Dive the Marianas Trench

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The deepest spot in the earth’s oceans is the Challenger Deep in the Marianas Trench in the western Pacific, at 10,994 meters. The BBC has a magnificent interactive graphic of the Trench. Pause as you descend to play the clips at various depths. (And yes, you’ll see the same CIO dating commercial at every stop!)

Hat tip to Talking Points Memo.

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There was a recent show on the history channel’s Modern Marvels regarding this dive. On the way down the plexiglass porthole cracked, but they continued the dive. They would have been instantly crushed had it given out. Then when they reached the bottom of the trench (and actually saw life nearby), they dumped the ballast from the sub, which then proceded to cloud the whole environs and because there were no currents to clear it away they couldn’t see anything, so they decided to come back up. The dive was never repeated.

That’s deep!

DavidK said:

There was a recent show on the history channel’s Modern Marvels regarding this dive. On the way down the plexiglass porthole cracked, but they continued the dive. They would have been instantly crushed had it given out.

That’s one the Hysterical Channel got wrong. Scroll down the BBC graphic to the interview with Don Walsh, the U.S. Navy officer who rode the Trieste down. The port that cracked was not part of the pressure capsule, and there was no danger of implosion due to it.

Per wikipedia: “After passing 9,000 meters one of the outer Plexiglas window panes cracked, shaking the entire vessel.”

At 30,000 ft. a sharp crack rang through the ship, shaking it violently. The water pressure outside wasmore than 6 tons per sqare inch., and even a slight fracture in the hull would have meant certain death. It proved to be only an outer Plexiglas windowpane which had splintered under the pressure. The inner hull remained watertight. “A pretty hairy, experience,” admitted Walsh. (ref. cited: http://bjsonline.com/watches/articl[…]0022_3.shtml)

Having windows on the large ballast tank makes little sense.

In the video on the BBC graphic, Walsh says

Well, at 30,000 feet, round there, there was this great ‘bang.’ We … uh … it was unusual. We hadn’t had that experience before. I was able to look out through the … there was a viewport in the entrance hatch, not the main viewport, but the entrance hatch. I looked out of that, and I could see there was a window back there that had cracked. Well, that window was not a pressure boundary. It had nothing to do with the integrity of where we were. But we knew that we were still alive and the Trieste was performing normally, so we just continued the dive.

He makes it sound much less threatening than my impression of the Hysterical Channel’s account or even the Walsh quote the Wikipedia account provides. Having spent several years at sea and been aboard a submerged nuclear submarine, though, I can imagine the startle response when that window cracked!

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This page contains a single entry by Richard B. Hoppe published on February 24, 2012 1:43 PM.

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