http://themindunleashed.org/2014/08...ign-14000-mile-hour-vacuum-tube-railroad.html Certainly an interesting idea... the above is just a short excerpt.
Isn't this old news? I agree with mathman as well: Imagine the legal fess and zoning hearings and payoffs and kickbacks. And all that.. I just want my own 700 hp custom and my own damned road, thank you. Just like all the other true Murricans! :bugeye: (Unlike a lot of folks, I can build that car. Couldn't drive it any more, but I can build it.)
Hyperloop is from 2012. The projected construction costs are severely underestimated and they'll never make money at $20 a ticket. A 120 mile non-stop trip on a regular Amtrak train from my local station is $28 and they lose money every single year (nationally too). The Concorde lost money every single year, until British Airways took over and started charging almost $10,000 (roundtrip) per seat. Today's conversion rate puts the £8,292 ticket at $13,910.24 for London-New York roundtrip.
The idea of a vactrain has been around for some decades now, at least as old as Robert Salter's proposals of 1972 and 1978: The Very High Speed Transit System | RAND, Trans-Planetary Subway Systems: A Burgeoning Capability | RAND However, it has never been tested at full size, as far as I know, and such a system would require a LOT of testing before it could reasonably be considered safe enough for human passengers. There are also problems with the cost estimates. This system is to be run in a viaduct, an extended bridge. It's hard for me to find cost estimates for viaducts, so I'll use the Cypress Street Viaduct - Wikipedia It was a 5-mile (8-km) replacement of an earlier one that was destroyed by the Loma Prieta earthquake of 1989. It was originally estimated at $650 million, but it grew to $1.25 billion, because of some extra work. It's a 6-lane highway, though it looks 8 lanes wide. It's one of the Interstates, so its lanes would be 12 ft wide. If the four possible lanes of each half of the highway were wrapped into a square tube, one would get about 12 ft * 12 ft on the inside, about right for a train. So one gets $130 to $250 million per mile. The line would have to be *very* straight, with the exception of the Earth curving underneath it, and that means that its distance is the great-circle distance of 350 mi. With the originally-estimated cost and the actual cost of the Cypress Structure, that comes to about $46 billion to $88 billion. That's not counting the vacuum pumps or the magnetic-levitation propulsion system or the computer control system. There would also be the big problem of NIMBY opposition. The proposed California high-speed-rail line has already provoked a lot of NIMBY opposition, and a pair of big tubes on stilts seems almost like NIMBY bait.
By comparison, the high-speed-rail line proposed for California uses existing technology, and very successful technology at that. Technology in successful service at both the eastern and western ends of Eurasia: east Asia and Europe. In Europe, high-speed lines are almost continuous between the English Channel / North Sea and southern Spain, a distance around 2820 km / 1750 mi. The route is: Amsterdam - Rotterdam - Antwerp - Brussels - Lille - Paris - Lyon - Valence - Avignon - Montpellier - (gap) - Perpignan - Barcelona - Zaragoza - Madrid - Cordoba - Malaga Its great-circle distance is 1880 km / 1170 mi. There's also a branch from Lille to the Chunnel, and a high-speed line from the Chunnel to London.
I think it's a super-cool idea, especially when proposed by Musk who likes to make good things happen. It might eventually result also in sub-ocean travel routes around the world -- faster than a speeding bullet (as in Superman Please Register or Log in to view the hidden image! ).
The Concorde was my first thought: engineering marvel, economic nightmare. The problem with the pneumatic train is that it has to be long-distance to be of any value; nobody needs to go ten blocks in two seconds. But a large system poses large problems before it can even begin to produce revenue. By contrast, look at the cell-phone system. It developed from the inside out, as it were; a small number of cells in large cities grew into a global network.
My question with this... if you intend to do it all in a vacuum, then obviously the cars need to be self-contained atmospheric pods... but beyond that - how long does it take to "evacuate" the entrance/exists from the main line? You'd have to have the entire train enter a giant "airlock", establish the vacuum, then allow it to enter the main line, which is already a vacuum... else, how long would it take to establish a vacuum in an area as large as a trans-continental train line?
Well: 1) it's not a vacuum, it's just very low pressure and 2) there's nothing that says the entire tunnel has to be pressurized for loading. You can open a hatch on the outside of the tunnel when the car is there, open the car hatch, accept whatever leakage you get around the edge, unload/load, and close both doors again. All that being said, the comparison between hyperloop and a much simpler light-rail track would be a no brainer; the light rail track would be orders of magnitude cheaper, can still be solar powered, and could easily reach commercially viable speeds (100+ MPH.) The right of way for an elevated track is easier than an on-grade system and rail technology is fully developed. I've often wondered why Vegas casinos don't get together and fund a high speed rail line from Victorville to Vegas. It would increase traffic to their casinos, the route is an established high traffic route, and it would be faster than flying. Add gambling on the train and you'd make money from the get-go.
Strictly speaking, what's usually called a vacuum is very low pressure. But even a very low vacuum, a few percent of outside atmospheric pressure, the inside-outside pressure difference will be nearly all of the outside pressure. So one has to maintain that pressure along the entire length. That's not very fail-safe. Yes, an airlock. I agree, though a vactrain would likely also be electrically powered, and electricity is the easiest way to deliver energy from most renewable sources. There's already a planned system, the XpressWest, but it has not gotten very far. I don't know how far the casinos have gotten in funding it. Most of its route will be in California, so there'd be only about 15 minutes of gambling on board it, when it's in Nevada.
Agreed. It just makes it easier to pump down. Well, no, an airlock is a chamber where pressure can be drawn down and brought back up. In my case you'd just align the two doors, open them (not pump anything up) then close them (and not pump anything down) and you're on your way. Losses are the (small) volume between the two doors and seal losses. Unless you got an Indian tribe to operate the on board casinos . . .
My first reaction to something like this is, what if there's an emergency? You can't just stop the train and get out, because you're surrounded by a tube at near-vacuum pressure. Rescuers would also be hampered by this tube because even if they could break through, it would cause sudden compression shockwaves. I know that's similar to an airplane, because you can't just stop the plane and get out either, but for reasons that appeal more to "common-sense". Of course you can't just exit the airplane while it's in the air. But with a train "on the ground", people would go crazy if they can't evacuate. All it would take is one accident in the relatively early history of hyperloop commercial operation, and everyone would rage about how stupid it is to be trapped in a tube. Investors would cut and run. On top of this, I'm pretty skeptical about those low construction costs. Also, calling it "crash-proof" is just asking for trouble. There is no such thing as crash-proof transport, land, sea, air, space, anything. I could be wrong, of course. After all, I can't fathom how a tunnel is cheaper to carve for the Chunnel, rather than a bridge. The English Channel water is perfectly shallow enough to drive pillars for a bridge. But they dug a tunnel anyway. Don't they worry about earthquakes? Also there are already a lot of elevated monorails where you can't just stop and exit because you're up so high, but I believe those are mostly low-speed city commuters instead of high-speed lines between cities.
