Very long pipes use expansion/contraction sections that may not be possible for a vacuum sealed system that has to be incredibly straight to allow the passage of a train, and can flex pretty significantly for earthquakes, seasonal temperature changes, etc.
Earthquakes keep getting brought up as if they’re not devastating to absolutely everything we already use. What if an earthquake hits a regular train? Or a bridge, or a house. only a vacuum tube is susceptible to earthquakes.
If any part of the hundreds of miles of tube suddenly stops being a vacuum chamber, every train all along the tube is going to be hit by air rushing in, at the speed of sound, with all the turbulence that implies, while its already moving at full speed. It might be possible to engineer a capsule that will keep the people inside alive when that happens, but it is not at all the same as e.g. rail, where “stop moving fowards” depletes essentially all the energy in the system.
The major strategy on CWR is pretensioning, but there are also multiple kinds of expansion joints used in different circumstances. I’m not saying it’s impossible to do the same with a vacuum chamber, but I am saying there’s no simple reliable answer, and certainly no answer so obvious and bulletproof that it doesn’t even require testing before you could start construction.
Elon Musk either didn’t know or didn’t care that his company wasn’t doing the required engineering and testing to make a real functioning hyperloop.
Very long pipes use expansion/contraction sections that may not be possible for a vacuum sealed system that has to be incredibly straight to allow the passage of a train, and can flex pretty significantly for earthquakes, seasonal temperature changes, etc.
Earthquakes keep getting brought up as if they’re not devastating to absolutely everything we already use. What if an earthquake hits a regular train? Or a bridge, or a house. only a vacuum tube is susceptible to earthquakes.
If any part of the hundreds of miles of tube suddenly stops being a vacuum chamber, every train all along the tube is going to be hit by air rushing in, at the speed of sound, with all the turbulence that implies, while its already moving at full speed. It might be possible to engineer a capsule that will keep the people inside alive when that happens, but it is not at all the same as e.g. rail, where “stop moving fowards” depletes essentially all the energy in the system.
You deal with thermal expansion the same way you do with continuous welded rail.
The major strategy on CWR is pretensioning, but there are also multiple kinds of expansion joints used in different circumstances. I’m not saying it’s impossible to do the same with a vacuum chamber, but I am saying there’s no simple reliable answer, and certainly no answer so obvious and bulletproof that it doesn’t even require testing before you could start construction.
Elon Musk either didn’t know or didn’t care that his company wasn’t doing the required engineering and testing to make a real functioning hyperloop.