Americas Cup
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@Snowy isn't the hole in front of the foils, closer to the bow, so as the stern lifts the hole goes deeper?
edit:
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@Kiwiwomble On our boat the foils seem to be aft of the mast though. There is no mast on the boat in the photo and it could be a bit of an optical illusion due to that green line? I don't think the foils are amidships but could have that wrong. Might be different on Patriot. It would seem logical that the foils are supporting the bulk of the weight so they would have to be aft nearer the center of gravity as most of the mass of the boat is aft. Aircraft wings are positioned to give a small pitching moment between CoG and centre of pressure (lift). That creates a natural "righting" moment in pitch which can be controlled, otherwise you are just balancing on a pin head but they aren't normally too far away from each other as you have to create drag to counter the pitching moment.
I have read the AC75 class rules and I think that they can vary that as part of the design. Maybe they got it a bit wrong? We have capsized too though. The original concept had them well aft:
That might not have worked and they have them forward now. I'm going to have look more closely!
There actually appears to be another hole behind the foil in that pic too...
The buoy on the bowsprit is clue that it was in trouble.
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@Snowy I think they are in front of the mast, they also have the rudder giving lift (to a much smaller extent) at the stern
so I think the hole is about here
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@taniwharugby said in Americas Cup:
Peter Lester was saying something inside the hull had to have come loose for it to cause a hole like that.
The way it landed it didnt look like it would have caused too much stress to the hull to cause a crack.
having seen a fair bit of busted carbon in my time from bike crashes - carbon doesn't break clean through like that
i'd suggest that part of whatever the divers were doing on the water was to cut that hole to get something out / save something / get airbags inside.
Even something punching through something at high speed wouldn't leave a hole as clean as that.
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@WillieTheWaiter Different angle pics show a rather ragged edge, and it is not a perfect square.
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@taniwharugby said in Americas Cup:
Peter Lester was saying something inside the hull had to have come loose for it to cause a hole like that.
The way it landed it didnt look like it would have caused too much stress to the hull to cause a crack.
I assume this is the same interview
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@Kiwiwomble yeah, although the 2nd part of my post, was my thinking, nothing to do with Lester.
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great press conference, their aiming to be back on the water for the semi's
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@Kiwiwomble Looks too far forward to be the hydraulics but nice work with the box. Arrows are more traditional, but things evolve and you aren't Australian (even though you live there).
Yep it does look like foils about amidships and the rudder sure helps with lift astern. That all means that it should have gone down like a stone. I dunno.
Do they have buoyancy tanks or watertight bulkheads? They did get help very quickly too.As @Machpants says I think that hole was bit rougher than it appears unless that had already been trimmed it to repair.
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@Snowy in the presser they said they do have a lot of inherent buoyancy and then got a lot of floatation devices under it, he mentioned the coast guard giving them a couple of "airplane type life rafts" they inflated under it
my coverage cut out just as he was explaining the hole but a sailing mate dumbed it down for me
"..so the boat has transverse structure and longitudinal structure - picture like a grid of strong bits like the wall of the house. When the boat slammed down on the angle, the pressure of the slam just popped out the weak bit in between the frame (like putting your hand through the plaster in between the frame)"
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@Kiwiwomble said in Americas Cup:
"..so the boat has transverse structure and longitudinal structure - picture like a grid of strong bits like the wall of the house. When the boat slammed down on the angle, the pressure of the slam just popped out the weak bit in between the frame (like putting your hand through the plaster in between the frame)"
Sounds pretty accurate. I used to build fibreglass boats but nothing like the carbon fibre stuff and I thought they could do away with some of the ribs and stringers due to the strength of the product they were using. Must still have some to maintain the structure, (or not), when things go wrong.
The puzzling thing about that is the impact on the water, in itself, shouldn't have been enough to rupture the hull unless there was something to exacerbate it, like heavy equipment. Then you have to ask why was that not reinforced /strong enough to deal with it?I'm sure that all of the teams are trying to work that out now.
The combination of strength, weight, hydrodynamics, aerodynamics, ergonomics makes these machines engineering marvels to me.
Chuck in some human factors too, and you have some entertainment.
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@Snowy maybe they landed on a shark, plenty about at present apparently.
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@taniwharugby said in Americas Cup:
@Snowy maybe they landed on a shark, plenty about at present apparently.
Failed to "jump the shark?"
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Hutchinson confirmed the hole had been caused by internal pressures after the boat slammed down from its leap out of the water as they tried a difficult tack-bear away at the final mark while leading Luna Rossa.
“It’s fine when it lands flat on its heel but when you land on the side, the structure inside just guillotined the panel and out it came.”
Alarm bells rang when one of American Magic's chase boats found a large section of the hull floating nearby, confirming Hutchinson's worst fears as he had plenty of water splashing around him aboard the crippled AC75.
Hutchinson emphasised fixing the hull would be the easy part. An ultrasound of the hull began at 3am on Monday and took seven hours, giving them some reassurances.
“If you have concerns or worries, it’s dealing with what’s inside the boat … the hardest part is the electronics.”
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@Machpants said in Americas Cup:
Hutchinson confirmed the hole had been caused by internal pressures after the boat slammed down from its leap out of the water
Sounds like my first guess.
The electronics is interesting - surely they have spare parts? They also have some time.
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@canefan said in Americas Cup:
@taniwharugby said in Americas Cup:
@Snowy maybe they landed on a shark, plenty about at present apparently.
Failed to "jump the shark?"
Someone get the Fonz!
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@Snowy said in Americas Cup:
@Machpants said in Americas Cup:
Hutchinson confirmed the hole had been caused by internal pressures after the boat slammed down from its leap out of the water
Sounds like my first guess.
The electronics is interesting - surely they have spare parts? They also have some time.
yeah, he confirmed they had spares for everything they need and they can still steal some stuff from Defiant like the foil arm mechanism which apparently is rooted
also confirmed the hydraulics are a closed system so is fine, he said if that had been damaged then they would have been screwed as that would have taken a lot longer to install a new one that the electronics
Theyre using lots of different people to help, he said ETNZ are "finished" or at least winding down with their boat building so have offered up their local boat builders to help manufacture sheets of carbon fibre, for example, that then their team can just install
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@Godder said in Americas Cup:
@canefan said in Americas Cup:
@taniwharugby said in Americas Cup:
@Snowy maybe they landed on a shark, plenty about at present apparently.
Failed to "jump the shark?"
Someone get the Fonz!
He would have kept cooler than Deano during that turn....
