A 5-mile test track won't be big enough to examine the biggest concerns: thermal and seismic. The alpha brochure linked to in the OP barely touches on the two. Here [1] is a better analysis/take-down of what thermal issues such a long structure will encounter. (TL;DR: A 400-mile long continuous structure will need to accommodate 1000 feet of thermal movement over it's length and lifetime.) Seismic is another beast: it requires a much more thorough examination than the cursory glance it was given in the alpha paper.
Thermal expansion is not really an issue that gets worse with distance, as the track can simply be made from independent segments connected with expansion joints. The issue is being able to cross from segment A to segment B not the number of such segments. In other words if it works on a test track it scales just fine, but getting that first connector to work is the hard part.
Earthquakes require active dampening which defiantly increases costs, but a larger issue is how to cross fault lines as you need a very large turning radius so very long segments of track need to be able to move. AKA you can't do this: http://pubs.usgs.gov/fs/2003/fs014-03/pipeline.html Unless you’re willing to really slow down.
PS: Also of note, you are going to need safety exits on a fairly regular basis and some way to quickly add air to the pipe as people are not going to be able to walk hundreds of miles in case of an issue.
Thermal is an issue that gets worse with distance. Did you look at the article that I posted above? If you are proposing expansion/slip joints at every pier, that runs directly counter to the proposal which states that expansion joints will only be needed near the stations. [1, pg. 27] If we go according to the proposal, the slip joint at the stations on the test track will only need to accommodate ~9 feet of movement (5280x5x6.5x10^-6x100)/2 compared to something an order of magnitude higher for a full-scale track.
Successfully designing for earthquakes does not necessarily mean active damping. (That is, it is not "required" as you state.) Yes, many large structures use specially designed mass or viscous dampers for dynamic loading (Citigroup Building, NYC; Taipei 101; Millennium Bridge, London), but others are designed to fail safely such that life and structure are preserved to the greatest extent possible. Specifically for bridge structures, there is the notion of plastic hinging in visible locations. [2] This way, the failures can be identified and repaired before normal use resumes. Here are some relevant state DOT guidelines. [3]
Similarly the tube for the Hyperloop doesn't HAVE to free-float against its foundations. It might be easier or harder depending on various factors to work on expansion joints or doing the tube equivalent of CWR. You'd probably work on both to figure out which is easier in the long run.
Considering that it's a 9-11ft diameter tube with about 1" wall thickness, it's going to be pretty stiff, especially relative to traditional rails. The moment of inertia means that it should be very resistance to bending or buckling under compression and under tension steel is usually very good.
Given that there are going to be plenty of turns that the track has to make, I would look at doing a combination of two things:
1. Working towards a CWR style solution
2. Allow some movement so that the corners can take up the slack as the tube expands
The turns are very gradual and sweeping. But you could imagine that there's a virtual intersection between two straight portions that you determine by drawing lines from the straight portions until they meet. The actual turn will take place far from here, but it's instructive. So as the tube expands, the actual curve is going to move ever so slightly from the neutral position towards the virtual intersection. So long as there is enough room on the pylons to accommodate this, things will be pretty good. The tube will go from being curved 0.1 degrees per 100 feet to 0.105 degrees per 100 feet (or something like this) but this can be designed for and ensured that it doesn't cause the tube to buckle or collapse. It's engineering, not the utter unknown.
That is one of the coolest articles on field engineering I've seen in a while. Thanks a lot for sharing it - it really brings out how something like the hyperloop can be tackled. So far, thermal effects have been my main point of curiosity, but the idea of calibrating the steel to take care of it will likely be the ... easiest? way around the problem.
At their desired vacuum pressures, the steel doesn't need to be anything special, so I would love to see the mechanical engineering that goes into designing the 5 mile track's materials.
The engineering to do a 5 mile section is pretty straightforward. It's only 5 miles long (25000 feet) and around 250 joints.
1. Giant foundations and just handle the thermal stress by not letting anything move
2. Figure out the slip joints really well to soak up the ~125 feet of travel and still hold a good vacuum
3. Figure them out OK and just install extra vacuum pumps since there are only ~250 joints
4. Try out some/all of these options on 500 feet of tube in parallel to see how it all performs and don't make a final decision on the whole 5 miles until you have real cost numbers
The other thing I'll mention is that you don't need the steel to be continuous in order to hold a vacuum. You need the inside face of the tube to be smooth in order to not jerk around the vehicles, but all the sealing could be done on the outside with clamp-on seals. If the average continuous tube piece is 100 feet long and the max thermal expansion is 0.5% then you only need a half-inch gap between the tube pieces.
If your air bearings are say 3 feet long each and divided into 10 sections internally which are fed through orifices so that no one section can rob all the pressurized air flow then you're never going to lose more than 10% of your bearing force and you should be able to glide right over these 1/2" gaps with no problems. And if there are some problems a few accumulators (plain air tanks or pressurized bladders) inline with the supply lines would probably increase the momentary recharge capabilities enough to negate the problem.
700mph is 1000 feet per second or 12 inches per millisecond. That means a 1/2" gap is crossed in just 40 microseconds or so.
Thank you for the additional info. I am skeptical merely because they were quite hand-wavy about temperature accommodations, and it certainly is/was simplistic to think that ALL thermal movements can be accommodated for only at stations. (Especially if it's a direct and exclusive SF-LA route) Yes, the cross-sectional properties of the tube are going to be phenomenal, but I've always operated under the assumption that you don't try to resist thermal movements, regardless of the strength of the cross-section. You let them dissipate and design for the deflection (e.g., at the bearings and abutments), rather than the stress (buckling/tensile) in the beam. If we start allowing stress to develop in the superstructure tube, I can't imagine what the cyclic fatigue impacts of that temperature stress will be. (Maybe it's not significant...)
I am no rail expert (though I am a civil/structural guy), but even continuous welded rail isn't always continuous for hundreds of miles. [1] I think that there are two factors at play: continuity in the maglev/rail structures, and continuity in the superstructure/tube. I do not know what maglev devices look like, but if they do look like traditional rail, then agreed that a CWR solution seems to be the way to go. That being said, no matter how stiff the tube is, it too will have to accommodate thermal movement. My gut reaction is to call everything tube related simply supported, allow for (6.5x10^-6x100ft.x100deg = 0.065 feet) ~= 0.75" of expansion or contraction at each pier, and surround this expansion zone with a metal sleeve of 2"+ greater diameter than the main tube. Simply supported, multi-span structures are a well-studied problem. Adding in the continuity of the rail/maglev structures are what make it hairy, IMO, and the interplay between seismic considerations and thermal considerations becomes important. As far as I can see, it's very important for the maglev structures to be continuous to ensure for smoothness and speed of the ride.
For example, given that you make the superstructure spans simply supported, you have these nearly perfect "mass-on-a-stick" seismic models with well defined, and relatively short periods. Then, you have much longer continuous sections of rail/maglev equipment that contain releases on a far fewer number of span segments. These will have much longer periods of vibration. Maybe I'm stretching here, but the connections between the maglev/rail and superstructure seem like a place that is rife with potential for failure and stress during a seismic event. (I would not want a life-safety issue being my most prominent failure point.)
If you're dealing with bridges or buildings then you're right of course, you don't stress anything and you just let the stress dissipate through various movements.
But thermal stresses are very small, for "normal" steel it's 13e-6 per degree C. If you figure that the temperature variations in CA aren't going to be more than say 40C (and that's probably too much) then you're looking at 520e-6 or basically 5e-4.
As far as strain goes, that's not a terribly big number at less than 0.1% especially considering that most of the stress/strain graphs will go up to 10% or more and the first 1% are usually WELL within the linear elastic region. That means that you're talking about doing perhaps only using a few ksi of the steel's strength for the thermal effects.
Excuse my arcane units, but it is what I am familiar with:
ΔL=αΔtL; ΔL/L=αΔt; ϵ=ΔL/L; ϵ=αΔt; E=f/ϵ; f=ϵ/E; so f=αΔtE
ΔL = change in length due to temperature
L = restrained length
f = stress that arises due to full restraint
E = Young’s modulus
ϵ= strain
α= coefficient of linear thermal expansion
Using AASHTO numbers for structural steel:
f= 6.5x10^-6 (1/F)* 100 F * 29000 ksi = 18.85 ksi
That's a big chunk of the elastic 50 ksi range, and it's greater than a good portion of the allowable ranges from the table on page 41 of this PDF [1]. As you might already seem to know, AASHTO doesn't consider temperature loading for fatigue limit states, and in the Strength limit states it considers the force effects to be halved. (Though the displacement effects are multiplied by 1.2) Regardless, fully restraining these things at their ends doesn't seem like a good idea. Am I missing something in what you're talking about? Yes, the strain is low but fatigue generally works in terms of stresses.
So I guess it depends a lot on the kind of steel that you're using and what you're designing to. Do you need the full 100F range? Can you get a lower expanding steel for a nominal price increase if you're going to buy many mill run's worth? Are you going to have to build to bridge standards, or can you get away with something else? It's sort-of a bridge, but sort-of not. From a technical perspective you don't need as much safety factor since you've in total control of the vehicle load which isn't true on bridges. I don't know what the regulatory considerations on safety factor are especially since it would probably qualify for its own category since it bears little resemblance to anything that's man-rated like bridges or buildings.
You might also be able to get some nice double-whammy effects from using something like a514 since it's corrosion resistant, has a higher elastic yield, and may well have a reduced thermal expansion coefficient. If you increase the strength and decrease the expansion at the same time then instead of blowing 40% of your "budget" on thermal it might only be 10%. And since you're covering such a large range of climates you might be able to rate every 10 or 20 miles of loop based on the climatic averages in that region instead of looking at the absolute min and absolute max for the whole thing. It might add a few extra weeks of design but make things a lot more feasible.
Correct me if I'm wrong, but the linear elastic region usually ends somewhere around 0.2-5%, meaning 1% strain is not well within the linear elastic region. If you just do σ_y/E, you'll get the yield strain. Using rmxt's numbers you get 0.17% yield strain. Using [1] for 1018 steel you get 0.155% yield strain. The strains you calculated are not insignificant.
I guess it depends on the material you're looking at. The system designer would probably be the best person to ask. Are you going to make it out of 1018 or a36, or are you going to use something that's higher performance? Does the increased cost of the stronger steel get offset by the reduced weight?
You can get a36 for about $1/lb in small quantities. You can get corten (a588) for about $2/lb in small quantities. But the a588 has a yield strength about 50% higher than the a36, so strength-for-strength it's a pretty decent deal.
If you need 1" of a36 then you're going to need only 2/3" of a588 so it's only 33% more expensive. Combine that with the weathering properties which can reduce your maintenance intervals substantially (this is the same steel they make sea containers out of) and your lifetime cost might well be lower.
Further since your tubes now weigh less you might be able to get away with either smaller pylons or greater pylon spacing, both of which might be advantageous.
So you're right that the strain is non-trivial but that's only if you pick basically the toughest, least strong steel available. It's pretty easy to go stronger and to not lose too much toughness and gain other desirable features such as corrosion resistance, and in the process make the strain less significant relative to the elastic region.
If their test has a station every X feet, then the track needs to follow that same rule. Granted, if they suggest you can build a test track station every X feet and the full scale model over 10x feet then that's an issue with their model. But, again it does not get worse due to the total number of stations just the ratio of stations to track.
Anyway, you don't need active dampening to keep the structure intact, but a 750mph vehicle suddenly needing to lift 10 feet in the air you’re going to need a lot of head room not to hit the top of the tube. Not to mention rapid left right displacement. Granted, cost/benifit let em die yada yada.
The design only calls for one station at each end. Many people have said that the best way to deal with thermal expansion is to let the ends (at the 2 stations) move ~500 feet at each end. The alternative is expansion joint every so often along the tube.
If you do that, though, then all of your support structures the whole way through need to allow the tube to move inside of them. The tube is supposed to be supported every 100 feet or so (if I remember correctly) so that means that the last pylon has to be at least 500 feet from the station and that the tube has to be able to slide inside the support.
I suspect that you'd see a lot of wear on the tube that's sliding over the pylon supports as it might go through at least one if not several heating and cooling cycles daily. I could see two cycles if you've got side heating after dawn, midday shade under the solar panels, and then late afternoon heating after the solar panels stop casting a shadow over the tube. You might get another cycle if you have two parallel tubes with two parallel lines of solar panels above them.
I think that there are a lot of options for reducing friction wear. My first thought would be to put wheels between the tube an its supports (attached to the supports, not the tube).
You're increasing the cost a lot there because the wheels need to be on bearings because you've going to have to hold the tube with some amount of preload. You can't just let it rest on the wheels, the wheels have to be pressed onto the tube at all times because the vehicle is moving very fast and any kind of minute deviation up or down will result in substantial forces between the tube and the vehicle which have to be transmitted through the wheels and into the foundation and eventually into the ground.
So now you have wheels, bearings, preload springs, hinges, travel arms, etc. Instead of a big piece of plate that is welded to the tube and bolted to the foundation you're talking about a big apparatus with moving parts and precision bearings. The plate and welding might cost $500 per. The other might cost $20k apiece. A person can buy a lot of rebar and concrete and forms and whatnot for $20k.
I don't imagine any sort of suspension would be needed. The system is always loaded (with only a slight increase when the vehicle is over a given support because the tube is most of the weight). It needs bearings, but they don't have to move quickly or be particularly low friction. Even if the bearings failed the tube would just slide; you would want to replace them before too much wear, but it would not be urgent.
If that is too complicated, just put in replaceable slide plates. More regular maintenance, but fewer moving parts.
But don't we have a window of minutes to shut down the system in case of an earthquake? I thought we could get advance warning from P waves. (This doesn't work if you're in the epicenter, unfortunately.)
If the car gets badly damaged, but the passenger stays alive, and the system can be fixed in a reasonable amount of time, then this is fine performance for a major earthquake event. High speed trains have similar performance in the same situation.
> But don't we have a window of minutes to shut down the system in case of an earthquake?
No.
> I thought we could get advance warning from P waves. (This doesn't work if you're in the epicenter, unfortunately.)
Yes, but the advance warning is on the order of seconds, not minutes (per Wikipedia, for deep, distant, large earthquakes, 60-90 seconds is possible, but that's still at most a minute and a half.)
Even so, I thought that the failure mode for tube misalignment of hundredths or even tenths of an inch would result in stoppage, and perhaps damaged "track" and cars, with trapped passengers. This isn't so different from the performance of high speed rail during natural disasters.
I'd imagine that there's a great deal of prior work, research, and implementation detail on Maglev trains in Japan on this very issue. Not to say that you're not right, but that this test track is probably precisely what's needed for an initial test, since the other issues (commonly solved with expansion joints) are being actively tackled/solved by many different industries.
According to Wikipedia [1], the only 3 passenger service operational Maglev lines have lengths of 18.95 miles, 5.5 miles, and 3.8 miles, which are in China, Japan and South Korea respectively. That would make it seem like it is far from a "solved" issue.
They have a web site.[1] They claim to be hiring. They claim to have funding. The web site looks like someone loaded up the generic cool new startup template and stuck in some concept art in the indicated places. There's no useful information about the technology or the business.
The big problem with this is not the technology. It's land acquisition. As with high speed rail, you need a right of way that's straight or has very large radius turns. There are sections of I-5 that are straight enough, but high-speed travel between Bakersfield and Tracy isn't that useful. Tunnels can help, but are not cheap.
China is building high speed rail through urban areas on pylons. As with most elevated rail, the reality is much wider and more heavily built than the concept art. (China's maglev is a one-off demo; China's high speed rail system is huge.)
This is not Musks project, this is a collective of unpaid academics backed by a kickstarter knockoff and a PR firm in El Segundo
"Now, the company Hyperloop Transportation Technologies Inc. (which is not affiliated with Musk or Tesla) "
Musk is building his own
"Separately, Musk has said he plans to build his own 5-mile test track, likely in Texas, for companies and students to test out potential Hyperloop designs."
They are going to do what they did to my friends project. Parade the techies around, get it funded, and then "lose" half the money
"he 5-mile test track is estimated to cost about $100 million, which Hyperloop Transportation Technologies hopes to pay for with its initial public offering (IPO) later this year, according to Navigant's blog. "
Land while probably an inevitable hot topic, is not actually what would classify as a problem for a project that if sees full scale deployment will most surely have government backing thanks to eminent domain. Yes, the project will still be expensive, but any land owner that tries to be a hold out in selling isn't going to prevent the project.
Well the team seems to be comprised of some former engineers from SpaceX and the board has some deep pockets. Its possible they have connections to Musk and some insight on how to launch grandiose projects.
"The 5-mile test track is estimated to cost about $100 million, which Hyperloop Transportation Technologies hopes to pay for with its initial public offering (IPO) later this year, according to Navigant's blog."
Run away, run far far away. They might as well do a kickstarter. Seriously, what sort of "business" is a 5 mile test track?
Lets say you charged $25 for a "5 minute ride on the hyperloop!" and you got 8 people in it, and you had perfect efficiency, and you ran non-stop for 10 hrs a day, 7 days a week then $100M is 414 days. And that isn't including the cost of running the ride in the first place. I guess I'll find out why they think I should think about investing in their S-1 but for right now, I am totally not seeing it.
Well obviously the end goal for Hyperloop Transportation Technologies isn't to run a 5-mile test track amusement park. It's a test track, quite simply a test to work out the kinks and try and make hyperloop a real thing. It almost certainly won't work, but at scale it would be big dollar territory (California's high speed rail effort alone is $68 billion and China is spending many times that).
As an IPO this sounds similar to most biotech/pharma startups. These companies routinely IPO in the $50-100 million range when all they have is a patent, some promising data but no approved clinical trials and no business.
Of course it's different because there's a clear post-IPO acquisition market for biotechs. Not quite as clear who would buy Hyperloop if it's proven to work...
Meh. If I give you $100 for a 1*10^-6% stake in your company with a guarantee that you will pay me back at least $100 before honoring any other debts or issue, are you really a ten billion dollar startup?
It's most entertaining to subtract any preference off the top of the valuation. I wish it became a trend. Particularly for preferences with multipliers!
The purpose would be to learn more about the inevitable practical problems that come up between a system concept that pencils out to be more efficient and a real operating system. I think we stand on the shoulders of giants giving an incredible science and tech foundation to work upon. However, all that knowledge can give us a false sense of how difficult it is to cross into unknown territory (e.g. when assembling a new system from well understood elements, like hyperloop).
I understand the purpose, but what I don't understand yet is why would you ask retail investors to fund it at this level of risk? Remember, these guys aren't associated with Musk in any way [1], they are just taking the ball and running with it. So huge risk, probably going to flame out, very small chance they become the folks with the 'expertise' in building Hyperloop type systems and thus the primary engineering contractor for building them.
Since they aren't one of the big engineering infrastructure companies (Halliburton, Bechtel, Etc.) its unclear what they can do if they run into hiccups (like say nobody can fabricate the parts they need).
So do a $100M series A? Sure I could see that, a collection of billionaires wishing to bet on them making something that can work, but we should have trained people in the 90's to not buy stock in companies that have no hope of revenue in the forseeable future. (and say what you will of the recent Tech IPO's they have all had revenue)
[1] "Now, the company Hyperloop Transportation Technologies Inc. (which is not affiliated with Musk or Tesla) has inked a deal with landowners in central California to build the world's first Hyperloop test track"
As long as the investment context is disclosed, why shouldn't there be long range, high-risk investments available in the market to interested buyers?
Edit: I agree with you that the risk is very, very high. But, it at least gives a non-zero potential for investment return - which on that level is better than, say, Kickstarter.
This statement : "why shouldn't there be long range, high-risk investments available in the market to interested buyers?"
Implies that they are not, and it is not true. Long range, high risk investments are available to any interested buyer.
Generally the challenge that comes up is that the SEC has set standards for someone to meet in order to be a "qualified" investor. Some people interpret those standards as a way of "keeping people out" of investing, but that is not the case. They are there for two reasons, one so that when those people lose all of their investment they aren't "damaged" and more importantly so that unscrupulous sales people cannot dupe people who are unable to distinguish risk for themselves into investing.
So I understand when a smart person who is chafing under the restriction of not being qualified from preventing them from a certain investment. But they have to realize that they are not the ones being protected. The elderly who are being promised a "guaranteed" 20% return on the last of their life savings by a boiler room broker, they are being protected.
Further, qualifying, is simply a matter of building up your portfolio to demonstrate you have the knowledge and presence of mind to make those decisions and if they go badly you knew the risks. The youngest person I've met who was a qualified investor was one pretty much right out of high school. He had started with $5,000 in a Charles Schwab account (his college fund) and moved it over to E-Trade when it was at $30,000 and was over a million about a year after he had graduated high school. He read a lot, developed a much deeper understanding of finance than I will probably ever have, and showed me just what was possible for someone determined to get there. Nearly every day there are stocks that move up by more than a few percent, and if you can anticipate that movement more often than not you can move a portfolio along.
And I would have no trouble whatsoever with these guys on a road show trying to drum up investment. And as I've said I'll read their S-1 with interest. I would not want them to do this raise on the general market because that opens up defenseless people to get hurt by folks who just want to push shares.
I'm no expert in this area, but when you mention qualified investors, I think you're describing private investment where qualified investors are required because those investments otherwise have a much lower bar of disclosure and analysis. The thought is investors there need additional protection and if you're qualified you can fend for yourself.
On the public market, the disclosure requirements are much higher, and you're more likely to find analysis, public articles and reports or other analysis you can buy. As far as I know, there's no qualified investor provision for buying stocks on the public market. In the end you can personally wish this company doesn't offer an IPO, but I don't think there's any systematic rule that prevents it as long as they file all the required disclosures and find a financial firm willing to do the administrative work of putting the shares on the public market. (Again though I'm no expert here... so it would be interesting to learn more.)
On the public market, one could class many tech companies in the long-term, high risk, show little to no profit category.
Selling an unready product to retail investors indicates more of a desire to pay themselves six figure dalaires for 5 years and then somberly declare the thing a failure.
This reminds me of the Seattle Monorail, which continues to operate today. For a few dollars, you can ride swiftly and smoothly from one part of Downtown Seattle to another part of Downtown Seattle.
Some day, scientists hope, the value of the monorail will be seen. That day, we expect to extend the rail line to other communities. Meanwhile, we just pulled a tunneling machine out of its boring hole, continue to expand the Link Light Rail system, and are developing various trolley-based solutions such as the ones in South Lake Union and First Hill.
not a great use of transportation dollars, think of how many EV buses they could buy, which on the whole buses tend to go where people want and do it more often than light rail which not only costs a fortune to build but maintain as well
We had a mayor (McGinn) that wanted to connect neighborhoods with light rail and trolleys. We voted him out to get the crazy tunnel plan. And after spending all this money, we're going ahead with light rail and trolleys.
Everyone's been hearing about Bertha and the tunnel calamity, but almost nobody's heard about the trolley that connects 6 neighborhoods, was installed in about 6 months, and it's already done.
I won't defend that project specifically because I know nothing about it, but I would like to offer a couple of comments:
As a passenger, I have always found the experience of riding rail to be far superior to riding a bus for a lot of reasons including but not limited to speed and comfort.
A train generally has much higher capacity than buses, and if well utilised, a lower operating cost per passenger. An ideal transport system will use trains for the high traffic trunk routes and a tightly integrated bus system as feeders for the train line. It should never be expressed as an either/or proposition. Both are necessary.
When traveling from Seattle to LA, Greyhound buses are better than Amtrak trains for several reasons: faster, cheaper, easier to book, and less risk of Civil Asset Forfeiture.
Amtrak does not qualify as a proper rail system . . . besides, the comment was clearly referring to municipal transit. For Seattle to LA, I can't imagine any rail system ever beating flying.
You should not. But a lot of (more positively thinking) people might like the risk/reward. After all, Elon is 4 for 4 in making people fabulously wealthy off very-hard-to-do projects (I know he's not officially involved but some of his people are like Sacks and Pishevar are).
For me, it isn't a positive / negative thinking thing. What I struggle with is the series of steps that this company goes through which have it justifying a valuation of even $100M (which it won't because nobody IPO's all of the equity, so for a $100M raise they are probably assuming a $1B valuation).
If you have some thoughts on how that would work please share them. I'd like to learn.
I'm guessing (and I will know more when I read their S-1) that they build their test track, they prove out the concept, then win a contract to build a larger one from one of the states? So how far does that $100M get them? Does it get the 5-mile track built and operating? Looking at other complex projects, say the London Eye, which cost $100M in 1999. And it's just a Ferris wheel. I don't know of a 5 mile rail project that has cost less than about half a billion but I would certainly grant you that those tend to be bid on by cost+ contractors.
So I'm just trying to connect the dots on how they "go to market" as it were.
I want this to succeed. I want to engineering team(s) to crush all the issues that people have raised here and elsewhere. That being said most cutting edge engineering projects like this don't make money for a very long time and I wouldn't invest any money I want to see a return on.
That's an interesting one. This is actually contrary to most conventional wisdom regarding such projects, rail for instance does not have a reduced cost / mile if the distances get longer. (Airtravel does, however).
Presumably for the IP and institutional knowledge that is generated by actually designing a working prototype. Then HTT could propose actually building one with them running the project.
When the US government literally loses track of $100 million in cash, no one blinks an eye. When a guy who has built an electric car company AND a space rocket company proposes a revolutionary transportation alternative and has people excited enough to spend $100 million on it, people go nuts.
I can't believe how small-minded some people are.
From the article "Separately, Musk has said he plans to build his own 5-mile test track, likely in Texas, for companies and students to test out potential Hyperloop designs."
It's not necessarily a bad thing to have dissenting opinions. $100m is a LOT of money, especially for an experiment. As an IPO, to raise that amount of cash at what is essentially an angel-round's worth of information seems... aggressive. Cool idea? Sure. Doesn't mean everyone has to jump on board. An echo chamber isn't helping anyone either.
I could see this becoming a new way to transport goods but as outlined in the hyperloop white papers there is little room for error when transporting people and I'm not so sure that's the best, initial approach.
I think using this as a delivery system first, prove it out and increase safety as you go along is the way to go. It should be far cheaper to do it on physical goods first (hell you may even be able to skimp on the safety in some aspects), make lots of money transporting things and then work on a people version.
We'd like to think that there is little error when it comes to transporting people, but most (if not all) of our current means of transportation are prone to accident. Here's some stats:
- For planes, there were 4,394 near-misses in 2012 [1]
- There were an estimated 5,419,000 automobile accidents in 2010, just in the US, resulting in 32,999 deaths [2]
- And the recent Amtrak train derailment, which could have been prevented (although why the prevention mechanism needs to be in the track, and not on the train itself seems strange). [3] There is also an estimated 2,280 collisions at public/private crossings resulting in 267 deaths in 2014. [4]
The question in my mind is whether the proposed Hyperloop system would be more prone to accident than our current systems of transit. I doubt our current means of transit would fare well under some of the proposed scenarios in the comments.
Oh I'm in complete agreement with you I just think it would be cheaper / more profitable to initially transport goods (saving money on safety features you may need for people) and then using that to build up to people transportation. Rather than hoping an IPO gives them enough money just for a test track I'd rather them hope for far less money and test transporting non-humans.
As opposed to Elon Musk being a sacred cow who we cannot criticise at all without being attacked/downmodded?
The Hyperloop, to put it generously, has a lot of "unanswered questions" and practical limitations. Just considering the safety (and escape) of this thing takes you into areas that raise legitimate concern.
I'm not going to discount it completely with aircraft still around and failing as badly as they fail, it might be workable, I just want to see some figures on how much it will cost Vs. Maglev (a technology already deemed too expensive to deploy on the medium to large scale), and more so how much it will cost to make it safe.
Would I love to go across the continental US in a few hours? Heck yeah. Will I be able to afford it if it has Concord's ticket price? Likely not, I'll fly.
I wouldn't worry about an air valve being left open quite as much as the vacuum being broken because a big chunk of concrete (or whatever) is now sucked into the tube in the path of the train.
Perhaps in the very unlikely event it ever rains again in California, water in the tube could be an issue, or lightning damage. That brings up the logical question of how many customers you'll have if none of them have any water to drink. Perhaps this would make more sense as a project under the Chicago Regional Transit Authority, or parallel to the existing Acela track on the coast.
No. Depending on the failure mode, maybe, but that is not the concern here.
A slow leak that the high-vac pumps cannot deal with is a slow deceleration.
A massive crack will cause quite the stir in the tube. Think of a balloon. When you inflate a balloon you put, maybe, 1.1 atms more into it. This is about 1/10th that of the hyperloop system. You know how loud even a simple party balloon can be, and the forces that you deal with.
Hyperloop is based on a reduced air pressure tube, not an evacuated tube. Additionally, there's inlets in the front of the capsules to actively move air/pressure from in front to underneath/behind.
I don't really know how that alters what you've stated, if at all, but it didn't seem to be addressed, so I figured I would throw it out there.
I would not call it gradually rising. Pods would be moving at huge speeds and then hit viscuos fluid (compared with vacuum)
It would be like hitting a wall. Pod should be constructed like supersonic jet to avoid crash.
The biggest problem with this headline is that it suggests that the hyperloop is "getting" a test track. When the actual situation appears to be that the hyperloop is getting a plan for a test track that is heavily contingent on highly speculative funding.
If it actually had a test track, then most of the discussion in these comments could be obviated.
I'm clearly missing something important because otherwise somebody would have built this already, but instead of using the fans for levitation as proposed, why not keep using the magnets?
I'm imagining a tube with (8?) magnets equally-spaced around the perimeter so that the carriage inside automatically stays centered in the tube. We already know how to toggle the magnets to produce forward motion (see maglev trains). Could still use the partial-vacuum to keep drag down. And you remove the single-point failure mechanisms of the fans on the carriage and minor misalignment of tube segments.
I think it's because you'd need a continuous line of magnets over the full tube, as opposed to accelerators at intervals so it's probably orders of magnitudes cheaper. I don't know about the reliability of compressors but I'd say you could have a couple onboard if they're an issue.
"If the position of the wall deviates from straightness by a few thousandths of an inch, you could crash ... if you lose the vacuum in the tube, everybody in the tube will crash ... the vehicle's compressor ... can't fail, or the pods will crash ... The 5-mile test track is estimated to cost about $100 million, which Hyperloop Transportation Technologies hopes to pay for with its initial public offering (IPO) later this year."
This article will one day be featured in a museum exhibit on laughably divorced-from-reality bubblethink.
Exactly. How can you do an IPO without any earnings? NYSE requires at least $10 mil over 3 years before they even list a company - I'm assuming other exchanges are similar. And if they don't list it on a major exchange, I doubt they can raise that amount of money...
There's an exchange called NASDAQ that have different sets of financial requirements you can satisfy to get listed. Some of them don't require any earnings at all, e.g. Nasdaq Global Select Market, Standard 4.
My thoughts exactly. It sounds like the co-creator of Maglev thinks he created the ultimate transportation vehicle, and is completely unwilling to accept that while expensive, those problems can be overcome using new technology.
This is hard for me to do because 1) I probably respect Musk more than any living engineer, 2) I can't stand the CHSRA and their incompetence, and 3) I'm arguing from my comparatively unsuccessful keyboard against someone who is in every way my superior when it comes to engineering and business, and I know I'm gonna be the one to look like a fool here. But I'm going to do it anyway and try as best as I can to avoid the middlebrow dismissal.
Hyperloop is a nerd dream and it doesn't have a chance at financial success. The fundamental problem has nothing to do with the technology, which appears amazing and viable. If anyone can overcome the few nagging engineering issues, Musk and Co are the ones to do it. No, it has to do with not having a viable market plan, suffering from very common delusional assumptions in business models that have fucked over railroad capitalists for well over 2 centuries now, including three major railroad bubbles (Railway Mania as well as the Panics of 1893 and 1873). [1]
The faulty assumption is that the viability of the railroad hinges on the ability to go from major city to major city as fast as possible. This is only partially true. Of course you want to be as fast as possible, but the worst possible way to be as fast as possible is to eliminate stops in smaller cities and towns, which is exactly what Hyperloop is planning on doing. Those small towns usually end up being the most prominent drivers of revenue, overshadowing the large-city-to-large-city revenue by an order of magnitude. Even the CHSRA business plan shows that their revenue model does not depend heavily on the SF<->LA passenger volume.
You can typically think of demand for travel in terms of cultural dependencies. I have a need for employment, therefore I travel to work. I have a need to visit family, therefore I travel to family. I have a need for tuna, therefore I travel to the wharf market. I have a need for a visa, therefore I travel to the embassy. These cultural dependencies result in a demand distribution for travel that roughly fits a power law profile. The demand for near travel (x > 0) is exponentially greater than further travel (y > x). It is not hard to speculate that the passenger miles travelled by Angelenos traveling to work outweighs the aggregate passenger miles travelled between Los Angeles to San Francisco on any given day...LA County's Metropolitan Transit Authority alone accounts for 5.4M passenger miles a day [2], approximately equivalent to 14,000 passengers traveling between SF and LA. More importantly, the larger the city, the more your cultural needs are met by your own city. If you live in Los Angeles, your probabilistic need to travel to San Francisco is much lower than someone from Fresno, because your needs are mostly met by Los Angeles. When I lived in Stockton, I travelled to Oakland or San Francisco almost on a weekly basis...but now that I live in Seattle, I travel outside of the Puget Sound region maybe 2-3 times per year.
In the very beginning, this faulty assumption was actually a safer assumption to make than it is today, due to the lack of airlines and automobiles. The railroad literally was the fastest way to get from city to city, with no exceptions. But now it isn't. Once you go over about 300 miles, a well timed trip by plane is often as fast or faster (a lot of people will say that 500 miles is the threshold of competitiveness, but travel market share peaks and then drops off after about 300 miles). Under 100 miles, the freedom of a car to leave without a schedule often makes cars faster. Any time you have competition, you lower your market share, with your comparative competitiveness determining how much market share you lose.
So this is how it has played out hundreds if not thousands of times in the history of railroads: 1) Some big city businessman sees a slow trip to a city that he commonly has to travel to. He sees a demand for faster transportation. He throws together a business plan that makes the correct assumption that City A has X people, City B has Y people, and a fast connection between them will yield Z% market share of the travel D demand between them. He figures that in order to get that fast travel time, he can only stop at the largest cities in between...or possibly no stops at all! He then looks up a similar city or railroad (lets say B & S railroad), looks at ridership figures, and tries to back into D, and then inflates the Z figure to reflect the fact that his railroad will be faster because there are fewer stops. Therefore his revenue model becomes X * 0.5D * Z * P + Y * 0.5D * Z * P (where P == ticket price) 2) He sells some stocks and bonds (or in the case of modern capitalism, lobbies for grants), and builds a railroad. From this article, it looks like this step is starting. 3) After a few months, he realizes his model is inaccurate. At this point, he will do one of two things: either advertise more or remove stops to make it faster, both of which exacerbate the cash flow problem. 4) After about a year, he is bankrupt. The bondholders reclaim as much as they can by selling the railroad to some other capitalist who will with high assurance do exactly the same thing, but with a greater chance of success due to a much lower investment. And thus plays out the railroad consolidation game.
In terms of the model, his failure was actually three failures multiplied together. 1) He assumed that the ridership of B & S railroad was primarily between termini. This meant his D figure was too low because he vastly underestimated the demand to and from the small intermediate cities. 2) He assumed that B & S ridership figures were rides at full terminus-to-terminus prices, therefore inflating P. 3) He assumed that D was a linear function of population, ignoring that the larger the city the lower the cultural need for travel, thereby inflating D. The only thing he got right was X and Y.
The practical implication of this is that if you want a successful, profit-maximizing railroad, you need to optimize the need for speed with the need to pick up passengers along the way. If you are a capitalist that cares about maximizing profit, this unfortunately means having a railroad that looks like a slow kludge, because it means making unglamourous stops in unglamourous towns. And it also means that technophile idealism puts you at a competitive disadvantage.
[1] for more information/history, this is a great writeup, with a couple chapters that clearly describe this delusion. It is very long, but amazingly interesting and worth reading outside of this reference for anyone interested in technocapitalism or bubble economics. http://www.dtc.umn.edu/~odlyzko/doc/hallucinations.pdf)
> These cultural dependencies result in a demand distribution for travel that roughly fits a power law profile. The demand for near travel (x > 0) is exponentially greater than further travel (y > x).
But don't you think you're failing to account for cultural dependencies that arise as a result of travel possibilities? Of different types of travel altogether?
For example, a 45 min subway commute is average in NYC [1]; as a result, going 30 min on the subway to meet someone who lives an hour away is not a big deal whatsoever. Since Metrocard costs don't vary by distance or time, and you have 8 million people used to lengthly amounts of subway travel, inter-city friends and relationships are more varied and spread out over space. [2]
If we assume that the Hyperloop is _not_ a railroad, or an airplane, and will have different types of time/distance payoffs, then we would have to assume a different form of demand curve altogether. For example: Japan's high speed trains -- and most importantly, their extreme reliability (like, to-the-minute) -- make long-distance commute a completely viable mode of transit. When high-speed trains are so reliable, you can have 9 minute transfer overlaps between two different trains going hundreds of kilometers, expanding range due to the UX, so to speak, of travel. It's qualitatively different than just a faster Amtrak or a slower plane.
If the hyperloop delivers on the promise of being substantially faster than air travel for its route, then presumably that makes a terminals-only approach more viable than it would be for HSR. (Which isn't to fully argue against your post).
That is true. A terminals-only Hyperloop would definitely capture more of the market share than a terminals-only HSR.
I'm assuming you already acknowledge this, but successful marketing involves positioning to avoid competition and attempt monopoly on the market segment (It seems Thiel is the latest to rebrand this concept). Low-cost stops at minor intermediate cities is a competitive advantage that no airline would ever be able to compete with, as the costs of takeoff and landing are huge relative to the cost of the trip.
Major city termini > 300mi apart, however, is a huge competitive advantage for airlines. No matter how fast you get, you are always going to give up some market share to airlines on more marginal considerations like schedule flexibility, seat size/comfort, baggage limitations, etc. That is a huge and potentially very expensive rabbit hole for competition that a city-to-small-town transportation system can mostly ignore.
Now combine Hyperloop with self driven cars that you can take at your convenience in both ends to arrive to your destination and most of the problems you stated seem easy to overcome.
Probably in a few years, when the hyperloops are ready, owning a car won't be as usual as now, but you'll be able to pick a self driven one paying per mile or a fixed per monthly quota.
They will presumably be building this out in the middle of nowhere in CA, not in a downtown urban core. But it is helpful to be in driving distance to a metropolis with a high degree of excellent engineering talent.
People from out of state assume everything in CA is nuts expensive but you have to remember the state is also full of farmland, forests and deserts.
I was thinking it makes sense in that California, sort of following I-5, is where the Hyperloop would supposedly go... but no. There's no reason to construct a proof of concept track there. Go buy some flats in the middle of nowhere and get a working prototype going first.
Makes sense if you're Musk and want to jot down to Santa Monica to see your mistress Friday evening. (Come on seriously this is what this is all about, you know it, I know it) Not so good if you want to commute to your worker bee cubical job Monday morning.
Isn't hyperloop not supposed to be efficient unless it runs over 1000 miles or something like that? It has to basically ride in the valley of a soundwave and to get up to speed and back to rest takes the majority of the time and a good amount of runway.
In the article they quote someone as saying if you lose the vacuum everyone crashes? That seems to be exactly opposite what I read in other articles. Is that true?
if we're going to build a 5 mile evacuated pipe while not try to use it as a prototype of a space launch? At modest 50G acceleration the exit speed would be 2.5km/s - not a production, but it would be a good test prototype to get real funding for the real deal to the top of Kilimanjaro.
Because you'd still hit dense air at the top with 2.5km/s. You would need to go a about as high as the blackbird could fly to exit the tube with some sort of grace. (Or maybe even higher.)
The wording of this article is interesting. I personally know the people behind this project. This is from a PR firm, and kickstarter knockoff who 'lost' a lot of my friends startups money
This company (Hyperloop Transportation Technologies) got no funding, Hyperloop Technologies did ($8.5m).(which is in reality a PR firm called jumpstarter pr in El Segundo)
They are hoping to raise the funding at IPO
"Now, the company Hyperloop Transportation Technologies Inc. (which is not affiliated with Musk or Tesla) has inked a deal with landowners in central California to build the world's first Hyperloop test track"
"The 5-mile test track is estimated to cost about $100 million, which Hyperloop Transportation Technologies hopes to pay for with its initial public offering (IPO) later this year, according to Navigant's blog."
Musk is building his own
Separately, Musk has said he plans to build his own 5-mile test track, likely in Texas, for companies and students to test out potential Hyperloop designs.
[1] http://www.leancrew.com/all-this/2013/08/hyperloop/
Thermal effects on Maglev research: https://www.lib.utexas.edu/etd/d/2007/kimh10315/kimh10315.pd...
EDIT: Apologies for the negativity... I hope this reads as more of thoughtful criticism, rather than as being hypercritical.