California Billionaire Unveils Futuristic 'Hyperloop' Transport...
Source: Reuters
[font size="5"]C[/font][font size="3"]alifornia billionaire Elon Musk took the wraps off his vision of a futuristic "Hyperloop" transport system on Monday, proposing to build a solar-powered network of crash-proof capsules that would whisk people from San Francisco to Los Angeles in half an hour.[/font]
In a blog post, Musk, the chief executive of electric car maker Tesla Motors Inc described in detail a system that, if successful, would do nothing short of revolutionizing intercity transportation. But first the plan would have to overcome questions about its safety and financing.
The Hyperloop, which Musk previously described as a cross between a Concorde, rail gun and air-hockey table, would cost an estimated $6 billion to build and construction would take 7 to 10 years. Eventually, according to the plan, it would jettison more than 7 million people a year along one of the U.S. West Coast's busiest traffic corridors.
As many as 28 passengers could ride in each pod and the system could even transport vehicles, according to the 57-page design plan.
Musk, who in the past has hinted at the hopes of building such a system, proposed the Hyperloop as an alternative to a $68 billion high-speed rail project that's a major priority of California Governor Jerry Brown. It would be safer, faster, less expensive and more convenient, Musk said in the blog post...
Read more: http://www.reuters.com/article/2013/08/13/us-musk-hyperloop-idUSBRE97B0U320130813
joshcryer
(62,269 posts)It can get super technical at times but otherwise it's a nice and mostly non-technical read. It's actually an ingenious concept. The dang thing coasts most of the way. The energy to power it is free. The ability to build it fully realizable. It can be built right on the I-5 median (I personally think you'd want a retaining wall built too to keep cars from hitting the pylons; something which wasn't really discussed).
You can read the PDF here: http://www.teslamotors.com/sites/default/files/blog_images/hyperloop-alpha.pdf
To think, this could be built for a fraction of the cost of the $60 (more like $100) billion dollar bullet train idea that is inconceivably expensive.
davidpdx
(22,000 posts)The west coast has one of the worst transportation infrastructures in the country in terms of getting up and down the coast. Amtrack is slower then a dead snail, the bus is great if you like the possibility of being hacked to bits, leaving the only other option of flying.
I live in Korea and I've had adult students ask me about taking the bus between cities and myself as well as other people told them not to because it's not safe anywhere. Maybe we are exaggerating a bit, but you never really know when the nut cases might hack you to bits.
bananas
(27,509 posts)Bombtrack
(9,523 posts)Something like this was featured in the movie but not in detail.
dipsydoodle
(42,239 posts)of the old "suck / blow" systems that department stores had as late as the fifties which moved cash around the building. Such systems were also used to move small parts around manufacturing units as late as the sixties and maybe even later.
freshwest
(53,661 posts)dipsydoodle
(42,239 posts)freshwest
(53,661 posts)One's items are dropped into an elongated cylinder made of plexiglas that flips open and closes tight at one end. Hit a button and a sheet of plexiglas slides down to create a vacuum and woosh it goes to the teller and vice versa.
I was imagining an air tight cylinder to carry people, naturally with the vacuum on the outside. The system I'm speaking of has the device at either end to create the movement.
I like drive throughs if I have to drive miles to get to some place. It saves time from getting in and out, locking up, finding parking, waiting in a line inside and all that. The bank is the only place I still see these, though.
PoliticAverse
(26,366 posts)Nihil
(13,508 posts)(At least in the main one near me - goes between each till and the main cash centre
using plastic shuttles about the size of a small drinks bottle.)
What was old is new again (or something like that)
dipsydoodle
(42,239 posts)My son works at their head office - I will ask him what he knows about it. None anywhere near me have such gismos.
Eleanors38
(18,318 posts)Left Coast2020
(2,397 posts)While riding in this thing, would we get to hear music from, "The Tubes?"
Sen. Walter Sobchak
(8,692 posts)As in to discard something into the sea, atmosphere or space?
kentauros
(29,414 posts)My guess is the writer wanted a word like "jet" and picked "jettison" from a list without having a clue as to what it really meant.
davidpdx
(22,000 posts)It takes me 10 1/2 hours to fly from Seoul to SFO, it would probably cut it down to 3 hours.
Bernardo de La Paz
(48,966 posts)In any case, it is not possible to erect a line of pylons across the Pacific Ocean to support the tube.
struggle4progress
(118,237 posts)Commercial jets cruise at 500 - 900 mph. He's talking about zipping through tubes beside the highway at 1100 ft/sec
He's nuts
Bernardo de La Paz
(48,966 posts)You are still living in 1965, when the land speed record jumped from 434 mph to 555 mph (894 kph).
Currently the land speed record is 763 mph (1228 kph)
Anyway, so what if it is 40 minutes instead of 30. I'm not going to complain about the extra ten minutes.
Elon Musk has been highly successful by thinking clearly and being open to ideas that others reject because they aren't ordinary.
He is demonstrably not nuts.
struggle4progress
(118,237 posts)Nobody in their right mind will hurdle through a tube at such speeds
freshwest
(53,661 posts)DetlefK
(16,423 posts)distance = 1/2 * acceleration * time²
With 1G acceleration for half the distance of 700,000m and 1G of decelaration for the other half, travel-time for the whole distance would be all in all approx. 530 seconds, that's about 9 minutes.
Top-speed would be approx. 2650 m/s, that's approx Mach 9.
EDIT:
With 0.5G, travel-time would be 750 seconds, that's 12.5 minutes.
Top-speed approx Mach 6.25.
With 0.25G, travel-time would be 1060 seconds, that's about 17.5 minutes.
Top-speed approx Mach 4.4.
freshwest
(53,661 posts)DetlefK
(16,423 posts)For the first half of the route you feel slightly heavier and tiled backwards, for the second you feel slightly heavier and tilted forwards. Inside the capsule, you have no way to witness the actual speed.
Earth rotates at highway-speed and we don't feel that either (except for coriolis-effect 'n stuff).
And it's so big that people can't imagine it anyway.
muriel_volestrangler
(101,271 posts)since the engineering problems multiply once you are supersonic. I'd also say that even 9 minutes of deceleration at 0.25g would not be popular - it's a fair time to be tipped forward.
DetlefK
(16,423 posts)700km with 300m/s that's 39 minutes. AND acceleration and deceleration are not in there yet.
muriel_volestrangler
(101,271 posts)And if we add up the section lengths in the paper, we see they reckon their route is 570km. And we also see he is designing to not go faster than sound:
Bernardo de La Paz
(48,966 posts)Summary (pg 41 of pdf):
300 mph (480 kph) for the Los Angeles Grapevine South section at 0.5g.
Total time of 167 seconds
555 mph (890 kph) for the Los Angeles Grapevine North section at 0.5g.
Total travel time of 435 seconds
760 mph (1,220 kph ) along I-5 at 0.5g.
Total travel time of 1,518 seconds
555 mph (890 kph) along I-580 slowing to 300 mph (480 kph) into San Francisco.
Total travel time of 2,134 seconds (35 minutes)
pg 42 of the pdf:
freshwest
(53,661 posts)They're not breaking the sound barrier in doing so. That kind of movement is as you describe.
Breaking the sound barrier is for test pilots I would suppose. Except, IIRC, the Concorde did that, high enough in the atmosphere to prevent complaints over sonic booms. I remember those as a kid when planes were doing it. IDK if they damaged much property, but they had to stop.
Some of this stuff is older tech. I don't see any problem with the system, and seeing things go by is not what I'm talking about.
Someone on the thread thought it was not possible to send people that fast - don't remember who it was and I've got to do some stuff here.
VanillaRhapsody
(21,115 posts)are not going to like not having windows to see as well as feel that effect.
DetlefK
(16,423 posts)VanillaRhapsody
(21,115 posts)thats what prevents me from having motion sickness in subway trains....
muriel_volestrangler
(101,271 posts)There will not be any left-to-right or up-and-down oscillation. It will be a steady force, just like gravity is; it will feel as if you are tipped back during acceleration (for about a minute at a time), and tipped forward during braking. Cornering will be done with the capsule tilting to the side so that the force you feel will still seem 'down' onto the couch. It will be extremely smooth (it has to be - the clearance between the capsule and the tube floor is about one millimetre).
Someone else brought up claustrophobia, which I think would be more of a problem - there's some confusion, but most reports say the interior of the capsule is just 1.1m, ie 3 foot 7, high. I think that includes the thickness of the couch, so you won't be able to sit up.
VanillaRhapsody
(21,115 posts)its about feeling movement but not seeing it and visa versa. Its why on a boat when you feel seasick....you look for land...so you can see the movement your body is feeling..
I cannot even play first person shooter video games because of the phenomenon. It's also why you don't get it when you drive and why you let the person with motion sickness sit in the front seat...
muriel_volestrangler
(101,271 posts)You won't feel movement; when the acceleration starts you'll notice one change in the direction of what you perceive as gravity (which your mind, without external reference points, will interpret as the capsule tipping forward a bit), then that direction will be steady for a minute, then the direction will revert to normal.
VanillaRhapsody
(21,115 posts)I couldn't feel movement in a video game...BUT the worst motion sickness I ever had was after playing a first person shooter. I don't think you understand the concept of what motion sickness is...
Edditted to add:
Motion sickness or kinetosis, also known as travel sickness, is a condition in which a disagreement exists between visually perceived movement and the vestibular system's sense of movement. Depending on the cause, it can also be referred to as seasickness, car sickness, simulation sickness or airsickness.[1]
Motion sickness can be divided into three categories:
Motion sickness caused by motion that is felt but not seen
Motion sickness caused by motion that is seen but not felt
Motion sickness caused when both systems detect motion but they do not correspond.
Simulation sickness, or simulator sickness, is a condition where a person exhibits symptoms similar to motion sickness caused by playing computer/simulation/video games.[1]
The most common theory for the cause of simulation sickness is that the illusion of motion created by the virtual world, combined with the absence of motion detected by the inner ear, causes the area postrema in the human brain to infer that one is hallucinating and further conclude that the hallucination is due to poison ingestion. The brain responds by inducing nausea and mass vomiting, to clear the supposed toxin.[5] According to this theory, simulation sickness is just another form of motion sickness.
The symptoms are often described as quite similar to that of motion sickness, and can range from headache, drowsiness, nausea, dizziness, vomiting and sweating. Research done at the University of Minnesota had students play Halo for less than an hour, and found that up to 50 percent felt sick afterwards.[9]
One common suggestion is to simply look out of the window of the moving vehicle and to gaze towards the horizon in the direction of travel. This helps to re-orient the inner sense of balance by providing a visual reaffirmation of motion.
In the night, or in a ship without windows, it is helpful to simply close one's eyes, or if possible, take a nap. This resolves the input conflict between the eyes and the inner ear. Napping also helps prevent psychogenic effects (i.e. the effect of sickness being magnified by thinking about it).
muriel_volestrangler
(101,271 posts)The vestibular system's sense of movement detects changes in the forces your head experiences. But the capsule will change those forces very rarely - and smoothly (and in just one direction - fore and aft) - once when it starts accelerating, and once when it stops accelerating. These are separated by about a minute. Without an external reference, it will feel like the couch has tipped (if you've flown, you may have noticed this as an aircraft accelerates down the runway. But it will be smoother than an aircraft - there can be no sideways or up and down motion).
With a video game, you see a constantly changing screen, so there are repeated mismatches between your vision and your sense of motion. Similarly, with sea-etc.-sickness, you get constantly changing motion, and it's much worse when you cannot see a true horizon (I do get seasick in sailboats, and sometimes feel queasy if I read in cars, so I do have some idea what it's like). But it takes a continued disagreement in the signals, rather than one momentary disagreement, as the acceleration starts.
Eleanors38
(18,318 posts)theHandpuppet
(19,964 posts)Juts curious.
Bernardo de La Paz
(48,966 posts)Accelerating (in real units) 0 to 100 kph in 6.4 seconds is 0.44 G.
Accelerating (in provincial units) 0 to 60 mph (97 kph) in 5.4 seconds in 0.5 G.
Tesla cars do 0 to 60 in 3.9 seconds to 5.9 seconds.
A 2012 Toyota Camry SE (V6) does 0-60 mph in 5.7 seconds (probably with some tuning).
2011 Ford F-150 FX4 Super Crew EcoBoost 4x4 (V6) 0-60 mph 6.0 seconds.
theHandpuppet
(19,964 posts)Appreciate the explanation.
Ian David
(69,059 posts)And the thing doesn't roll on wheels; it glides on a curtain of air.
DetlefK
(16,423 posts)$12 billion. How did the critic arrive at $12 billion?
The distance is 735km, let's say a gauge is installed every 10 meters, that's 73500 instruments.
Pressure-gauges capable of going down from 1 bar to sub-mbar-range cost a few hundred bucks, tops. Round it up to $1000 per piece for cables, installation and computerization.
My number is $73.5 million for the hardware...
muriel_volestrangler
(101,271 posts)Musk reckons $10 million for the cost of the vacuum pumps for the entire system, including the airlocks at the stations. Maybe it's a question of what you want to do if a leak is detected - just a safe shutdown/conversion to working in atmospheric pressure mode for the whole tube, or an attempt at maintaining the low pressure in sections away from the leak? If the latter, you would presumably need a lot of pumps, all along it.
DetlefK
(16,423 posts)IIRC the counter-force by air-friction scales linear with air-density, so approximately linear with pressure.
0.5 bar would already be a decent increase in max velocity. I doubt, he would have to go below 0.1 bar, which is easily achievable. And at this pressure, a leak wouldn't be catastrophic: The pressure would slowly rise over time, like air flowing out of a balloon, especially if such a huge vessel has to be filled.
The pumps could run 24/7, it wouldn't make a difference to the procedures.
If a leak is detected, send out a repair-crew by car and weld the hole shut.
Optimal pressure would be restored within hours to days. (Within minutes in a gallon-sized vessel, but this is a huge tunnel we are talking about.)
EDIT:
You can estimate about the same price for the pumps, so let's say $200 million. Not even close to the several billion dollars that were brought up.
muriel_volestrangler
(101,271 posts)The capsules have to be able to maintain a decent speed while coasting for significant distances.
DetlefK
(16,423 posts)1 mbar: Can be build up with rotary vane pumps, which work between 1 bar and 0.01 mbar. There are also gauges that work in that range. And rubber gaskets on the flanges would be good enough.
Looking for leaks on a vaccum-vessel is a really time-consuming and unnerving job, but the pumps wouldn't have a problem at this pressure: Any hole big enough to cause trouble (millimeter-sized and bigger) would be visible with the naked eye and either located on a flange or a weld.
At this pressure, the pressure-gradient is very small, so it would be hard to locate a small leak with a warning-system (apart from having a bad pressure in general).
My advice would be to have a surveillance-crew check the welds on the pipeline year-round, maybe once a week. (earthquake-area!)
muriel_volestrangler
(101,271 posts)Checking welds once a week for a 350 mile pipe (needing access all round it) would be a notable cost.
DetlefK
(16,423 posts)The power of the pumps and the measurements of their pipes. And of course the size of the leak.
Distance wouldn't matter for the pumps. 1mbar is still such a high pressure, that any increase would immediately spread out evenly along the whole tunnel.
Okay, once a week is too much, but once a year is definitely not enough.
Maybe shut the whole thing down for a week every 3 months...
freshwest
(53,661 posts)DetlefK
(16,423 posts)Levitating the train on an air-cushion wouldn't work at these low pressures.
And tracks always have the risk of too much friction.
Maglev only has air-friction, but I have no estimates for cost and efficiency.
muriel_volestrangler
(101,271 posts)A lot of the cost advantage of this design is to keep most of the system a simple metal tube - no built-in machinery for most of the 'track', just occasional booster sections, and for inclines.
liberal N proud
(60,332 posts)Jim Powell, a co-inventor of the bullet train and director of Maglev 2000, which develops high-speed transport systems using magnetic levitation, said the system would be highly vulnerable to a terrorist attack or accident.
What a lame ass reason for criticizing the plan.
DetlefK
(16,423 posts)liberal N proud
(60,332 posts)Crossing a bridge, is a risk, they could blow it up or just stop and blow up a busy highway. To think that a new proposed system is any more vulnerable than another is ridiculous.
Posteritatis
(18,807 posts)Something new? Terrorists could attack it!
Something large? Terrorists could attack it!
Something more convenient? Terrorists could use it!
etc.
Bin Laden's giggling from wherever he wound up, for certain.
liberal N proud
(60,332 posts)Eleanors38
(18,318 posts)Its liquid fuel rocket engine provided part of its thrust in the opposite direction thru small holes in the highly-tapered nose, thus providing a small though constant "envelope" of cavitation in the water = far less resistance and far greater weapon performance: 9 mile range, well over 200 knots & 1.5 ton warhead.
Kingofalldems
(38,425 posts)hunter
(38,304 posts)90% of the time building something new, increasing "productivity," or going faster is the WRONG answer.
This civilization needs to slow down and enjoy life. The death race has got to stop.
I'd rather take a slow train from San Francisco to Los Angeles, time to take in the scenery, open the window and smell the orange blossoms on a nice day, and most of all, have the time to do that.
Travel by automobiles, aircraft, or tubes is not my idea of "progress."
Stretching weekends from two to three days, vacations from two to six weeks or more, that's my idea of progress.
Our current notions of "productivity" are bullshit.
hughee99
(16,113 posts)and less time getting there. Some people would rather spend the day with family or friends in another city than with strangers on a train, no matter how nice the scenery is.
hunter
(38,304 posts)Maybe the U.S. military could get me there in a day, but commercial transport takes longer to arrange and it's expensive.
My parents bought their dream retirement home years ago and I've never seen it because I can't afford to get there.
I do see my parents when they visit. Every two or three years they come back to California to visit everyone who can't visit them. They fly over the ocean, but then they ride the bus, hitch rides, and stay with friends, family, and folks they've met in their travels.
I was fortunate to see Europe as a kid, a year on the road with my parents and all my siblings. But I wouldn't recommend that sort of travel to anyone. We did not fly, we took a train across the U.S.A., sleep in your seat class, and a ship across the Atlantic, bunks in a room without windows class, and no return ticket. Many parts of Europe were still very poor just like we were poor.
Travel for pleasure is a privilege of wealth. Until we discover cheap fusion energy, control our population, and otherwise demonstrate some sort of intelligence as a species, it will always be thus. Ordinary people don't travel for pleasure. They don't fly, they don't stay at the Holiday Inn, and they don't rent cars. They travel for work, or recklessness, or desperation. All my ancestors came to the U.S.A. in the 18th and 19th century out of recklessness or desperation. Tired of being a sailor? Jump overboard in San Francisco, swim, and run! Hungry and cold in Northern Europe? Mail-order bride to polygamist Salt Lake City doesn't look so bad.
I saw Europe as a kid because my parents are reckless. I'm fairly well traveled because I'm reckless. My wife and I did not pass the reckless tradition on to our kids. We did not take them on reckless travels. If they've gone on their own reckless travels as young adults we haven't heard about it... yet.
Our modern fossil fueled transportation system is unsustainable. The carbon dioxide spilled will probably sink this civilization. Unless something changes there will come a time when fast transportation can no longer be supported, even for the very wealthy. A huge fossil-fueled infrastructure is required to build and maintain jet airliners and other high speed transportation systems. I don't think this civilization is going to last. I'd like to build a civilization that's more resilient.
When and if humanity can get it's act together, then maybe something like this evacuated tube transport becomes safe and sustainable.
tabasco
(22,974 posts)What kind of commie idea is this anyway - transporting people without OIL??
Piedras
(247 posts)The Hyperloop does have some significant technical challenges facing it, but so does any ambitious idea. Its also not a new idea. Proposals like it, usually known as a vactrain, have circulated for the last 100 years. Yet there are significant problems with the Hyperloop specifically with the way its being discussed and framed. Many of the same media outlets that have spent the last five years criticizing every detail of the California high speed rail project have today been reporting on the Hyperloop concept without the same levels of skepticism that theyve brought to HSR even though HSR is a commonplace, proven technology whereas the Hyperloop is a concept on paper.
The Hyperloop as proposed by Mr. Musk does not go from downtown San Francisco to downtown Los Angeles. It stops short of both, particularly from LA. So its touted travel time in comparison to high speed rail is unknown and/or misleading. It can carry only 28 people a time compared to 1,000 to 1,200 people on board a high speed rail train. It bypasses intermediate stops in the California Central Valley like Fresno, Bakersfield, and other cities so far fewer people would benefit from it.
The cost estimate for the Hyperloop seems to be overly optimistic as does its time to begin operation. Robert holds that much of the time to begin operation of High Speed Rail is due to political consideration and opposition from NIMBYs, that a Hyperloop would most likely face too.
Further High Speed Rail is a mature technology around the world, with further improvements to come, while a Hyperloop is unproven with unknown risks.
Stop And Move another blog Roberts links to takes a critical look at the travel time for the Hyperloop proposal:
Hyperloop trip between downtown LA and downtown SF:
1 hour from LA to Sylmar via Metrolink
20 minute transfer
35 minutes to Dublin
20 minute transfer
1 hour 10 minutes from Dublin to LA via BART (oops, this probably should be Dublin to SF)
Total: 3 hours 25 minutes
An entire hour more than traditional HSR! It turns out that stopping at the edge of the metropolitan area, where nobody is actually going, sort of kills your time advantage. You see the same when comparing rail vs air. Sure, planes fly at 550mph....but the airports aren't your destination.
So, if the above is accurate the journey time from SF to LA could be longer via a Hyperloop!
There are many more good points about the likely costs, travel times, political realities to be faced, safety considerations, and time to begin operation in the two blogs linked to above.
Bernardo de La Paz
(48,966 posts)Re: 28 people per time: that is a bogus argument, rather like saying that cars are useless for carrying people from LA to SF because they can only take 5 people per time. Multiple capsules would be in the system at any given time, just like there could be multiple trains at different points on a track and multiple cars on a highway.
The advantage of 28 people per capsule is that there would be so many capsules going that you wouldn't have to make a reservation: just show up at the station and take the next one.
Re: NIMBY: Musk makes the valid point that the Hyperloop pylons would be placed alongside the existing I-5 highway and would require very little in the way of new right of ways. Those right of ways would be much like electrical transmission towers in farmers' fields that they are very used to and would not pose a problem for anybody.
By contrast, the California High Speed Rail would require a lot of new right of ways and that is part of its expense.
Piedras
(247 posts)I'm not convinced that Hyperloop, HL for short, would have a passenger capacity equal to High Speed Rail, HSR. Not unless some unknown number of additional tubes each way are built would equal the capacity of a two track high speed rail system.
With 28 people per HL capsule it would take roughly 40 of them to equal the passenger capacity of one high speed train. How often could the capsules depart? If one leaves every 30 seconds it'd take about 20 minutes for them all to equal one (nearly) full train. If the HL capsule headway instead is two minutes it would take well over an hour for them to to transport as many people as one single train.
In time there will be many high trains per hour. Perhaps four to six high speed trains departing per hour in each direction. With a fifteen, or six, minute headway for trains at peak times people could travel almost any time they wish to.
It would take additional HL tubes and capsules to move as many people per hour as HSR will be able to, at considerable added cost for more tubes and right of way.
Building a HL system all the way from downtown SF to downtown LA will involve considerable cost for its right of way too. It can't all go alongside Hwy I-5, which would unlikely be "free". The owners of the Tejon Ranch are opposed to giving up right of way. Many miles will have to go through the SF Bay Area and metropolitan LA, where right of way will be very costly.
Those built up areas are likely to have NIMBYs oppose a HL on elevated pylons. More rural farmers and ranchers may too.
Fewer Californians benefit. Going from SF to LA via I-5 bypasses millions of Central Valley Californians. Californians who will be able to ride HSR. Those bypassed Californians are less likely to politically support an expensive Hyperloop.
Bernardo de La Paz
(48,966 posts)If the cost of building Hyperloop is $12 billion and the HS Rail is $70 billion, then you could build six Hyperloops for the cost of one rail line. If you use the same corridor you could probably build them together for less cost by using bigger pylons with two or three
tubes in parallel.
For $70 billion you could run Hyperloop from San Diego to Vancouver, British Columbia with a spur to Las Vegas.
Piedras
(247 posts)Last edited Wed Aug 14, 2013, 02:20 PM - Edit history (1)
Clem, a participant in the California High Speed Rail Blog has eight "show stoppers" doubting the viability Elon Musk's HyperLoop proposal. A big dump of all my thoughts on the HyperLoop
kudos for trying, but the concept is not even half-baked.
My list of show stoppers
Show Stopper #8: 0.5g acceleration seems a bit excessive for a comfortable ride. You want this to feel like a swift elevator or subway, not like a roller coaster. 0.5 g is firmly in roller coaster territory and requires the passenger to be strapped in at all times with drinks and laptops put safely away. (Oh and how do you strap in a Model X?) Try more like 0.15 or 0.2 g. This has large and costly impacts on the acceleration sections; the reason for keeping the acceleration so high is to keep the acceleration sections short.
Show Stopper #7: There is little in the document that discusses the cost, size or weight of environmental control and life support systems, basically providing a safe and comfortable environment for the passengers inside. The driving case here is not based on journey times, but on emergency evacuation where it is conceivable a capsule could languish in the tube for quite a while. (How long would repressing the whole tube take, before emergency hatches can be accessed and opened?) This vehicle subsystem would not be unlike a business jets environmental control system, which is neither small, simple, light-weight, nor cheap.
Clem has six more HyperLoop "Show Stoppers" at the above link.
Show Stopper #6 Thermal issues
Show Stopper #5 Branching issues
Show Stopper #4 Vacuum issues
Show Stopper #3 Security issues
Show Stopper #2 Safe stops and restarts issues
Show Stopper #1 Equipment failure issues
There is a (mostly) well informed discussion of HyperLoop issues in blog linked to above.
Bernardo de La Paz
(48,966 posts)Piedras
(247 posts)Clem's list of eight HyperLoop "show stoppers" counts down to Show Stopper #1 Equipment Failure:
Eight HyperLoop Show Stoppers
- the time for the preceding capsule to clear a junction and free the routing through the junction to be changed for the following capsule
- the time for the route through the junction to be changed
- the time for the control system to confirm the new route is clear
- the time for the following capsule to perform an emergency stop if the new route is not clear for whatever reason
- a bit of extra time for safety margin.
This is no different than for HSR, and the resulting minimum headways are usually several times longer than the emergency braking distance. HSR deals with the capacity limitation imposed by the minimum headway by (1) packing a huge number of people into one vehicle, e.g. two double-decker trains coupled together with over 1200 passengers, and (2) by operating at top speeds that strike an optimal balance between reasonable braking distances and close headways. Hyperloop cant strike this balance: in order to work, it requires very high speeds (and greater emergency braking distances), can carry only a few passengers per capsule, and requires relatively short headways. The two-minute headway assumed in section 4.1 is speculative at best, and its not at all a given that the Hyperloop could ever provide the same transportation throughput (in passengers per hour per direction) than plain old HSR. Not by a long shot. The minimum headway question is fixed guideway system design 101, and may be the Achilles heel of the whole concept. It is not sufficiently addressed in the document.
hunter
(38,304 posts)The land's bought, no reason to turn it all over to cars and trucks.
We ought to be doing everything we can to discourage automobile commutes, short-hop airline routes, and the like.
There's no excuse for more than four lanes of fossil fueled highway traffic or sub-1000 mile continental airline traffic.