Emirates Team New Zealand.

[Ex Machina]

Actually, if you watch that capsize again, very closely, I don't think the initial crash was the issue. Look at the tension on the rig. It's on when it crashes and only comes off right at the end, right when the jib is trying to pull a shit ton of water up with it, and it looks like all that weight has pulled the bow around and crumpled it the way it did.

Yep jib took a ton of load from filling with water then forestay loaded up then bow broke , maybe

 

[ChairborneRanger]

AM break a boat, it’s a shit boat didn’t do a good enough job

tnz break a boat, oh it’s jolly difficult to model, they are doing their best..

nice and consistent as always 😉

AM had/have a great boat. Did a great job. unlucky to crash, but lucky to have the help of ETNZ to fix it.

 

[Sailbydate]

December 10th or before?

Maybe December 15? Probably built a mould for the bow and deck skins already. Just waiting for Dan's guys and girls to complete the framing reinforcements I shouldn't wonder.

 

[breezie]

Shrug. It is your assertion, why not try demonstrating it yourself?

dipstick !

 

[JALhazmat]

Maybe December 15? Probably built a mould for the bow and deck skins already. Just waiting for Dan's guys and girls to complete the framing reinforcements I shouldn't wonder.

Which would make it LEQ12 ( it is already by virtue of how they have used it) plus the fix modification taking it out of class (ac40)

which would mean that their new ac40 also needs a mod as does everyone else’s

they made a rod for their own back and everyone else’s sadly

 

[Sailbydate]

they made a rod for their own back and everyone else’s sadly

Shit happens, JAL. Had they not moded into LEQ12, switched off the driver aids and pushed the boat hard, the crash dive prolly would never have happened - and the obvious structural limits been found. And then what?

 

[enigmatically2]

Shit happens, JAL. Had they not moded into LEQ12, switched off the driver aids and pushed the boat hard, the crash dive prolly would never have happened - and the obvious structural limits been found. And then what?

Then perhaps another team would have done so. In which case NZ would have said it was their fcuking fault and there is nothing wrong with the design. So they would have to wait for the end of the delivery sequence before they will fix it

 

[JALhazmat]

Shit happens, JAL. Had they not moded into LEQ12, switched off the driver aids and pushed the boat hard, the crash dive prolly would never have happened - and the obvious structural limits been found. And then what?

People would have been sailing around in a poorly designed /or constructed boat?
at the end of the day, no one knows whether it was a design issue or construction issue

how they extricate themselves from this will be telling, they could throw the builder under the bus and say it was a one off issue with their boat and save the hassle of making any changes or it was built correctly, but underspec which puts the onus back on the design team and screws everybody schedule

 

[Scillyjosh]

I see that now in this video. Back to the drawing board. As mentioned, it does indicate that sims alone can't estimate forces in a good boat to water crash. You would think that the construction would allow for at least 5X expected forces, big divide by zero problem.
At least watertight crash bulkheads still work after all these years.

If you want a 5x safety factor on all structures then don't expect to see any boats foiling! That will be heavy. The whole point of doing the analysis, simulator testing and instrumenting boats is so you can close the gap between predicted and observed loads.

 

[The_Alchemist]

People would have been sailing around in a poorly designed /or constructed boat?
at the end of the day, no one knows whether it was a design issue or construction issue

how they extricate themselves from this will be telling, they could throw the builder under the bus and say it was a one off issue with their boat and save the hassle of making any changes or it was built correctly, but underspec which puts the onus back on the design team and screws everybody schedule

NZ would be required to supply the data showing it was a manufacturing defect vs a design defect. The boat builder would fight tooth and nail to defend the reputation of their manufacturing abilities. False claims could destroy their boat business.

 

[JALhazmat]

Or destroy the design teams reputation…
it’s lose lose either way.

 

[Sailbydate]

Then perhaps another team would have done so. In which case NZ would have said it was their fcuking fault and there is nothing wrong with the design. So they would have to wait for the end of the delivery sequence before they will fix it

So, I'm glad we agree, it's a good thing it's happened already. ;-)

 

[Sailbydate]

Or destroy the design teams reputation…
it’s lose lose either way.

Yeah. ETNZ desperately need to get a proper designer join its team, to try and save its rapidly fading reputation. I wonder what, Juan K is doing these days? ;-)

 

[barfy]

If you want a 5x safety factor on all structures then don't expect to see any boats foiling! That will be heavy. The whole point of doing the analysis, simulator testing and instrumenting boats is so you can close the gap between predicted and observed loads.

The supplied foil arms got at least that safety factor last cycle, as there was some disclosure around the second design, build, and test process.
I'm not saying all structures, but I would think bow hits and the crash bulkheads would be up there.
But I'm not privy to the design specs.

 

[Scillyjosh]

The supplied foil arms got at least that safety factor last cycle, as there was some disclosure around the second design, build, and test process.
I'm not saying all structures, but I would think bow hits and the crash bulkheads would be up there.
But I'm not privy to the design specs.

https://www.sail-world.com/news/217742/Americas-Cup-Foil-Arm-explodes-in-test-Video in this video the foil reaches 27.3 tonnes before breaking - a fully loaded AC75 is pushing 7.5 tonnes. We can bump that up to 8 tonnes to account for the side loading from the rig. Load factor on static load vs foil failure is ~3.4. This is not the safety factor!! This doesn't account for any dynamic loading, add between 1-2g of dynamic loading and suddenly you're looking at a safety around 2. Safety factor has to be applied to the expected design loading, it is not based on static load! In fact in the video they even say it broke at just over 2.1x the working load! Not sure where this 5x is coming from! For reference safety factors of 1.5-2 for planes and 5 if your a civil engineer making concrete bridges....

 

[barfy]

https://www.sail-world.com/news/217742/Americas-Cup-Foil-Arm-explodes-in-test-Video in this video the foil reaches 27.3 tonnes before breaking - a fully loaded AC75 is pushing 7.5 tonnes. We can bump that up to 8 tonnes to account for the side loading from the rig. Load factor on static load vs foil failure is ~3.4. This is not the safety factor!! This doesn't account for any dynamic loading, add between 1-2g of dynamic loading and suddenly you're looking at a safety around 2. Safety factor has to be applied to the expected design loading, it is not based on static load! In fact in the video they even say it broke at just over 2.1x the working load! Not sure where this 5x is coming from! For reference safety factors of 1.5-2 for planes and 5 if your a civil engineer making concrete bridges....

Obviously there is no data for the load cases on the bow so you are pulling

 

[Forourselves]

People would have been sailing around in a poorly designed /or constructed boat?
at the end of the day, no one knows whether it was a design issue or construction issue

how they extricate themselves from this will be telling, they could throw the builder under the bus and say it was a one off issue with their boat and save the hassle of making any changes or it was built correctly, but underspec which puts the onus back on the design team and screws everybody schedule

Wait, so 1 breakage and its a "poorly designed boat"? Jees the F50 must be a really shit boat then. That things had multiple breakages!

 

[Forourselves]

Storm in a teacup. Nothing to see here...

 

[Sailbydate]

Nice clean solution there. Should be a quick fix.

 

[Kiwing]

Before Dec 10th?