Railroad tank car vacuum implosion

What Hacker News said

Cites dj_gitmo · 2014-08 · on “Vacuum airship”

This rail-bound tank was probably not designed with weight savings as a prime considerations. [this video] Still, this is a fascinating idea and I would love to see someone make a serious attempt at it.

Cites beloch · 2014-08 · on “Vacuum airship”

At atmospheric pressure, a given volume of hydrogen weighs approximately 7% (there is some variation with temperature) of an equivalent volume of air. All that is needed to contain hydrogen at atmospheric pressure is a membrane it can't pass through. The inwards force exerted on the membrane by the atmosphere is perfectly balanced by the outwards force exerted by the hydrogen gas. The only structural material required is for the purpose of harnessing the lifting power of the enclosed gas, providing an aerodynamic shape, etc.. Conversely, a vessel containing a vacuum must be built to withstand the 101,325 N/m^2 net inward force exerted upon it by the atmosphere that is not balanced by the out

Cites mikewarot · 2021-03 · on “Early SpaceX engineer crawled inside an imploding rocket on a jet”

Airplanes aren't pressurized to sea level... so as they went up, the air inside the tank vented outward into the airplane... and a pressure vessel can easily withstand that... but the problem is that on the way back down to land, the pressure inside the airplane went up far quicker than it could get back inside the tank, so the tank had a much lower pressure inside than that outside the tank. You've obviously never seen what happens to a pressure vessel when the pressure gradient goes the wrong way... Here's an idea of what can happen: [this video] Imagine being on a plane when a very large object inside of it does that. It could have caused the airplane to implode as well, or have catastrophic d

Cites immmmmm · 2021-08 · on “The Tesla Dojo Chip Is Impressive, but There Are Some Major Technical Issues”

not fully related but i was doing some reading on various "new sustainable ways of transportation" and, since they're building the biggest hyperloop test track near my place, i found this interesting video of some of problems one might get trying to put vacuum in a pipe: [this video]

Cites parasense · 2022-02 · on “Hyperloop lays off half of its employees as it pivots away from passenger travel”

Here is your reality: [this video] You're not entirely wrong however. There is effectively one atmosphere differential at sea level, but framing the difference that way is at worst intellectual dishonest, or at best a rather naive understanding. In actual reality there is a very long tube, and all the surface area is under pressure. In metric is 10,000 kg per square meter, multiplied by all the square meters down the length of tube. Of course this simplified understanding ignores the weight of the transport capsule inside, which causes a momentary higher differential. And, the hyperloop won't work at sea level, as others have pointed out, it would have to be underground to avoid thermal expansion

Cites pontifier · 2023-02 · on “Vacuum Balloons”

I can't believe nobody has shown how violent vacuum implosions can be. Here are some of my favorite vacuum implosions: Train car imploding: [this video] Vacuum chamber imploding: [LINK]

Cites pfdietz · 2023-06 · on “Titanic tourist sub goes missing sparking search”

> a buckling mode, which is inherently unstable. As soon as it goes, it goes all at once. Example of implosion of a railroad tank car: [this video]

Cites Ruthalas · 2023-06 · on “Missing Titanic Sub Faced Lawsuit over Depths It Could Safely Travel To”

This is likely less the case when the pressure differential is ~480 bar. Failure is going to occur on the order of fractions of a second at those huge pressures. (Fortunately?) Here's a pressure vessel failing at only 1 bar: [this video]