“At that depth, the pressure outside the submersible is about six tonnes per square inch.Within 13 months he notched up dives at ever lowering depths from 300ft in a US navy diesel sub left over from WWII down to 120 times that for the final mission in the Trieste in 1960. Weren't they tested under such amounts of pressure? As far as I know, plexiglass can hold pressure of up to 20,000 PSI before it can actually crack.
Stresses of greater magnitude but short duration will not generally cause stress-crazing.So, a square Plexiglass sheet with a span/depth ratio of 16 will fail at 16000 psi. One possible explanation would be a manufacturing or testing failure, where the conditions in the tests were different in some slight but significant way, or where the tests actually unknowingly weakened the bathyscaphe.Thanks for contributing an answer to Engineering Stack Exchange!To subscribe to this RSS feed, copy and paste this URL into your RSS reader.However, we (or at least I) have no idea what the span/depth ratio was in the Trieste, nor do we know if perhaps Plexiglass was weaker back then.Engineering Stack Exchange is a question and answer site for professionals and students of engineering. “If all of Greenland melts - and it is melting - the sea level will rise between 14 and 17 feet,” he says. Is that the ultimate applied load or the maximum internal stress it can withstand?
“Eight out of 10 of the world’s largest cities are coastal, and around 44 per cent of the world population lives within 60 miles of the coast.
Bathyscaphe Trieste: The Bathyscaphe Trieste lifted out of the water, circa 1958-59. Trieste, a research bathyscaphe, was the development of a concept first studied in 1937 by the Swiss physicist and balloonist, Auguste Piccard. It only takes a minute to sign up.Whether the four or so hours it took to reach 9000 meters is enough to cause stress-crazing, I can't say, but maybe that was it. A deep-submergence vehicle (DSV) is a deep-diving manned submarine that is self-propelled. World War II abruptly terminated Piccard's work in Belgium on his deep-sea research submarine, a bathyscaphe, and he did not resume it until 1945. Several navies operate vehicles that can be accurately described as DSVs. Naval Historical Center Photograph. U.S. In fact, in 1963, it was used to locate the sunken nuclear submarine USS Thresher. In 1960, Lieutenant Don Walsh of the US Navy and Swiss oceanographer Jacques Piccard navigated the Trieste bathyscaphe into the Mariana Trench. Ask him what the biggest threat to it is right now and the answer is instantaneous: “ignorance”.It is a race against time. Due to their extreme conditions, they wouldn’t be able to fix it until they had made the long journey back to land through the silent abyss.They checked their instruments but found nothing awry, so continued.
Why did the first layer of plexiglass Window panes crack on the Bathyscaphe Trieste while descending down to the Mariana Trench? “I didn’t know what the damn thing was at first,” he says of the vessel in which he completed some of his most staggering journeys.“It sounded like an interesting thing to do and different from what I was doing day-to-day on my submarine.” Six decades on, Walsh’s admiration for the ocean has not waned.
With rising sea levels, the ocean is coming down your street.”We urge you to turn off your ad blocker for The Telegraph website so that you can continue to access our quality content in the future.They spent 20 minutes there identifying the source of the explosive sound – a cracked acrylic window towards the back of the sub's entrance tunnel caused by the immense pressure of the water surrounding them. As far as I know, plexiglass can hold pressure of up to 20,000 PSI before it can actually crack.The datasheet also has the following statement (page 5):As to how it wasn't tested for such loads, it almost certainly was. I'd guess it's the applied load, but it isn't clear (to me, at least) from the datasheet. What isn't clear to me, however, is what precisely is meant by that.