They are very different systems. The above one uses compressed air to move the trains. Hyperloop trains move in near a vacuum (1/1000 atmospheric pressure) using magnets in the tube. It only uses compressed air to levitate above the bottom wall of the tube, and also to reduce air friction on the front, but the thrust comes from magnets.
This is one of those 'space elevator' type ideas : very expensive to setup but once done is relatively cheap to run. The main setup cost here - believe it or not - is the creation of the vacuum. Not only the energy required to evacuate some volume but the structural integrity required everywhere to keep it that way. This makes an equivalent stretch of highway look cheap, at least in the short term which is alas going to be the probable investor timeline.
As Elon points out in the embedded video the market currently has no price signal for pollution or like downsides - the tragedy of the commons writ large - and thus the ultimate costs of alternatives are poorly estimated. But this also applies to the hyperloop itself and not just the existing paradigm. High grade metals* are very expensive and dirty to make. What electricity generation mode is going to drive the pump-down of the tube ? You can't grant the likes of hyperloop a free ticket on these analyses just because it is different/new or apparently cleaner. It could be the same error in disguise.
But it's technically do-able at least. I think the best payoff however would be in freight movement** rather than people. Vacuum is dangerous for people. Lack of fresh air kills. Somewhat akin to climbing a ladder a vacuum represents an immediately accessible energy differential which can be suddenly equalised. Many transportable goods are largely indifferent to this risk. Like the Hindenburg a single accident will destroy usage ( and yet we tolerate the daily maiming with our cars, go figure ).
Cheers, Mike.
* Think of it like an unterseeboot : a non-trivial exercise in keeping separate fluids with radically different densities. With the people on the inside.
** One would prefer high volume, low speed and low drag transport methods for that. Errr .... don't we have two of those three already ? :-) :-) I recall the research effort to make & maintain laminar flow on aircraft wings down to the scale of the otherwise static layer adjacent to the metal skin, by pulling air through small holes in the upper wing surface. This did work and reduced drag nicely. Only the energy cost of the system to do exactly that exceeded the gain from drag reduction. Hence a plane with that facility installed used more fuel when the laminar flow device was operating than when turned off. Oh well .....
( edit ) One could reduce the strain on the containment vessel while also having good flow characteristics for movement within by having a working fluid with low density for a given pressure ( at ambient conditions ). That would be .... wait for it .... drum roll .... hydrogen gas! So you put that in the tube and for much the same reasons as we put it in balloons too. But I'm sure someone already knows that. Hopefully not Hindenburg redux ...
( edit ) Well lookie here. The speed of sound in H2 gas is 1270 m/s ( 1 atmosphere @ 20 C ) ie. four times that of air. This indicates that the various instabilities and turbulence at speed etc will be rather reduced and also the H2 is far easier to shove around through fans etc ( low Reynold's number ). The solar cells could make and maintain the hydrogen in the tube.
( edit ) The Reynold's Number is dimensionless and basically represents the tendency to transfer momentum from some large scale object of interest ( wing, fan blade, soup spoon ) to that of the molecules in the surrounding fluid. Sort of a viscosity measure that encodes the scale of the system in question too. Here we want a low value, but in other circumstances you might want it higher eg. mixing the components of chocolate. :-)
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
Slaps oneself around the face (slap slap) OK brain in gear.
Ummm, can I take a rain check on that?
Sorry Chris, I was working off Elon's document which seemed to leave a few issues begging for detail. The basic idea of the hyperloop is to get air out of the way in order to go fast. So for me at least the initial point of discussion has to be the fluid in which the vehicle sits.
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
The Japanese had experienced some interesting phenomena with their high speed bullet trains. When entering a long tunnel at high speed the air was compressed so that when exiting there was a massive "explosion" like a sonic boom. This caused the locals located near these tunnels to complain. If I remember correctly one solution was to redesign the front of the trains along with a change to the tunnel entrances/exits to eliminate/reduce the volume of this condition.
The Japanese had experienced some interesting phenomena with their high speed bullet trains. When entering a long tunnel at high speed the air was compressed so that when exiting there was a massive "explosion" like a sonic boom. This caused the locals located near these tunnels to complain. If I remember correctly one solution was to redesign the front of the trains along with a change to the tunnel entrances/exits to eliminate/reduce the volume of this condition.
The newer trains are less boxy in the front, I always thought that was for aerodynamic efficiency, guess it's for other stuff too.
I really do have my doubts whether this will be commercially viable in reality, but it's interesting technology that may have other spin offs.
I think it could lead to a morphed form of transportation as an offshoot. I for one would not want to be travelling a the speed of sound through a tube. Just a one centimeter offset could be disastrous.
I think that there is an amount of political involvement here. Look, the Japanese have had the Shinkansen Bullet train since 1964
Quote:
The maximum operating speed is 320 km/h (200 mph) (on a 387.5 km section of the TÅhoku Shinkansen). Test runs have reached 443 km/h (275 mph) for conventional rail in 1996, and up to a world record 603 km/h (375 mph) for maglev trains in April 2015.
If the hyperloop concept was feasible don't you think they would have done it as the world experts in fast transport. If it ever does get built it will likely end up like Concord, technically innovative, only for the mega rich, and will close due to safety concerns and being unprofitable.
Waiting for Godot & salvation :-)
Why do doctors have to practice?
You'd think they'd have got it right by now
RE: Elon needs to check a
)
They are very different systems. The above one uses compressed air to move the trains. Hyperloop trains move in near a vacuum (1/1000 atmospheric pressure) using magnets in the tube. It only uses compressed air to levitate above the bottom wall of the tube, and also to reduce air friction on the front, but the thrust comes from magnets.
This is one of those 'space
)
This is one of those 'space elevator' type ideas : very expensive to setup but once done is relatively cheap to run. The main setup cost here - believe it or not - is the creation of the vacuum. Not only the energy required to evacuate some volume but the structural integrity required everywhere to keep it that way. This makes an equivalent stretch of highway look cheap, at least in the short term which is alas going to be the probable investor timeline.
As Elon points out in the embedded video the market currently has no price signal for pollution or like downsides - the tragedy of the commons writ large - and thus the ultimate costs of alternatives are poorly estimated. But this also applies to the hyperloop itself and not just the existing paradigm. High grade metals* are very expensive and dirty to make. What electricity generation mode is going to drive the pump-down of the tube ? You can't grant the likes of hyperloop a free ticket on these analyses just because it is different/new or apparently cleaner. It could be the same error in disguise.
But it's technically do-able at least. I think the best payoff however would be in freight movement** rather than people. Vacuum is dangerous for people. Lack of fresh air kills. Somewhat akin to climbing a ladder a vacuum represents an immediately accessible energy differential which can be suddenly equalised. Many transportable goods are largely indifferent to this risk. Like the Hindenburg a single accident will destroy usage ( and yet we tolerate the daily maiming with our cars, go figure ).
Cheers, Mike.
* Think of it like an unterseeboot : a non-trivial exercise in keeping separate fluids with radically different densities. With the people on the inside.
** One would prefer high volume, low speed and low drag transport methods for that. Errr .... don't we have two of those three already ? :-) :-) I recall the research effort to make & maintain laminar flow on aircraft wings down to the scale of the otherwise static layer adjacent to the metal skin, by pulling air through small holes in the upper wing surface. This did work and reduced drag nicely. Only the energy cost of the system to do exactly that exceeded the gain from drag reduction. Hence a plane with that facility installed used more fuel when the laminar flow device was operating than when turned off. Oh well .....
( edit ) One could reduce the strain on the containment vessel while also having good flow characteristics for movement within by having a working fluid with low density for a given pressure ( at ambient conditions ). That would be .... wait for it .... drum roll .... hydrogen gas! So you put that in the tube and for much the same reasons as we put it in balloons too. But I'm sure someone already knows that. Hopefully not Hindenburg redux ...
( edit ) Well lookie here. The speed of sound in H2 gas is 1270 m/s ( 1 atmosphere @ 20 C ) ie. four times that of air. This indicates that the various instabilities and turbulence at speed etc will be rather reduced and also the H2 is far easier to shove around through fans etc ( low Reynold's number ). The solar cells could make and maintain the hydrogen in the tube.
( edit ) The Reynold's Number is dimensionless and basically represents the tendency to transfer momentum from some large scale object of interest ( wing, fan blade, soup spoon ) to that of the molecules in the surrounding fluid. Sort of a viscosity measure that encodes the scale of the system in question too. Here we want a low value, but in other circumstances you might want it higher eg. mixing the components of chocolate. :-)
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
Oh cor blimey, I got a bit
)
Oh cor blimey, I got a bit lost there.
Slaps oneself around the face (slap slap) OK brain in gear.
Ummm, can I take a rain check on that?
Waiting for Godot & salvation :-)
Why do doctors have to practice?
You'd think they'd have got it right by now
RE: Oh cor blimey, I got a
)
Sorry Chris, I was working off Elon's document which seemed to leave a few issues begging for detail. The basic idea of the hyperloop is to get air out of the way in order to go fast. So for me at least the initial point of discussion has to be the fluid in which the vehicle sits.
Cheers, Mike.
I have made this letter longer than usual because I lack the time to make it shorter ...
... and my other CPU is a Ryzen 5950X :-) Blaise Pascal
The Japanese had experienced
)
The Japanese had experienced some interesting phenomena with their high speed bullet trains. When entering a long tunnel at high speed the air was compressed so that when exiting there was a massive "explosion" like a sonic boom. This caused the locals located near these tunnels to complain. If I remember correctly one solution was to redesign the front of the trains along with a change to the tunnel entrances/exits to eliminate/reduce the volume of this condition.
RE: The Japanese had
)
The newer trains are less boxy in the front, I always thought that was for aerodynamic efficiency, guess it's for other stuff too.
MIT Team Wins SpaceX
)
MIT Team Wins SpaceX Hyperloop Design Contest
I really do have my doubts
)
I really do have my doubts whether this will be commercially viable in reality, but it's interesting technology that may have other spin offs.
Waiting for Godot & salvation :-)
Why do doctors have to practice?
You'd think they'd have got it right by now
RE: I really do have my
)
I think it could lead to a morphed form of transportation as an offshoot. I for one would not want to be travelling a the speed of sound through a tube. Just a one centimeter offset could be disastrous.
I think that there is an
)
I think that there is an amount of political involvement here. Look, the Japanese have had the Shinkansen Bullet train since 1964
If the hyperloop concept was feasible don't you think they would have done it as the world experts in fast transport. If it ever does get built it will likely end up like Concord, technically innovative, only for the mega rich, and will close due to safety concerns and being unprofitable.
Waiting for Godot & salvation :-)
Why do doctors have to practice?
You'd think they'd have got it right by now