>>1142

So what I heard is 5" thick carbon fiber cylinder, steel endcaps and almost stand up in it so let's give them the benefit of the doubt and say 5 feet ID. 22ft long so assuming hemi endcaps then 17ft cylinder bonded ends 5'10" dia.

Additionally what we have is 12,500 ft depth, so 3800m and 5500psi. That's a lotta p.

According to my napkin calcs, that wouldn't be enough if it was all steel, close though. Given Aluminum with a .07 thickness to diameter ratio given infinite length, that would get to about 3500m without buckling, so not enough.

But for carbon fiber... well Google tells me the Young's modulous is 200 GPa min (29,000ksi) that's as good as steel minimum. With a tensile strength of 3 GPa min, 450ksi, big.

Ok, so it looks to me like it had a healthy safety factor in theory which is surprising.

So let's talk windows. 1ft diameter assuming it had a window, at that depth I doubt they'd use acrylic. So let's say 5000psi for the apparent elastic limit. The t/D ratio is about .35 for minimum safety. So it would be about 4-5 inches thick too, nothing shocking.

So if it's ideally ok, what happened?

My theory notes: