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."

Comments

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).