this post was submitted on 24 Jun 2023
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The Titanic director has made 33 dives to the shipwreck and visited ocean depths in a submersible he built himself. He compares OceanGate to the Titanic in that both ignored safety warnings.

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[–] PabloDiscobar@kbin.social 36 points 1 year ago (2 children)

Pressure hulls should be made out of contiguous material like steel, titanium, ceramic or acrylic, he explained, in order to do modeling and finite element analysis to "understand the number of cycles that it can take." That's not the case with a composite material, like carbon fiber, made of two different materials blended together.

"And so we all knew that the danger was delamination and progressive failure over time with microscopic water ingress and ... what they call cycling fatigue," he added. "And we knew if the sub passed its pressure test it wasn't gonna fail on its first dive ... but it's going to fail over time, which is insidious. You don't get that with steel or titanium."

[–] rigatti@lemmy.world 9 points 1 year ago (1 children)

Damn, I didn't realize Ja knew so much about materials science.

[–] Unaware7013@kbin.social 15 points 1 year ago (1 children)

Apparently he built the sub he used to go to the titanic and into the Mariana trench. Dude must be intimately familiar with this sort of thing with that experience.

[–] kestrel7@kbin.social 1 points 1 year ago

He honestly seems like a fairly accomplished and responsible citizen scientist compared to the Oceangate clown (RIP).

[–] kestrel7@kbin.social 2 points 1 year ago

Like, I don't trust carbon fiber for my bicycle frame and stick to steel because that shit cracks easily. I can't believe this guy rolled the dice with carbon fiber on a fucking deep-sea submarine.

[–] ikantolol@kbin.social 14 points 1 year ago (2 children)

feels like they probably knew that in their heart the moment they see the $30 Logitech controller...

[–] static@kbin.social 20 points 1 year ago (2 children)

Using a game controller is not that unusual.
but it was wireless, that is bad.

[–] PabloDiscobar@kbin.social 6 points 1 year ago (1 children)

What was the controller commanding btw?

[–] TimeSquirrel@kbin.social 8 points 1 year ago (1 children)

The thrusters on the outside. The goal was to minimize hull penetrations for cabling and things.

[–] PabloDiscobar@kbin.social 4 points 1 year ago (1 children)

Thank you, so the signal went through the water a little bit. We had a struggle about it in a different thread.

[–] Flaky_Fish69@kbin.social 1 points 1 year ago

Probably not, actually. carbon fiber is opaque to blue tooth. Even a single ply carbon shell is enough to block it. My DLG r/c airplane uses an arramid section for the antenna.

[–] Hyperreality@kbin.social 1 points 1 year ago (1 children)
[–] SpacemanSpiff@kbin.social 4 points 1 year ago

I’ve heard of this. Out of curiosity (because I don’t actually know), do you know if the controllers used in military applications are literally “off the shelf” or if they’re “Xbox-like”, which is what most descriptions about them say.

In other words, I suspect the military(s) using these type of controllers are not just ordering them off Amazon and using them as-is, whereas it sounds like that’s exactly what OceanGate did.

[–] kabe@lemmy.world 18 points 1 year ago* (last edited 1 year ago) (4 children)

I know the controller seems corny, but it turns out that even the US Navy have used Xbox controllers.

The real red flags here were the carbon fiber hull and the fact that the Titan wasn't even certified or properly tested to ensure it could survive the stress of repeated dives to such extreme depths.

It's kinda insane that OceanGate got away with taking paying tourists down in that thing for as long as they did.

[–] PabloDiscobar@kbin.social 7 points 1 year ago (1 children)

Cmdr. Reed Koepp told USA Today at the time the controllers were cost-effective and came with an added bonus — young sailors already knew how to handle them.

At least two major weapons systems that the US military is focusing on utilize Xbox-style controllers, Task and Purpose reported in March.

Girguis said making fun of the gaming controller in the submersible was appealing because it's "an easy target" but that a lot of undersea vessels "use similar controllers."

It's a question of quality control. Military grade equipment is not the same as consumer grade equipment. That's why we have grade in the first place.

[–] RoboRay@kbin.social 28 points 1 year ago* (last edited 1 year ago) (1 children)

"Military grade" is not a statement of high-quality... it's a statement of specified minimum capabilities and characteristics to satisfy a contract. It's quite common for off the shelf commercial equipment, even stuff targeted at home consumers, to meet or exceed MIL-STDs.

[–] PabloDiscobar@kbin.social 3 points 1 year ago* (last edited 1 year ago) (1 children)

What do you think quality means? Go pick some IC's and you will see that the best quality is kept for military grade operations like operations in very low temperature for example. An IC designed with a high swing in operational temperature will require much more thinking than a consumer IC.

[–] RoboRay@kbin.social 13 points 1 year ago* (last edited 1 year ago) (1 children)

Thanks for providing an example supporting what I said.

[–] PabloDiscobar@kbin.social 1 points 1 year ago* (last edited 1 year ago) (1 children)

Cool...I'm glad that you understand better what quality means. Now if you have a different definition of quality that's a different story.

[–] RoboRay@kbin.social 0 points 1 year ago (1 children)
[–] PabloDiscobar@kbin.social 1 points 1 year ago (2 children)

Well, sorry to disappoint you but if a circuit endures higher temperature swings than another then it is of a better quality than the other one. This attribute is part of the quantification of quality. But feel free to explain yourself.

[–] rusticus@kbin.social 3 points 1 year ago

"Military grade" does not necessarily mean higher quality. It just means it meets the requirements of the military for a specific purpose. Could actually be pretty shit quality. But you'd already know that if you had read RoboRay's initial comment.

[–] Zana@kbin.social 5 points 1 year ago

To be fair the Xbox controllers are probably more reliable.

[–] kestrel7@kbin.social 3 points 1 year ago

I believe the Navy uses xbox controllers for controlling periscopes, not the entire submarine.

[–] meldroc@kbin.social 1 points 1 year ago

Yeah, it wasn't the video game controller that failed...

[–] Haan@kbin.social 12 points 1 year ago

Okay, but what does Ja Rule think?

[–] itsjustallergies@lemmy.world 4 points 1 year ago (3 children)

Glad to see James Cameron weighing in because James Cameron knows the people need James Cameron's opinion

[–] SpacemanSpiff@kbin.social 32 points 1 year ago

I think if you read the article you’ll find he’s actually an expert in this, on multiple levels. I had no idea previously.

[–] Hyperreality@kbin.social 17 points 1 year ago (1 children)

James Cameron's not faking expertise in deep sea diving. He did a solo dive to the deepest-known point on Earth back in 2012.

[–] Unaware7013@kbin.social 25 points 1 year ago (1 children)

In a submarine he built himself. Cameron has every right to comment on this event, he's legitimately a subject matter expert.

[–] PabloDiscobar@kbin.social 2 points 1 year ago (2 children)

afaik, he piloted it, he did not build it. He brought cameras.

[–] livus@kbin.social 3 points 1 year ago

He was part of the team that designed and built it according to this Science.org article.

[–] rusticus@kbin.social 1 points 1 year ago (1 children)

And yet not 2 posts up you quote Cameron in a way that makes him sound like he has significant knowledge about the structural integrity and construction of a high pressure tolerant vessel.

[–] PabloDiscobar@kbin.social 3 points 1 year ago* (last edited 1 year ago) (1 children)

I pulled an extract of the article. The extract doesn't say that he built the sub, he is educated on the subject, that's it.

[–] rusticus@kbin.social 1 points 1 year ago

It's not clear what you are trying to say. He obviously funded it and piloted it and had to be intimately involved in its construction, including oversight and planning. He took the thing down to the bottom of the Mariana Trench. Are you arguing that he doesn't know as much about the construction of the sub as a guy welding a joint or tightening a bolt? I'm pretty sure that most people would say that if you could name one person that "built" the sub it would be him. He is arguably the world's expert on this topic.

[–] gk99@kbin.social 5 points 1 year ago

More than we need some armchair commenter trying to diss someone who's an expert in this field because...?

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