31–40 of 100 posts
One can take comfort from this in a perverse way. The failure of the submersible was entirely predictable and should surprise no one. The alternative would be more troubling.
And perhaps like the Tacoma Narrows bridge it will end up being a cautionary tale for future engineers.
Earlier quoted context omitted.
My question is just... why? It's not like carbon fiber was any cheaper than just making the thing out of steel or titanium like literally every other submersible. It just doesn't make any sense. You have none of the weight penalties that exist in aviation, so the heavier and the thicker the better.
As I understood it, you do have a weight penalty for a sub. You need to get back up by powered movement, or down by it. You are limiting your dive time either way. They can’t use foam for flotation at that depth. There is a concrete like “synthetic foam” if you want unpowered rise to surface but it’s expensive. I read early on they wanted carbon to be light enough to get back up by releasing weights on powerloss. Fro…
Fun experiment: Take a roll from some toilet paper, squeeze it somewhat evenly at the ends. It is kond of stable. Then peel the layers apart, ans squeeze again. The same would happen if the composite tube delaminated at one of the end cap rings. This whole thing is beyond infuriating.
> It was previously stated by the CEO that each time he descended to that depth, the viewport deformed several inches inward. It takes an incredible level of density to ignore this once, but multiple times? Can someone tell me what happens to a human body when suddenly exposed to ~5000 psi? Edit: I looked it up. The human body almost instantly incinerates. It takes a matter of milliseconds.
The money phrase: >>take off their engineer hats and put on their manager hats
This is what kills people.
To boil it down to one short course in engineering ethics:
Whenever anyone tells you to do act like a manager instead of an engineer when making a technical decision, tell them, in no uncertain terms, and as politely or impolitely as needed to make the point: to fuck off; physics is physics, and neither knows about, cares about, nor yields to human concerns.
(Unless, of course, you are OK with living decades of your remaining life after the accident knowing you accepted a blood-money paycheck to do bad engineering.)
Is your current job, or your company's immediate future worth possibly killing people?
Earlier quoted context omitted.
As I understood it, you do have a weight penalty for a sub. You need to get back up by powered movement, or down by it. You are limiting your dive time either way. They can’t use foam for flotation at that depth. There is a concrete like “synthetic foam” if you want unpowered rise to surface but it’s expensive. I read early on they wanted carbon to be light enough to get back up by releasing weights on powerloss. Fro…
Especially if you buy your material because it is past shelf lofe, don't use an autoclav and forgoe curing. Fun experiment: Take a roll from some toilet paper, squeeze it somewhat evenly at the ends. It is kond of stable. Then peel the layers apart, ans squeeze again. The same would happen if the composite tube delaminated at one of the end cap rings. This whole thing is beyond infuriating.
I haven’t read that. But, that’s not an option. Carbon won’t just cure on its own, ever. It will be a shitty sticky mess forever. It had to be cured somehow.
As to the carbon expiration. I don’t know what that was. I suspect it could be epoxy like in prepreg, but I doubt prepreg here. And it could be shelf life of the carbon itself as it can be hydrophilic in some cases.
After an initial reluctance to follow this story, mostly due to the hysterical media coverage of a pointless rescue operation, my engineering half of my brain got interested. I am by no means a materials engineer nor a naval architect, but I was involved in some Design FMEAs and wrote thesis about the manufacturing of structural, pressurized aerospace carbon fiber parts. Some things I came across, which are in line w…
I've seen this claim repeated over and over with this single photo [0] with a display mount circled.
It was immediately obvious to me that the pattern of lights on the roof in that photo isn't coming through the 5" hull, but that the monitor is instead screwed into a liner of some sort. Additional evidence [1] seems to agree.
[0]: https://twitter.com/williamlegate/status/1672335515004162050
[1]: https://twitter.com/ohshutupskeeees/status/16723781759707504...
> From all available sources, it is apparent that the viewport was designed and certified down to a depth of 1300 meters, not 4000 meters. Wow. What kind of hubris could look past that huge red flag? Apparently the kind that thinks it is interesting that it deforms by several inches and not scary
Sounds like a simple experiment to build a titanium sphere and fix the same spec'ed viewport on it and send it down to 4000 meters. Perhaps a lawyer for a plaintiff with deep pockets will call for such a demonstration to be performed.
Earlier quoted context omitted.
Especially if you buy your material because it is past shelf lofe, don't use an autoclav and forgoe curing. Fun experiment: Take a roll from some toilet paper, squeeze it somewhat evenly at the ends. It is kond of stable. Then peel the layers apart, ans squeeze again. The same would happen if the composite tube delaminated at one of the end cap rings. This whole thing is beyond infuriating.
> don't use an autoclav and forgoe curing. I haven’t read that. But, that’s not an option. Carbon won’t just cure on its own, ever. It will be a shitty sticky mess forever. It had to be cured somehow. As to the carbon expiration. I don’t know what that was. I suspect it could be epoxy like in prepreg, but I doubt prepreg here. And it could be shelf life of the carbon itself as it can be hydrophilic in some cases.
After an initial reluctance to follow this story, mostly due to the hysterical media coverage of a pointless rescue operation, my engineering half of my brain got interested. I am by no means a materials engineer nor a naval architect, but I was involved in some Design FMEAs and wrote thesis about the manufacturing of structural, pressurized aerospace carbon fiber parts. Some things I came across, which are in line w…
> Despite claiming otherwise on their homepage (archive.org still has it) they did attach equipmwnt directly to the carbon hull on the inside by screwing (!) to the hull. Result, all the fibers cut by the screws don't take any load whatsoever anymore, increased risk of delaminations (the hull is compressed, the screw on the inside isn't) I've seen this claim repeated over and over with this single photo [0] with a di…