I read something in the Guardian about water being able to get into carbon fibre weave on a molecular level under extreme pressure, causing it to delaminate. Plus, each time you use it, like a steam locomotive boiler, the whole normal pressure - high pressure- normal pressure cycle stresses everything each time you do it, so you can only do it safely so many times before tiny cracks can start.
I know a little bit about carbon fibre and stresses. Not at serious depths like that,but in a slightly different way. I have a Specialized Roubaix race bike. It is Carbon r,which is Specializes own make. It certainly acts different, when riding it, on a hot day, than a cold day, due to ‘flex’ and tensile strength . The temperature certainly effects it, in weird ways.
Yes, the thing about all composites is they are not materials in the sense that steel and aluminium are. They have different properties in different directions; they are structures in their own right before you make a bigger structure, like a bike, F1 car, plane or submersible, out of them. They are also a nightmare to join to other materials, like, er, titanium, and as for putting bolt holes in, then you are just asking for trouble. Then, they don't like being left in water - osmosis of boat hulls, anyone? Compound that with pressurising the water to 40 atmospheres and you might imagine that softening and delamination of the outer layers might be something to think about. The aircraft industry regards composites as 'black metal' and has hugely conservative design factors to deal with all these uncertainties. I did a quick calc of the hull stresses and I wonder whether they took any account of anything other than the newly built, perfectly manufactured, idealised design case. The CEO comes over as a complete **** (sorry I didn't intend to get round the swear filter, I've just left it up to your imagination what I think of him)
I saw James Cameron on TV talking about the parallels between the captain of the Titanic steaming at full speed, on a moonless night, towards icebergs that he’d been warned about, and the CEO of the Titan, who’d been warned many times that he was running a potential death trap. Ironically they both paid the ultimate price, over a century apart but within yards of each other. I’ve been to two Titanic exhibitions, the touring one when it visited Manchester, and a smaller one on board the Queen Mary at Long Beach, I’ve touched ‘the big piece’, a 15 ton chunk of the hull, when no one was looking. When I went to the touring exhibition, the first room was nearly dark, with a big green bell hanging down. The information board explained how Frederick Fleet, lookout in the crow’s nest, saw an iceberg dead ahead. ‘He rang this bell three times’. It made the hairs on my neck stand up a bit. Not a bell like this, this bell.
Quite a good expo in Southampton as well. Find the whole thing rather creepy. Remember Ballard when he first found her getting confused when his sonar was telling him he was right next to it, but all he could see was blackness. The "blackness" was her vast hull towering over him. That would freak me right out...
Reading earlier that the implosion would have occurred possibly as quickly as a millisecond followed by an explosion with those inside vaporised with little or more likely no perception of the event even happening! Eek!
Seems it was the reverse of that, the son didn’t want to go. If the media reports are to be believed.
What away to go. I want to go peacefully, like my grandfather, in his sleep. Unlike the passengers on the bus he was driving…
I think as @docjohn says, as quite a few seemed to have warned Stockton Rush, the submersible was built from an unsuitable material. I was listening to one of the “naysayers” who said there is simply not enough flex in the carbon fibre to cope with the huge difference in pressure from the surface to a couple of miles down. Very sad that Rush was seemingly so blind to this.
Literally, back of the envelope calcs would tell you that a carbon fibre hull was a bad idea. The hull monitoring system was completely pointless. The elastic energy in the hull at that depth - imagine a compressed spring - was the equivalent of 2 hand grenades....
It's sobering to think of the pressure on the sub Assuming it reached the bottom at 3800m (380atm) That's a huge weight which is about 4 million Kg/m²
Better than being 2 days in Really doesn't make sense . Can't understand why other guys in that business who seem to be convinced that it would possibly lead to a disaster and did not shout out to possibly prevent them from going through with this exploration . If someone told me of that pressure down there as you mention , and then go around the mini sub tapping it and observing it's make up and SIZE it would be a big no no from me .
I saw a Drain the Oceans programme about USS Thresher, a nuclear submarine lost during deep diving trials. The last garbled message indicated that they had lost control and exceeded their test depth, probably due to a leak caused by dodgy pipe work brazing. Obviously they were rather anxious to find the wreckage, particularly before the Russians could. What they found was a lot of tiny pieces, that looked like they’d been through a shredder.
It’s thought that’s partly why Putin was so slow to accept outside help when the Kursk sank, didn’t want Russkie navy secrets getting into Western hands.
Seems like they said their bit then shut up. While saying their bit, the concern seemed to be the negative impact a disaster for this sub would have on THEM and their fellow exploration type submarine livelihoods. You can only say so much before you look like you're bitching and trying to undermine the opposition as it were.
Perhaps they had the decimal point in the wrong place, when working out the pressures,etc…It can happen, to the best of us …
