4 ms·

It's traditional in deep submersibles design, dating back to bathysphere. You probably weren't hanging around when they were designing them

• bagels 3y ago
  Tradition itself is probably the worst rationale for an engineering solution. Maybe it's the right way for other reasons?
  • jhugo 3y ago
    I didn't interpret "traditional" as the rationale, but rather just pointing out that they're always done that way — I assume/hope for good reasons other than tradition.
  • jojobas 3y ago
    Traditions emerge from "other reasons". There is probably not enough excess buoyancy to open the hatch without flooding, so without external support you're dead anyway.
  • bandyaboot 3y ago
    I could see that as being the simplest/least failure prone way to design a closing mechanism that doesn’t need to resist the immense pressure to maintain integrity, but rather is held more forcefully to the hull as the pressure increases. Certainly you could design something like that that bolts from the inside instead, but perhaps the problem with that is that they cant exactly carry along with them various tools and equipment they might need in the event that there is difficulty reopening it.
    • varjag 3y ago
      If you pass out, how do they get you out?
      • gizmo 3y ago
        Two hatches? One opens from the inside one opens from the outside? I'm sure there are other solutions. But as somebody else already pointed out: even if you get out in the middle of the ocean you're in real trouble, which makes the hatch issue kind of moot.
        • varjag 3y ago
          And that's twice the sealing surface to potentially fail.
          • jacquesm 3y ago
            It could be the same hatch. Very common on submarines.
  • varjag 3y ago
    You know what's the worst? Someone barging in into an established engineering domain and making spot judgements. This is simply incredible hubris that often is the hallmark of stupid but educated people. If some brilliant improvement occurred to you in the first 5 seconds of hearing about some technical solution chances are this thought visited others in the past 100 years working on the problem for a living. And if you hang around the problem just a wee longer and start actually thinking you quickly begin start to see the rationale why it was discarded. Like here, when there's a problem with air supply and the inhabitants are incapacitated, how do you open the bloody thing? But no, our hero never gets as far, he's already in a sister thread explaining how dumb it is seat belts get stuck when you pull them too fast or something.
    • jliptzin 3y ago
      It sounds like they could use some improvements, 5 people are probably dead now. Out of how many trips in that submersible? I don’t know, just wondering, but it can’t be that many. Certainly not comparable to commercial airlines. So that’s a pretty high failure rate. Being able to open the vessel from the inside in an emergency probably wouldn’t have saved them, it’s just the first thing that is too much of a red flag for me to personally ever step foot in that thing. I also don’t even understand why that vessel needs to be manned at all. With today’s high def cameras and displays, including VR, they could outfit an unmanned vessel with high def cameras everywhere, a fiber optic tether to the surface to carry the high def signal (or even wireless to some degree if they could make that work), and the operator could sit in a control station either on the boat at the surface or streamed over the internet from home, controlling the vessel however he wants, with high def screens to simulate the viewing experience of being in the vessel. I’ll bet it would get you 99% of the way there without having to risk your life. It’s not like anyone is getting out of the thing to swim around the titanic in scuba gear anyway.
      • varjag 3y ago
        There is no hint that its probable demise had anything to do with hatch design so far. This is a recreational dive, there's absolutely no need for it as for most recreational activities.
• canadianfella 3y ago
  [dead]
• mariuolo 3y ago
  Do passengers also need to undergo decompression before exiting the craft?
  • erik_seaberg 3y ago
    No, the crew remains at 1 atm and the hull bears the pressure difference. Ocean pressure at the Titanic’s depth is over 400 atm (6000 psi!) but the oxygen level in normal air becomes toxic even at lower pressures. Technical divers use nitrox mixes, and the hyperbaric chamber record is 70 atm for a couple hours by breathing 0.5% oxygen and 99.5% hydrogen. (This mix can’t even explode, not enough oxidizer.)