Anyone following the submersible lost near the Titanic?

Discussion in 'General Science & Technology' started by Seattle, Jun 20, 2023.

  1. Seattle Valued Senior Member

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    They are about 400 miles off the coast of Boston, in about 12,000 feet of water and communication has been lost since Sunday. No signs on the surface, no communications from below. It's not looking good.

    I'm guessing there a crack/implosion or their oxygen system/rebreather failed and everyone passed out. I think there would be ways of dumping ballast and surfacing even if power were lost and I'd think back communications gear would be available especially for the surface.

    So, the options as to what happened don't look good.
     
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  3. wegs Matter and Pixie Dust Valued Senior Member

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    It sounds unimaginably terrifying. I’ve read that if/when found, the vessel would need to be opened from the outside. Apparently, the entire crew is dead-bolted inside which means they can’t “break out” if it surfaces. There's no mechanism inside of the sub for the crew to open on their own if/when it emerges. Time is truly of the essence for this rescue mission.

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    Last edited: Jun 20, 2023
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  5. C C Consular Corps - "the backbone of diplomacy" Valued Senior Member

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    We should be close to where it would be ludicrous that a quasi-autonomous submersible was not available and in service, where AI takes over after _X_ amount of time transpires with no human operator activity. Automatically establishing communications with the surface (sending telemetry), and perhaps even being programmed safely to return to the surface if no return contact ensues. (Granting that a problem was merely life-support related rather than also other major technical problems.)

    Given ROVs and UUVs, at the very least a remote control link option should be available if watercraft still aren't Jetson status worthy in the above respect. Any tour industry of this sort should get itself out of troglodyte country if it's truly devoted to safety.

    If an AI autonomous recourse was the case, those on the surface would then know almost for certain that the submersible was either destroyed or so devastatingly kaput/damaged that it equated to much the same, if still no communication or independent self-rescue response ensued.
    _
     
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  7. origin Heading towards oblivion Valued Senior Member

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    I spent some years on a submarine, I just cringe at the thought of this.
     
  8. Seattle Valued Senior Member

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    I think it's most likely (given the other circumstances) that there was either a catastrophic implosion or something catastrophic from within such as a fire or the rebreather system failed.

    Otherwise they could have snagged on something and lost power or the ability to communicate but I think this scenario is the least likely.

    The third is that they are on the surface and no one has located them and I agree that would be hard to do. I've been scuba diving when the large commercial boat was to pick us up, we could see the boat and it was still hard for the boat to see us due to the waves and distance involved. Imagine a small submersible in the middle of the Atlantic Ocean, painted white and largely carbon fiber!

    However, I have to assume that the submersible, when on the surface, would have access at least to portable radios or EPIRB units. What I don't know (anyone here know?) is whether radio waves could get through the thick carbon fiber shell or the titanium end plates.

    I tend to think that if they have been on the surface all this time that they would be able to at least use some backup radio but maybe not? Even if they are on the surface, they are bolted in and will still run out of air soon.

    Everything still points to catastrophic issues (external or internal) from the initial communication loss given all that has followed otherwise they would be on the surface and they don't seem to be.

    This structure didn't seem to be tested a lot and they may not be taken into account material fatigue. Given the immense pressures it may be that the hull could stand this environment for a few cycles and then just fail.

    On paper it's supposed to be good to 14,000 feet but they are operating pretty close to that and I'm not sure that the carbon fiber has ever been tested to failure or the actual submersible tested to that depth or material fatigue taken into account?
     
  9. James R Just this guy, you know? Staff Member

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    From what I've heard/read, and from what I know about submarines operating at those depths, I have to assume that, most probably, all the occupants of the sub are dead.

    Many scenarios are plausible. A catastrophic failure of the pressure vessel, followed by implosion, is one possibility. A fire on board that led to the crew being overcome by smoke inhalation is another. An imbalance of gases in the air in the sub is yet another.

    At the depth at which the sub was operating, there isn't much room for error. Unfortunately, it appears that this particular sub had many possible design flaws.
    I don't think it had a "rebreather". I could be wrong. If the gases weren't managed properly - the carbon dioxide levels, for instance, that could lead to loss of life. If the oxygen levels rose too high, that could lead to an electrical fire, similar to the one that killed the Apollo 1 astronauts.
    Apparently, the designer made a design choice to restrict communications available between the sub and the surface, because he didn't want to be bothered by demands for status updates from the surface while he was pootling around in the sub.

    On a previous solo dive in the sub, communications with the surface were lost in a similar way, which is probably one reason why the surface crew didn't immediately panic when communication was initially lost. Instead, they waited about 10 hours before raising the alarm.
    That's correct. But even if there was a fire on board or something like that, exiting the sub at 4 km under the surface would not have been an option, even if there was some facility for opening the hatch from inside.
    There are very few companies/agencies that have the necessary technical capabilities to mount any kind of rescue mission at the depth of the Titanic. I would guess that there simply isn't enough time to get the necessary equipment onsite and save the crew, now.
    I think communication was lost at around the time the sub was meant to release the weights it was using to cause it to descend - when it would have been approaching the ocean floor. It is possible that the sub could have got snagged after that, of course. But maybe something went wrong on releasing the weights.
    Possible they are on the surface, I suppose, but it seems the less likely possibility to me.
    I don't think we can assume there was any communication gear on board, other than the telemetry link (which obviously failed). I'm not sure if voice communication was even available.
    If the sub was, in effect, a Faraday cage, the answer would be that radio cannot not penetrate the hull.
    It is not clear whether an actual test of how long the air supply would last with five people on board was ever made. Some people apparently did some theoretical calculations, but was any real-world testing done for this scenario? It is not clear. Similarly, as far as I'm aware, no actual testing was done to see whether the sub would withstand the pressure at the depth of the Titanic. There was a previous successful dive to a significantly lower depth, but that doesn't necessarily prove anything.
    The communication loss was more or less expected, based on the experience with previous dives of this sub. The question is: what else could go wrong? What was actually done to test whether the sub could safely operate at the depth they sent it to?
    Right.
    Yes.
    That's a theoretical prediction. If I understand correctly, it has never actually been tested at that depth, let alone with 5 people on board.

    Obviously, this will be a tragedy if five people have lost their lives due to deficiencies in design and testing.
     
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  10. James R Just this guy, you know? Staff Member

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    Update:

    It appears that some equipment might arrive onsite in time to help the occupants of the submarine, if they are still alive.

    A Canadian P-3 aircraft had reported detecting "underwater noises" in the search area for the sub. It is possible that these could be caused by something banging on the metal of the sub from inside, but the sounds could have other causes and are difficult to interpret.

    The Royal Canadian Navy ship HMCS Glace Bay is expected to arrive at the scene of the search on Thursday at midday local time. Onboard the ship is a medical team specialising in dive medicine, and a six-person mobile hyperbaric recompression chamber. If the sub is located, the recompression chambers on board this ship can be used to treat or prevent decompression sickness.

    A Canadian Coast Guard Ship, the Terry Fox, is already at the scene, on standby to load search and rescue equipment and personnel.
     
  11. James R Just this guy, you know? Staff Member

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    In 2018 the OceanGate company that runs these "tourist" trips on its sub was issued a serious warning about safety problems with the Titanic voyage. More than thirty people including industry leaders, deep-sea explorers and oceanographers said in a letter to Mr Rush that the company’s “experimental” approach and its decision to forgo a traditional assessment could lead to potentially “catastrophic” problems.
     
  12. Seattle Valued Senior Member

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    I'm not a "materials" guy but when I saw them "gluing" the titanium to the carbon fiber and I've heard nothing of actual life cycle testing and environmental test and testing to failure, it just doesn't look like there was any "robustness" to the design process.

    Boeing takes a section wing and puts weight on it until the wing breaks both to see what weight that is and also how it fails, suddenly, deformation first, etc.

    Other mechanical system where flexing would occur, I'm sure, are tested over and over to "guarantee" a certain number of cycles. You would want the submersible to be able to go much deeper than 14,000 feet if you are going to routinely take it to 13,000 feet.

    It's one thing to be able to handle a slow buildup of pressure and another when it suddenly runs into a hard surface and force is directed at one spot. They should a least be able to shoot up a line with a float attached (mechanically controlled for inside the hull) to mark the spot on the surface over the submersible.

    You certainly should be able to use a radio on the surface, by design, even if this one can't.

    Decompression shouldn't be an issue however. They are at ambient surface pressures.

    Regarding the reports of banging. There is probably banging on the Titanic just due to the metal structure and currents but I saw something about the banging coming 30 minutes a part so I guess that is a good sign potentially. I hope they can at least get a ROV down there to at least search the area immediately around the Titanic.

    I can't help but think this is a misidentified, naturally occurring sound. After this many days I doubt (?) they would still have the presence of mind to be banging on the hull every 30 minutes. I also question whether one could hear a bang against carbon fiber but maybe banging on the titanium would do the trick?
     
    Last edited: Jun 21, 2023
  13. James R Just this guy, you know? Staff Member

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    Seattle:

    I agree.
    4 km of line is a lot to carry on a small sub. And releasing a float that isn't tethered the sub wouldn't be useful, because the float can drift a long way as it ascends 4 km.
    It sounds like this one only had a custom text-messaging system for communication between the sub and surface. It would have to be a radio system, I think. No voice. No emergency locator beacons. Some automated telemetry was transmitted when the system was operating - e.g. the sub's depth - but in the four previous dives that system had always failed.
    If they aren't at ambient surface pressures, then the most likely alternative is that they are at ocean-floor pressures (380 atmopheres or so) and dead. Fingers crossed.
     
  14. James R Just this guy, you know? Staff Member

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    I'm not hearing anything about any vessel being able to arrive on time and also be capable of mounting a rescue from the ocean floor. There's a cable-laying ship nearby that has some capacity to operate at depths of 3 km, apparently, but that's not deep enough for this. Some organisations have offered to send robots to search for the sub, but that's a separate issue from recovering it. At some point, this will become a salvage operation rather than a rescue.

    Right now, there's about 24 hours of air left for the crew - if the estimates are accurate.
     
  15. Seattle Valued Senior Member

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    They may not be able to carry that much line, but as with diving, it really just requires tough "twine". That may still be too bulky of course.

    The text system is a sonic system, radio doesn't work under water. They have (supposedly) a pinging system as well (every 20 minutes). That's what is even more puzzling (to me). Most systems like that (the ping) would be surface mounted and self contained with it's own battery) so that should be going off regardless if the main hull lost power.

    The only hope that I can see is if it is tangled in something and a ROV can help untangle it and then it can rise on its own (there are systems that work even without battery power). That's the 1% hope though. Most signs point to a hull implosion on Sunday it seems to me.
     
  16. James R Just this guy, you know? Staff Member

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    Thanks. That makes sense.
    Hmm... I don't know have any information on how things are powered on this sub.
    I thought that, in general, these kinds of subs tend to have some kind of mechanical way to release ballast weights, so that the sub can rise to the surface even if all power is lost. Either this one doesn't have that, or it didn't work, or it wasn't triggered for some reason. Or, I guess there's a slim possibility that the sub has surfaced and is bobbing around somewhere, unnoticed.
     
  17. Seattle Valued Senior Member

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    One way it doesn't work is if the hull implodes suddenly.

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    I've read that it has the two systems (text and ping). The ping locator, sounds to me, similar to the emergency locator beacon on an aircraft which is self powered. It makes no sense if the two black boxes and the emergency locator beacon (aircraft) only work with main battery power.

    I'd like to see much more information on all the systems on this just out of curiosity. Apparently it has a lot of redundancy where rising to the surface is concerned but I'm not getting the vibe that there was enough redundancy for the other systems but who knows? I certainly wouldn't get in an untethered system with a bolted on hatch that could only be unbolted from the outside. Yikes!

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    Last edited: Jun 21, 2023
  18. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member

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    One report I've read, possibly not reliable though, suggested they didn't even have an ELT (emergency location transmitter), and that more than one person at the company previously warned that their "experimental" approach could result in "minor to catastrophic" issues. I think the current state could be defined as somewhere between minor and catastrophic. One employee was fired after voicing his concern (although reports suggest this was for disclosure of confidential information).

    So time running out, even if they are still alive (which underwater sounds suggest might be the case), and they don't even know where they are, neither coordinates not depth, so outlook is, unfortunately, bleak.
     
  19. exchemist Valued Senior Member

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    I have seen a story that one issue raised by the ex-employee was the lack of certification of the glass viewing port to the requisite depth. But that would lead to sudden implosion, not consistent with these reports of sounds.
     
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  20. Sarkus Hippomonstrosesquippedalo phobe Valued Senior Member

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    Yeah, I saw that story. Certified to 1300m or so, somewhat shallower than the 3800 to the Titanic. Apparently the waiver they signed prior to going mentioned possible death at least 3 times on just the first page.
     
  21. wegs Matter and Pixie Dust Valued Senior Member

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    I just read this after my post in Dave’s other thread related to this topic.

    Yes, why did they not heed the warning? Whyyyy??

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  22. exchemist Valued Senior Member

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    $$$$, probably.

    And perhaps some seepage of the prevailing culture of "move fast and break things", dismissal of experts as stick-in-the-muds that hold people back, etc. Even the aviation industry has not been immune, as the Boeing 737 disasters show.

    In my personal view, submariners should employ an aviation culture. People going down 4k even more so. Space culture perhaps. But that is costly of course................
     
  23. Seattle Valued Senior Member

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    All they need to do is employ submariner culture.

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    That was the problem, they didn't really seem to have any professional submariners as advisors.
     

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