all run to the back, to keep the bows up when we get to A mark and we know it's coming, but they can't shift as much (relative) balast aft, as we do in that situation.

I still think it needs more volume in the bows to help prevent this nose diving. That was the cure for the early Blades, as well as some of the A cats.

You may recall years ago, when the mega cat Playstation had to have it's bows modified, enlarged, etc. The first time they took it out in big wind and waves, they also stuffed the bows and nearly pitched it right over.

The only beach cat I've felt 'safe' on in a big wind bear away was the Inter 20, and it's known for it's huge, fat bows. When I look at the design of the AC72's, I see A cat like, skinny bows. Great for keeping weight off...but not so good for preventing a picth pole.

Remember, they cannot simply 'dump the main' when it gets blowing too hard and you want to bear away, like we can. If they are going to keep going out in 25knots, they'll need bigger bows, or a much better righting system!

It looked very similar to this earlier pitchpole, on the 45' version, nearly identicle;

http://www.youtube.com/watch?v=-KNql99zT6s

Now, watch this next video of the first sail of Oracle 17. Pay particular attention to what the bows are doing, they always seem to be pointing down. Near the end of the vid. at 1:50, they are just cruising back to the dock, not pushing it, not even blowing too hard, but going downwind, and the bows are looking like they want to dive.

http://www.youtube.com/watch?v=Sr055W97l4o

Go to 'full screen' you'll have a better look.


Blade F16
#777
Re: AC72 Oracle Team USA Spaceship has landed [Re: P.M.] #253641
10/18/12 04:44 PM
10/18/12 04:44 PM
Joined: Sep 2007
Posts: 757
japan
erice Offline
old hand
erice  Offline
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Posts: 757
japan
the recovered platform looks a lot better than it did after it had turtled and was filling as it disappeared off into the pacific night

[Linked Image]


eric e
1982 nacra 5.2 - 2158
2009 weta tri - 294
Re: AC72 Oracle Team USA Spaceship has landed [Re: P.M.] #253642
10/18/12 04:47 PM
10/18/12 04:47 PM
Joined: Jan 2005
Posts: 6,049
Sebring, Florida.
Timbo Offline
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Timbo  Offline
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Sebring, Florida.
I can hear them on the docks now:

"Hey...get some Duct Tape! And HURRY!"


Blade F16
#777
Re: AC72 Oracle Team USA Spaceship has landed [Re: Timbo] #253644
10/18/12 07:57 PM
10/18/12 07:57 PM
Joined: Nov 2002
Posts: 465
FL
sail7seas Offline
addict
sail7seas  Offline
addict

Joined: Nov 2002
Posts: 465
FL
http://www.youtube.com/watch?v=JLX1XPCQodk
In this video it looks like OR-S is the only AC45 in the group letting out the wing on the bear away. I wonder if the AC72 had the same wing trimmer.

Re: AC72 Oracle Team USA Spaceship has landed [Re: waterbug_wpb] #253646
10/18/12 08:36 PM
10/18/12 08:36 PM
Joined: Jun 2002
Posts: 1,658
Florida Suncoast, Dunedin Caus...
catman Offline
Pooh-Bah
catman  Offline
Pooh-Bah

Joined: Jun 2002
Posts: 1,658
Florida Suncoast, Dunedin Caus...
Originally Posted by waterbug_wpb
do you think the foils may have hurt the hull's ability to recover from the nose-dive during the turn down?

Since those things aren't adjustable, I would figure at some point the foils were actually trying to dive for lobster along with the bows...

And having 131 feet of wing pushing didn't help, either...


They are adjustable. They can adjust the angle of attack. There is a learning curve here and they missed the setting for the conditions at hand. If you check out Sailing Anarchy ,Tide Tech shows that the conditions changed when they made that last bear away. Had they had the time or knowledge to set the foil properly they may have been alright.

They are not counting on forward buoyancy to keep the bows up. They are counting on the foils for that.


Have Fun
Re: AC72 Oracle Team USA Spaceship has landed [Re: sail7seas] #253647
10/18/12 08:59 PM
10/18/12 08:59 PM
Joined: Nov 2011
Posts: 382
SE MI / NE IN
rehmbo Offline
enthusiast
rehmbo  Offline
enthusiast

Joined: Nov 2011
Posts: 382
SE MI / NE IN
Originally Posted by sail7seas
http://www.youtube.com/watch?v=JLX1XPCQodk
In this video it looks like OR-S is the only AC45 in the group letting out the wing on the bear away. I wonder if the AC72 had the same wing trimmer.


So is the lesson then to travel-in when starting to stuff as the apparent wind shifts aft? Part of that makes sense, but when the apparent wind is at 90, It would be really tough to override the instinct to dump the traveller. Not sure I'd have enough time to think about it...


Jeff R

H18, C2 USA1193
cramsailing.com
crescentsail.com
Re: AC72 Oracle Team USA Spaceship has landed [Re: rehmbo] #253649
10/18/12 10:39 PM
10/18/12 10:39 PM
Joined: Jun 2001
Posts: 12,310
South Carolina
Jake Offline
Carpal Tunnel
Jake  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 12,310
South Carolina
Originally Posted by rehmbo
Originally Posted by sail7seas
http://www.youtube.com/watch?v=JLX1XPCQodk
In this video it looks like OR-S is the only AC45 in the group letting out the wing on the bear away. I wonder if the AC72 had the same wing trimmer.


So is the lesson then to travel-in when starting to stuff as the apparent wind shifts aft? Part of that makes sense, but when the apparent wind is at 90, It would be really tough to override the instinct to dump the traveller. Not sure I'd have enough time to think about it...


Past a certain point, you are just screwed. IF you can keep your speed up through the turn you are better off as you apparent wind will remain more forward. When the boat stuffs hard enough to go over, I don't think anything you can do will save it. Sail in, sail out, it's only going to change the angle with which the mast hits the water. Once it stuffs, the momentum and wind pressure are working against you and you have no helm. I've been out where it took three or four attempts to bear away to get through the turn. The trick was to get through the turn as fast as the foils would let you when the waves and wind are just right. The faster you can make that turn, the better off you will be. Get your speed as fast as possible, hang on, and yank it through hopefully just short of your rudders stalling.

These guys were just hugely overpowered and as they bore away, the rudders were probably stalled and about 1 second later and another second after that, there wasn't enough rudder in the water to have any influence over the direction of the boat.

That wing is ONE HUNDRED AND THIRTY FEET TALL!!! That's a lot of tomahawk momentum!


Jake Kohl
Re: AC72 Oracle Team USA Spaceship has landed [Re: P.M.] #253651
10/19/12 01:34 AM
10/19/12 01:34 AM
Joined: May 2006
Posts: 1,383
Kingston SE South Australia
JeffS Offline
veteran
JeffS  Offline
veteran

Joined: May 2006
Posts: 1,383
Kingston SE South Australia
There was a thread on here a long time ago about a guy that made a CO2 cartridge with balloon that you could inflate to stop a mast turtling, would something like that have stopped this wing filling with water which stopped the righting?


Jeff Southall
Current boats
Nacra 5.8 1703 Animal Scanning Services
Nacra 5.8 1667 Ram Raider
Nacra 18 Square
Arrow 1576
Re: AC72 Oracle Team USA Spaceship has landed [Re: JeffS] #253652
10/19/12 03:44 AM
10/19/12 03:44 AM
Joined: Feb 2009
Posts: 43
where the wind never blows
Lockenfisch Offline
newbie
Lockenfisch  Offline
newbie

Joined: Feb 2009
Posts: 43
where the wind never blows
Originally Posted by JeffS
There was a thread on here a long time ago about a guy that made a CO2 cartridge with balloon


... you can buy one. Just search for: Secumar Auto Inflation Anti-Inversion Mast Float

Somehow not very common. I've never seen a boat equipped with it. Propably because getting a beach cat out of the 100% turtle position by manpower is not so difficult, as far as the boat is not too wide like Tornado, H21, or others.

That "airbag-recovery" could work on any boat I guess.

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