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The Race To Create a Hyperloop Heats Up (wsj.com)
An anonymous reader writes: When Elon Musk unveiled his idea for the "Hyperloop" transportation system based on capsules zipping through depressurized tubes, much was made about the enormous technical challenges the system would face in development. However, that didn't stop a number of companies and organizations from starting to work on it. Several companies are pushing the development work hard, and it's shaping up like a race to a workable prototype. University teams are only increasing their efforts as well. "The Illinois team enters the SpaceX contest with a strong competitive edge. This is its fourth Hyperloop design project, the first dating to fall 2013, and the Hyperloop is now a part of the MechSE curriculum. The team has assembled an interdisciplinary network of faculty from aeronautical engineering, thermal dynamics, mechanical engineering, electronic engineering and software, and two of the team members have interned at SpaceX."
"The pod has been pressurized to minimize the G forces effects on a passenger."
Really? How is that little trick performed?
I love Jesus, except for his foreign policy.
TFA lost me here:
"The pod has been pressurized to minimize the G forces effects on a passenger"
You can pressurize a pilot suit to redirect blood flow in order to mitigate g-forces in a fighter plane, but this is nonsense.
they should bury it so it can be a straight line tube cutting into the earth's curvature. Then you can just "fall" from Los Angeles to SF with no propulsion needed. The theoretical transit time, ignoring the friction, is 43 minutes. the energy you need to supply is to overcome the friction. Since gravity will be both accelerating this and decelerating this there's no need for a complex propulsion system, decelleration system with energy reclamation. Less to go wrong, and less abrupt acceleration of the passengers, and probably greater safety.
Of course the hard part of this is you have to tunnel underground to make a straight line cutting in to the earth. Since LA to SF is about 400 miles along the surface and the earth's circumference is about 25000 miles this means arc length is about 0.016 radians. thus 25000/2/pi*(1-cos(0.016/2)) = 0.127 miles.
so the center of this would be roughly 1/8th of a mile buried or 672 feet at the deepest point (ignoring the mountains). This doesn't seem radically crazy as a depth for boring a hole.
Some drink at the fountain of knowledge. Others just gargle.
Since the top speed is barely supersonic, wouldn't the g-forces here be comparable to a commercial jet plane?
boy, painting this fence is really fun.
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff
1. the majority of americans outside a handful of cities still consider public transportation to be a mark of poverty and avoid it at all costs. others cant be bothered to even consider a greyhound to the next state, let alone a train, and once they arrive the local public transit infrastructure based on their destination is either so poor as to be unusable or nonexistent through legislative fiat.
2. We cant keep up. our bridges, roads, highways and railroads are crumbling further into the dirt each year, and neither body of legislation seems capable of passing meaningful funding. the hyperloop would surely face the same fate as a majority invested government project that eventually turned into public private, then abandoned once the payout wasnt suitable for corporations, and finally maintained at about a quarter of its original capacity.
3. the initial projection for this works project (and, it would be a works project) is six billion dollars. America cant manage to keep its government running for more than 2 years at a time in this foul year of our lord 2015. It wont fund education, its states wont fund healthcare, and its been cutting federal public transit funding for 35 years. the only way a hyperloop is getting built is if it somehow includes a rider to invade a neighbouring country.
the only real reason companies even thought of doing work with the hyperloop is to do what companies do: suckle at the taxpayer teat. You start by investing in a renewable effort, secure grants and loans, develop a few proof of concept ideas, sell out to a capital management firm, and then declare bankruptcy.
Good people go to bed earlier.
Larry Niven's book World Out of Time has a "hyperloop" system in it. And I can't help but think other SF writers may have come up with something similar before that.
The notion that Musk came up with this 'idea' is ludicrous.
Why would Elon Musk open-source an idea this valuable, while also leaving the door open to step in himself?
Because the idea has been in the public domain for decades, including the whole depressurized tubes bit, maglev, and electric propulsion via external coils.
For now Elon Musk, it seems, is calling his invention home to see what it’s become.
Not his invention ...
"Transparent" is a shit show that trades on every stereotype going. A man in drag is NOT a transsexual.
Imagine a section of tube going splitting away from the main network. It has an airlock shortly after the split, then gently curves up a tunnel through a mountain, and exits at a rather steep angle upwards. Then there's a quick-acting airlock at the opening.
A special train is loaded - a rocket adapted to travel through these tubes. It speeds up to the regular Mach 1 in the "civilian" section of the tunnel, then goes down the branch and gains another 2-3 Mach. The airlock at the end opens right before the rocket reaches it, then the hyperloop propulsion module drops on a parachute while the rocket ignites its engines. We've just shaved off first 1.5km/s out of the required 9 or so needed to reach orbit - and with the tyranny of rocket equation, that's quite a bit of savings!
45 5F E1 04 22 CA 29 C4 93 3F 95 05 2B 79 2A B2
Speed has nothing to do with G-forces. Acceleration. Also, pressurizing a "pod" means the atmosphere, and that isn't doing anything for or against g-forces. Like the above poster said, you can put some air bladders in a tight-fitting suit but that's for like 5+ Gs, which would probably kill the ordinary American civilian these days.
Like lasers.
Just add Shark
Build a Man a Fire, and He'll Be Warm for a Day. Set a Man on Fire, and He'll Be Warm for the Rest of His Life.
Go to a bank at the drive- in teller station and you have proof of concept immediately. They only need to use a vacuum but the air removed from the front of the carrier could easily be pumped in behind the carrier and a bit more added as well if speed or distance requires the added boost. There is no question that it works the only question is the expense balanced against the benefits.
a pipe dream..
I'm probably being Toronto, Canada centric but when I look at the number of 18 wheelers travelling between Windsor, Toronto and Montreal (520 miles a bit longer than LA to San Francisco) I would think that a hyperloop with the 401 highway, eliminating big rigs, would make a lot of sense in terms of reduced traffic, wear on the road and truck/driver costs.
According to http://www.thetruckersreport.c... it costs $1.38 USD/mile and let's assume that each truck is carrying 100,000 lbs of cargo. Along with that, there are 10k trucks travelling the route (https://canadaalive.wordpress.com/2014/01/18/highway-401/) for a total cost of $7,280k per day or more than $2.6B per year.
Going back to Musk's estimate of $6B for LA to SF, I think that the Windsor to Montreal route could be done for a similar amount (ie quite flat with no mountains and no earthquakes) which means that a 5 year ROI could be conceivable for putting a hyperloop between Windsor and Montreal (with a stop at Toronto) with the bonus of less traffic jams.
Why isn't somebody this analysis for LA to SF or other city pairs where's there's lots of commercial truck traffic to validate the hyperloop process and demonstrate a track record and demand for passengers?
Mimetics Inc. Twitter
The author doesn't know what G-forces are, that's all. They were trying to say that the person isn't exposed to a vacuum.
I hate to bring up our imminent arrest during your crazy time, but we gotta move.
G-forces have little to with speed. G-forces are caused by *acceleration*. F=ma, after all. So it really isn't about the top speed, it is about how fast you get to that speed, and how gentle the curves in the tube (if any) are.
It's discussed in the Hyperloop Alpha document, although I can't be bothered to dig it up right now - I recall that the numbers were what I'd call "a bit roller-coaster-ish", but nothing too bad. Note that there is no "lateral acceleration", as the craft is not locked into a fixed orientation with respect to Earth - "down" is always the direction where G-forces are the most intense. Passengers face acceleration/deceleration forces and vertical (downward) forces.
G-forces are the main limiting factor to Hyperloop velocity in most places - the more the track has to bend in order to follow roads, avoid mountains, etc, the slower it has to move. So bends are the biggest factor in determining trip times. Technically Hyperloop is also limited by the speed of sound in the tube, but it's not as big of an issue as curves, at least over routes like LA/SF. And it's an issue that can be avoided - with more pumping, one could inject a sparse light gas, which can support dramatically higher speeds of sound. Elevated temperatures also raise the local speed of sound, and given how sparse the gas in the tube is, it's probably not going to be very good at ditching the heat imparted to it by the passing craft - so its equilibrium temperature may be well elevated over ambient without any extra effort.
I hate to bring up our imminent arrest during your crazy time, but we gotta move.
You know, rather than speculating, you could actually read how it works before talking about it (hint: no, it uses neither rails nor maglev)
I hate to bring up our imminent arrest during your crazy time, but we gotta move.
You really need to adjust your idea of timing. You can't instantly accelerate and decelerate without liquefying your passengers internal organs. You would have a maximum acceleration rate, as well as a maximum braking rate in order to not kill people.
Also, you can't just build this next to existing freight rail lines - the US freight rail system was designed for a maximum straight-line speed of 69 MPH. The route you suggest has a HUGE turn in it from headed east-southeast towards Puyallup, to due north towards Auburn. Even if you could take that thing at the speeds talked about with these Hyperloop systems, the centrifugal forces would cause severe "distress" on the passengers.
They chose the I-5 corridor through central California for a very good reason - it's very flat (except for when you get to the San Gabriel mountains right before LA), and very VERY straight.
Slashdot still doesnâ(TM)t support Unicode after it was added to the HTML standard in 1997.
But if we remove Fox "News", should we also remove all the left wing propaganda "News" organizations at the same time? I guess than we are left with BBC?
APK likes to ask for responses to the same things over and over. Maybe he just likes the responses?
His cares are all about money.
2016 is in three weeks!!
Can you give me the Powerball numbers for the December 5th drawing?
Add this to the list with self driving cars as a solution in search of a problem.
Which is usually the case for new technologies that aren't simple refinements of things that people are already doing. I've been through this multiple times -- introducing managers to desktop computers; LANs; Internet; and the Web. These were all in the very earliest days solutions in search of a problem as far as pragmatic managers were concerned. They knew how to do their job without a computer on every desk connected to almost every other computer in the world, so why would they need such a thing? Well, you don't need it until you figure out how to use it.
That said, the two examples you allude don't fall into that category of tech that accomplishes unfamiliar things. The Hyperloop is a straightforward replacement for other modes of intercity travel: plane and rail in particular. Self-driving cars are an alternative to driving yourself. If you imagined either of these things existing and being competitively priced, you'd have no difficulty in picturing how you'd use them.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
they're not building 1950's style switched telephone systems in Africa either - they're building cellular networks because it's the modern way to do things.
The so-called 'high speed rail" that has been proposed in the US is a fucking joke, and a very expensive one at that. I'll give you a hint - the majority of the proposed high speed rail corridors are a whopping 20 mph over what Amtrak currently does.
Slashdot still doesnâ(TM)t support Unicode after it was added to the HTML standard in 1997.
We can't seem to build high-speed rail in the US, which is a proven technology.
Well you put your finger on the problem right there. We Americans have a novelty fetish; we're the only country that could go from putting our first man in orbit to landing a man on the Moon in seven years, then totally lose interest in manned spaceflight. The fact that other countries have done high speed rail successfully makes tackling all the complicated and expensive things you need to make it work profoundly uninteresting to the average American.
That said, they are building a high speed rail link between LA and San Francisco, but while that's an eminently practical project, particularly when you consider the impact on places in between on the line like Bakersfield and Fresno, it's boring. The train won't be the fastest in the world; until we're talking the fastest train or train-like system, Americans won't like the idea.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
My basic point is that you're criticizing a system that you don't even know the most fundamental details about. Start with actually reading the Hyperloop Alpha document, then come here. I'm obviously not going to sit here and debate the finer points of a topic with someone who is just now learning what the thing even is.
I hate to bring up our imminent arrest during your crazy time, but we gotta move.
I didn't even know that there are so many people here on Slashdot who see fit to criticize Hyperloop without understanding even the most basic concepts of what Hyperloop actually is
For the fourth time this thread: it's not a maglev vactrain. It wouldn't even work in a vacuum.
I hate to bring up our imminent arrest during your crazy time, but we gotta move.
Same could (may) have been said of cars themselves.
"If you have nothing to hide, you have nothing to fear." - Every fascist, ever
Alon Levy, transit expert (particularly about costs of construction,) has this recent update about the proposal. His earlier analysis brought up a number of concerns about cost and how it would actually work. Basically, at the speeds that are claimed, the required gentleness of the curves means expensive construction. Or just going fast and cheap and thus having barfing passengers.
It's psychosomatic. You need a lobotomy. I'll get a saw.
The author doesn't know what G-forces are, that's all.
This is the root of problem with schemes like this. They are hyped up by people who don't have a technical clue, and decided upon by politicians ditto.
The GP was talking about instant acceleration (meaning in this context going instantly from 0 to 760mph). I think that merely liquifying is being optimistic: they'd probably be vapourised.
Nevertheless, Strapp showed that we should be OK with 46g (let's leave the last 0.2, as a safety margin) - as long as we ae Strapped in.
Yes, building a track/road/ski-run/railway/sliding-surface (I'll give you the honour of chosing the terminology) in a vacuum tube sounds much cheaper and easier than building in the open air.
None of the above. And it's not a vacuum tube. Hyperloop wouldn't work in a vacuum.
Again, if you want to actually have a discussion of the plan, you're going to have to actually read the plan first. I'm not sure what's difficult about this concept for you.
I hate to bring up our imminent arrest during your crazy time, but we gotta move.
No concerns.
"Outdated business models" is code for "I don't like paying for things, but want them anyway"
[Wikipedia] The Hyperloop ... operates at approximately one millibar (100 Pa) of pressure. .......is proposed to operate by sending specially designed "capsules" or "pods" through a continuous steel tube maintained at a partial vacuum.
No-one has ever created a perfect vacuum*, so the word "vacuum" tends to mean something close to it. One thousand of atmospheric pressure is pretty good going as a "vacuum" in for a mega-structure 100's of miles long. I work in heavy engineering - we would call that a "vacuum" and and would be quite pleased to maintain one as low as that in a vessel much smaller.
But you are right to emphasise the "vacuum" being partial here as some air is essential to the air film aspect.
Nevertheless, my point still stands that this is a staggeringly large "vacuum" vessel from an engineering design point of view (the point of view I am seeing from) which will be staggeringly expensive to build, whatever Elton Musk and his followers might believe.
*Nearest thing was behind a parasol dragged behind a space vessel in very high orbit, and even that was not perfect.
First off, stop reading Wikipedia. You can read the actual concept design document, Hyperloop Alpha, if you actually want to learn about the proposal.
No, "One thousand(sic) of atmospheric pressure" is not "pretty much as good as a "vacuum". Hard vacuums operate at around a trillionth of atmospheric pressure. At a thousandth of atmospheric pressure, even if you weren't in a tube you'd face relevant wind resistance at those sorts of speeds. Inside a tube, you build up a dense column of air in front of you while dragging hard vacuum behind you. This column of air would rapidly slow the capsules. The old concept - vactrains - was to operate in hard vacuum to prevent this. In order to coast at high speed in Hyperloop, the capsules have to shunt the air to behind them via compressors. However, unlike an airplane, the magnitude of air being moved isn't huge (it's non-propulsive), so battery-powered water-cooled compressors are sufficient to handle it.
The reason for Hyperloop choosing not to operate in hard vacuum is severalfold. One, it's much cheaper to maintain low pressures than a hard vacuum - it requires dramatically lower pumping costs (both capital and operating) to operate at a thousandth of atmospheric pressure than a trillionth. Two, the cost needed to deal with the low pressures on the capsules (the compressors) is not unreasonable. And three, they make use of the air in the tubes to provide lift, avoiding expensive maglev options. Basically, they took a look at the old maglev vactrain concepts, found what made them expensive, and found a way to eliminate those things by making it not maglev and not a vacuum.
Their design parameters make the tube itself not much more complicated than an oil pipeline (see above in the thread for a comparison between the two). And oil pipelines are not unreasonably expensive to build.
A basic aspect which you should have known before you even started talking about the concept.
I hate to bring up our imminent arrest during your crazy time, but we gotta move.
You just failed Physics 101. Speed has no relation to g-forces, unless you are going in a curve.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
"One thousand(sic) of atmospheric pressure" is not "pretty much as good as a "vacuum". Hard vacuums operate at around a trillionth of atmospheric pressure. At a thousandth of atmospheric pressure, even if you weren't in a tube you'd face relevant wind resistance at those sorts of speeds.
My original and subsequent comments have not been about the propulsion, suspension or air resistance; they have been about the cost and challenge of building the tube. No, I have not read the concept design document (we are not the design committee here), but I have got the point that it is in a tube kept at a near vacuum.
From the structural point of view it does not matter whether the internal absolute pressure (I'm trying hard to avoid the word "vacuum" as it seems to give issues) is a millibar, microbar, 10 millibars, 100 millibars or even a perfect vacuum - the structural design of that tube will be the same.
No it will not be as simple or cheap as an oil pipeline.
Oil pipelines have internal pressure (ie above atmospheric) which makes them structurally simpler because the pipe walls are in tension - which most structural material is very efficient at holding. OTOH, the Hyperloop tube walls will be in compression so there is the additional failure mode of wall buckling to consider - unstable implosion of the pipe in other words. With a tube 4m diameter (I got that from Wikipedia too) this is likely to be the dominant structural consideration. To avoid implosion buckling, steel walls will need to be either uneconomically thick, or will need to be copiously re-inforced with circumferential flanges and longitudinal ribs - unlike oil pipelines. One solution would be to make the tube of concrete which is far cheaper than steel, so the walls could be thick and hence more stable against implosion buckling - but then there would be far more self-weight to consider, negating the "advantage" of light pods/capsules/cars/whatever-they-are-called.
A further difference from oil pipelines is that the latter can make relatively abrupt changes of direction. Eg, to cross a small valley, the oil pipes can simply dive down into it and rise up the far side, on relatively low and normally-spaced pedestals all the way. The Hyperloop could not do this - it would need a high viaduct like any conventional railway - in fact it would be far fussier than a conventional railway to keep the lateral and vertical accelerations within passenger tolerance at its high speed. Maybe the landscape is featureless where the Hyperloop is going (I don't know); otherwise some very serious civil engineering is going to be required on its route.
Yes, I know it's about acceleration. But I'm curious why the hyperloop can't speed up gradually. After all, the G-forces in a jet plane are pretty much bearable unless we're talking about fighter pilots.