When I was on Okinawa a Marine was standing on a cliff with some buddies when a rogue wave knocked him off and carried him out to sea. Thirteen hours later he was found, still treading water, and plucked out alive. Now, the waters around Oki are relatively warm, especially compared to the North Atlantic, but thirteen hours? – phenomenal.
Titanic tourist submarine missing 6-19-2023 (Debris field found, passengers presumed dead. 06-22-23)
Thanks for the update. What a grisly way to go. Fast though.
Unless a momentary disconnect somehow caused the sub to ram something hard enough to damage the hull, I don’t see how it could be a contributing factor. That seems unlikely, especially as any sane engineer would design that failure state as a signal to go to either “all engines off” or “stationkeeping” modes. (Granted, “sane engineer” might be assuming too much.) Based on projected descent time and the time contact was lost, I infer that they should have had about 1300 feet of open water left and that the sub normally traveled at around 1 mile per hour. A catastrophic collision due to control failure seems wildly unlikely, even if the control software was designed by a moron.
The sub imploded. Trying to blame that, even in part, on the controller just seems bizarre to me at this point. The only reason people kept talking about the controller is that many perceived it as a “toy”, rather than just another interface device, and in their minds, “toys” have no place in Serious Business.
Were they bolted in/out the craft via removal/reinstallation of one of the titanium end caps? Or did the carbon fiber hull have an opening for a hatch? Just curious.
One thing that struck me as odd, one of the chief engineers under the employ by Mr. Rush suggested NDI of the hull, apparently causing a row and ultimately resulting in his being terminated on the spot. What kind of lunatic would do that?
NDI stands for “Non Destructive Inspection”, right? Basically X-rays, or something similar. Let’s take a look at this thing, the carbon-fiber, look for evidence of voids or delamination and see what’s what. I doubt if it’s particularly expensive. It is used for aircraft all the time.
The carbon fiber piece had no holes or openings. I’m seeing references to that sort of thing on line now and I’m not sure where it is coming from. The porthole opening was in one titanium end cap. The other end cap had the hatch, or rather seems to have been the entire hatch.
The carbon fiber cylinder was epoxied to a fitting that allowed the end caps to be bolted onto it. I’ve seen a video of the epoxy process used and… well, it might have been OK for a non-pressurized homebuilt aircraft, but not for something subjected to the forces involved.
My guess - and keep in mind I am not any sort of expert, I really am just guessing here - is that either the carbon fiber composite, after several cycles of compression/decompression, had developed enough internal flaws to come apart abruptly, or one of the end seals failed. I’m leaning towards the carbon fiber spontaneous disassembly, but what the hell do I know, right?
It’s called arrogance and hubris.
It is used for aircraft all the time but no, in many instances it’s not inexpensive. For carbon fiber composites you can use x-rays, ultrasound, thermography, and a bunch of other techniques - here’s a wiki on it.
All of these testing methods have limitations, and aerospace it still working on better methods both for making composites and evaluating them both before and after they are put into use.
Um… What? That can’t be right. Lie if you must. This debacle will be studied for years.
How “expensive” is the NDI? About.
$500? $5,000? $50,000?
You could say we’re at the “De Haviland Comet” stage of deep submersible transport for ordinary paying passengers. Let’s hope the next models are more like 707s (or DC-8s, or Sud Caravelles).
But we have 75 more years of materials science now (especially, testing procedures), so De Haviland couldn’t be blamed much, but the Titan’s company can be, it seems.
It seems to be one of those “If you have to ask…” price things, but from what I’ve read, it can cost millions to NDI test an aircraft fuselage, and it requires everything to be stripped off/out of it. So, testing the sub would likely have required completely disassembling it, cost more than they could make back on a single trip, and told Rush something he didn’t want to hear. (If an executive fires an engineer for suggesting a test, I’m inclined to assume that the executive expects the test to show a problem they don’t want to admit.)
- Please do not accuse me of lying.
- Please follow the link to the video. Starting around 9:35 on the video there is actual footage from OceanGate showing actual construction of the Titan, specially, bonding the sealing ring to the carbon fiber cylinder with the use of epoxy.
The voice over covers issues with the method used in this case. I will let it speak for itself.
It depends on the test and what is being tested. Some types of composite testing are only effective for thin objects and the cylinder in question would be too thick for those methods. Most of them require disassembly and shipping of components to a test facility. Sure, you might be able to get some small parts testing for just a few thousand but testing the Titan’s cylinder would likely have cost into the six digits at a minimum.
I actually think we’re a bit past that. Deep submersibles have been around for decades, they aren’t really that new. Rush was doing some… unique things with his, but we already have quite a bit of knowledge on how to build things that go down deep and reliably come back up, from both military and civilian sources.
This is more like we’re in the 707 era but someone decided to ignore post-De Haviland practices and build another Comet thinking he could to it right this time.
Moderating:
Don’t accuse other posters of lying outside the pit. Discussing with other mods as to whether this should be a warning, etc.
It’s often said one should never explain a joke.
This is not an accusation of lying, it is a widely used, light-hearted satire pointing out how absurd some situations can be. They glued the end bells on.
Or put another way “YOU’VE GOT TO BE FUCKING KIDDING ME!!!” e.g., “Tell me that isn’t true. Please. Lie if you must.”
I’m amazed you’ve never seen that before or how it could be misconstrued.
When CBS Sunday Morning ran a piece on the Titan earlier this year, they showed video of how the crew is bolted in. The titanium end cap with the porthole window is the ‘hatch’ and is attached by bolts. It starts at about 4:30 or so in this clip:
Moderating:
That phrase is not in my vernacular, and presumably not in @Broomstick 's. So she took offense. That’s when you should have explained what you meant, and apologized for inadvertently offending.
Had you done so, there would have been no mod note to offend you.
I’d like to remind you that it’s not appropriate to argue moderation in the thread. You could have DMd me to explain. Or explained what you meant framed as an apology to Broomstick, rather than as a protest about moderation.
Watching a couple minutes beyond that, it does seem like a real clown show. Floats becoming detached? How freaking hard is it to keep floats like that attached to a platform? I mean, relative to what the company is supposed to be able to do—take a submersible to a depth of 4000 meters and then return while keeping 5 occupants alive—how can it be so hard to get basic procedures like that down? Absolute clown show…
But then they have that passenger talking about the sub like it’s some super important voyage of discovery, an “expedition,” not the multi-millionaire/billionaire equivalent of camping out in one’s own backyard with a tent you paid a neighborhood kid to pitch for you (with the added caveat that the tent could implode at any moment and transform you into a bloody paste for the house staff to clean up).
True.
Irrespective of any misunderstandings about phraseology, you might be interested to learn that the major subsections of the Boeing 787 fuselage and wing are made of carbon fiber. The subsections are permanently connected together at final assembly using epoxy glues. Not the kind of stuff you could buy at Home Depot, but glues nevertheless.
Epoxying very large CF components together, and epoxying them to non-CF components, is a well-developed manufacturing technique. Traditional notions of bolts, studs, torqued nuts, rivets, gaskets, etc. do not work well with CF materials. So high tech glues are the answer. An answer requiring extreme care and precision in the planning and execution. Which latter safeguards may have been skipped at OceansGate.
IIRC, that’s how they attached the wing skins on the Grumman AA-1 Yankee – back in the '60s.
A British TV production company were planning to film aboard the submarine; the show’s researchers examined it and deemed it unsafe.
This exploration company were warned enough times.