Beyond Titan - physics and the deep sea

[TokyoStories]

Continuing our crash course in all things deep-sea.

I thought the carbon fibre hull had a thin outer coating of laminate?

Because they thought it would give sufficient warning, but sadly they were wrong in this case.

It may well be that the warning system has activated in this case and the occupants knew the structure was weakening, before the catastrophic failure happened.

Whats the point in having microphones listening for the structure losing integrity because it would be too late by the that point right?

I think it's problematic in a small sub like the Titan which doesn't have the power to rise quickly and get itself out of trouble, if the pressure was too extreme. So the microphones could pick up an integrity loss, but what was going to happen in order to get them back up to a safer depth? Yet another thing not properly planned for. Honestly the Titan seems to be almost to be a prototype that would need further refinement before passengers (paying or otherwise) evder went down in it.

I'm guessing they cover the name for legal reasons.

Real carbon fiber only truly comes in one way, the standard black/grey weave that we're all used to seeing. You've seen things advertised as a coloured carbon fiber, but that's not the real story. For example, if you see something advertised as silver carbon fiber, it's actually another material like aluminized fiberglass or silver Texalium.

Source.

What Color Is Carbon Fiber - TextileTuts

I'd love to know the thought process behind it.

From your article:

The color of 100% pure real carbon fiber is Black/Grey. Carbon is black-colored by nature; without blending carbon fiber with other fibers, it’s not possible to dye it in other colors.

One for the lawyers, I guess...any sponsors involved..

I know the airlines do it for both brand and legal reasons, whatever they are.

This aircraft got left in full view in front of the airport terminal for ? a week while the investigators started work but got a liberal application of white paint within bout 24 hours of the engineers breaking it..

https://simpleflying.com/airbus-a340-written-off-before-delivery/?newsletter_popup=1

I had assumed as the material was offloaded by Boeing that it was like the CRFP used in the fuselage etc, and to be honest I don't really care. I do know carbon is black, though! Composites may be other colours, as that interesting article explains in this paragraph:

The natural color of carbon is black. However, when it is used in manufacturing different products, carbon can be mixed with other materials to produce a variety of colors. The most common colors for carbon fiber are black, grey, and white.

and to be honest I don't really care

That's pretty obvious.

No need to be rude.

Interesting you plucked that bit out and ignored this statement though:

The most common colors for carbon fiber are black, grey, and white.

Okay, can you find a source which is not a textile magazine, and doesn't contradict itself?

Again, I watched the carbon-fibre being wound around the Titan cylinder and it was black.

You can't argue with people who are convinced they are right despite a preponderance of evidence otherwise.

Sums up Stockton Rush nicely.

There's a psychological term called groupthink. Whereby the desire for the group to all agree at all costs and conform overrides common sense and people expressing unpopular opinions (the guy who got fired for the health and safety)

For which see the Asch Conformity Experiment

https://www.simplypsychology.org/asch-conformity.html

Heh, nicely done!

It was better than your shitty source! As I said, I don't really care. As I've also said, I am not a designer of experimental submersibles. Nor am I an engineer. Anything I've understood to be so about the composition of the sub, is just what I've understood to be so. As I've said, it is my understanding... Maybe what I've concluded from what I've read is wrong.

But it strikes me, you are also not involved in any way with the design or manufacture of submersibles.

Discussing the physics of deep sea diving reminds me of a documentary about a the Blue Hole of Dahab, called 'The Sacred Truth'. It's a grim watch. Between 130 and 200 scuba divers have perished exploring it. IIRC it looks quite benign and an easy dive but isn't, the film exploring why so many die.
I don't have a link to the film but there are plenty of You Tube videos and articles about the Blue Hole.

Ah yes I recently wrote about this in my psychology degree. I find it so interesting. Other conformity experiments were the Stamford prison experiment and the milgram shock experiment. All illustrate how humans conform when faced with others all agree and when faced with authority

Any physicists around? I'm wondering looking at the sizes of the pieces of debris (especially the one far right with all the wires hanging out in the Reddit graphic @Locutus2000 linked above) and the reports of human remains, if this "implosion" was less high powered than we've been assuming on this thread. I would have assumed the wires and human remains would have been destroyed by heat

I know that factors like how deep it was (ie. how severe the difference was between the internal air pressure and the sea pressure) would have made a difference to the strength of the implosion

I've also read that you can't have a slow leak on a submersible like this at depth because it's just a big implosion.

But is there any way something could have happened do you think to mean the collapse of the sub was less powerful than we imagined?

But it must have been quite deep if it was 1.45 hrs into its trip.

I'm thinking for example of the difference between if you stick a pin in a balloon and it goes bang (I know this isn't directly analagous) as compared to if you stick a bit of sellotape over it first and you get a slow leak.

I'm also wondering why the Oceangate logo is covered up. I realise they have sort of "wrapped" all the bits (not very effectively) presumably to try to preserve evidence but the taping of the logo is very deliberate. Is it an "out of respect" thing? Or a don't-want-to-give-these-murderers-free-advertising thing? Or maybe it has some damage that no one needs to see, like teeth embedded in it?

Just seems odd and there doesn't seem any rational explanation provided anywhere either officially by the coastguard or unofficially by the media

I wonder about the large piece recovered- the one with all the cables/ wires, was this part hidden inside the pointy tail?
It just seems too big to fit there, but I suppose its must fit there, that’s the engine right?

I think I’ve given facts and figures in an earlier post but I posted a demo of the collapsing can which shows what happens when air pressure outside is 100 000 pascals (that Newtons per square metres) this causes the can to buckle - residue of coke is still inside the can and outside still exists. The sub would have had 310 times bigger (minimum) the pressure different from outside to instant. Any small fracture or hole or fatigue would have resulted in a coke can scenario but with about x400 the pressure different of the YouTube collapsing can. Human tissue is soft - bone a bit harder but easily crushed or imploded into crumbs - metals are much denser and are stiffer (higher young modulus that human tissue) and therefore also compressed with no air - a bit like the can - they will remain

no slow leaks it would have been immediate catastrophic failure

I'm thinking the implosion blew the sub apart which is why they found the separated big pieces (separated along the joins, basically). So unlike the tanker in the video that collapsed in on itself, the sub blew apart, so the people inside would have been subjected to the immense water pressure and died instantly.