Hyperloop: Another Potential Disruptive Idea
Hyperloop By Elon Musk, Chairman, Product Architect & CEO, Tesla
“When the California “high speed” rail was approved, I was quite disappointed, as I know many others were too. How could it be that the home of Silicon Valley and JPL – doing incredible things like indexing all the world’s knowledge and putting rovers on Mars – would build a bullet train that is both one of the most expensive per mile and one of the slowest in the world? Note, I am hedging my statement slightly by saying “one of”. The head of the California high speed rail project called me to complain that it wasn’t the very slowest bullet train nor the very most expensive per mile.
Marc’s note: Musk has put forward another potential disruptive idea that if enacted could disrupt terrestrial transportation as we know it. Musk has made it clear he doesn’t have the time to devote to this project but would be willing to collaborate with others and having someone else take the lead. Any takers?”
Update: In a teleconference Musk said his thinking has changed and he would like to build a “demonstration article”.
“The underlying motive for a statewide mass transit system is a good one. It would be great to have an alternative to flying or driving, but obviously only if it is actually better than flying or driving. The train in question would be both slower, more expensive to operate (if unsubsidized) and less safe by two orders of magnitude than flying, so why would anyone use it?
If we are to make a massive investment in a new transportation system, then the return should by rights be equally massive. Compared to the alternatives, it should ideally be:
Safer
Faster
Lower cost
More convenient
Immune to weather
Sustainably self-powering
Resistant to Earthquakes
Not disruptive to those along the route”
Download the Hyperloop Alpha document (PDF).
Everyone seems to be saying “I’ll reserve judgement until it’s built”. Well, in that case, it’s never going to get built! We have to judge it *before* it’s built, and I judge it thusly: Badass.
Judging projects before they started is how we got to the Moon. Just sayin’…
There is a way, though: build a small demonstration model, just large enough to conclusively prove that the concept would work, and spark excitement in people (like me) who have difficulty getting excited by talk.
EDIT: never mind
Folks
I just think it’s cool that “Tinker” from this site is getting some love from the press- as he was the first out of the gate a few weeks back with any kind of correct guess regarding the specs/operating design.
Tinker is amazing.
yeah gooooooooo tinker 😀
No need for me to say anything about tinker now, lolol my track record speaks for itself lol
GREAT TO KNOW HE NOW HAS ELON’S EAR!!!!
HIS MEGA LIFTER MAY BE BUILT YET!!!! LOLOL
PS First rectanglar shaped fuel tank/rocket to fly into space to make Gravity wheel sections
GO TINKER!
Update from conference call- Musk says a system from LA to SF is 7- 10 years away. I wonder what Space X and Tesla will each look like then…
I Wish Gene Roddenberry was alive to have seen the PDF and heard the conference call.
The man saw this coming back in the early 70’s with his TV pilots Genesis II and Planet Earth. His term for a Hyperloop type system was a “Subshuttle”- and was probably based on/ and or similar to that infamous Rand Study from ’72:
http://www.rand.org/content…
Genesis II, that’s the movie I was thinking of as well.
Perhaps Musk could call the demonstrator’s capsule Lyra-a and give it two navels.
Ha! Spit take on my coffee from that one. Oh, and if anyone is curious- Yes Rod Roddenberry (Gene’s son) is all over the connection to his father’s vision. Rod Tweeted this to me- The Original Matt Jeffries art:
Very cool. And here’s one for you. They don’t look much alike, but both are very impressive from the front.
Very cool. and here’s one for you. Lyra-a doesn’t look much like the Hyperloop capsule, but both are impressive from the front.
Maybe Mr. Bezos would be interested in a smaller version for package delivery?
Scrap the bullet train and build this. No guts bo glory!
The idea has been around from the early 1900’s, but that doesn’t mean it’s bad. If anything, more recent advances in magnetics, high-temperature superconductors, vacuum systems, etc. mean that this needs a serious re-look. Mr. Musk has an excellent sense of timing, the absolutely most important characteristic of a successful entrepreneur. We should look seriously at this.
My first thought was that this system needs to transport you and your car from city to city. What if you were driving your Tesla down the highway and you got in the hyper loop lane and you aretaken on a beltway where you batteries, motor, chassis are left behind and you and you car body become part of a pod and tou arrive in other city with new chassis, charged battery’s ready to go.
My point to be really successful this system shouldnt compete with cars but make cars fly at 700 mph
Musk has his car chassis very simple and modular many of his different models may share the same chassis. Just bolt new body style on!
Robert Heinlein wrote about a very similar system in the 50’s and 60’s.
But the person who puts this to practice will be credited with its invention.
And rightly so. The idea for the airplane predated the Wright Brothers, and there were previous attempts to bring the idea to reality. But it was the Wrights, who possessed a unique gift of engineering insight, and put their nose to the grindstone and painstakingly ground out the details who made the idea work. Hats off to Heinlein et al for the vision, but if Elon pulls this off his efforts will have a revolutionary impact on transportation.
This often-repeated claim has long baffled me. Glenn Curtiss actually made the first observed flight in the US, not the Wright bothers. Also, whereas most of the Wrights’ aircraft and compoment designs were dropped, being inefficient, most of Curtiss’ designs were kept and implemented in production aircraft. Curtiss got a raw deal. The Wrights, like Columbus, must have had good PR people.
Do you have evidence of this first powered flight by Glenn Curtiss?
See Steve Pemberton’s response to my post. I had it wrong.
I have been to the Glenn Curtiss museum in Hammondsport, NY and it is really good. It’s a small museum somewhat off the beaten path but was well worth the trip. The museum gives you an idea of what a talented person Curtiss was and his unique life of accomplishments leading up to the powered flight demonstration that I think you are referring to in 1908, and his subsequent important contributions to aviation.
Meanwhile the Wright’s achievements are pretty well documented, starting in 1899 and progressing through their constantly improving gliders, leading to the first controlled and sustained powered flights at Kitty Hawk in 1903, which were observed by three government lifeguards, a local businessman, and a teenager. One of the lifeguards took the famous photograph using Orville’s camera. And their continued improvements of their powered models leading to their first public flight demonstrations starting in Europe in 1908 (a month after the Curtiss demonstration flight in the U.S), which resulted in a lot of apologies from people who had publicly scoffed at the Wrights claims about what they had achieved in powered flight, after they saw how capable and precisely controlled the Wright’s airplane was.
Whereas the Wrights had little interest in publicity, Curtiss was a showman, a former motorcycle manufacturer who sold the motorcycles that he built by using them to break speed records. He followed the same pattern when he got into the airplane business. Nothing wrong with that, but that’s how he got out front in the public eye first. And I’m not minimizing his importance to early aviation. His decision to use ailerons (although he did not invent them as is commonly believed) allowed him to advance beyond the Wrights who still believed that wing warping was more effective, but which couldn’t be scaled up very easily.
Thanks Steve. I did a lot of research when I first started working with planes, but that was a lot of years ago now and my is memory obviously not what it once was. I do remember reading about legal battles and patent rights fights and thinking it unfortunate that such a romantic business should be marred by money matters. But I guess it’s no different today with space endevours, and now we have the added pain of excessive (and often seemingly pointless) politics.
You bring up an interesting parallel, comparing today’s situation with what the Wright’s had to deal with. They were fairly secretive about their early achievements as they didn’t want competitors to copy them while they were still securing patents, or spur competitors on by revealing what they had accomplished. It backfired on them because their refusal to do demonstrations caused a lack of credibility and a lack of interest from potential buyers. Eventually the competitors including Curtiss were catching up and getting a lot of attention so the Wrights had to go public with their airplane, but really by then it was too late.
It’s the same situation that the commercial space companies are in today, too much secrecy and you don’t get interest or investors. Too much openness and the competition can take advantage of it. It’s a real tightrope walk, and a miscalculation as the Wright’s discovered can lead to falling off the high wire
1902 First powered flight Richard Pearce in NZ might be a wiki to check. Again not a self promoter. PR gets your 15 minutes of fame.
Whether or not the Wrights technically beat the many rivals to first-flight, your comment was: “there were previous attempts to bring [the idea for the airplane] to reality. But it was the Wrights, who possessed a unique gift of engineering insight, and put their nose to the grindstone and painstakingly ground out the details who made the idea work.”
This implies that the Wrights were something special. That without them, airplanes would have remained “just an idea”. But of course that’s nonsense. Had the Wrights never existed, aviation would have barely noticed. (Indeed, US aviation may have progressed more easily with the overly litigious brothers hacking at its roots.)
But isn’t that true with all inventions, if the first person didn’t invent it someone else eventually would, maybe sooner, maybe later. I think what makes the Wright Brothers historically important is that while everyone else was basically guessing at the problem, the Wrights were drilling in and discovering the fundamentals and physics of flight, and using these insights to influence their designs, whereas all that their contemporaries could do was basically trial and error, with no real understanding of why things were or were not working. And with their extremely limited resources the Wrights were duplicating on a micro scale what aeronautical researchers would be doing later, for example using a wind tunnel. Meanwhile in the exact same timeframe Samuel Langley, who had a lot more resources available, approached the problem with much less understanding and he failed.
It’s why we give credit to Robert Goddard even though others had made rockets before him (although not liquid fueled), and Goddard’s rockets were never actually used for any practical purpose, and at the time his work wasn’t even noticed by anyone (except by the Germans). Goddard, like the Wright Brothers was pressing in to understand the fundamental problems of rocket power and then he applied that knowledge to produce successful demonstrations of rocket flight, with only a handful of people standing around to observe them, similar to the Wrights.
Not always. Many key inventions, like steam power and steel, were independently invented and abandoned several times. Even concrete.
IMO, the key to whether an invention/discovery’s “time has come” is simultaneous “invention” by multiple parties. Usually with disputes over priority. And that’s what you see with powered flight. People from Romania to Tasmania were playing with kites and gliders and engines through the 1890’s and many achieved powered flight by within a few years of each other.
You talk of the Wright brothers’ systematic studies, but that was also veiled in secrecy. Whereas others believed that development of aircraft was a common pursuit and information should be shared. Hence the Wright bros secrecy didn’t really contribute much to aviation. It developed in spite of them, not because of them.
[1893 quote by Lawrence Hargrave: “The flying machine of the future will not be born fully fledged and capable of a flight for 1000 miles or so. Like everything else it must be evolved gradually. The first difficulty is to get a thing that will fly at all. When this is made, a full description should be published as an aid to others. Excellence of design and workmanship will always defy competition.”]
During the early part of their glider development the Wright Brothers actually had the open source attitude that you are describing. For example Wilbur Wright went into great detail about their glider and what they were learning from their Kitty Hawk test flights in a speech that he made to the Western Society of Engineers in September 1901.
http://invention.psychology…
For a brief period of time after their first powered flights the Wright Brothers were relatively open to doing demonstration flights and were willing to discuss what they had accomplished, although they were no longer willing to divulge details or allow people to photograph their airplanes. Should they have instead offered their achievement as a gift to the world and not tried to profit from it? Sure, I agree with that. I wish more people had that attitude as it is increasingly rare. I think that is what I admire most about Elon Musk. But as I mentioned before it’s a tightrope and I think Elon is aware of that, that too much openness can backfire in a world of wolves.
Do not make the political problems harder than they have to be. Avoid LA to SF because they are already getting new train lines – the rail companies will use their political connections to stop you.
Find a a pair of growing cities that are joined by neither a direct train link nor an interstate road. Build the first hyperloop tube between those.
Agreed, assuming it can be completed in time to make a difference.
Revision: This all hangs on available funding, of course. The California systems appears to have committed funds, whereas other localities perhaps can’t come up with that kind of money in a hurry. If the CA authorities can be convinced of the advantages before proceeding too far, then maybe they’d think about switching designs. I’m guessing that the contract penalty clauses that are already in effect, if any, will be a major factor.
I agree..I say Chicago to Indianapolis…flatter cheaper land fewer earth quakes…(two states to help fund it! one of them with a surplus)
I’m trying to get my head around the $9 B number…that seems a magnitude or two off.
The design calls for a suspended vacuum sealed structure around 380 miles long (distance from LA to Frisco)
To me each mile would be easily upwards of a billion dollars. The design calls for an earthquake proof column every 50 yards. These columns are also to withstand the intermittent extreme forces of the capsule passing through. With sophisticated sensors for detecting vacuum leaks far in advance of the capsule passing through. Oh includes 100s of miles worth of solar panels.
I think the more accurate estimate — just for building would be ~400B or so. That doesn’t include the land acquisition costs, because one cannot simply use an existing highway for this (this concept requires a straight cylinder to minimize G-forces). It also doesn’t count the cost of multiple entry / exit points along the way, it doesn’t count R&D and testing that would be needed.
Really, this concept would be realistically $500B dollars over ~10 years.
pretty sure it is reduced pressure, but not vacuum and the pod itself moves some of the air from in front of it to create the air hockey effect and reduce resistance.
Correct. The PDF very clearly says reduced pressure, not vacuum; and a fan system on the front of the capsule is proposed to move some of the air from in front of the capsule to behind it, reducing air friction.
Bilal’s estimates above were apparently made without him having read the documenation.
ouch one of my fav board regulars slams me!!
my point is was that an air pressure of one-tenth of 1% of earth sea level is as near a vacuum you can get in what is nearly a 400 mile long volume
Not a slam my good man, a discussion. I know the reality is that none of us have the time to read every supporting document and article. There just aren’t enough weeks in a day to read everything that interests us. If I had a time machine, I’d want it to be the kind that stretches and shrinks time, not the move-through-time kind. That way we could find enough time for the good stuff and shoot through the bad stuff quickly.
Also…I like the concept (even with a much larger cost estimate). We need a useful, envelope expanding, productive job maker like this. And it is not that expensive even with my more liberal cost estimate of $500B
I’m sure it’ll be paid back many times over.
Agreed Bilal. And if it proves to be cost effective, then I predict a lot of other cities / states / countries will be seriously looking at ‘loops of different lengths for their own. That will mean a whole lot of construction jobs.
And the major component manufacturer(s) of the initial CA system will be the logical choice for manufacturing those components for both the domestic and export markets (or leasing their patents and designs). Realizing this, I think, should make the initial bids very competitive.
And finally, given the very favorable energy and environmental characteristics of operating a Hyperloop, I wouldn’t be surprised to see governments offering economic incentives for those who decide to build a ‘loop system.
Musk said to run it right a long the existing highway to get around the huge expense of aquiring new property. 158400^2 feet of solar panels per mile @ 35 dollars a sqft only 5.5 million per mile for panels, not counting installation. I do not see how you are getting 1 billion a mile .. WAY WAY over the mark
Bilal you are spot on. Cost is off over a magnitude IMHO also. Yes it is on pylons, but the curves must be gradual, constructed out over newly acquired real estate right of ways. That real estate has to be purchased, figure the cost of that in Cali. Terminal area land must also be purchased in highly dense population centers. Only “free passage” is underground, and that comes with stratospheric tunneling costs.
Add to that that the world has changed, to the “new world order.” These pylons are perfect terrorist targets. The concept is suspending 3 meter diameter 3.5 cm thick steel tubes on pylons. All you do is take a few down together and you will probably drop a few miles of pipe. Ever see high tension towers fall once the wires are snapped by an ice storm? They fall like dominoes. Take the tube out and the entire system is down. There are no “detours” to secondary roads or rail beds.
Cute concept, nice masters thesis write up in the PDF file, spruced up with futuristic industrial art. There is a reason he went open source with this. Connect the dots and you will know why.
Connect the dots for me moose. why????
My first thought about 5 years ago was to build such a system between Ottawa Canada and Washington DC. The logic is that it would be an excellent test and could aid in the unification of Canada and the US rather than see Canada align more deeply with the EU. If such a system worked well both Canada and the US could then build a network, I would suggest Mexico but the country is basically in anarchy and very unstable. If the US is forced to invade Mexico again putting this loop in place would aid in assuring that the country is re-built in a stable manner, perhaps using some of it’s former citizens to aid in economic redevelopment. My personal impression is that if we have to invade Mexico due to Mexican government sponsored cartels invading border states we should consider allowing Mexico to become a State, because we will end up paying for it’s reconstruction anyway.
Canadians have been invading our country for hundreds of years, only they’re so polite we just don’t see it.
shhh…
ehh!
The thing is that they look just like us…
I think it’s too early to put a firm price on what it would cost. A lot depends on variables that are hard to pin down such as politics. However even if the cost was double his first estimate of $6 billion, that’s still considerably lower than the $60 billion estimated for the California high-speed rail.
Even though none of the concepts proposed are brand new or yet-to-be-proven, there are enough less-than-mature technologies being combined to guarantee that cost and schedule will fluctuate considerably over the course of this rather lengthy program. But if cost bracketing shows it to be within the realms of cost advantage, I think it would be crazy not to go ahead with a demonstrator/pilot project, assuming that one or more sources will put up the money, considering the price tag of the current proposal.
I would recommend thinking of the demonstrator project as continuing life as a further development article, because the first attempt is never optimized, and because actual use will demonstrate necessary improvements and revisions.
I would assume that they’d start by fully completing a single first station to next station section to better define the requirements and, more importantly, better define the ALL of the costs associated with it.
If I were the CA authorities, I’d be seriously considering issuing and open RFI to all comers to 1) evaluate the Musk proposal, and 2) offer changes and/or alternatives. I think they still need a lot of data, and to do a lot of work, in order to make an informed decision.
CA bullet train: “You can buy better,, but you can’t pay more.”
What are the operating costs? Pulling a vacuum sufficient to allow 800 mph pods isn’t cheap. Mucho engineering yet to be done.
A few questions I had initially:
What happens if there’s an earthquake or some terrorist attack?
How much will it cost to build and operate?
How many people will it be able to carry regularly? What would they be charged for a ride? Will this support the operating costs?
Seems like a lot of hype but no specifics.
agreed …
what if there’s a problem in transit ? a medicial emergency ? or if you need to use the washroom ??
what about the rockies ? building over them ? or through them ??
could you build a standard railway for $6B ?
what about the EPA process ?
is the technology/cost so critical that you can only build a semi-recumbent passenger cabin ? sure it looks “sexier”, but it’s way less practical.
I never knew the Rockies were between LA and SF?????? Am I so old that they have moved since I went to school?????
The PDF has some basic answers to most of the questions you pose. As for the terrorist angle, I hate it when people bring that up as a reason not to build something. Why build anything? A terrorist might attack it. A busy highway bridge is just as vulnerable as a hyper loop track.
I didn’t bring it up as a direct reason why not to build it. The fact is now after 9/11 for big expensive projects, terrorism needs to be taken into account. This would likely raise costs more.
These issues exist for any transportation system, including cars and bicycles; they would be addressed. There are specifics in the attached PDF document.
The terrorist problem is the one I’d worry about, but then again, it also exists for any transportation system. At least for new systems the problem could be addressed in the design before it’s built.
I think the cost would be less than people seem to be imagining because so much of it is going to be modular, using the same components over and over, which reduces both manufacturing and installation costs, and expedites repairs. By comparison, other systems. even something as simple as a road, requires a unique design and construction project for every bridge, overpass, or elevation change.
Did you read the PDF all they way through? It is filled with specifics including cost breakdowns for each part of the system, the number of people carried in each pod, the estimated amount charged per ride, the expected frequency of runs, earthquake vulnerability mediation, how various emergency scenarios would be handled, the thickness of the tube wall, atmospheric pressure, power consumption, where the power will come from, etc. etc.
I didn’t see the pdf file since I was reading the article. Thanks for pointing it out, I found the link at the end of the post.
In preparing bids, more accurate values are when you use actuals. When is $6billion estimate is less than the bullet train, it appears he hasn’t taken everything into account. It appears his cost is just to build the structures. Not seen are cost to construct it on site, hauling materials in, getting local labor to build it, including purchasing right of ways. I’d be curious how it would handle off nominal occurrences such as power failures.
A power failure at a particular accelerating station would simply mean that the pods passing that station would not accelerate. They still might have enough inertia to make it to the next accelerating station and thus be able to continue, if not they would coast to a stop. Wheels would then drop down, powered by electric motors the wheels would move the pods to emergency exits which are stationed at intervals.
In case a pod had a power failure and got stuck, and wasn’t able to “limp” to the next emergency exit, the system would be re-pressurized so that workers could reach the passengers and lead them to an exit.
If a pod lost cabin pressure, oxygen masks would drop down like on an airliner. In case of prolonged or severe loss of cabin pressure in a particular pod, the entire system would be re-pressurized, then after the passengers in that pod are safely out, the system can be depressurized again and service resumed.
Regarding terrorist attack, it would most likely be more disruptive than deadly. Unless the terrorists could precisely time an explosion to the passing of a pod (which they can’t see because it’s inside the tube). What would more likely happen is that a section of tube would be blown out which would cause immediate pressurization of the system. All of the pods in the system would be directed to stop. In theory a pod near the blast sight might run into dense air before it is able to stop, creating some g forces on the passengers. And of course worst case scenario is that a pod can’t stop in time and reaches the opening. Not to minimize it but that would be 28 passengers compared to 500 people on an A380.
As for the disruption, the tube construction is relatively simple, steel tubes with concrete pylons, so I’m guessing that it wouldn’t take long to repair a damaged section of tube. If only one direction of tube were damaged, they could “single track” on the other direction, of course that would cut the frequency in half while waiting for the other section to be repaired.
If a pod lost cabin pressure the occupants would succomb to the low pressure very quickly. Oxygen masks would not help. The implosive force from re-pressurizing the whole tube quickly would be very destructive. A vacuum environment is dangerous. This is the case in outer space where we send trained astronauts and also inside this proposed hyperloop tube.
It’s the same on airplanes, the oxygen masks are only good when there is a leak that reduces cabin pressure, but they are not much help for a rapid decompression at 35,000 feet. And imagine Concorde routinely at 55,000 feet during the decades that it was flying. Your consciousness time at that altitude is measured in seconds not minutes, and there is a limit to how fast the pilots can get the get the plane down to a lower altitude.
Good point that Hyperloop will be putting passengers in a near space environment. At 100 Pascals it will be like putting people on a medium altitude X-15 flight.
So clearly a top priority is making leak proof cabins, the same requirement that Virgin Galactic has. As far as I know the “spacesuits” that SpaceShipTwo passengers will be wearing will provide oxygen, but they won’t be pressure suits. Of course I realize the difference between adventure seekers who are signing waivers, and regular passengers riding mass transit. But think back seventy-five years ago, if you told a DC-3 passenger that one day people would be routinely riding in airplanes at 55,000 feet with only pop-down oxygen masks for protection, they might have dismissed that as being too dangerous for anyone but military pilots and thrill seekers. As it turned out Concorde failed financially, not because people were afraid of high altitude flight.
Regarding re-pressurization they would probably open up a valve near the stricken pod, the pressure would flow in both directions and eventually reach the pod. How fast they could safely do this is a good question, hopefully quick enough as during that time the passengers would be subject to 150,000 ft. altitude if they had a total loss of cabin pressure.
William:
Not as bad as you think. In an emergency the entire tube could be repressurized in less than half a minute non explosively. Just well placed valves the right diameter. Simple physics. When repairs and servicing is done, pump the air out again. Once pumped out, they only need a small amount of energy to maintain the low pressure.
Safety is not just the price of doing business, it comes first regardless of cost. If there’s a problem, let the air back in. Safety must be an engineered part of the whole system, not an oversight or addition.
In case of system failure re-pressurization, the pods would come to a stop pretty quick but they be perfectly safe doing so.
tinker
The pdf was interesting reading but the whole design is very impractical. Using high power compressors to suck air from in front of the pod and create an air cushion would produce enormous amounts of heat in a closed system. If the pipe is pumped down to a soft vacuum then how would an air cushion effect work? And running each pod on batteries seems a stretch. I can’t see anyone wanting to spend 30 minutes inside a black tube going 760 mph. Following the I-5 corridor is impractical because there are too many curves, resulting in high G forces and other unwanted effects.
1) The heat created by the compressed air is dealt with using a water cooling system, which carries the heat to the end of the route where it is released. Also the air cushion is not created entirely by the compressors, at certain speeds the 0.05 degree angle of attack of the skis will trap a thin layer of air underneath the skis providing part of the cushion. 2) In a soft vacuum the air cushion works through pressure differential just like it does in a full vacuum. 3) The pods don’t really “run” on batteries, the batteries power the compressors which provide the cushioning, the motive power comes from linear accelerators located at various points along the route. The electricity for the accelerators comes from a stored energy system which is recharged by solar panels which run the length of the route. At high speed, the pods have plenty of inertia to propel them between acceleration points through the thin atmosphere, riding on a cushion of air. Of course the acceleration points will be located closer together in sections where the speeds will be lower such as the beginning and ending of the route, and also areas where the turn radius is tighter. 4) As for no one wanting to sit inside a tube for 30 minutes, don’t we already do that in airplanes for hours on end? 5) The I-5 corridor route will not be followed exactly due to the turn radius issue that you mentioned. However most of the route will fit alongside or within the median of I-5. 6) G forces will be limited to 0.5g
I read all of that in the pdf and don’t think this hyperloop idea would work. With a tube pressure of 1 T the skis would have to be the size of airplane wings to provide any lift and they would heat up from air friction. What keeps the pod from buffeting or corkscrewing? How do the accelerators work? There is no power source in the pod to accelerate it. All the motive power comes from outside the tube using linear motors. Therefore the pod has to have inductive windings or permanent magnets for the linear motor to act against. There will be electrodynamic drag in the steel tube with the former or the pod will stick to the steel tube like a fridge magnet with the latter. If it did work then who would want to be shot down a tube at 760 mph with all the heat generated by the compressor stored as super-heated steam in the next compartment?
“All the motive power comes from outside the tube using linear motors“
The key is that they are linear induction motors, and just like any induction electric motor it has a rotor “inside,” as opposed to an armature (an armature has windings, a commutator and electrical connections through brushes, whereas a rotor is just laminated iron on a shaft).
If the system that recovers and stores electricity on decelerating and braking used alternators, they will require armatures instead of simply rotors, but that whole system will be internal, not transferred out side the capsules (unless they plan on transferring excess power to the grid system).
The heat generated by all of these systems combined will be much less than you seem to think. A typical factory induction motor has a fan blade outside of one end bell and under a protective air cap, and this provides all the cooling necessary. Considering all of the air flow that will be going on in the tube as a capsule passes any point (some of it even naturally laminar flow) I think cooling can be solved easily enough. Remember, the system doesn’t have to be “cold,” just not too hot to cause either component damage or passenger discomfort.
You should read the pdf. The proposed design has an air turbine that would generate a lot of heat. That heat would be stored as super-heated steam inside the pod. I don’t think you know what an induction motor is. An induction motor has windings on the rotor. It isn’t “just laminated iron on a shaft”. But my point is that this “rotor” part that is in the pod would be a source of electrodynamic drag in a steel tube; or any kind of conductive tube for that matter.
This is somewhat similar to NASA saying they’re going to send astronauts to an asteroid, which ain’t gonna happen.
It’s okay to dream, we all want futuristic hover boards, space elevators, and 1000 mile an hour trains to San Fran lol!
This thing, which ain’t gonna be built, would cost several hundred billion dollars and you know it.
Comparing a NASA asteroid mission with a Musk endeavour just doesn’t work.
It may or may not work, that’s too early to say but the mere fact that Musk is proposing it and backing an initial trial, speaks volumes. His track record is pretty good. If anyone can prove if it can work, it’s Musk. To simply dismiss the idea is ludicrous.
I didn’t say it wouldn’t work.
I said: “This thing, which ain’t gonna be built, would cost several hundred billion dollars and you know it”.
And it’s very, very much like the NASA asteroid mission, which ain’t gonna happen neither.
Do you have something to support that several hundred billion dollar estimate?
I disagree. (Simplifying,) a Musk plan typically takes into account costs and returns right from the start, whereas a NASA plan typically concentrates on results and then afterward looks at the costs.
Thanks! I have little time to read these days. I will read it soon.
Folks!
And what a ride it’s been for me too and the darn thing isn’t even at the drawing board stage yet.
If you’re wondering why I haven’t been posting lately… when your sorry butt gets kicked out of semi-retirement by an entrepreneur billionaire, for whatever reason, you get that butt up an moving… fast!
That’s what I did. After Elon Musk called my flow chart “the best guess” (I wasn’t even close!) I went into high gear turning that little bit of ‘fame’ toward getting the clarity back into the Hyperloop Saga.
I was ‘picked up’ by a website to write an article which took almost two weeks but we had an impact last week that brought the story down to Earth some.
My second article was published today. That one took 4 hours. I’m learning.
So, don’t know where this will lead but I’ll have time to catch up and comment here now! Maybe now that I have a ‘reputation’ as a writer Kieth will let me put something together for you.
All your comments, discussions and replies have helped me be a better writer, never an easy thing for me, so thanks for all the help I never knew I was getting.
tinker
The English Channel Chunnel and train (35 miles) and the Japanese Seikan tunnel train (60 miles) are each about a magnitude shorter than the LA to SF route. They cost about $8 billion and $4 billion respectively. The Japanese tunnel goes through an earthquake prone region. Both of these tunnels might be larger diameter than the Musk system requires. I am not certain why if those two systems could be built, why the Musk system would be more challenging?
Agree, especially since they had to bore huge tunnels for those.
I find one curious omission in the details given in the PDF — he talks about decelerating to a lower speed, and he talks about an emergency braking system, but there is nothing about the actual braking system, which would be used almost as much as the acceleration system. Or are we supposed to assume that the induction system alone does braking to a stop?
The braking system adds significant problems, such as heat dissipation and potential high-rate mechanical wear (depending on the design), but also adds potential features, like recovering and storing electrical energy derived from any mechanical braking. Sound limiting is also a potential tricky task with high speed braking systems. The toughest design issue for the braking system I think would be maintaining the air bearing suspension at very low speeds and when actually stopping when aerodynamic lift drops to zero. The external pressure bearing is going to take a lot of expensive trial and error testing, and what would provide redundancy if it fails?
Also, I see nothing for solar cell array maintenance and cleaning. I’m no expert, but I am suspicious of the idea of covering the entire Hyperloop with solar arrays and expecting the entire system to stay intact and electrically connected 100% of the time, or even close to 100%. The arrays will need some sort of physical covering to protect them from overhead threats and weather, which will increase cost and decrease their efficiency (and if it ever snows in California the train will be out of commission once battery power is depleted).
Steve:
The same ‘stators’ they use to accelerate can be used to slow the pods down at the end the same way electric cars use regenerative braking and pump power into the grid at the same time. The stators can be used on down-slopes to maintain a constant velocity.
There was a lot left out but it was an ‘alpha’ release. But, there’s enough to work with for folks to be seriously considering it (I know this for a fact).
I give a postmortem in my second article on motherboard. Easy to find if you are interested!
tinker
“Reverse the polarity!”
You’ve got so many capsules in the system, you could use the recovered energy from braking to offset the acceleration of another capsule. No need to dump energy into the grid.
Paul:
Exactly! Even if the power is dumped into battery packs it can be returned to the system right away.
Maybe they can even recharge the batteries in the pods a bit through induction!
tinker
Thanks Tinker. I was just considering that, both mechanically and electrically, stopping is not the same as slowing down, so they’ll have to be treated as separate requirements.
Good work, my friend. Grab the momentum and ride the wave to the end. This whole concept would appear to be scalable, so you may be looking at more than just one ‘loop in California. And with any luck, you can have a nice little “Conceived in Canada” decal put on the sides of every car.
Steve
My thought on seeing this is that Musk should first try to get Fed Ex or UPS interested. They ship much cargo that could fit in smaller vehicles than would be needed for passengers. This sort of system would be useful for sending cargo modules between hubs.
It seems to me that the fundamental problem is that many failure modes will be catastrophic. At 800 mph, the slightest misalignment could cause a collision with the tube wall and a sudden release of kinetic energy that would crush and incinerate the passengers.
What if it had some kind of backup safety mechanism that prevented collision with the tube wall?
I find it quite amusing to read all the naysayers comments. Rather than say ‘how can this be done?’ they continually look for reasons why it can’t happen.
Musk is a positive person otherwise there’s no way he would have managed to get his 3 companies working or even his original Zip2 company unlike many posting here.
The biggest challenge a project such as this one has isn’t going to be technical (there’s no new technology required) but political. Just imagine how much political capital can be brought for $60 billion as opposed to the cost of the Hyperloop and the way Musk has costed it, it wouldn’t be a government run project but commercial and therefore much more efficient.
Pity Elon’s so busy.
Since the vehicles are to have a fan in the front I wonder if it would be cheaper just to give each of them a turbofan and dispense with the expensive maglev propulsion system.
The vehicles are about the size of a small business jet. They could be based on that without wings. You would make the engines be electrically powered rather than burning jet fuel.
Since the engines are electrically powered they don’t need a combustion chamber or turbine, so they would be cheaper and lighter.
Also, since jet planes typically fly at 30,000 feet at air pressure 1/3rd atm the requirements of evacuating the tunnel would be cheaper.
Bob Clark