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Pipeline Mass Transit?
pipingguy writes "'Evacuated Tube Transport (ETT) is a new kind of transportation system that requires less than two percent of the energy of current transportation methods. It is also much safer, and can be faster. [...] Anyone can visualize 2 tubes (one for each direction) along a travel route. Air is permanently removed from the tubes; so travel takes place without friction. Pressurized passenger capsules (like a 2 - 8 person airplane cabin), travel in the tubes on thin steel wheels or on nearly frictionless Maglev. Airlocks allow access without admitting air to the tubes. Linear motors (as used on new rollercoasters) accelerate the capsules. During most of the trip the capsules coast; using no power. When the capsules slow down, linear generators recover most of the electrical energy used to accelerate the capsules.' Some CG images and drawings here, the FAQ is here." MSNBC had an article on monorails a few days ago. Don't bother making Simpsons jokes, the article has them covered already.
From their website "For fiscal operation, both corporate and public operation is encouraged by the non-exclusive, low cost licensing plan. The license promotes both cooperation and competition."
"Eve of Destruction", it's not just for old hippies anymore...
They say that the pods (or whatever you call them), will run on thin steel wheels, I suppose because they think that the thinner the wheels, the less friction or something, which shows that they obviously never took general college physics, because if they did, they would know that friction is not dependent on how big the contact area is.
Eagles may soar, but weasles don't get sucked into jet engines...
You'll never keep a vaccum with this.
Not with the hundreds of miles of tube.
Not with termal expansion/contraction.
Not in an active city with people building, digging holes, running infrastructure.
Not in an even remotely seismic active area (remember the earthquake in NY?).
While its a cool idea, its just that, an idea. There's no way to overcome the problems and still make it as durable and cost less than existing technology.
I'm out of my mind right now, but feel free to leave a message.....
http://www.pbs.org/wgbh/amex/technology/nyundergro und/secret.html
True, but they're also hard to produce, brittle, and very, very expensive.
Magnetic field strength falls off very quickly: "From single conductor sources, magnetic field strengths decrease directly proportional to the distance from the source (1/D). From multiple conductor sources, magnetic field strengths decrease as the square of the distance (1/D). And, from coils or loops, magnetic field strengths decrease as the cube of the distance (1/D)" (grabbed this quote here.)
Someone further down was talking about superconductors; while in theory much more energy efficient, there are none currently that don't require massive cooling systems to lower them to the necessary temperatures. The cost of laying out miles of superconductors below ground is mind-boggling.
A neodynium magnet is incredibly powerful for its size(I've managed to squash a thumb between two hard drive magnets while being stupid), but the field strength fall-off means that a huge mass would be required. It might even be cheaper to build a superconducting system after all.
Since when does no air == no friction?
If you take two sticks into space and rub 'em they're still going to wear against each other. No?
-- El Sacarino tiene gusto de la chocha
I'm not sure if that makes this a "new" idea. In a paper Robert Goddard, the father of modern rocketry, wrote in his freshman year at Worcester Polytechnic Institute, he proposed, "in detail a railway line between Boston and New York, in which the cars were run in an evacuated tube and were prevented from metal-to-metal contact with the guide rails by electromagnets." This quote is from a Goddard Biography by Edward Pendray. Goddard estimated a Boston to New York travel time of 10 minutes.
Exactly this concept of transportation has been under consideration in Switzerland for a long time under the name Swissmetro. The idea is to link the major population centers together, creating in effect a single country-wide city. The technology is ready to build the demonstration track from Geneva to Lausanne (~30 km), but so far, the government and the Federal Assembly have been unwilling to shell out the CHF 1.5 bio (about /$ 1 bio) required to do it.
Go hither for a cool simulation video or thither for technical details, or even yonder for the math.
This concept has been looked in for the last 20 years in Switzerland under the name of "Swissmetro".
A quick summary of it here.
The most complete analysis of the project I've seen here.
Basically, it's probably doable, but the major roadblock is a VERY strong political support (even in a very pro-mass transit country like switzerland), because of the massive costs to validate the faisability of it. In Switzerland, that support has not materialized in the last 20 years.
-- p a n a p i c - panoramas des alpes: Mont-Blanc, Mont-Rose, Cervin, etc...
Not a bad way to do this calculation, if you don't have access to calculus and the like. Unfortunately, your answer is wrong, because the radius of the Earth is a touch under 7000 kilometers, not 13000 as you claim.
An easier way to do this would be to remember that the centripetal force required to keep an object with mass m moving in a circular orbit of radius r and speed v is just m*v^2/r. Equate that to the force of gravity at sea level and you have that:
v^2 = g*r
Just think of gravity as being the "string" that keeps the satellite in its circular path. At sea level, this works out to 8.3 km/sec or thereabouts. Incidentally, it can be shown that the minimum escape velocity is just this number multiplied by the square root of two.
Cheers,
Mouser
That's interesting, but then you have traded one wind resistance for another. Instead of train/air you have air/tunnelwall. And you have many KM's of surface area to drag against now.
I've had enough abrasive sigs. Kittens are cute and fuzzy.
I agree. I lived in London, UK for two months last spring, and I was amazed. The underground stops at midnight, but the busses run all night long. And getting into and out of London is relatively easy as well. Admittedly, I walked a lot more than I would be willing to in the US, but in the heart of London, you don't usually have to go more than 3 blocks to get to a station on the underground.
I knew several people who lived outside of London, as well - and only two of them had cars.
As a whole, Americans are too lazy to make public transportation viable. Unless you're in a big city, the only people who take the bus are people too poor to have a car - and since so few people use the buses, there is no incentive to a) have busses stop more often, or b) put stops closer together.
I couldn't even get a job this summer because I didn't have a car...
Have you read the Moderation Guidelines Addendum?
I talked with American (car mechanic ironically) who just returned from a trip to Russia, and he was amazed by availability of all the options of mass transit - buses that go 24 hour a day, trams, trains that go to almost every town (and do this often and fast).
Maybe you should come to NY... I live in a small part of NYC (Staten Island) and even here there are buses that run 24/7. A bus usually comes every half hour all day. There's also a ferry that goes to manhatten (when people talk about NYC, they're usually talking about manhatten), from staten island, at least every hour (every 15 minutes during rush hour.) There's the metro north also, I can take a train to just about any place in the state of NY for a few dollars. The buses and subways cost $1.50 (the ferry is free and express buses are like coaches, comfy seats and stuff, they're $3.)
There's also this great little card called a metrocard. You can go to just about any deli or small store or whatever and pick one up. They usually have $15 metrocards, they work on buses and trains, when you get on the bus you just stick the card in the slot and get on, very quick and very easy. You can refill them too, much easier than carrying change or tokens. The trains have turnstyles so you just slide the card through and go through the turnstyle. You can also transfer from one thing to the next, like lets say you needed to take the S74 (S is for staten island, 74 is the route) to the ferry and needed to get onto the 1 train in manhatten, you just pay for the bus and on the metrocard you get a transfer (or you ask the driver for one if you payed with tokens or change) and you get onto the train for free.
Imagine if two of these pressurized cars collide, and their seals break. All their air would escape into the tube, and any passengers that survived the impact would suffocate in a fairly gruesome Total-Recall-like manner.
The safety section of their FAQ doesn't even address this.
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
Read the thread before you post...
They are talking about the fact that there will be SOME gas in the tube, not much, but it will be there.
Aerospace engineers have been doing this kind of problem in the lab for years, we call them shock tubes, you can also check google.
"I'll have a Guinness, no wait, make that a Coors Light" -Grad student I work with, who shall remain anonymous...
They have no intention of building anything, just make money for their shareholders from tha patents. And this encourages innovation? All it does is put a roadblock against someone who really wants to build it.
From their site ("company summary" page)
Our aim is to generate returns for our shareholders by acting now to acquire control of important blocks of intellectual property (patents and trade secrets) in the ETT field. We currently own the patent and trade secret rights to Evacuated Tube Transport, the first practical evacuated tube transport technology. We believe that these ultra efficient and environmentally benign systems, will become key components of numerous future worldwide transport systems. ET3.COM INC. intends to take full advantage of the generic nature of this unique technology by securing the intellectual property rights on the lion's share of all specific applications, new devices, and novel systems issuing from it. Management also believes that we are well positioned to gain control of other major intellectual property by developing new patents and trade secrets through our own internal efforts and by developing patent-exploitation agreements for the patents and trade secrets belonging to others.