14 ms·

We Think We Know What Elon Musk's Hyperloop Is

228 points by wtracy 13y ago

andymoe 13y ago
He has already said it is not an evacuated tube though he chooses his words very carefully in all the talks I've seen. It comes up in just about every long interview he has done over the past year.
anologwintermut 13y ago
Lets assume it is some kind of maglev in a buried tunnel. How does this effect right-of-way? My understanding is the problem for building even a simple high speed train from LA to SF is principally NIMBYism and the resulting lawsuits . This causes costs to sky rocket as you get delays. Does digging a tunnel underground solve that ?
- jacques_chester 13y ago
  It will depend on the jurisdiction. In Australia, for example, what's under the ground generally belongs to the Crown in right of the particular State or Territory. In general, however, almost any amount of haggling, land resumption / compulsory purchase and rezoning is cheaper than building tunnels. We talk about disruptive startups. Bringing the cost of tunnels down by an order of magnitude would be fairly ... seismic. (Unfortunately, the Earth is restless and heartless).
- venomsnake 13y ago
  I suppose the authorities will just use air travel as precedent - nobody needs your permission to build air corridor above your house.
  - sliverstorm 13y ago
    I think it's even simpler than that; when you own property, don't you typically only own a certain distance down into the ground?
    - RyJones 13y ago
      Depends if you have the mineral rights or not. You could argue that digging the tunnel is just a very inefficient way of mining your minerals (if you were a property owner, with mineral rights, wishing to stall the project). If you didn't own the mineral rights, there isn't much you could do if the tunnelers took care not to damage your (above ground) property. https://en.wikipedia.org/wiki/Mineral_rights https://en.wikipedia.org/wiki/Mineral_rights
  - lmm 13y ago
    There were lawsuits over this when air travel was getting started.
    - twistedpair 13y ago
      Limits are above and below ground. The FAA has a limit of 2000ft on structures. Beyond that you'll need to go to the mat to get special dispensation to go higher.
- tsotha 13y ago
  It does, but when they dug a tunnel for the LA subway it cost a billion dollars per mile, so I'm hoping that's not his grand idea.
  - snogglethorpe 13y ago
    Keep in mind that America is famously horrible at doing public projects of this sort cost-effectively (e.g. the NYC 2nd ave subway is roughly four times more expensive per mile than similar projects in other countries, including very expensive countries like Japan). There are various reasons for this, but a lot of it seems to be dysfunctional bidding rules etc. that result in few bids and poor methods for choosing the winner. Other countries manage to do similar projects for vastly lower costs, and it seems pretty likely that an intelligently run private project in the U.S. could also manage to do a good job of keeping costs down. [It's not just labor costs, etc either—total cost per mile is remarkably similar all over the world, both in cheap countries and expensive ones, except in the U.S.]
    - DennisP 13y ago
      And Musk is remarkably good at lowering costs on expensive projects.
rdl 13y ago
I'd rather see something essentially a ramjet-in-a-tube, similar to UW's RAMAC space cannon launcher. Essentially, a long tube filled with correct mixtures of natural gas and oxygen, where a double-cone shaped projectile is accelerated through external (railgun?) means into the breech, and then the compression of gas detonates it right behind the projectile, accelerating it like a ramjet at constant acceleration. For a shuttle, you deaccel by running in reverse from midpoint. It'd be like $100 in natural gas to send 100 people from SF to LA at mach. You'd have to build a low-pressure 1-4m diameter pipeline, totally something we know how to do already for water pipes and natural gas pipelines. If I had $50mm (or access to that level of capital), I'd probably build one as a LEO satellite launcher. Put 20kg satellites into LEO, full of Ka-band gear, for $100k each, several times a day, 365 days a year. On the side of a mountain in Kenya/Ethiopia/Somalia.
- venomsnake 13y ago
  How do you brake this thing in normal operation? How do you break this thing during emergency? Edit: Fixed typo
  - sounds 13y ago
    I think his proposed business model (a satellite launch service) would not concern itself with braking. If you needed to abort, your only chance would be after launch. So this would probably not be useful for human cargo.
    - Groxx 13y ago
      >I think his proposed business model (a satellite launch service) would not concern itself with braking. I didn't interpret it that way: >It'd be like $100 in natural gas to send 100 people from SF to LA at mach.
      - sounds 13y ago
        Ok, fair enough. I wasn't taking that sentence very seriously. I suppose he could try to get people to ride it, especially if he only operated out of a country where the regulations were lax enough. No way he could do that in SF or LA though.
ricardobeat 13y ago
This was the most thrown around idea right around when the Hyperloop story came up. Nothing new here. He also publicy said “It is not an evacuated tunnel”. Previous discussion: https://news.ycombinator.com/item?id=4815665 https://news.ycombinator.com/item?id=4815665, https://news.ycombinator.com/item?id=4806059 https://news.ycombinator.com/item?id=4806059 and https://news.ycombinator.com/item?id=4813416 https://news.ycombinator.com/item?id=4813416
- FD3SA 13y ago
  Indeed, putting the old clues together with his new hints narrows it done quite precisely. It will be a Ground Effect lifting body on an electromagnetic rail. The lift is provided by aerodynamic effects, and thrust is provided by electromagnetic force. Based on the details of the design, it would be capable of supersonic speeds like the Concord, while employing Ground Effect like an air hockey table, and propelled like a Rail Gun. The biggest challenges will be keeping the vehicle stable and at a constant distance from the power rail at high speeds, as aerodynamic disturbances can destabilize the vehicle. Given Elon's expertise with rockets, this should not be too difficult. EDIT: An prototype of a ground effect train: http://www.youtube.com/watch?v=EaOnrIRf_Mg http://www.youtube.com/watch?v=EaOnrIRf_Mg Elon's will use electromagnetic propulsion instead of electric fans. EDIT 2: I just realized this may be Elon's electric jet idea. He may use a ram-air electric jet at high speeds, and only use the power rail to get the vehicle to supersonic speeds where the ram-air engines are most efficient. This would make it MUCH cheaper than maglev by eliminating the power rail on the majority of the track. EDIT 3: Rail gun diagram. http://www.howstuffworks.com/rail-gun1.htm http://www.howstuffworks.com/rail-gun1.htm The walls of the guideway will likely house the propulsion system.
  - InclinedPlane 13y ago
    Musk has said that his idea of the hyperloop involves a system that "can never crash". Assuming that he's not just talking about really robust safety protocols and instead is referring to some inherent property of the system I think there's probably some missing detail here. Although I think overall this is probably pretty close.
Groxx 13y ago
>The VHST would have to be underground. Anyone have any idea why? It seems to me like seismic shifting underground would be many times worse than above-ground, if only because you have to dig to make room (either before or after such shifts).
- sounds 13y ago
  NORAD and the LHC are examples of successful underground projects that have addressed the seismic issues. I agree with you that to reach the level of safety consumers will demand, more thought needs to go into it. But it's not impossible, which was kind of in line with what the article was saying.
  - Groxx 13y ago
    Are there earthquakes around NORAD (it has long underground tubes?) and the LHC? I really have no idea, and Google is failing me (and it's slow going, very bad internet connection at the moment). And I feel I should point out that the LHC doesn't cross major fault-lines like any trans-USA transportation system would have to do (or even SF to LA, which is explicitly used as an example, and presumably that's much easier than LA to NY (which also crosses the San Andreas fault line)). Anyway, I'm questioning underground tubes in places where the earth moves at "about 33 to 37 millimeters (1.3 to 1.5 in) a year across California."[1]. While that's not much per year, it adds up, and presumably such a large project would be built to last more than a couple decades (or plan for fairly routine major construction work to keep things straight). [1] https://en.wikipedia.org/wiki/San_Andreas_Fault#Plate_movement https://en.wikipedia.org/wiki/San_Andreas_Fault#Plate_moveme...
    - dm2 13y ago
      This search has some good links: https://www.google.com/search?q=effect+of+earthquakes+on+tunnels https://www.google.com/search?q=effect+of+earthquakes+on+tun... I don't have a structural engineering background so I'm having a tough time imagining how someone could make a train-track or hardened tunnel "flexible" but I'm sure there are many ways. It doesn't seem too hard to predict the movement of the plates and build in automatic adjustments for the track/tunnel. Have a way to automatically extend track/tunnel and move it laterally to adjust for any minor plate movement. It seems like it would be cheaper and just as effective to build higher speed rail beside of existing rail lines. Or maybe some sort of independently powered train cars that are private so that there are no unnecessary stops, more automated, and can travel faster. Train tracks likely already have to compensate for the faults somehow, though their probably slightly simpler. Regenerative breaking would be nifty technology to build into the trains/cars/vehicles and musk has teams with significant experience in these fields. I imagine that, with all the of top-tier engineers that Musk has on his payroll at tesla, spacex, and solarcity, he can get plenty of suggestions for how to overcome or prevent several feet of movement in the track, humans have done more complicated stuff than that. Then make sure to make redundancy and backup of backups to prevent loss of life and help prevent gridlock in the event of a major disaster (vehicles could go backwards maybe?).
cookingrobot 13y ago
As long as we're guessing, here's my idea. An electrically propelled train in a tube. Instead of evacuating the tunnel you have ducts in the walls that vent the high-pressure air from in front of the train to the low-pressure sides/bottom/rear of the train. This should reduce the energy wasted trying to push a shockwave through the tunnel, and would use the air pressure to keep the train off the walls. This would fit with his "air-hockey" comment, and wouldn't be an evacuated tunnel - which he said it isn't. edit: And the "loop" part of the name is because the air ducts are loops the same length as the train. They move the air directly from in front where it's high pressure to the rear where it's low pressure.
- nitrogen 13y ago
  My guess: Musk is throwing random keywords at the Internet, then feeding all the speculative ideas generated by smart geeks to his engineering team until they come up with the real product ;-).
  - nickik 13y ago
    The Hivemind is read.
  - nitrogen 13y ago
    After I posted this, I noticed a top level comment with the same idea from an account that's been dead for nearly two years, apparently for posting an Office Space joke: stiller 3 hours ago | link [dead] At this rate, Elon can simply wait until somebody comes up with a viable plan and say, "yes, that's what Hyperloop was all along." https://news.ycombinator.com/user?id=stiller https://news.ycombinator.com/user?id=stiller
  - saraid216 13y ago
    Robert Jordan actually joked he did this with his novels. He'd just read fansites to see what was the most plausible explanation for an event and go with it.
- mbenjaminsmith 13y ago
  I would go one step further and say that the mechanism you describe would also keep the train off the floor (and would possibly be handled by the train, not the tunnel). It seems to me that using electromagnets for propulsion only and not for levitation would drastically reduce costs. I could only guess at the aerodynamics but I have a feeling you could just give the train a flat bottom and make the end of the train pointed like the intake of a jet engine. At speed it would compress the air and force it between the train and the floor of the tube in a way similar to how an air bearing functions. (Actually all sides, assuming it was rectangular, would work in the same way.)
stiller 13y ago
At this rate, Elon can simply wait until somebody comes up with a viable plan and say, "yes, that's what Hyperloop was all along."
alwaysinshade 13y ago
> Hyperloop is a “cross between a Concorde, a railgun and an air hockey table.” I'm thinking Wing in Ground Effect [1], where small vehicles are launched to supersonic speeds using electromagnetic slings (and perhaps then use their own power to super-cruise to the destination and eventually decelerate). You wouldn't need much infrastructure - the cost would be in the vehicles and launching mechanisms. [1] http://en.wikipedia.org/wiki/Wing_In_Ground_Effect http://en.wikipedia.org/wiki/Wing_In_Ground_Effect
- schiffern 13y ago
  That doesn't sound very "immune to weather" to me.
- omegant 13y ago
  It must be inmune to weather and take into account that it will be supersonic at least, so it must be covered. Also Elon is very good at going to the basics of the problem like: -Cost of installing the system -pass rights -cost of raw material -current state of technology (lots of legacy tech on transportation) and "easy" improvements of Efficiency with improved implementation. Given that thanks to his actual business he has great knowledge of high speed aerodinamics, electromagnetism electrical propulsion and energy storage.. My bet is towards an elevated light tube (not vacuum) that works as a induction propulsor for the vehicle and condensor battery(you may use solar panels on top to recharge it). Also it insulates the "train-plane" from the weather and the exterior from the sonic shock. The vehicle will be like a electromagnetic train but just for impulsion and braking, it will use the shock waves and ground effect to hold the weight and stabilization. That way the electromagnetic fields don't need to be generated with expensive systems. The tube could use high voltage lines right of way and some simple metal towers to hold the actual system. I don't know if it makes sense but if something like this really can work it will be way cheaper that current high speed trains, vacuum capable tube or spinning megatons of steel at high speed through highly populated areas(a mechanical failure has the capability of wiping entire neighborhoods like a wire lawn mower).
SuperChihuahua 13y ago
While that article says it will take 21 minutes to travel from LA to NY, Elon explained that the Hyperloop will make you travel from LA to SF in less than 30 minutes. It's a matter of definition, but I believe the Hyperloop is slower.
rayiner 13y ago
You have to love a guy you looks at massive, capital-intensive projects and thinks "I should do that" instead of "shit let's do something easier."
- abcd_f 13y ago
  Let's do a beautiful ToDo app :)
  - vidarh 13y ago
    I sometimes think the perfect todo app is harder than colonising Mars.
    - yen223 13y ago
      It really isn't.
      - XaspR8d 13y ago
        It's hard to say when neither has been done yet.
      - deleted 13y ago
        [deleted]
      - vidarh 13y ago
        I'll believe that if someone manages to make a perfect todo app before Mars is colonised. I very much doubt I'll see that happen.
    - peterjancelis 13y ago
      In that case I'm all for a future with imperfect todo apps.
    - prof_hobart 13y ago
      I think the problem is that most people at least have a reasonably clear idea on what colonising Mars would look like. I doubt that there's two people on Earth who agree on exactly what a todo app should do.
deftnerd 13y ago
A previous HN discussion brought up the possibility of a Launch Loop and several descriptions of that proposal seem to fit very well. A Launch Loop is an iron cable just 2 inches thick that runs inside of a sheath at tens of thousands of miles an hour. The sheath has electromagnets inside of it to accelerates the cable. The motion of the cable would cause the loop to curve and raise into the sky. To outside observers, it would look like a giant version of the St. Louis arch with the peak nearly in low earth orbit, but only a few inches thick. The magic comes with the fact that the iron cable can be used for travel by using electromagnetic attraction to the iron cable through the sheath. What's interesting is that while there are several engineering challenges, unlike a space elevator, this wouldn't require any materials technologies that don't already exist today. The iron cable could be made by existing forges that make the cabling for bridges, and the electromagnetic sheath could borrow a lot of existing technologies from the hard drive manufacturing industry. It would also fit with his previous work on Space X and Solar Cities to some extent. A launch loop can be used to transport cargo or passengers high enough that the energy required to get them into orbit is very inexpensive, which ties into his Space X work. The external sheath of the Launch Loop could have solar panels on it to power the electromagnets that help keep the loop in motion, and even when the sun goes down, millions of tons of iron spinning like a flywheel has enough kinetic energy to keep going until the sun rises again. I wouldn't be surprised if he ran across the concept when he was researching ways to get into space before he founded Space X, and it's his "Step 2". Lastly, if you had a giant cable stretched across the sky that worked kind of like a bicycle brake cable in its sheath, but the cable was running through the system at 30k mph in a giant loop, what better name than Hyperloop? It also explains why a trip that he describes as being twice as fast as an airplane would take 30 minutes. It takes more time to go to LEO and back down Keep an eye out for Musk buying any patents on electromagnetics or him buying a oceanic cable-laying ship. http://en.wikipedia.org/wiki/Launch_loop http://en.wikipedia.org/wiki/Launch_loop
- btilly 13y ago
  That suggestion fits amazingly well. I have no idea how I missed that previous HN discussion, but I must have. Because I'd remember if I'd seen that suggestion.
richtr 13y ago
Since we are generally speculating here, is there any possibility the Hyperloop could be a suborbital craft to escape the atmosphere and thus reduce journey times dramatically. That doesn't really work for "San Francisco to LA" but Richard Branson has mentioned this as an objective for Virgin Galactic "within the next 20 years". I'd be surprised if SpaceX, and hence Elon Musk, were not also looking in to this considering the technology they are creating.
- john_w_t_b 13y ago
  I hope this is it. Suborbital hops between cities would be a spectacular ride. Minimal ground infrastructure needed also.
oelmekki 13y ago
> History has shown that some obvious projects, such as tunneling under the English Channel proposed in the time of Napoleon, can be delayed for centuries because of political pressures I really don't see why, french empire and united kingdom were such good friends :) On a side note, I feel very sad to consider we could have a mean to travel the world at cheap cost for four decades, and it still cost a salary and sometime about 24h to go to the other side of the world. With all other things Musk has talked about, it really makes think humanity seriously lags.
- JackpotDen 13y ago
  If you want a good head screw, think about the Baghdad battery and the Antikythera mechanism. Now imagine if the Turing church hypothesis was figured out back then.
ck2 13y ago
This is like something you'd read in popular science a decade ago where they are theorizing the 22nd century. But people are very messy, annoying creatures. Imagine all the social problems of a typical jet or subway ride today, now put them in a closed tube across the country. The ride may take 30 minutes but the TSA line will be an hour to grope you. At best this would work for cargo. But we'll have automated, self-driving semitrailers decades before this ever happens.
BuddhaSource 13y ago
Elon Musk knows how to keep Tesla and himself in the news. Tesla is successful so far only because of his strategic marketing. People have build great stuff in the past but not really appreciated because they did not market well. There is huge learning from this. I personally like his execution.
- pbreit 13y ago
  Don't forget that the car itself got the highest rating ever from one of the most independent reviewing organizations in existence. But, yes, the marketing is pretty terrific, too.
presspot 13y ago
Standing on the downtown BART platforms you can't help but think about (and literally feel) the massive amounts of air being pushed around by the trains. An evacuated tunnel would do wonders for both efficiency and hair styles.
AliAdams 13y ago
Successfully isolating from earth movements would be my biggest worry about a project like that. The system is going to need a good bit of flexibility built in.
ubernostrum 13y ago
So he's going into the burrito business?
- bigiain 13y ago
  Exactly what I thought. (For those not "in" on the joke: http://idlewords.com/2007/04/the_alameda-weehawken_burrito_tunnel.htm http://idlewords.com/2007/04/the_alameda-weehawken_burrito_t... )
IvyMike 13y ago
Supposedly, sections of the East Side Access subway project in New York cost upwards of one million dollars per foot. I can't imagine how much a vacuum-sealed tunnel would cost.
- potatolicious 13y ago
  The costs of East Side Access is almost entirely due to tunneling deep under one of the most heavily built-up areas on the planet, without disruption to either above-ground or underground activities. Musk's system, if it works, will cost a bundle on this fact alone. Any corridor that would justify such a high speed system would also be stupidly expensive to build through, both to acquire the rights to, and to construct without completely destroying everything along its path.
deleted 13y ago
[deleted]
tachyonbeam 13y ago
The article makes it seem like politics are the only problem. Another problem is that this would be very very expensive. Magnetic levitation train tracks are already expensive. How much is it going to cost to build a vacuum tunnel with some sort of magnetic propulsion system built into the walls of it, not to mention the supporting infrastructure (vacuum pumps, power distribution, safety exits, maintenance tunnels)? Probably not achievable with the current cost of labor and parts (and all the overbilling happening everywhere). Then there's the danger. What if an earthquake happens? What if the tunnels leak and air or water seeps in? What if your magnetic stabilization system fails for a fraction of a second and your train floating at 14000MPH grazes against the sides of the tunnel? If an accident happened in one of those tunnels, it could easily kill everyone onboard, and disable the tunnel for months. It's a really nice and futuristic idea, the kind that would once again make the world a smaller place (commuting from SF to NY for work, anyone?), but it probably won't happen until we can really prove such a thing is safe, and we change from capitalism to an economical model where we build things like this because, you know, they're good for humanity as a whole. Personally I think a project like this would be good for the American economy, but then so would massive investment in solar power plants. Instead you guys gave fat checks to the banks.
danielmendoza 13y ago
Odd that this article popped up on Yahoo today: http://news.yahoo.com/blogs/trending-now/futuristic-high-speed-tube-travel-could-york-los-171007828.html?vp=1 http://news.yahoo.com/blogs/trending-now/futuristic-high-spe... "A company called ET3 has plans in the works for the Evacuated Tube Transport, a high-speed transportation tube that uses magnetic levitation."
Dnguyen 13y ago
Can I build a generator on top of this? Since it's a metal object, I just need to build some magnetic rings along the way, et voila!

228 points by wtracy 13y ago

He has already said it is not an evacuated tube though he chooses his words very carefully in all the talks I've seen. It comes up in just about every long interview he has done over the past year.

anologwintermut 13y ago

Lets assume it is some kind of maglev in a buried tunnel. How does this effect right-of-way? My understanding is the problem for building even a simple high speed train from LA to SF is principally NIMBYism and the resulting lawsuits . This causes costs to sky rocket as you get delays. Does digging a tunnel underground solve that ?

jacques_chester 13y ago
It will depend on the jurisdiction. In Australia, for example, what's under the ground generally belongs to the Crown in right of the particular State or Territory. In general, however, almost any amount of haggling, land resumption / compulsory purchase and rezoning is cheaper than building tunnels. We talk about disruptive startups. Bringing the cost of tunnels down by an order of magnitude would be fairly ... seismic. (Unfortunately, the Earth is restless and heartless).
venomsnake 13y ago
I suppose the authorities will just use air travel as precedent - nobody needs your permission to build air corridor above your house.
- sliverstorm 13y ago
  I think it's even simpler than that; when you own property, don't you typically only own a certain distance down into the ground?
  - RyJones 13y ago
    Depends if you have the mineral rights or not. You could argue that digging the tunnel is just a very inefficient way of mining your minerals (if you were a property owner, with mineral rights, wishing to stall the project). If you didn't own the mineral rights, there isn't much you could do if the tunnelers took care not to damage your (above ground) property. https://en.wikipedia.org/wiki/Mineral_rights https://en.wikipedia.org/wiki/Mineral_rights
- lmm 13y ago
  There were lawsuits over this when air travel was getting started.
  - twistedpair 13y ago
    Limits are above and below ground. The FAA has a limit of 2000ft on structures. Beyond that you'll need to go to the mat to get special dispensation to go higher.
tsotha 13y ago
It does, but when they dug a tunnel for the LA subway it cost a billion dollars per mile, so I'm hoping that's not his grand idea.
- snogglethorpe 13y ago
  Keep in mind that America is famously horrible at doing public projects of this sort cost-effectively (e.g. the NYC 2nd ave subway is roughly four times more expensive per mile than similar projects in other countries, including very expensive countries like Japan). There are various reasons for this, but a lot of it seems to be dysfunctional bidding rules etc. that result in few bids and poor methods for choosing the winner. Other countries manage to do similar projects for vastly lower costs, and it seems pretty likely that an intelligently run private project in the U.S. could also manage to do a good job of keeping costs down. [It's not just labor costs, etc either—total cost per mile is remarkably similar all over the world, both in cheap countries and expensive ones, except in the U.S.]
  - DennisP 13y ago
    And Musk is remarkably good at lowering costs on expensive projects.

rdl 13y ago

I'd rather see something essentially a ramjet-in-a-tube, similar to UW's RAMAC space cannon launcher. Essentially, a long tube filled with correct mixtures of natural gas and oxygen, where a double-cone shaped projectile is accelerated through external (railgun?) means into the breech, and then the compression of gas detonates it right behind the projectile, accelerating it like a ramjet at constant acceleration. For a shuttle, you deaccel by running in reverse from midpoint. It'd be like $100 in natural gas to send 100 people from SF to LA at mach. You'd have to build a low-pressure 1-4m diameter pipeline, totally something we know how to do already for water pipes and natural gas pipelines. If I had $50mm (or access to that level of capital), I'd probably build one as a LEO satellite launcher. Put 20kg satellites into LEO, full of Ka-band gear, for $100k each, several times a day, 365 days a year. On the side of a mountain in Kenya/Ethiopia/Somalia.

venomsnake 13y ago
How do you brake this thing in normal operation? How do you break this thing during emergency? Edit: Fixed typo
- sounds 13y ago
  I think his proposed business model (a satellite launch service) would not concern itself with braking. If you needed to abort, your only chance would be after launch. So this would probably not be useful for human cargo.
  - Groxx 13y ago
    >I think his proposed business model (a satellite launch service) would not concern itself with braking. I didn't interpret it that way: >It'd be like $100 in natural gas to send 100 people from SF to LA at mach.
    - sounds 13y ago
      Ok, fair enough. I wasn't taking that sentence very seriously. I suppose he could try to get people to ride it, especially if he only operated out of a country where the regulations were lax enough. No way he could do that in SF or LA though.

ricardobeat 13y ago

This was the most thrown around idea right around when the Hyperloop story came up. Nothing new here. He also publicy said “It is not an evacuated tunnel”. Previous discussion: https://news.ycombinator.com/item?id=4815665 https://news.ycombinator.com/item?id=4815665, https://news.ycombinator.com/item?id=4806059 https://news.ycombinator.com/item?id=4806059 and https://news.ycombinator.com/item?id=4813416 https://news.ycombinator.com/item?id=4813416

FD3SA 13y ago
Indeed, putting the old clues together with his new hints narrows it done quite precisely. It will be a Ground Effect lifting body on an electromagnetic rail. The lift is provided by aerodynamic effects, and thrust is provided by electromagnetic force. Based on the details of the design, it would be capable of supersonic speeds like the Concord, while employing Ground Effect like an air hockey table, and propelled like a Rail Gun. The biggest challenges will be keeping the vehicle stable and at a constant distance from the power rail at high speeds, as aerodynamic disturbances can destabilize the vehicle. Given Elon's expertise with rockets, this should not be too difficult. EDIT: An prototype of a ground effect train: http://www.youtube.com/watch?v=EaOnrIRf_Mg http://www.youtube.com/watch?v=EaOnrIRf_Mg Elon's will use electromagnetic propulsion instead of electric fans. EDIT 2: I just realized this may be Elon's electric jet idea. He may use a ram-air electric jet at high speeds, and only use the power rail to get the vehicle to supersonic speeds where the ram-air engines are most efficient. This would make it MUCH cheaper than maglev by eliminating the power rail on the majority of the track. EDIT 3: Rail gun diagram. http://www.howstuffworks.com/rail-gun1.htm http://www.howstuffworks.com/rail-gun1.htm The walls of the guideway will likely house the propulsion system.
- InclinedPlane 13y ago
  Musk has said that his idea of the hyperloop involves a system that "can never crash". Assuming that he's not just talking about really robust safety protocols and instead is referring to some inherent property of the system I think there's probably some missing detail here. Although I think overall this is probably pretty close.

Groxx 13y ago

>The VHST would have to be underground. Anyone have any idea why? It seems to me like seismic shifting underground would be many times worse than above-ground, if only because you have to dig to make room (either before or after such shifts).

sounds 13y ago
NORAD and the LHC are examples of successful underground projects that have addressed the seismic issues. I agree with you that to reach the level of safety consumers will demand, more thought needs to go into it. But it's not impossible, which was kind of in line with what the article was saying.
- Groxx 13y ago
  Are there earthquakes around NORAD (it has long underground tubes?) and the LHC? I really have no idea, and Google is failing me (and it's slow going, very bad internet connection at the moment). And I feel I should point out that the LHC doesn't cross major fault-lines like any trans-USA transportation system would have to do (or even SF to LA, which is explicitly used as an example, and presumably that's much easier than LA to NY (which also crosses the San Andreas fault line)). Anyway, I'm questioning underground tubes in places where the earth moves at "about 33 to 37 millimeters (1.3 to 1.5 in) a year across California."[1]. While that's not much per year, it adds up, and presumably such a large project would be built to last more than a couple decades (or plan for fairly routine major construction work to keep things straight). [1] https://en.wikipedia.org/wiki/San_Andreas_Fault#Plate_movement https://en.wikipedia.org/wiki/San_Andreas_Fault#Plate_moveme...
  - dm2 13y ago
    This search has some good links: https://www.google.com/search?q=effect+of+earthquakes+on+tunnels https://www.google.com/search?q=effect+of+earthquakes+on+tun... I don't have a structural engineering background so I'm having a tough time imagining how someone could make a train-track or hardened tunnel "flexible" but I'm sure there are many ways. It doesn't seem too hard to predict the movement of the plates and build in automatic adjustments for the track/tunnel. Have a way to automatically extend track/tunnel and move it laterally to adjust for any minor plate movement. It seems like it would be cheaper and just as effective to build higher speed rail beside of existing rail lines. Or maybe some sort of independently powered train cars that are private so that there are no unnecessary stops, more automated, and can travel faster. Train tracks likely already have to compensate for the faults somehow, though their probably slightly simpler. Regenerative breaking would be nifty technology to build into the trains/cars/vehicles and musk has teams with significant experience in these fields. I imagine that, with all the of top-tier engineers that Musk has on his payroll at tesla, spacex, and solarcity, he can get plenty of suggestions for how to overcome or prevent several feet of movement in the track, humans have done more complicated stuff than that. Then make sure to make redundancy and backup of backups to prevent loss of life and help prevent gridlock in the event of a major disaster (vehicles could go backwards maybe?).

cookingrobot 13y ago

As long as we're guessing, here's my idea. An electrically propelled train in a tube. Instead of evacuating the tunnel you have ducts in the walls that vent the high-pressure air from in front of the train to the low-pressure sides/bottom/rear of the train. This should reduce the energy wasted trying to push a shockwave through the tunnel, and would use the air pressure to keep the train off the walls. This would fit with his "air-hockey" comment, and wouldn't be an evacuated tunnel - which he said it isn't. edit: And the "loop" part of the name is because the air ducts are loops the same length as the train. They move the air directly from in front where it's high pressure to the rear where it's low pressure.

nitrogen 13y ago
My guess: Musk is throwing random keywords at the Internet, then feeding all the speculative ideas generated by smart geeks to his engineering team until they come up with the real product ;-).
- nickik 13y ago
  The Hivemind is read.
- nitrogen 13y ago
  After I posted this, I noticed a top level comment with the same idea from an account that's been dead for nearly two years, apparently for posting an Office Space joke: stiller 3 hours ago | link [dead] At this rate, Elon can simply wait until somebody comes up with a viable plan and say, "yes, that's what Hyperloop was all along." https://news.ycombinator.com/user?id=stiller https://news.ycombinator.com/user?id=stiller
- saraid216 13y ago
  Robert Jordan actually joked he did this with his novels. He'd just read fansites to see what was the most plausible explanation for an event and go with it.
mbenjaminsmith 13y ago
I would go one step further and say that the mechanism you describe would also keep the train off the floor (and would possibly be handled by the train, not the tunnel). It seems to me that using electromagnets for propulsion only and not for levitation would drastically reduce costs. I could only guess at the aerodynamics but I have a feeling you could just give the train a flat bottom and make the end of the train pointed like the intake of a jet engine. At speed it would compress the air and force it between the train and the floor of the tube in a way similar to how an air bearing functions. (Actually all sides, assuming it was rectangular, would work in the same way.)

stiller 13y ago

At this rate, Elon can simply wait until somebody comes up with a viable plan and say, "yes, that's what Hyperloop was all along."

alwaysinshade 13y ago

> Hyperloop is a “cross between a Concorde, a railgun and an air hockey table.” I'm thinking Wing in Ground Effect [1], where small vehicles are launched to supersonic speeds using electromagnetic slings (and perhaps then use their own power to super-cruise to the destination and eventually decelerate). You wouldn't need much infrastructure - the cost would be in the vehicles and launching mechanisms. [1] http://en.wikipedia.org/wiki/Wing_In_Ground_Effect http://en.wikipedia.org/wiki/Wing_In_Ground_Effect

schiffern 13y ago
That doesn't sound very "immune to weather" to me.
omegant 13y ago
It must be inmune to weather and take into account that it will be supersonic at least, so it must be covered. Also Elon is very good at going to the basics of the problem like: -Cost of installing the system -pass rights -cost of raw material -current state of technology (lots of legacy tech on transportation) and "easy" improvements of Efficiency with improved implementation. Given that thanks to his actual business he has great knowledge of high speed aerodinamics, electromagnetism electrical propulsion and energy storage.. My bet is towards an elevated light tube (not vacuum) that works as a induction propulsor for the vehicle and condensor battery(you may use solar panels on top to recharge it). Also it insulates the "train-plane" from the weather and the exterior from the sonic shock. The vehicle will be like a electromagnetic train but just for impulsion and braking, it will use the shock waves and ground effect to hold the weight and stabilization. That way the electromagnetic fields don't need to be generated with expensive systems. The tube could use high voltage lines right of way and some simple metal towers to hold the actual system. I don't know if it makes sense but if something like this really can work it will be way cheaper that current high speed trains, vacuum capable tube or spinning megatons of steel at high speed through highly populated areas(a mechanical failure has the capability of wiping entire neighborhoods like a wire lawn mower).

SuperChihuahua 13y ago

While that article says it will take 21 minutes to travel from LA to NY, Elon explained that the Hyperloop will make you travel from LA to SF in less than 30 minutes. It's a matter of definition, but I believe the Hyperloop is slower.

rayiner 13y ago

You have to love a guy you looks at massive, capital-intensive projects and thinks "I should do that" instead of "shit let's do something easier."

abcd_f 13y ago
Let's do a beautiful ToDo app :)
- vidarh 13y ago
  I sometimes think the perfect todo app is harder than colonising Mars.
  - yen223 13y ago
    It really isn't.
    - XaspR8d 13y ago
      It's hard to say when neither has been done yet.
    - deleted 13y ago
      [deleted]
    - vidarh 13y ago
      I'll believe that if someone manages to make a perfect todo app before Mars is colonised. I very much doubt I'll see that happen.
  - peterjancelis 13y ago
    In that case I'm all for a future with imperfect todo apps.
  - prof_hobart 13y ago
    I think the problem is that most people at least have a reasonably clear idea on what colonising Mars would look like. I doubt that there's two people on Earth who agree on exactly what a todo app should do.

deftnerd 13y ago

A previous HN discussion brought up the possibility of a Launch Loop and several descriptions of that proposal seem to fit very well. A Launch Loop is an iron cable just 2 inches thick that runs inside of a sheath at tens of thousands of miles an hour. The sheath has electromagnets inside of it to accelerates the cable. The motion of the cable would cause the loop to curve and raise into the sky. To outside observers, it would look like a giant version of the St. Louis arch with the peak nearly in low earth orbit, but only a few inches thick. The magic comes with the fact that the iron cable can be used for travel by using electromagnetic attraction to the iron cable through the sheath. What's interesting is that while there are several engineering challenges, unlike a space elevator, this wouldn't require any materials technologies that don't already exist today. The iron cable could be made by existing forges that make the cabling for bridges, and the electromagnetic sheath could borrow a lot of existing technologies from the hard drive manufacturing industry. It would also fit with his previous work on Space X and Solar Cities to some extent. A launch loop can be used to transport cargo or passengers high enough that the energy required to get them into orbit is very inexpensive, which ties into his Space X work. The external sheath of the Launch Loop could have solar panels on it to power the electromagnets that help keep the loop in motion, and even when the sun goes down, millions of tons of iron spinning like a flywheel has enough kinetic energy to keep going until the sun rises again. I wouldn't be surprised if he ran across the concept when he was researching ways to get into space before he founded Space X, and it's his "Step 2". Lastly, if you had a giant cable stretched across the sky that worked kind of like a bicycle brake cable in its sheath, but the cable was running through the system at 30k mph in a giant loop, what better name than Hyperloop? It also explains why a trip that he describes as being twice as fast as an airplane would take 30 minutes. It takes more time to go to LEO and back down Keep an eye out for Musk buying any patents on electromagnetics or him buying a oceanic cable-laying ship. http://en.wikipedia.org/wiki/Launch_loop http://en.wikipedia.org/wiki/Launch_loop

btilly 13y ago
That suggestion fits amazingly well. I have no idea how I missed that previous HN discussion, but I must have. Because I'd remember if I'd seen that suggestion.

richtr 13y ago

Since we are generally speculating here, is there any possibility the Hyperloop could be a suborbital craft to escape the atmosphere and thus reduce journey times dramatically. That doesn't really work for "San Francisco to LA" but Richard Branson has mentioned this as an objective for Virgin Galactic "within the next 20 years". I'd be surprised if SpaceX, and hence Elon Musk, were not also looking in to this considering the technology they are creating.

john_w_t_b 13y ago
I hope this is it. Suborbital hops between cities would be a spectacular ride. Minimal ground infrastructure needed also.

oelmekki 13y ago

> History has shown that some obvious projects, such as tunneling under the English Channel proposed in the time of Napoleon, can be delayed for centuries because of political pressures I really don't see why, french empire and united kingdom were such good friends :) On a side note, I feel very sad to consider we could have a mean to travel the world at cheap cost for four decades, and it still cost a salary and sometime about 24h to go to the other side of the world. With all other things Musk has talked about, it really makes think humanity seriously lags.

JackpotDen 13y ago
If you want a good head screw, think about the Baghdad battery and the Antikythera mechanism. Now imagine if the Turing church hypothesis was figured out back then.

ck2 13y ago

This is like something you'd read in popular science a decade ago where they are theorizing the 22nd century. But people are very messy, annoying creatures. Imagine all the social problems of a typical jet or subway ride today, now put them in a closed tube across the country. The ride may take 30 minutes but the TSA line will be an hour to grope you. At best this would work for cargo. But we'll have automated, self-driving semitrailers decades before this ever happens.

BuddhaSource 13y ago

Elon Musk knows how to keep Tesla and himself in the news. Tesla is successful so far only because of his strategic marketing. People have build great stuff in the past but not really appreciated because they did not market well. There is huge learning from this. I personally like his execution.

pbreit 13y ago
Don't forget that the car itself got the highest rating ever from one of the most independent reviewing organizations in existence. But, yes, the marketing is pretty terrific, too.

presspot 13y ago

Standing on the downtown BART platforms you can't help but think about (and literally feel) the massive amounts of air being pushed around by the trains. An evacuated tunnel would do wonders for both efficiency and hair styles.

AliAdams 13y ago

Successfully isolating from earth movements would be my biggest worry about a project like that. The system is going to need a good bit of flexibility built in.

ubernostrum 13y ago

So he's going into the burrito business?

bigiain 13y ago
Exactly what I thought. (For those not "in" on the joke: http://idlewords.com/2007/04/the_alameda-weehawken_burrito_tunnel.htm http://idlewords.com/2007/04/the_alameda-weehawken_burrito_t... )

IvyMike 13y ago

Supposedly, sections of the East Side Access subway project in New York cost upwards of one million dollars per foot. I can't imagine how much a vacuum-sealed tunnel would cost.

potatolicious 13y ago
The costs of East Side Access is almost entirely due to tunneling deep under one of the most heavily built-up areas on the planet, without disruption to either above-ground or underground activities. Musk's system, if it works, will cost a bundle on this fact alone. Any corridor that would justify such a high speed system would also be stupidly expensive to build through, both to acquire the rights to, and to construct without completely destroying everything along its path.

deleted 13y ago

[deleted]

tachyonbeam 13y ago

The article makes it seem like politics are the only problem. Another problem is that this would be very very expensive. Magnetic levitation train tracks are already expensive. How much is it going to cost to build a vacuum tunnel with some sort of magnetic propulsion system built into the walls of it, not to mention the supporting infrastructure (vacuum pumps, power distribution, safety exits, maintenance tunnels)? Probably not achievable with the current cost of labor and parts (and all the overbilling happening everywhere). Then there's the danger. What if an earthquake happens? What if the tunnels leak and air or water seeps in? What if your magnetic stabilization system fails for a fraction of a second and your train floating at 14000MPH grazes against the sides of the tunnel? If an accident happened in one of those tunnels, it could easily kill everyone onboard, and disable the tunnel for months. It's a really nice and futuristic idea, the kind that would once again make the world a smaller place (commuting from SF to NY for work, anyone?), but it probably won't happen until we can really prove such a thing is safe, and we change from capitalism to an economical model where we build things like this because, you know, they're good for humanity as a whole. Personally I think a project like this would be good for the American economy, but then so would massive investment in solar power plants. Instead you guys gave fat checks to the banks.

danielmendoza 13y ago

Odd that this article popped up on Yahoo today: http://news.yahoo.com/blogs/trending-now/futuristic-high-speed-tube-travel-could-york-los-171007828.html?vp=1 http://news.yahoo.com/blogs/trending-now/futuristic-high-spe... "A company called ET3 has plans in the works for the Evacuated Tube Transport, a high-speed transportation tube that uses magnetic levitation."

Dnguyen 13y ago

Can I build a generator on top of this? Since it's a metal object, I just need to build some magnetic rings along the way, et voila!