You young'uns posting on this Web site ain't old enough to remember much of anything, say, from the mid 20'th century. About that time period, there was a flowering of ideas to meet the challenges of passenger transportation in an ever more crowded as well as prosperous world where everyone wanted to travel everywhere.
The Jumbo Jet as well as an American and a pan-European version of a supersonic transport (SST) were on the drawing boards. The Japanese made waves with their Shinkansen. Highways were eventually to be automated where "drivers" would become passengers, but in the mean time, a group at Cornell had this concept called The Century Expressway, taking the best ideas of the Interstate and the Autobahn to come up with a controlled-access road with specially qualified vehicles (and drivers, there were thoughts to competence or sobriety tests of reaction time on roads to gain access), with the idea of 100 MPH auto travel with a high degree of safety.
Of the many ideas, one was the "tube train", meaning, travel between major cities in trains (steel rail was specified because levitated vehicle concepts back then were "air cushion" and maglev was more speculative). The tube would either be in a vacuum or at least reduced air pressure so as to reduce aerodynamic resistance. Furthermore, the tunnels between stations would be sloped that a train accelerated by simply being allowed to roll downhill whereas the uphill roll into the next station would slow the train down, accelerating and retarding the train through the force of gravity without added energy expenditure. Do some subway lines do this, even a little bit?
I remember that social critic, train enthusiast, NARP board member, and author Peter Lyons of "To Hell in a Day Coach" was dismissive of the plan as not being a proper train where you could look out the window and see the landscape roll by, calling passengers on such a train akin to "scared rabbits rapidly scurrying through burrowed tunnels."
Let's just allow that it was just a concept, and in some future where tunneling is done automatically by robotic machines, maybe there will be some use for it. Keep in mind that scientists, engineers, and planners entertain a variety of seeming impractical concepts in case conditions change that they become of merit.
My Father was an engineer and developer of such transportation concepts at GATX, yes, the tank car people, the same people who dreamed the dreams we are speaking of. In the manner of "digging a hole to China", if one had the technology to construct tunnels along straight lines through the center of the Earth, this tube train could achieve the following:
The travel time between any two points on the globe would be exactly 4 hours and 40 minutes. Playing the "straight man" to Father so he could tell the punch line to his joke, I asked for his explanation. A frictionless train in "free fall" in a straight-line tunnel connecting any two stations on the globe would have a mathematically determined travel time of 40 minutes -- essentially half the time for a spacecraft to orbit the Earth. The other 4 hours? You need 2 hours at each end for local surface transportation, clearing security, immigration, and customs . . .
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
Oh yeah, Ely Beach and the Pneumatic Transit Company. It's been years, but I read a magazine article about it years ago, I think in National Geographic. It wasn't economically viable but a section still survives (sorry, don't remember where) in all it's Gilded Age glory.
Isambard Kingdom Brunel came up with a vacuum propelled railway in the 1850's. That was a bust as rats and mice had a bad habit of eating the greased leather flaps that sealed the system. I believe the French tried the same system and had the same critter problems. C'est la vie!
John WR henry6Oddly enough one of the first subway ideas for NYC was an air compressed tunnel pushing the car through a tube. Wasn't that for the then Hudson and Manhattan Railroad (now the PATH trains)? And isn't the idea still used to ventilate the tunnels?
henry6Oddly enough one of the first subway ideas for NYC was an air compressed tunnel pushing the car through a tube.
Wasn't that for the then Hudson and Manhattan Railroad (now the PATH trains)? And isn't the idea still used to ventilate the tunnels?
He was talking about Alfred Ely Beach and the Pneumatic Transit Company.
This is not a vacuum system, it's compressed air. "Suction" was used to reverse the train in its short tunnel, but in practice I doubt this would have been the 'preferred' method.
I fail to see any 'parallel' with ventilating the vehicle tunnels. There you want high flow at minimum pressure -- you are exchanging the atmosphere, not using it to power something.
I didn't read the articles but inferred from the comments that its that time of the decade when someone trots out the "bank canister in an airless tube = no air resistance = super fast!" idea.
So basically you need to construct massive infrastructure at enormous cost then build what is effectively a spacecraft to move into that tube. Why not just forgo the tubes, put your spacepod on top of a small rocket or carrier aircraft, and do suborbital hops at faster speeds and lower costs?
ontheBNSFWell no I was just suggesting that using pneumatic tubes wouldn't be astronomical to add proportional to something without tubes.
And you probably said that with a straight face.
I strongly advise you to figure out some more about guideway construction and materials before making such a claim seriously.
Making a tube that is vacuum-tight and independent of a high-speed guideway is nontrivial, even before you take up the issues of operation and maintenance. Making a tube that is vacuum-tight, structural, and capable of the fine alignment adjustments needed in long-term service is... well, let's just say likely to be enough "proportional to something without tubes" to make even national governments lie down and cry.
Now, it is true that if you are going to spend billions to run arrow-straight tubes below grade for most of their run, there is only slightly greater expense to tube the brief sections between mountainsides. But then you get to the issue of pumping cost vs. achieved speed for the runs where vacuum operation in tubes is practical. (Or did you think you could run multiple trains on short headways in a vacuum tunnel...)
As noted, if you are going to the expense of building the necessary tubes, you'll be far better off with hydrogen than vacuum. Assuming you have a business model that works net of the cost of the tube building...
What about ventilating the PATH tunnels?
ontheBNSFVacuum Tube Maglev Trains are the Future. Also google Vactrain or a different approach to the technology ET3 which involves pods. I view trains to be the superior solution because they offer more space and carry people more efficiently than individual vehicles.
A much better tube-train system is that propounded by Arnold Miller, which uses a tunnel filled with hydrogen and a train driven by propfans and 'suspended' on gas bearings. Speed of sound *in hydrogen* is about Mach 2.4 equivalent; lower aerodynamic resistance (even though gas viscosity is surprisingly high) and there is not the hopeless exercise involved with keeping long sections of a tube evacuated while retaining the necessary ability to decelerate smoothly for stops or termini.
Just the opposite of a conventional vehicle, the fuel is ingested, and the oxidizer cryogenic (LOX). Interestingly, Miller wants to retain the 'combusted' water on board rather than venting it into the train's wake.
Some interesting collateral and video, and scientific treatment of the physics involved, on the Web.
RME
Phoebe Vet & how do construction prices in China compare to prices in the USA? In 2009 Congress estimated HSR would cost $22 to $27 million per mile. That was above ground and using much existing ROW. Do you believe that you can drill or dig hundreds of miles of subway tunnels and add the machinery to evacuate the air for just another $3 million per mile?
& how do construction prices in China compare to prices in the USA?
In 2009 Congress estimated HSR would cost $22 to $27 million per mile. That was above ground and using much existing ROW. Do you believe that you can drill or dig hundreds of miles of subway tunnels and add the machinery to evacuate the air for just another $3 million per mile?
Well no I was just suggesting that using pneumatic tubes wouldn't be astronomical to add proportional to something without tubes. The price of conventional maglev in Orlando is around 20 million per mile compared to 18 million dollars for Shanghai's maglev I wonder how much more that would cost with pneumatic tubes? The truth is HSR is more expensive than maglev. Maglev is being rejected for political reasons mostly and backwards compatibility reasons of course maglev has less regulations so that partially contributes to price differentiation.
more info on the airless tubes
http://nextbigfuture.com/2010/08/very-low-air-pressure-maglev-train.html
Railroad to Freedom
zugmann Somebody's been watching Futurama...
Somebody's been watching Futurama...
Who was the legendary guy who used to make all those "quirky" posts on here some years ago?
C&NW, CA&E, MILW, CGW and IC fan
Dave
Lackawanna Route of the Phoebe Snow
No, this was long before H&M was even thought of...before Aster built the IRT...and maybe even 20 years before then.
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Phoebe Vet It's technologically feasible, but the cost and the bureaucracy would be astronomical.
It's technologically feasible, but the cost and the bureaucracy would be astronomical.
Well it costs about 3 million dollars a mile more than conventional HSR atleast in China. So it certainly costs more than existing technology but it is not astronomical.
Oddly enough one of the first subway ideas for NYC was an air compressed tunnel pushing the car through a tube.
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any
henry6 What? It would like being in the cannister/transporter at a bank drive through window! No thanks!
What? It would like being in the cannister/transporter at a bank drive through window! No thanks!
From the title I though you meant trains with computer systems that used vacuum tubes rather than transistors.
Vacuum Tube Maglev Trains are the Future. Also google Vactrain or a different approach to the technology ET3 which involves pods. I view trains to be the superior solution because they offer more space and carry people more efficiently than individual vehicles. The technology could very easily replace Airplanes atleast as a form of land travel. Such a system could be powered by thorium or other sources of energy. https://www.youtube.com/watch?v=E7M3EOD_GzEhttps://www.youtube.com/watch?v=nSJXvQu4hjwhttp://www.popsci.com/scitech/articl...tlantic-maglevhttp://www.dvice.com/archives/2010/0...-hatches-p.php
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