10 ms·

Winning Hyperloop design revealed by MIT engineers

146 points by goodcanadian 11y ago

revscat 11y ago
How can the winning design be one that carries neither passengers nor cargo?
- bcook 11y ago
  I thought the contest posed by Musk was a request for a proof of concept. A test loop.
  - Animats 11y ago
    It's not a loop. Musk's test track is straight. Hyperloop Transportation Technologies is talking about a 5-mile loop. That's more interesting, because cornering is hard. The MIT system is maglev against a passive track. The Transrapid system, used in the Shanghai airport maglev, requires an active track, which is why it's so expensive. Maglev with a passive track means a simpler track but high power consumption on the vehicle. Power has to be supplied to the vehicle in some way. MIT is using batteries, which is fine for a 1 mile run, but doesn't scale. The Incheon airport maglev just started service yesterday. It's not high speed rail, but it's much faster than most airport trams.
    - mattbeckman 11y ago
      If only there was someone related to this project that had experience building a business based on using batteries for transportation where other people have previously thought wasn't possible ...
      - kuschku 11y ago
        Tesla is based on not using expensive batteries, but instead the common "same as in every laptop" type. They can't magically increase battery lifetime, and that's why Hyperloop will either end up as Transrapid in vacuum (VacTrain, concept for many decades) or not at all.
        grandinj 11y ago
        But given that trains stop periodically, and we know how to build rapid-recharge energy storage devices, that might not be a problem
        kuschku 11y ago
        This is HSR done on even larger scale. It will travel nonstop for 600km+. Recharging is an issue there. (I don’t know if you have ever used High Speed Rail, but usually it’s a direct city-city transport, only connecting the largest cities in the region, and often going for a long time uninterrupted. Many countries, like Germany and Japan, even decided to put HSR onto completely separate rails)
- Tsagadai 11y ago
  First you need to prove that it can move before you work out what it can move.
UnoriginalGuy 11y ago
Any hints about how a broken down hyperloop train would be evacuated? Or what happens if the tunnel suddenly pressured (e.g. aircraft/lorry hit a section dislodging it)? Also how resistant is the design to earthquakes given the high negative pressure (i.e. how will the flexible joints be built to both withstand the pressure and move enough during an earthquake without derailing the train)? How will maintenance be done on the system?
- salmonet 11y ago
  No idea, but I'm sure people had similar thoughts about airplanes when they were experimental. I, for one, am very happy to see bold experiments like this in transportation.
- ajmurmann 11y ago
  I don't have a reference at hand but recall vaguely that all these issues were addressed in Musk's original document.
- consp 11y ago
  The guys from the team from Delft told me there would be a shockwave which the pods can easily resist and after about 30 seconds the tube is pressurized and the passengers can escape. The idea is that there will be hatches every [n] meters to allow an exit from the tube if needed. The rest are all good questions
  - ackfoo 11y ago
    Hatches with ladders down to the ground? Great way to increase cost and diminish reliability exponentially. Let's put a failure point every [n] meters. Notwithstanding, this is a distraction from the biggest problem, which is that a decompression of one vehicle will require recompression of the entire segment of the hyperloop, stopping all vehicles in the segment. At the ambient near-vacuum pressure inside the hyperloop, humans cannot survive for more than a few seconds even with supplemental pressurized oxygen masks. There is absolutely no way to deal with the decompression of a single vehicle other than (a) recompress the loop or (b) plan for the occupants to be dead by the next stop. The problem is not even decompression itself. Any failure of a sensor or failure of communication with the vehicle for more than about 1s must be interpreted as a decompression, with shutdown of the loop, because to do otherwise is to plan for the death of the occupants. Commercial travel at very low ambient pressures has significant caveats. A plan to deal with these is going to be central to wide acceptance of the system. This is the greatest design challenge of the hyperloop.
IIAOPSW 11y ago
where's the part that sucks air out the front and moves it to the back? You know, the whole damn point of the hyperloop. Right now this is just a fancy maglev.
- mikeyouse 11y ago
  The test track is too short to get up to full speed so the compressors wouldn't provide any functionality at this scale.
  - IIAOPSW 11y ago
    Right but then what's the point. That you can run a maglev in a tunnel?
    - pinktennisballs 11y ago
      Evacuated tunnel. And actually it is a big deal considering the speed of travel which presents new problems. Also all designs are focused on scalability of system
      - kuschku 11y ago
        But then stop calling it Hyperloop, and call it the VacTrain it is. Nothing revolutionary, has existed for many decades as concept.
- bobbles 11y ago
  They talk about a vacuum tube and so on but specifically the point of the hyperloop was that it WASNT a vacuum tube
- om42 11y ago
  I mentioned in another comment that there are a couple different designs for levitation and all of them do not need a compressor system anymore. Even the air bearings can rely on on-board tanks of compressed air (even at full scale). The compressor is too expensive to implement and would require high power which isn't feasible since it adds cost and weight to the batteries.
politician 11y ago
Anyone else suspect Hyperloop is a transport technology destined for use off-planet where it wouldn't be plausible to pave roads everywhere, where there isn't sufficient atmosphere to support flight nor oceans to float boats? Evacuating the tubes would be far easier on the moon or on Mars.
- VeilEm 11y ago
  Something along the lines of a hyper loop is the kind of shower thought anyone would have while they're stuck in traffic. "What if we just made super fast tunnels to get us places so I don't have to sit here and deal with this shit right now." Only in this case it was Elon Musk having the thought.
  - prawn 11y ago
    I think that's very unfair. When it was announced, a team had been working on the practicalities and included detailed diagrams and calculations. Yes, he had the team at his disposal, but it didn't just gain attention because he has a recognisable name.
    - mikeash 11y ago
      I didn't read that as name recognition, but rather that Elon Musk is one of the few people with both the resources and the drive to turn ridiculous shower thoughts into real projects. If it was Bill Gates, he'd just dismiss it as silly and get back to wiping out malaria or whatever, and if it was me then I wouldn't be able to make it go anywhere.
      - asddubs 11y ago
        If I had a boatload of money, I'd make an electric car, but like, make it awesome. Give it like a really big battery so it can go really far, and make it like a proper car. Oh no we're out of towels
  - retr0h 11y ago
brosky117 11y ago
I think it is funny to hear the objections of all the armchair scientists and commentators. I'm sure glad we have people like you who can see straight to the problems with the Hyperloop that no one has ever thought of. You're right. Let's just give up on this whole idea :|
- nether 11y ago
  Most of these guys just read some Rust tutorials though. That has to count for something.
- erispoe 11y ago
  Solving problems is not ignoring them and wish they go away. One of the biggest problem with transportation infrastructures in the US is the cost of the right-of-way. This is barely touched by Hyperloop (the project doesn't account for these costs) because it focuses on the technical solution, that is actually the easiest part. The PG motto is more relevant than ever: make something people want. In that case, make something that people will want in their backyard. Selling is the hard part.
  - simplemath 11y ago
    This is 100% the biggest problem with the concept. Good luck getting a closed tube through a municipality, let alone a major city, let alone across an entire state.
    - sailfast 11y ago
      I'm guessing (hoping?) that these things are going to be a hell of a lot quieter and less pollutant than diesel trains so perhaps it would be something I wouldn't mind living next to or around.
  - deleted 11y ago
    [deleted]
  - vidarh 11y ago
    A large part of the reason for how hyperloop is structured the way it is, is exactly because of right of way: The proposal calls for pylons and for the route to largely follow the highways in order to be able to take advantage of existing right of way to minimize those issues as much as possible. It might very well be that they should have spent more effort on that aspect, but they didn't ignore it. And the PG motto is great if you want to make money as fast as possible with as little risk as possible. It's not nearly so great if your goal is to make a major change to society.
yawaramin 11y ago
Even if the Hyperloop is only ever used to move cargo, replacing cross-continental trains, it would still be a very big win.
- protomyth 11y ago
  Why? Cargo is what we do best in the US and it doesn't care how fast it gets to the destination. Further, the car shown is far too small to replace the 125 car unit trains we send around the US. We have a larger, harder to replace cargo infrastructure than any passenger system.
  - Nikker 11y ago
    The picture depicts one car though. That would likely imply that you could send multiples though the tube, kind of like rail cars are sent along the rails. The big thing is that these will travel much faster.
    - protomyth 11y ago
      Look at the volume of the car, it is tiny compared to rail. Faster isn't a big help since we already have efficient air for that. Heck, we still use barges for cargo. Plus, the whole evacuated tube would play hell on cargo loading because of the added requirements. Speed buys very little given cargo is fine with traveling all night.
      - deleted 11y ago
        [deleted]
  - richardw 11y ago
    Do there exist any small packages that we would like to get between these points faster than they currently do?
    - dragonwriter 11y ago
huuu 11y ago
More about the winning teams: http://hyperloop.tamu.edu/news-release-january-30-2016/ http://hyperloop.tamu.edu/news-release-january-30-2016/
tbabb 11y ago
Maglev, huh. Does that imply the track has to have embedded coils / permanent magnets? If so, seems like that pretty much explodes the cost, no?
- om42 11y ago
  There were a couple designs at Design Weekend including MIT's design where they use passive magnetic system instead of the active magnetic systems (Maglev) found on most high speed trains. By inducing Eddie-currents, they don't have to rely on embedded coils, just permanent magnets. Supposedly the teams using the passive magnetic system say the costs are low enough currently since you save power (no high power usage) and don't need to lay out specialized coils on the track. There are couple difference designs that will be tested at Design Weekend, including the air bearings proposed in the alpha paper along with magnets and wheels.
  - tbabb 11y ago
    Curious what the heat losses are on eddy currents. I guess we'll see...
- InclinedPlane 11y ago
  It's not maglev. For fuck's sake, can people at least read the wikipedia entry on the topic before commenting on it? It uses an air cushion to reduce friction, it uses linear induction motors to accelerate trains along a route, most of the time it will cost. That means the fixed costs of the whole thing are low. The cars are pretty simple and low cost. The accelerators are also simple and make up a tiny fraction of the length of a track. Most of the track is just a partially evacuated tunnel, which is cheaper to build than a maglev track.
  - tbabb 11y ago
    > It's not maglev Oh wow, this is too much. From the article: > "The MIT pod has magnet skis that lift it during high-speed cruising" So, in your own words, "For fuck's sake, can people at least read the article before commenting on it?" The was the whole reason I brought it up. The original design called for air bearings; the MIT team did something apparently far more expensive. This is concerning.
pinktennisballs 11y ago
Virginia Tech, 4th place team, will soon release its full pod design at www.hyperloopvt.com. Several of the top 5 teams had similar designs to the MIT pod. The teams at the top were all very close in quality.
gene-h 11y ago
Here's a bit more on the specs of MIT's design: http://hyperloop.mit.edu/ http://hyperloop.mit.edu/ From the lift to drag ratio(14) and cruising speed provided(110 m/s), we can compare it's performance to other forms of transportation(neglecting air drag) using the Von Karmen Gabrielli diagram[0]. Using the inverse of the L/D ratio as the specific tractive power and using the updated Von Karmen Gabrielli diagram in [1], we find that performance is expected to be a bit better than that of a commercial plane. This is pretty promising. Although power required for stabilization and overcoming air drag should be taken into account. [0]https://en.wikipedia.org/wiki/Von_K%C3%A1rm%C3%A1n%E2%80%93Gabrielli_diagram https://en.wikipedia.org/wiki/Von_K%C3%A1rm%C3%A1n%E2%80%93G... [1]http://www.ingenia.org.uk/Content/ingenia/issues/issue22/Imperial.pdf http://www.ingenia.org.uk/Content/ingenia/issues/issue22/Imp...
- flexie 11y ago
  But 110 m/s - that's 396 km/h or 246 mph - about the speed of a high speed train in Asia or Europe, give or take. And that is when the pods are empty. Sure, without the friction of the rails and the air you save energy, and maybe you can build the whole thing cheaper, and that's lovely and all. But wasn't the ambition to go much faster than a train? I thought this was about reaching speeds of airplanes... If we are at speeds around or below 200 mph when the pods are full, SF - LA would still take a couple of hours. A French wheeled TGV could have done that 35 years ago. A Japanese wheeled Shinkansen could have done that even before. A Japanese or Chinese maglev version of the last 1-2 decades could easily beat that. And that's without being stuck in a dumb tube. By the time the hyperloop becomes a reality, if ever, there will be tens of thousands of miles of high speed rails around the world. The hyperloop is a sizeable amount of current hype and a future loop with pods that barely match yesterday's high speed trains. These high speed trains, engineering wonders that actually exist, don't receive any attention in press. I'd say that the hyperloop has been remarkably good at sucking the air out of the room.
  - creshal 11y ago
    > A French wheeled TGV could have done that 35 years ago. A Japanese wheeled Shinkansen could have done that even before. A Japanese or Chinese maglev version of the last 1-2 decades could easily beat that. On very few select tracks – the Shinkansen could drive 500 km/h, but is still limited to 320 because of a lack of suitable high-speed tracks. Same goes for the TGV, and the Germans don't even bother with trains faster than 250 km/h. Speaking of which, Germany sold their maglev technology to Japan and China in the first place because there was nowhere to put it at all. With Germany's winding railroad network it's impossible to reach speeds high enough to justify maglev. 400 km/h sustained, over tracks longer than 400km, would already be a massive improvement over the status quo. Assuming, of course, the Hyperloop will be able to build a sufficient rail/tube network.
ck2 11y ago
I was thinking that while this will never work for people, at least Americans (just watch a group of us on a bus or plane) that this could work for same-day delivery for Amazon and others and it would only have to be a fraction of the size tube. You'd still need a last-mile delivery but you could do warehouse to warehouse transfers in an hour instead of days.
listic 11y ago
When will the final competition happen?
chrstphrhrt 11y ago
Very naive question: if the tube is a vacuum with no drag from atmosphere, why should a pod design be aerodynamic?
- sytse 11y ago
  It is a partial vacuum, there is less air but the remaining air still needs to be pushed out of the way.
lisper 11y ago
Too much attention is being paid to the pods and not nearly enough to the elephant in the room: how to handle thermal expansion in the track. See: http://www.leancrew.com/all-this/2013/08/hyperloop/ http://www.leancrew.com/all-this/2013/08/hyperloop/
- deleted 11y ago
  [deleted]
- tod222 11y ago
  There have been some comments, but I'm not sure I've seen this excellent take on the issue. From the linked document: > So what’s the value of getting the vibration mode shapes of this little section of the Hyperloop? Simple: it makes pretty pictures you can put in your proposal. and > Nothing in this section of the proposal has “demonstrated the capability of the Hyperloop,” nor was it intended to. This is not simply an error. This is eyewash for the rubes, the surest sign you’re dealing with a snake oil salesman. And now the winning design from MIT drops the air hockey suspension for conventional magnetic levitation. The purpose of Hyperloop isn't to build a fast, new LA-SF link, it's to kill the California High-Speed Rail project. It's a classic case of FUD. https://en.wikipedia.org/wiki/Fear,_uncertainty_and_doubt https://en.wikipedia.org/wiki/Fear,_uncertainty_and_doubt

146 points by goodcanadian 11y ago

revscat 11y ago

How can the winning design be one that carries neither passengers nor cargo?

bcook 11y ago
I thought the contest posed by Musk was a request for a proof of concept. A test loop.
- Animats 11y ago
  It's not a loop. Musk's test track is straight. Hyperloop Transportation Technologies is talking about a 5-mile loop. That's more interesting, because cornering is hard. The MIT system is maglev against a passive track. The Transrapid system, used in the Shanghai airport maglev, requires an active track, which is why it's so expensive. Maglev with a passive track means a simpler track but high power consumption on the vehicle. Power has to be supplied to the vehicle in some way. MIT is using batteries, which is fine for a 1 mile run, but doesn't scale. The Incheon airport maglev just started service yesterday. It's not high speed rail, but it's much faster than most airport trams.
  - mattbeckman 11y ago
    If only there was someone related to this project that had experience building a business based on using batteries for transportation where other people have previously thought wasn't possible ...
    - kuschku 11y ago
      Tesla is based on not using expensive batteries, but instead the common "same as in every laptop" type. They can't magically increase battery lifetime, and that's why Hyperloop will either end up as Transrapid in vacuum (VacTrain, concept for many decades) or not at all.
      - grandinj 11y ago
        But given that trains stop periodically, and we know how to build rapid-recharge energy storage devices, that might not be a problem
        kuschku 11y ago
        This is HSR done on even larger scale. It will travel nonstop for 600km+. Recharging is an issue there. (I don’t know if you have ever used High Speed Rail, but usually it’s a direct city-city transport, only connecting the largest cities in the region, and often going for a long time uninterrupted. Many countries, like Germany and Japan, even decided to put HSR onto completely separate rails)
Tsagadai 11y ago
First you need to prove that it can move before you work out what it can move.

UnoriginalGuy 11y ago

Any hints about how a broken down hyperloop train would be evacuated? Or what happens if the tunnel suddenly pressured (e.g. aircraft/lorry hit a section dislodging it)? Also how resistant is the design to earthquakes given the high negative pressure (i.e. how will the flexible joints be built to both withstand the pressure and move enough during an earthquake without derailing the train)? How will maintenance be done on the system?

salmonet 11y ago
No idea, but I'm sure people had similar thoughts about airplanes when they were experimental. I, for one, am very happy to see bold experiments like this in transportation.
ajmurmann 11y ago
I don't have a reference at hand but recall vaguely that all these issues were addressed in Musk's original document.
consp 11y ago
The guys from the team from Delft told me there would be a shockwave which the pods can easily resist and after about 30 seconds the tube is pressurized and the passengers can escape. The idea is that there will be hatches every [n] meters to allow an exit from the tube if needed. The rest are all good questions
- ackfoo 11y ago
  Hatches with ladders down to the ground? Great way to increase cost and diminish reliability exponentially. Let's put a failure point every [n] meters. Notwithstanding, this is a distraction from the biggest problem, which is that a decompression of one vehicle will require recompression of the entire segment of the hyperloop, stopping all vehicles in the segment. At the ambient near-vacuum pressure inside the hyperloop, humans cannot survive for more than a few seconds even with supplemental pressurized oxygen masks. There is absolutely no way to deal with the decompression of a single vehicle other than (a) recompress the loop or (b) plan for the occupants to be dead by the next stop. The problem is not even decompression itself. Any failure of a sensor or failure of communication with the vehicle for more than about 1s must be interpreted as a decompression, with shutdown of the loop, because to do otherwise is to plan for the death of the occupants. Commercial travel at very low ambient pressures has significant caveats. A plan to deal with these is going to be central to wide acceptance of the system. This is the greatest design challenge of the hyperloop.

IIAOPSW 11y ago

where's the part that sucks air out the front and moves it to the back? You know, the whole damn point of the hyperloop. Right now this is just a fancy maglev.

mikeyouse 11y ago
The test track is too short to get up to full speed so the compressors wouldn't provide any functionality at this scale.
- IIAOPSW 11y ago
  Right but then what's the point. That you can run a maglev in a tunnel?
  - pinktennisballs 11y ago
    Evacuated tunnel. And actually it is a big deal considering the speed of travel which presents new problems. Also all designs are focused on scalability of system
    - kuschku 11y ago
      But then stop calling it Hyperloop, and call it the VacTrain it is. Nothing revolutionary, has existed for many decades as concept.
bobbles 11y ago
They talk about a vacuum tube and so on but specifically the point of the hyperloop was that it WASNT a vacuum tube
om42 11y ago
I mentioned in another comment that there are a couple different designs for levitation and all of them do not need a compressor system anymore. Even the air bearings can rely on on-board tanks of compressed air (even at full scale). The compressor is too expensive to implement and would require high power which isn't feasible since it adds cost and weight to the batteries.

politician 11y ago

Anyone else suspect Hyperloop is a transport technology destined for use off-planet where it wouldn't be plausible to pave roads everywhere, where there isn't sufficient atmosphere to support flight nor oceans to float boats? Evacuating the tubes would be far easier on the moon or on Mars.

VeilEm 11y ago
Something along the lines of a hyper loop is the kind of shower thought anyone would have while they're stuck in traffic. "What if we just made super fast tunnels to get us places so I don't have to sit here and deal with this shit right now." Only in this case it was Elon Musk having the thought.
- prawn 11y ago
  I think that's very unfair. When it was announced, a team had been working on the practicalities and included detailed diagrams and calculations. Yes, he had the team at his disposal, but it didn't just gain attention because he has a recognisable name.
  - mikeash 11y ago
    I didn't read that as name recognition, but rather that Elon Musk is one of the few people with both the resources and the drive to turn ridiculous shower thoughts into real projects. If it was Bill Gates, he'd just dismiss it as silly and get back to wiping out malaria or whatever, and if it was me then I wouldn't be able to make it go anywhere.
    - asddubs 11y ago
      If I had a boatload of money, I'd make an electric car, but like, make it awesome. Give it like a really big battery so it can go really far, and make it like a proper car. Oh no we're out of towels
- retr0h 11y ago

brosky117 11y ago

I think it is funny to hear the objections of all the armchair scientists and commentators. I'm sure glad we have people like you who can see straight to the problems with the Hyperloop that no one has ever thought of. You're right. Let's just give up on this whole idea :|

nether 11y ago
Most of these guys just read some Rust tutorials though. That has to count for something.
erispoe 11y ago
Solving problems is not ignoring them and wish they go away. One of the biggest problem with transportation infrastructures in the US is the cost of the right-of-way. This is barely touched by Hyperloop (the project doesn't account for these costs) because it focuses on the technical solution, that is actually the easiest part. The PG motto is more relevant than ever: make something people want. In that case, make something that people will want in their backyard. Selling is the hard part.
- simplemath 11y ago
  This is 100% the biggest problem with the concept. Good luck getting a closed tube through a municipality, let alone a major city, let alone across an entire state.
  - sailfast 11y ago
    I'm guessing (hoping?) that these things are going to be a hell of a lot quieter and less pollutant than diesel trains so perhaps it would be something I wouldn't mind living next to or around.
- deleted 11y ago
  [deleted]
- vidarh 11y ago
  A large part of the reason for how hyperloop is structured the way it is, is exactly because of right of way: The proposal calls for pylons and for the route to largely follow the highways in order to be able to take advantage of existing right of way to minimize those issues as much as possible. It might very well be that they should have spent more effort on that aspect, but they didn't ignore it. And the PG motto is great if you want to make money as fast as possible with as little risk as possible. It's not nearly so great if your goal is to make a major change to society.

yawaramin 11y ago

Even if the Hyperloop is only ever used to move cargo, replacing cross-continental trains, it would still be a very big win.

protomyth 11y ago
Why? Cargo is what we do best in the US and it doesn't care how fast it gets to the destination. Further, the car shown is far too small to replace the 125 car unit trains we send around the US. We have a larger, harder to replace cargo infrastructure than any passenger system.
- Nikker 11y ago
  The picture depicts one car though. That would likely imply that you could send multiples though the tube, kind of like rail cars are sent along the rails. The big thing is that these will travel much faster.
  - protomyth 11y ago
    Look at the volume of the car, it is tiny compared to rail. Faster isn't a big help since we already have efficient air for that. Heck, we still use barges for cargo. Plus, the whole evacuated tube would play hell on cargo loading because of the added requirements. Speed buys very little given cargo is fine with traveling all night.
    - deleted 11y ago
      [deleted]
- richardw 11y ago
  Do there exist any small packages that we would like to get between these points faster than they currently do?
  - dragonwriter 11y ago

huuu 11y ago

More about the winning teams: http://hyperloop.tamu.edu/news-release-january-30-2016/ http://hyperloop.tamu.edu/news-release-january-30-2016/

tbabb 11y ago

Maglev, huh. Does that imply the track has to have embedded coils / permanent magnets? If so, seems like that pretty much explodes the cost, no?

om42 11y ago
There were a couple designs at Design Weekend including MIT's design where they use passive magnetic system instead of the active magnetic systems (Maglev) found on most high speed trains. By inducing Eddie-currents, they don't have to rely on embedded coils, just permanent magnets. Supposedly the teams using the passive magnetic system say the costs are low enough currently since you save power (no high power usage) and don't need to lay out specialized coils on the track. There are couple difference designs that will be tested at Design Weekend, including the air bearings proposed in the alpha paper along with magnets and wheels.
- tbabb 11y ago
  Curious what the heat losses are on eddy currents. I guess we'll see...
InclinedPlane 11y ago
It's not maglev. For fuck's sake, can people at least read the wikipedia entry on the topic before commenting on it? It uses an air cushion to reduce friction, it uses linear induction motors to accelerate trains along a route, most of the time it will cost. That means the fixed costs of the whole thing are low. The cars are pretty simple and low cost. The accelerators are also simple and make up a tiny fraction of the length of a track. Most of the track is just a partially evacuated tunnel, which is cheaper to build than a maglev track.
- tbabb 11y ago
  > It's not maglev Oh wow, this is too much. From the article: > "The MIT pod has magnet skis that lift it during high-speed cruising" So, in your own words, "For fuck's sake, can people at least read the article before commenting on it?" The was the whole reason I brought it up. The original design called for air bearings; the MIT team did something apparently far more expensive. This is concerning.

pinktennisballs 11y ago

Virginia Tech, 4th place team, will soon release its full pod design at www.hyperloopvt.com. Several of the top 5 teams had similar designs to the MIT pod. The teams at the top were all very close in quality.

gene-h 11y ago

Here's a bit more on the specs of MIT's design: http://hyperloop.mit.edu/ http://hyperloop.mit.edu/ From the lift to drag ratio(14) and cruising speed provided(110 m/s), we can compare it's performance to other forms of transportation(neglecting air drag) using the Von Karmen Gabrielli diagram[0]. Using the inverse of the L/D ratio as the specific tractive power and using the updated Von Karmen Gabrielli diagram in [1], we find that performance is expected to be a bit better than that of a commercial plane. This is pretty promising. Although power required for stabilization and overcoming air drag should be taken into account. [0]https://en.wikipedia.org/wiki/Von_K%C3%A1rm%C3%A1n%E2%80%93Gabrielli_diagram https://en.wikipedia.org/wiki/Von_K%C3%A1rm%C3%A1n%E2%80%93G... [1]http://www.ingenia.org.uk/Content/ingenia/issues/issue22/Imperial.pdf http://www.ingenia.org.uk/Content/ingenia/issues/issue22/Imp...

flexie 11y ago
But 110 m/s - that's 396 km/h or 246 mph - about the speed of a high speed train in Asia or Europe, give or take. And that is when the pods are empty. Sure, without the friction of the rails and the air you save energy, and maybe you can build the whole thing cheaper, and that's lovely and all. But wasn't the ambition to go much faster than a train? I thought this was about reaching speeds of airplanes... If we are at speeds around or below 200 mph when the pods are full, SF - LA would still take a couple of hours. A French wheeled TGV could have done that 35 years ago. A Japanese wheeled Shinkansen could have done that even before. A Japanese or Chinese maglev version of the last 1-2 decades could easily beat that. And that's without being stuck in a dumb tube. By the time the hyperloop becomes a reality, if ever, there will be tens of thousands of miles of high speed rails around the world. The hyperloop is a sizeable amount of current hype and a future loop with pods that barely match yesterday's high speed trains. These high speed trains, engineering wonders that actually exist, don't receive any attention in press. I'd say that the hyperloop has been remarkably good at sucking the air out of the room.
- creshal 11y ago
  > A French wheeled TGV could have done that 35 years ago. A Japanese wheeled Shinkansen could have done that even before. A Japanese or Chinese maglev version of the last 1-2 decades could easily beat that. On very few select tracks – the Shinkansen could drive 500 km/h, but is still limited to 320 because of a lack of suitable high-speed tracks. Same goes for the TGV, and the Germans don't even bother with trains faster than 250 km/h. Speaking of which, Germany sold their maglev technology to Japan and China in the first place because there was nowhere to put it at all. With Germany's winding railroad network it's impossible to reach speeds high enough to justify maglev. 400 km/h sustained, over tracks longer than 400km, would already be a massive improvement over the status quo. Assuming, of course, the Hyperloop will be able to build a sufficient rail/tube network.

ck2 11y ago

I was thinking that while this will never work for people, at least Americans (just watch a group of us on a bus or plane) that this could work for same-day delivery for Amazon and others and it would only have to be a fraction of the size tube. You'd still need a last-mile delivery but you could do warehouse to warehouse transfers in an hour instead of days.

listic 11y ago

When will the final competition happen?

chrstphrhrt 11y ago

Very naive question: if the tube is a vacuum with no drag from atmosphere, why should a pod design be aerodynamic?

sytse 11y ago
It is a partial vacuum, there is less air but the remaining air still needs to be pushed out of the way.

lisper 11y ago

Too much attention is being paid to the pods and not nearly enough to the elephant in the room: how to handle thermal expansion in the track. See: http://www.leancrew.com/all-this/2013/08/hyperloop/ http://www.leancrew.com/all-this/2013/08/hyperloop/

deleted 11y ago
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tod222 11y ago
There have been some comments, but I'm not sure I've seen this excellent take on the issue. From the linked document: > So what’s the value of getting the vibration mode shapes of this little section of the Hyperloop? Simple: it makes pretty pictures you can put in your proposal. and > Nothing in this section of the proposal has “demonstrated the capability of the Hyperloop,” nor was it intended to. This is not simply an error. This is eyewash for the rubes, the surest sign you’re dealing with a snake oil salesman. And now the winning design from MIT drops the air hockey suspension for conventional magnetic levitation. The purpose of Hyperloop isn't to build a fast, new LA-SF link, it's to kill the California High-Speed Rail project. It's a classic case of FUD. https://en.wikipedia.org/wiki/Fear,_uncertainty_and_doubt https://en.wikipedia.org/wiki/Fear,_uncertainty_and_doubt