Originally Posted by jcc
Originally Posted by HotRodDave
Originally Posted by jcc
Originally Posted by 360view
I have read that the composite shell was 5 inches thick but in the pictures the broken edges look more like ‘eggshells’ at first glance.

If the center section had been all titanium what would have been the added cost, is a thought.
Divide that cost by five passengers.
Compare to vacation voyage price per paying passenger.
Compare to passenger net worth in $.


The pictures you saw IMO are akin to seeing the body sheet metal after the wreck of a NASACR stocker, ie they were only the cosmetic outer shell, not the structure.

I read the original design called for a 7" thick pressure vessel, but they reduced it to 6". Properly manufactured 96" diameter cylinder shaped CF will handle 6K psi all day long, but cyclical fatigue life with that loading is above my pay grade. I don't know how low temperature might under rate it, and I have no idea what safety factor is at play. The most problematic aspect is the proper connection/retention of the CF with the needed Titanium hard points in the design and the likely source that initiated the fatal failure.

The CF material choice was likely a huge initial cost savings in material and fabrication, and a weight savings vs Titanium.



The white pieces you see in the salvage parts and in pictures of the sub before the dive are just a nice looking façade and have nothing to do with the carbon fiber tube holding the pressure... I have not seen any carbon fiber pieces in the recovered pics likely because it shattered and mostly floated off in the current. That brings us to why he chose CF instead of Fe or Ti, it could float with the air trapped inside where Ti and Fe would not float and would need propulsion capable of bringing it back up or 2.5 mile cable. This is why he thought he could not die, his theory was that the ballast that made it sink was supported by ropes that would dissolve in the sea water after a day or so and they would float back up and be found and rescued within the 5 days before the oxygen ran out. Some people are slamming him for using a cheap Ti and plexiglass end cap saying those likely were what failed (at least before the pics showed up of the parts) but in the pictures of recovered parts those appear to be totally intact. Some people seem to want the carbon fiber failure to have not been the cause because it is "new" and cool but from what I have seen they most likely caused the failure of the sub. Sometimes old and proven technology just doesn't need to be replaced. The CF evidently could not handle the cold and enormous load cycling, 5500 PSI is like having a modern 1/2 ton 4x4 4 door truck pressing on one square inch of the sub, if it had (just ball parking and probably a low estimate) 200 square feet of surface area with 5500# pressing on every square inch that is like having 28,800 of those 1/2 ton trucks pressing on the sub or over 158 MILLION pounds of force, you can evidently only load and unload 158 million pounds on the tiny sub before it gives up, based on testimony of previous "explorers" the thing would snap crackle and pop all the way down and back up so it should have been clear it was degrading with the cycles and was no doubt going to fail. As for what happened to the people inside they were crushed like a fly with a sledge hammer, whatever bits and pieces they have found of them are only going to be identified by DNA testing.


The 158 millions lbs you note is engineering wise irrelevant, and I will leave it at that.


Might be, but the fly being squished by the sludge hammer is a petty realistic vision. As I understand it, they believe the sub wasn't even 1/2 way down when it imploded. Picture, if you will, that squashed fly, now drifting 1/2 the distance towards the bottom of the ocean floor. Just how much would you expect to see still together as it passed through the drifting currents and past all the consistently eating sea creatures. Then supposedly, they think they can see human remains (parts of the squished fly) on the ocean floor? I'll be watching to see what human remains they think they are seeing at the bottom.

I think the media is trying really hard to distract the people from things going on that are actually important. They are telling you that can find traces of 5 humans on the ocean floor, but they can't find millions of missing and exploited children every day. Their focus it on the wrong things, and it isn't be accident.