Siegfried ,

Break-before-leak

hperrin , (edited )

No, low quality carbon fiber didn’t lead to the accident. A blatant disregard for safety, testing, and best practices led to the accident. Low quality carbon fiber just contributed a bit.

Pacmanlives ,

From what I remember it was supposed to be a simgle use vehicle that they kept using.The CF worked great those few time but would eventually wear out because of stress fractures. That's what I remember from when the accident happened so I could be wrong.

barsquid ,

I think "great" carries a sort of connotation as if engineers expect it might work once or twice. From the sounds of it, the better description of the submersible for the surviving trips might be that it worked miraculously. Basically divine intervention that they made it back even once.

werefreeatlast ,

I can show anyone that I can successfully apply low grade carbon fiber as flooring material. No matter what grade porcelain you use, you probably wouldn't use it for a submarine, car or plane body. It's all about proper engineering design based on sound science and testing of materials.

possiblylinux127 ,
@possiblylinux127@lemmy.zip avatar

The irony of this is wild

yesman ,

DAE remember that the OceanGate CEO bragged that Boeing helped them manufacture the sub?

At the time Boeing disavowed, but who you gonna believe?

ChicoSuave ,

Another whistleblower gone before their time

NutWrench ,
@NutWrench@lemmy.world avatar

Stockton Rush got a bargain on the carbon fiber he bought from Boeing because It was approaching the end of its shelf life and it was no longer acceptable for use in aircraft, let alone submarines.

Rush also made a number of claims about the involvement of Boeing and other companies, claiming they were "involved in both the design and construction" of his submarine. Those claims were not true. Boeing made it clear that they had NO involvement in any part of the sub's design or construction and they had simply sold Rush the carbon fiber.

_haha_oh_wow_ ,
@_haha_oh_wow_@sh.itjust.works avatar

CF just seems like a bad material to use for this purpose at all

possiblylinux127 ,
@possiblylinux127@lemmy.zip avatar

But it sounds cool

BastingChemina ,

CF is extremely light, so when you want to build something that sink it make sense to build it out of extremely expensive CF rather than cheap steel like every other submarine.

SparrowRanjitScaur , (edited )

It's also not great when the pressure is on the outside of the vessel. It's good at containing pressure because that leads to tension on the carbon fibers which is when they're their strongest. But when the pressure's on the outside of the vessel they're more or less useless.

Voroxpete ,

Yeah, at the point where you're resisting outside pressure your hull is basically just the plastic resin that the fibres are sealed in. Without that, the fibres are just a fabric bag.

Imagine if they'd said "We're diving down to the Titanic in a submersible with a plastic resin hull." Doesn't sound so great.

reddithalation ,

Your point makes sense, but an epoxy submersible definitely wouldn't make it down to the titanic intact even once, and there are some ways fibers could be put in tension by compressing the cylinder, so the CF was doing something, its just complicated. They shouldve just built a normal submersible though.

Chee_Koala ,

I guess everyone was right al along, that makes for a pretty boring article though 🤣

notaviking ,

Was the issues not multiple, like the carbon fibre hul not made using vacuum technologies but just like roll on the sheet and some epoxy in a warehouse, that carbon fibre being strong tensile wise but not compression wise, the titanium carbon fibre interface and their different stress deformations due to pressure, having the Titanic OST playing the whole time, like multiple safety shortcuts and maybe using a game controller as your only form of any interaction, like what happens if some kid bites the cable or something

ZapBeebz_ ,

Let's also not forget that there was no way to exit the submersible from the inside. The door was bolted on by the surface team. So if they had just lost power (instead of being crushed), they would've been floating on the surface with no way out. That's the another obvious horrendous design choice.

notaviking ,

I have worked in underground mines, and this scenario of being bolted inside gives me way more cluster phobia than any experience I have had

ZapBeebz_ ,

I work on submarines. Everything that company was doing gave me a panic attack. The SUBSAFE program exists for a reason. Like, there's a time and place for innovation, and when people's lives are on the line is NOT it.

notaviking ,

Usually these program's rules seem very tedious and restrictive and I can easily see one person looking at this and think they are in place to stifle innovation and keep the little guy out.

I remember how he said to not have regulatory approval because of of this or that, but why not get a regulatory expert to have a look, might not approve your vessel but might show clearly missed safety critical blindspots.

But these rules exist for a reason, they where usually written in blood, it's how I know this incident added rules to your SUBSAFE program.

ZapBeebz_ ,

SUBSAFE was implemented in 1963 following the loss of USS Thresher (SSN-593). It's a remarkably strict QA program for systems and components exposed to seawater/operating pressure. To our credit, we've only lost one submarine since 1963 (USS Scorpion, SSN-589, and she was never SUBSAFE-certified), so the program works.

Similarly stringent controls for the Titan would have either caught all the manufacturing defects in the carbon fiber, or prevented anyone from thinking it's a good idea to begin with. A big part of innovation is learning what rules you can reasonably bend/break, and which should never be touched. I tend to think pressure hull construction falls in the "never touch" category, at least not without a mountain of testing, data collection, fatigue life calculation, etc. along with communication with regulatory bodies to ensure you meet the principles of the regulation, if not the exact words (again, innovation has it's place).

notaviking ,

So cool you work on submarines that is extremely cool, I am in a way different industry, mining. Jeez I wished we had your safety record of only one lost submarine. Our industry has gone through a couple of mines in the same period.

But wow, how does the safety of submarines compare to other industries, granted outside of war times, like compared to trains or even other seafaring vessels

ZapBeebz_ ,

We benefit from the bottomless DoD budget for sure. We have the ability to spend as much as it takes on material and training to ensure reliability and safety for the crew. And it shows. We've had several undersea collisions (SSN-711 in 2005 and SSN-22 in 2021), and while both incidents were extremely serious, both boats made it safely back to port for repair.

hperrin ,

Claustrophobia?

notaviking ,

There's how you spell the word

turmacar ,

It bugs me that everyone harps on the controller. It's far and away the least suspect part of this.

Multiple generations of hardware iterations by many competing companies, well defined and understood software interface options, literally billions of hours of testing, easily replaceable, several axes of control, and a huge portion of the population has at least some experience with one.

There's a reason the military uses them when they can.

notaviking ,

I have no issues with the controller either think it was a great addition, were I had a gripe is that it was the only way to operate the vessel, so not an addition but the sum total of controls.

Like if you were bolted into a vehicle, with no way to interact with the outside except a tiny window and only a game controller, it is a lovely piece of efficient engineering and does everything you need, but if this controller maybe gets damaged for example it's cable was unfortunately pinched off by someone's shoe. When you realise at a 1000m the closest thing to a god is that controller working and taking you safely back to surface in time or being stuck and hoping the guy who got you into the mess, that his, only other plan the dissolvable ropes on the weights actually work and you get to surface and get found and unsealed before air runs out.

turmacar ,

Fair enough.

Top to bottom the design of the thing is just a testament to arrogance and "engineer's disease".

notaviking ,

I think this was the original sin, the root cause. One man's vanity and arrogance, which made him blind to his own shortcomings. He build something great, let us not lie, but we can clearly see in hindsight the obvious truth. Well if what people that know way more than I do are right, the vessel imploded quicker than the neurons in your brain, so it must've been an quick painless death

mbfalzar , (edited )

I mean, using a controller in and of itself is not suspect, but the model they used is the cheapest one you can get with a recognizable name and is known for being unreliable, which is absolutely a suspect decision to make when it's the only method of control

PsychedSy ,

For some reason I thought it was rolls of prepreg. I don't know that I've ever seen raw tows used with separate resin.

notaviking ,

Ok it probably was prepreg now that I think back, but I saw the application video where the just rolled it on no vaccume bags to remove any voids or cavities

PsychedSy ,

That's insane. No NDI then as well. Just fucking suicidal.

steersman2484 ,
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