Yes but the stress on a submersible would be like a wing subjected to 1000 g’s of force and then repeatedly cycled through expansion and contraction of dissimilar mated parts.
And there are aviation examples where this didn’t work so well. If I remember correctly there was an Airbus that had a horizontal stabilizer torn off from Excess stress.
Yes, submersibles experience vastly more stress. And are (or should be) made of vastly thicker materials to manage that stress. I’m not trying to defend the design of Titan. I’m just pointing out to folks who might not know that gluing large high performance structures together is not as crazy as it at first sounds.
You may be thinking of AA587. The vertical fin was torn off in significant overload, and the flight ended very quickly thereafter. In this case glue wasn’t an issue. But yes, that was an accident where questions about composite strength loomed large at first. And which were later determined to be false concerns.
To me, and I’m not a billionaire, I’d much rather sit in a lounge chair on a ship eating King Crab and food from a 5 star chef. Instead of viewing the titanic directly it could be done while looking through 3D goggles fed by a live feed from a remote unmanned mini-sub. The time spent ascending/descending could be put towards a well-put together presentation on the Titanic.
The view would be significantly better. A mini-sub could house 360 deg worth of cameras and could go where a manned sub couldn’t. The cameras could be tuned for a spectrum of light waves the human eye can’t see. The paying passengers could have some input on where the sub goes. They could switch between cameras on their own and the whole thing recorded on a Blu-Ray as a memento.
The accommodations would be luxurious vs a suffocating hell-hole. The view would be infinitely better than 4 people looking out a small porthole.
But I’[m not a billionaire.
Yes but In my way of thinking (not an engineer) the mating surfaces of plane parts are usually secondary to the forces applied. Think in terms of planes with folding wings. They’re held in place by a single bolt but it’s the attaching point taking the load and not the bolt.
I have no faith in the way this sub was constructed because of the lack of knowledge in the field and the difficulty in testing it for initial structural integrity and long term cycle strength.
I have little faith for the very same reasons.
Exactly! You’re talking about an experience a mere millionaire could afford. How do we maintain exclusivity at that kind of price? And if it’s an experience anyone could have, what’s the point? Clearly there is some ineffable something about seeing a wreck through a porthole rather than over a TV feed that is more valuable than comfort or safety.
(edited Magiver’s post to take out what I think was a typo)
Right, we know all that, one of the factors at issue here is the characteristics that tend to make carbon fiber suitable for aircraft components does not necessarily mean it will prove to be serviceable for submarines. Apples and aircraft carriers. That’s why the chief engineer was fired, he wouldn’t sign off on something that wasn’t adequately tested. That is what everyone is getting the vapors over.
Mr. Rust declined to do the necessary testing to ensure that these new, experimental materials and processes (like gluing stuff together) intended for a completely different environment would perform as intended. 12,000 feet ASL is a lot different than 12,000 feet down under.
Boeing of course did lots of testing for decades on this sort of stuff before getting an airworthiness certificate (and they don’t allow passengers or tourists on test flights, only necessary personnel who know what they are getting into)
Rust himself was a pilot, and flew experimental aircraft. I think he pushed the envelope a little too far, and as someone quipped, it pushed back.
Granted completely. Rush was a cowboy who got what was coming to him. Shame about the others.
My point, as explained above, was simply that being surprised about epoxy glue as a component in a CF structural system was/is misplaced. Nothing more is expressed or meant to be implied.
Yeah, one atmosphere vs. 400 atmospheres.
I wouldn’t trust anything or make any assumptions whatsoever, I’m surprised they didn’t do any testing, that’s what testing is about. Salt water, over time, maybe it does weird things to adhesives. I don’t know.
Carbon fiber, the adhesives used, none of it was adequately tested, it appears. Engineers can make some good assumptions or predictions but this was all “here there be dragons” territory. Carbon fiber has proven itself (mostly) admirable in the air, but you can’t pay me to test out 12,000 feet underwater. Let’s do some uncrewed tests for a while.
See where I’m goin’ with that? It might work. Maybe it won’t. Maybe it does, or maybe it doesn’t. We still don’t know as far as that goes.
Apparently another firm did some studies on carbon fiber for deep sea submersibles, and said not no but “hell no”. The .mil uses all sorts of excellent adhesives and epoxies, I’m not knocking them at all. The strongest stuff I recall using, was simply called “the pink shit”, because the color waspractically identical to bubble gum.
All that stuff requires rigid attention to detail in preparation, or it won’t work right. Supposedly Mr. Rust “got a deal” on expired carbon fiber from an aircraft company to wind up his homebrew tube for deep sea exploration.
I’d never seen it before, but the meaning seemed obvious to me.
I’d never seen it before, but the meaning for me was ambiguous.
I saw it as an accusation of lying.
Me too.
Polar Prince returned to St John’s, Newfoundland & Labrador.
Investigators from the Transportation Safety Board of Canada boarded the ship right away.
Rush has been quoted a few times as saying that they had micro-sonic monitoring to alert them if cracks were developing.
James Cameron thinks that might have happened, as the reports are that they dropped the ballast to bring them to the surface.
Having a monitoring system that gives perhaps a minute’s notice that you’re away from total system failure does not strike this non-engineer as a particularly strong warning system.
Well, it’s a warning system. Not an early warning system.
That’s extra.
Me three; and I also don’t think I’ve heard/seen it used before as the poster apparently meant it.
Not that it matters at this point, but I have seen that formation and I immediately understood it as a joking reference. But it’s also totally understandable that someone who didn’t know the usage would have perceived it as a flat accusation.
Count me as never having run across that construction. I was skimming trying to get through all the posts and took as: Please lie to me … make this not true. I see how it could be taken as an accusation.
I was offended by something said to me, but I wasn’t sure it was at me or in general so I left it alone.
I really think the deep sea mariner biz. needs to be more closely (or at all?) regulated. If you want to risk your life on what amounts to binder twine and duck tape so be it, but you shouldn’t drag other people along for your, “independent no-one-understands-my-genius dude bro” suicide “adventure.”