The Tech Behind James Cameron's Trench-Bound Submarine

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."

Re:units?

[Forty Two Tenfold]

Seems something is off.

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

Re:Hard?

[Caerdwyn]

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:Cameron

[citizenr]

Remember how he was going to single-handedly fix the Horizon oil disaster off the coast of Louisiana? Never happened. Actually, not a single thing this guy has made headlines for has actually panned out.

Cameron != Kevin Costner you retard

Re:Cameron

[Anonymous Coward]

Remember how he offered to help with the Horizon oil disaster off the coast of Louisiana? Never happened. BP said they didn't need his help.

Fixed that for you.

To answer your question, yes, you likely are the only one since you don't really know much about the topic you're blasting us with your opinion about.

Re:Hard?

[fnj]

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.

Re:units?

[FridayBob]

... 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.

Re:Hard?

[yodleboy]

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.

Re:Hard?

[hey!]

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.

You should read up

[dutchwhizzman]

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).