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Transportation Science Technology

The Tech Behind James Cameron's Trench-Bound Submarine 111

Posted by Soulskill
from the harnessing-thousands-of-seahorses dept.
MrSeb writes "Yesterday, James Cameron completed a five-mile-deep test dive in the Pacific Ocean, in preparation for a seven-mile (36,000ft, 11,000m) dive to Challenger Deep, in the Mariana Trench; the deepest place in the world. We don't know when the actual dive will occur, but it will probably be soon. At 36,000ft, the pressure exerted on the hull is 16,000 psi; over 1000 atmospheres, and equivalent to eight tons pushing down on every square inch of your body. Understandably, building a submersible (and equipment, such as cameras, motors, and batteries) that can withstand that kind of pressure, and then safely return to the surface, is difficult. This article digs into the technology required to get Cameron safely to the bottom of the ocean, film some 3D, IMAX footage, and then return to the surface."
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The Tech Behind James Cameron's Trench-Bound Submarine

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  • units? (Score:5, Insightful)

    by Anonymous Coward on Thursday March 08, 2012 @07:37PM (#39295399)

    How does one reconcile 16,000 psi with 8,000 tons per square inch?
    Seems something is off.

    Also pretty sure no human bodies will be experiencing that pressure

    • Re:units? (Score:5, Informative)

      by Forty Two Tenfold (1134125) on Thursday March 08, 2012 @07:40PM (#39295427)

      Seems something is off.

      Yeah, seems someone read "8" and then added three orders of magnitude. 1 ton = 2000 pounds.

    • Re:units? (Score:4, Insightful)

      by tsa (15680) on Thursday March 08, 2012 @09:22PM (#39296317) Homepage

      Who cares. Those units don't exist anyway. How many pascal are we talking about?

    • Re:units? (Score:5, Informative)

      by FridayBob (619244) on Thursday March 08, 2012 @09:28PM (#39296377) Homepage

      ... Also pretty sure no human bodies will be experiencing that pressure

      On the contrary, it's most likely that they have and will ... though not while alive.

      Some years ago I was into technical diving and learned that the deepest dive ever for a human was a simulated one in a pressure chamber. Using a special, and no-doubt constantly changing mixture of gasses that included plenty of helium, they were able to crank up the pressure to a simulated depth of about 750 meters (only about 7% of the Challenger Deep) before the "diver" could go no further. Apparently, his nervous system was no longer able to function properly beyond that point... just because of the pressure. His simulated ascent, by the way, took something like a month.

      I was somewhat disappointed to learn all this, because it meant that a really deep dive using a liquid rebreather, like in The Abyss (1989, James Cameron), would never be possible.

      • by pipingguy (566974)
        I think the issue here is pressure in the lungs, not percentage of gases breathed. Liquids are (mostly) incompressible.
        • You should read up (Score:5, Informative)

          by dutchwhizzman (817898) on Friday March 09, 2012 @03:20AM (#39298245)
          Diving breathing issues aren't about gas pressure, but about saturation of blood and tissue with gasses. At higher pressure, your blood and tissue take up way more gasses than they do at surface pressure. Therefor, if you dive deep, you will become equivalent to a soda bottle. If you surface too quick, it's like someone shakes you and then takes the cap of the bottle. All of a sudden, there will be bubbles in your entire body. Those bubbles will kill your (brain) cells, by oxygen deprivation.

          At higher pressures, gasses that are normally "inert" to the human body tissue, will form chemical bonds with your tissues, making the gasses poisonous. That is why there are different gas mixtures used for high pressure (deep) dives.

          Even if you can overcome this by using liquids to replace the gasses, it appears that your nerve tissue will have electrical/chemical problems transmitting signals at about 750 meters (75 times atmospheric pressure).
          • by pipingguy (566974)
            I guess I stand corrected, thanks.

            I wonder how often Slashdotters admit they were wrong.
      • by flyneye (84093)

        Also pretty sure no human bodies will be experiencing that pressure

        That made me think of a question burning in my mind. It is inconceivable that the trench would not be a spot for dramatic body dumping or suicides or just plain old fashioned accidents. What does a body look like under all that pressure?
        Also, it seems when someone may want something besides a body lost to the world, that would be a good place to drop it. Maybe they'll find some odd treasure.
        Enquiring mi

        • by FridayBob (619244)

          ... What does a body look like under all that pressure? ...

          Pretty much the same as at the surface.

          The notion that everything gets "crushed" at great depths is a common misconception. Submarines (and submersibles) run the risk of getting crushed at depth because they usually include cavities of air held at a constant surface pressure. Therefore, the deeper they go, the more their internal pressure gets out of equilibrium with the ambient pressure and the greater the risk becomes of violent equalization.

          On the other hand, not much happens to a human body (or an

    • The results will be really implosive!
  • Hard? (Score:4, Insightful)

    by kurt555gs (309278) <kurt555gs@@@ovi...com> on Thursday March 08, 2012 @07:43PM (#39295453) Homepage

    Isn't this 1961 technology we're talking about? Remember the Treste!

    • Re:Hard? (Score:5, Informative)

      by Caerdwyn (829058) on Thursday March 08, 2012 @07:47PM (#39295481) Journal

      Indeed, we do remember the Trieste [wikipedia.org].

      Just like going to the moon... something we did in the 60's, we've basically forgotten how to do for the lack of will to do it. So we have to reinvent the wheel, only this time in a more risk-averse environment (and therefore far more expensive to accomplish).

      • Re:Hard? (Score:5, Insightful)

        by yodleboy (982200) on Thursday March 08, 2012 @07:57PM (#39295569)
        why does the Trieste come up every time this new vehicle is the topic? The Trieste was an underwater elevator and no more. You went down, you saw a sliver of the bottom through tiny portals and you went up. It's less exploration and more "i got there first". Deepsea Challenger can actually, you know, MOVE. Sure they could have sent a robot, and maybe that gets you all hot and steamy. For me, it's nice to know that people are willing to explore somewhere now that manned space flight is on it's way out the door.
        • Re: (Score:3, Informative)

          by fnj (64210)

          Idiot. Trieste was self contained and (barely) self mobile horizontally, just like this thing. This thing can go up and down faster; and it has better batteries. And it uses syntactic foam for buoyancy instead of a thin hull filled with gasoline. That's basically it.

          Don't get me wrong; it's an improvement, and I'm happy to see the project under way. But both vehicles are minimally mobile down there. We're talking a fraction of a kilometer per hour.

          • by tsa (15680)

            We will probably build better Lunar modules too if/when we go back to the moon.

          • Re:Hard? (Score:5, Informative)

            by yodleboy (982200) on Thursday March 08, 2012 @09:43PM (#39296487)
            idiot? wow. did you bother going to the expedition site [deepseachallenge.com]? it says all over the place they will be using the sub's ability to move horizontally @ up to 3 knots while to explore various areas for up to 6 hours. That sounds more than fractions of a kph or minimally mobile. maybe they are overly optimistic, but it's a big improvement on the original Trieste.
            • by X0563511 (793323)

              You don't seem to know exactly how slow 3 knots are. 3 nautical miles in an hour, or about 3.5 "real" miles per hour. That's 12% faster than the average human walking speed.

              • by yodleboy (982200)
                slow, yes, but hardly immobile. even if they only move around @ 1 knot, that's potentially several miles of travel over a 6 hour mission.
        • by khallow (566160)

          why does the Trieste come up every time this new vehicle is the topic?

          Because it's the obvious thing to do. Why wouldn't one bring up the short history of exploration at this depth?

          The Trieste was an underwater elevator and no more.

          Completely irrelevant.

          For me, it's nice to know that people are willing to explore somewhere now that manned space flight is on it's way out the door.

          To the contrary, manned space flight is just beginning. And for much the same reason as the Trieste is compared unfavorably by you to the Deepsea Challenger.

        • Re:Hard? (Score:5, Informative)

          by hey! (33014) on Thursday March 08, 2012 @11:18PM (#39297067) Homepage Journal

          I suspect you are confusing a bathy*scape* with a bathy*sphere*.

          Trieste could operate submerged 24 hours and could move freely at a speed of 1 kt. It was succesfully used to search for the wreck of the USS Thresher (SSN-593), which it found at a depth of 8400 ft, so obviously Trieste was a very capable boat.

          In it's famous Challenger Deep mission it spent 20 minutes on the bottom made at least one important scientific discovery: sole and flounder swimming. Before that it was believed that vertebrate life could not survive at such pressures. Not a bad scientific haul for an 8h 23m work day.

          The bathy*sphere* was no scientific slouch either, making significant contributions to both marine biology and physics.

      • I think some people have the wrong view on why we don't do things that we have done before. The simplest reason is, been there, done that.

        As in, the challenge has been met. Now lets find a new challenge. Is there a compelling reason to go to the floor of the ocean? The moon? Yeah it would be cool and there is good science in both, but is there a need.

        Back in the fifties and sixties, if not the seventies, it was about East versus West. Funny how an arms race turned into a game of one up man ship along peacef

        • I think some people have the wrong view on why we don't do things that we have done before. The simplest reason is, been there, done that.

          As in, the challenge has been met. Now lets find a new challenge. Is there a compelling reason to go to the floor of the ocean? The moon? Yeah it would be cool and there is good science in both, but is there a need.

          Back in the fifties and sixties, if not the seventies, it was about East versus West. Funny how an arms race turned into a game of one up man ship along peaceful lines.

          Heh. I'll try to remember that when mass drivers in orbit have replaced ground-based nukes as our species' self-termination option.

        • by Caerdwyn (829058)

          Many compelling reasons, above and beyond the "we must explore" philosophical position (which is, admittedly, not an axiom). Let's get practical.

          How about recovering lost nuclear weapons [wikipedia.org], maintenance of deep-sea seismic sensors [sciencedaily.com] to detect and generate warnings for tsunami-generating underwater landslides? What about transoceanic optical fiber maintenance? Rescue of sailors from submarine accidents [wikipedia.org]? Maritime [wikipedia.org] accident [wikipedia.org] investigation [wikipedia.org]?

          This is important stuff. In the U.S. this has (unsurprisingly) typically be

    • The biggest problem with remotes that I see is the freaking long cable. But why couldn't they lower for want of a better term, a wireless access point to the bottom with a submersible and then release the sub when it gets down there. Then you would have real time control and the freedom of a tetherless vehicle. Only the access point would be connected to the surface. I am assuming it is better to put the access point down there because that much water would interfere with the control signals if they tried t

      • Losing subs because of a slight malfunction costs too much. It may in theory be a perfect solution, but the chances of the sub getting lost versus the costs of building one, currently make it an unprofitable risk. Even with the significant chance of snapping the umbilical, that is still cheaper than risk losing unmanned crafts. There are frequent stories of research vessels losing an unmanned sub, usually costing six figures or more. You don't hear much about commercial vessels losing subs, but the oil and
      • Wi-Fi has a range of a few feet underwater, if that. Radio waves do not propagate through a conducting medium, at least in any useful sense. 'Extremely low frequency' [wikipedia.org] waves (3-300 Hz) can propagate down a hundred meters or so. So radio ain't gonna cut it.

        Some deepsea systems have used sound down to some pretty deep depths, but it requires thousands of watts of transducer output.

  • Onion (Score:3, Interesting)

    by Anonymous Coward on Thursday March 08, 2012 @08:01PM (#39295605)

    Um, maybe it's not this simple, but...

    Lets say you have a submarine with a metal shell that can withstand the pressure at 1000 feet below sea level. (For simplicity, call it a pressure of '1000'.). You can lower it only that far into the water before the pressure exceeds the amount it can handle, and the shell collapses. Okay. Now, what if you place that shell inside an slightly larger one? Lower them both to, say 999 feet, then open a valve to let the water in between the shells. Close the valve, and drop the shells another 999 feet. The inner shell has the pressure of 999 pressing in, which it can withstand. But that 999 water also presses out. The outer shell then has 999 pressing out and 1998 pressing in, a net of 999 pressing in, which it can withstand.

    Repeat with however many layers you need, and you should be able to go down to the bottom of the Mariana Trench, no?

    • Re:Onion (Score:5, Insightful)

      by Ethanol-fueled (1125189) on Thursday March 08, 2012 @08:15PM (#39295723) Homepage Journal
      Heh, you're funny.

      So to go down to 10,000 feet below sea level, you'd essentially need ten shells, each with a valve, with each shell becoming a point of failure. And that's more of an ideal situation, not taking into account how you're gonna get shit in and out of the vessel.

      I work in this industry(shoutout to DeepSea Power and Light, here in San Diego), and we used pressurized oil to add structural integrity to certain electronic components. In fact, it was even mentioned in the article.

      You could have one onion layer of super-high pressurized oil, but it would essentially behave like a solid which could be pushed into the inner shell. Shit, why not, oh, just have one shell designed to withstand the pressure? Or, better yet, fill the whole vessel with oil pressurized to 1000 bar? That'll show those damn skeptics.
    • Re:Onion (Score:4, Interesting)

      by tragedy (27079) on Thursday March 08, 2012 @08:45PM (#39296013)

      A few problems with that approach. Among other things, I don't think you'd want an incompressible (or at least difficult to compress) fluid between the outer and inner shell. If it's "pushing out" on the outer shell, then it's also pushing in on the inner shell. Not to mention that you actually want to be able to see out of the thing with a window. Given the complexity of a window and how well our cameras work these days, the window represents a whole lot of complex engineering for very little benefit, but if you're going to have a manned craft, you might as well have a window, otherwise you have to shrug your shoulders and mumble when someone asks you why you bothered to actually go down there rather than spend that engineering money on a telepresence system you could operate from a ship on the surface or even from the comfort of home. So, if you need a window, you would have to have a window in every layer of your system and figure out a very complex system with super-high precision optics that work properly even when the high pressure has warped their shape. Then there's your connections between the controls in the inner part of the sub and all the equipment outside. I imagine the sub has two or more power systems with one or more for the cockpit and one or more living at outside pressure for the outside of the sub and with all the equipment outside the cockpit controlled "wirelessly" (or using the whole cockpit hull for a "wire" anyway). Having nested shells is going to require such a system to be very complicated and to be multi-layered as well, with each layer presenting another point of failure. Overall, you're better off in just about every way if your multiple shells are all merged into one shell.

      Essentially, the only special technology you need for a human to survive to that depth is a thick enough shell around them. Nothing technologically amazing or any new ideas needed. Having a well sealed hatch and a well-sealed window are the more complicated parts, since those may not deform evenly with the rest of the shell, but even those aren't really hugely complex engineering problems. The trickier problems are getting all the stuff that needs to survive _outside_ the shell to survive at that pressure and to not explode from internal pressure back up at sea-level. Every single little part needs to considered,and not just mechanically since, at that pressure, materials may have altered chemical and electrical properties. The cockpit is simple and well-understood by comparison.

      For some reason I'm not quite clear on, your suggestion has made me think of _Star Trek IV_, when Scotty trades the formula for transparent aluminium for plexiglass to make the aquarium for the whales since plexiglass is the best substitute for transparent aluminium. I still to this day have not been able to fathom why they couldn't just use regular, non-transparent aluminium, or whatever metal the Klingon ships inner structure was made from to make their tank. Why did it need to be transparent? I don't know and I don't know why this conversation so strongly reminds me of that.

      • by Baloroth (2370816)

        I still to this day have not been able to fathom why they couldn't just use regular, non-transparent aluminium, or whatever metal the Klingon ships inner structure was made from to make their tank. Why did it need to be transparent? I don't know and I don't know why this conversation so strongly reminds me of that.

        I've wondered this myself. I think it has to do with what happens when the whales suddenly find themselves inside a dark, enclosed space. They are used to an enclosure, so that wouldn't be an issue, but a non-transparent one might. Of course, Spock was supposed to have mind-melded to tell them it wouldn't be an issue. But I think the idea is without being able to see someone they know, they might freak out. And several pissed-off whales in an enclosed and not terribly strong space traveling through the vacu

      • by Zlotnick (74376)

        Because then you wouldn't have had the scene where the audience gets to see the whales transported to the tanks.

        To which you might say -- why didn't they just use shields to hold the water/whale solution in place?

        To which I say that's not a very interesting time-travelly solution, and smacks of the "reverse the polarity and run it through the deflector beam" panacea.

      • by EdIII (1114411)

        For some reason I'm not quite clear on, your suggestion has made me think of _Star Trek IV_, when Scotty trades the formula for transparent aluminium for plexiglass to make the aquarium for the whales since plexiglass is the best substitute for transparent aluminium. I still to this day have not been able to fathom why they couldn't just use regular, non-transparent aluminium, or whatever metal the Klingon ships inner structure was made from to make their tank. Why did it need to be transparent? I don't know and I don't know why this conversation so strongly reminds me of that.

        Because....... it's a movie?

        The average movie goer is not a terribly sophisticated person. Just slightly smarter than the average person watching a commercial. Keep in mind, that average is carefully calculated by some very smart people in Hollywood that understand the lowest common denominator and how to use that as an average. I know, but try to keep up.

        Most people will think of whales and where to put them, and that means an aquarium, no different than gold fish. Aquariums have transparent sides to t

      • by DarthVain (724186)

        Because if you use non-transparent aluminum you can't see the fucking whales and what kind of plot device would staring at a metal wall be! :)

    • I'd say it's not that simple. Being liquid, water is not going to be compressible enough to matter in this case, and off hand I'd guess (maybe someone can do the numbers if they want) by the time you hit your first 1000 the water is going to be about as compressed as its going to get, which at sea level is not at its freezing point by the way... it reaches it densest at about 4C, any colder it starts forming ice which is less dense than water and why you can't normally squeeze it solid (I say normally becau
    • I suspect what your trying to suggest is a thicker shell, approaching that which is required to withstand the pressure. I think you can dispense with putting water in it.

    • by EdIII (1114411)

      I have a feeling that you are the one who works at ACME and is responsible for all of Wile E Coyote's (Super Genius) failures.

    • by pipingguy (566974)
      I seem to recall that it was named, "Mariana's Trench" at one time. I posit that the Marianas of the world got together and had the apostrophe removed [angryflower.com]. Because, well, you know, like, oh, nevermind...
    • by Solandri (704621)
      It's been over a decade since I worked on this stuff. I had to look up the formula again [codecogs.com]. The stress inside a spherical shell in compression is equal to the (pressure x diameter) / (4 x thickness).

      The diameter term on top means that your multi-shell design will actually use more metal than simply making a single metal sphere thick enough to withstand the target pressure. Essentially, the optimized form of your multi-shell design is one in which each sphere fits perfectly inside the next, and there is
  • by jd (1658)

    After an unsuccessful attempt to film the sequel of Avatar at a depth of 36,000 feet in 3D resulted in the actors being squished into the ground under the intense pressures, Cameron vowed to continue filming the movie using a mix of scrapers to move the cast and stop-motion cameras to film the sequences.

  • So, it's a race then, between Cameron's Deep Sea Challenge and Hawke/Virgin Oceanic [wikipedia.org]'s Deep Flight Challenger [deepflight.com] (which I think is a lot cooler - it "flies" rather than just sinks).

    Don't know any dates for either attempt, other than '2012' for Deep Flight's first descent.

    • FWIW, Hawkes has been involved in one way or another in just about all of the deepsea subs. For my money, Cameron is hugely ahead of the Virgin project as far as reaching insane depths, although hats off to Branson & Virgin for creating a very cool sub that would be awesome to pilot at any depth and will have plenty of value over time (most of the ocean is much shallower than the Challenger Deep). I'd be money that Cameron's team will be the one, and only one, to return to the Challenger Deep any time t
  • by FiloEleven (602040) on Thursday March 08, 2012 @10:57PM (#39296921)

    Despite what you may have been told, we don't know everything. It's a small but important distinction.

  • by Thagg (9904) <thadbeier@gmail.com> on Friday March 09, 2012 @01:43AM (#39297825) Journal

    The bathyscape Trieste used a similar electromagnet-holding-shot system that Cameron's sub uses. They had a bit of a surprise after many successful dives.

    It seemed that the steel shot that they obtained in Europe had a substantial amount of impurities in it; and the system worked just fine. When they filled the hoppers with American shot, though, it was pure enough that the electromagnets didn't just hold the shot, it magnetized it! Even when the electromagnets were turned off, the shot stayed in the hopper.

    If I recall correctly (and I read about this 40 years ago!) they were able to dump the entire shot canister to get back to the surface.

  • by Anonymous Coward

    As I see it, the problems that they experience in construction all boil down to: prevent 3D objets from going 2D.

    Figures thats why Cameron is involved.

  • So, after making some of the best sci-fi action movies ever filmed, James Cameron kicks back with some dives to the bottom of the ocean.

    You know what the best part of it is? Nearly every dive he has done has been paid for by others. After filming titanic, he did a bunch of dives as "research" for his next movie, Avatar. I must have missed the underwater scenes in that film...

    Anyways, the beauty of doing it this way is :
    1. He gets to charge the investors in the movie for the costs of the underwater dives

    • by Solandri (704621)
      He's not "kicking back" doing this. He's always been a deep sea aficionado. Before Titanic, he directed The Abyss [wikipedia.org]. Rather than going the easy route by using sets and pretending everything was going on underwater, he actually filmed it underwater. In a way, I think filming Titanic was just an excuse for him to play around with submersibles and visit the actual resting place of the Titanic. I mean he didn't have to use real footage of the Titanic in his film - a model or CGI or footage of a different wre
    • by Wraithlyn (133796)

      His post-Titanic dives were for two underwater documentaries, Ghosts of the Abyss [imdb.com] and Aliens of the Deep [imdb.com], during which he also developed his 3D camera technology. He also did some TV in there too (Dark Angel and a couple other things). People make it sound like he was on vacation between Titanic and Avatar, but he has 5 directing credits during that period and advanced the state of the art for 3D, not to mention underwater exploration and filming. In between writing & directing the 2 highest grossing

  • He should invite Clive Cussler to come along for a ride. Maybe Clive will bring Dirk Pitt along too.

  • They should collect the old iron ballast pellets left behind by the last visitor to the Challenger Deep, Bathyscaphe Trieste.

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