RAILforum: Maglev Trains

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Posted by Vindezz (Member # 2830) on :

I'm doing some research on maglev trains and I was just looking for some opinions on the future(if any) of maglev trains in the US. Anyone out there have any ideas on this? Anyone think the cost of laying the track is worth it in the long run? I know the problem is they wouldn't be able to use existing rail track, however I have heard of ideas such as integrating wheels for existing track systems into maglev trains. Any ideas and or opinions would be very helpful.

Posted by MPALMER (Member # 125) on :

If it ever catches on I would think it would be due to political connections, and not because it makes economic sense.

Maybe if Bechtel or some other well-connected engineering firm got involved it could be a reality, but I would not expect anything for many years.

Posted by dnsommer (Member # 2825) on :

What follows are some findings from a Florida Maglev/HST comparison study. --Dave
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"The energy consumption per passenger kilometer for a 300 mph Maglev technology is considerably less than that of autos and airplanes, and comparable to that of the French TGV. If Maglev were to operate at TGV speeds, it would have an energy consumption in mega-joules per passenger kilometer about half that of the TGV. This is logical, since the aerodynamic drag of the Maglev is somewhat less than that of the TGV (smaller frontal area, more streamlined shape) at the same speed, and its magnetic drag is much smaller than the TGV rolling drag. The TGV is much heavier than a Maglev vehicle, which results in is having a large rolling drag force.
2. Cost of Maglev Guideways
The Maglev 2000 guideway cost is less than for a high-speed train like the TGV. The M2000 narrow beam guideway is projected to cost about $11 million per mile of 2- way guideway compared to about $15 million per mile for TGV type track. Constructing the TGV track is not cheap, since the roadbed must be dug to a considerable depth (~10 feet) to ensure stable trackage. Moreover, the TGV roadbed must be very straight and level, whereas the elevated Maglev guideway can be adapted much more easily to varying terrain and curving right-of-ways by banking and changing the height of the piers that support the narrow beams. It is not possible to elevate the TGV at a reasonable cost, because it weighs at least a factor of 10 more than a Maglev vehicle. Moreover, Maglev guideways involve far less disruption to the land and the environment than does the TGV, which has to occupy a fenced off, on-grade corridor which essentially cuts the surrounding land into 2 separate sections that are isolated from each other. Finally, Maglev guideways, because the weight load is distributed relatively uniformly under the vehicle (and the weight of a Maglev vehicle is much less than that of a locomotive), have structures that require virtually no maintenance and will last for many years. In contrast, high-speed trackage requires constant maintenance—the Japanese send out thousands of workers every night to push the tracks back into place—and their lifetime will be considerably less.
3. Maglev in Low Pressure Tubes
We have been studying the feasibility of operating Maglev in low-pressure tubes for some time. At pressures of a few torr, one could achieve speeds of thousands of miles per hour, traveling from New York to Los Angeles in less than one hour. However, the cost of tunneling—presently $30 million per mile and more—is too high for such systems. With advances in tunneling technology to reduce cost to $10 to 20 million per mile, such systems would become practical.
4. Maglev for Urban Applications
Maglev is very attractive for urban and suburban applications. First, it does not have to operate at 200 mph. For urban and suburban applications, 100 mph would be very attractive. At the acceleration rates normally experienced in autos (e.g., 0-60 mph in 10 seconds), a Maglev vehicle would reach 100 mph in 16 seconds, in a distance of 360 meters (1,180 feet). Second, with the Maglev 2000 electronic switch, Maglev vehicles do not have to stop at every station, but can bypass stations at full speed, only stopping at every 5th station on the line, for example. Passenger loading and unloading would be done at the off-line stations. Passengers would simply wait a few minutes until the appropriate vehicle for their particular stop came along. The low weight, low energy consumption and high average speed of Maglev vehicles make them very attractive for urban and suburban transport applications."

Posted by Dick H (Member # 2905) on :

More than likely you are aware of Japan's Maglev program, but if not, you might want to look here: http://www.jr-central.co.jp/info_e.nsf/doc/corp-infomenu_e
They just set a new world record of 560 km/h.
Japan's emphasis is on long distance transport to compete with the airlines.

Posted by ReadingT-1 (Member # 3011) on :

Vindezz

Old Dominion University is trying building a Maglev.
http://www.odu.edu/af/maglev/

Posted by Mr. Toy (Member # 311) on :

The excerpts from the Florida study are interesting. I have wondered about the energy consumption of maglev vs. more conventional trains. This report gives me a more positive view of maglev.

But building an infrastructure would take a very long time and cost a lot of money to make a practical network. Thus I think it will start slowly, with a few pilot projects. If it proves to be dependable and economical in actual use, it will grow gradually over many decades. I doubt it will be widespread technology in my lifetime. Maybe for the next generation.

Posted by TheBriz09 (Member # 3166) on :

The Florida study is indeed interesting.

On a related note, has anyone seen the Discovery Channel series called "Extreme Engineering?" One of the episodes was about the possibility of a transatlantic train tunnel using maglevs. You would be whisked through a tunnel 3,100 miles long at 5,000 miles an hour and travel from New York City to London in 54 minutes. Sound like fun?
http://media.dsc.discovery.com/convergence/engineering/transatlantictunnel/interactive/interactive.html

Posted by George Harris (Member # 2077) on :

I have been wanting to give a more informed answer on this line than I have right now, but here are a few things:

1. We must be sure that we are comparing like with like. When you are talking such things as seating, onboard services, other passenger amenities, these items are irrelevant to the method of propulsion, so remove them from the equation. They can be just as good or bad regardless of what is moving the box containing the people.

2. Most of the information so far is in promotional literature. That is, a very one-sided view.

3. Regardless of propulsion, we are carrying a box or tube with people inside. A lot of the weight car floor and above will be immaterial to the method of propulsion. Therefore, claims about huge weight savings (TGV outweighs maglev "by a factor of 10") are somewhat (highly!?) dubious. I would be highly skeptical about anything above about 1.5, if that much.

4. The issue concerning the depth of subgrade preparation for the TGV appears to be somewhat of a "straw man." Subgrade preparation and the nature of the foundation for a viaduct structure are highly dependent upon ground conditions and subsurface materials. So far, no one has figured out how to build viaducts for lower cost than moving earth within the normal range of cut and fill depths.

5. The slim guideway may not be permissible in revenue service. No way does it provide the evacuation walkway provision requirements in NFPA 130. When you look at an ordinary open deck railway trestle or steel bridge you see in the portion from ties up all that is necessary to guide the train. That is only 10 feet wide and 18 inches high. What goes below is based on the requirement to hold the weight of the train and provide sufficient stiffness against guideway deflection. It is very unlikely that a maglev guideway could be any thinner than an ordinary transit system viaduct, and with legally required safety walkways it will not be any narrower.

6. Aerodynamic resistance of about half that of the TGV? OK, the Japanese Shinkansen latest versions are also understood to have aerodynamic resistance somewhere in this low range. That is to say, aerodynamic resistance is a function of attention to detail in the shape of the body and a long period of operation and experimentation. It is essentially irrelevant to the propulsion system.

7. Line side noise was not mentioned, but at high speeds a lot of the noise from the passing train is aerodynamic, essentially overwhelming the wheel rail noise that predominates at lower speeds.

8. Need for shielding for the safety of passengers and their computers. You don't want to have to remove your pacemaker wearing passengers in body bags. Even in rapid transit vehicles, if you set your laptop, or a briefcase with computer discs on the floor in the vicinity of the motorized axles you are likely to find that you have scrambled your files. Given the much larger magnetic flux requirement to levitate as well as move the vehicle, some very serious magnetic shielding will be a necessity.

9. The energy consumption appears to be higher than conventional rail for similar service. That was a significant factor in the Chinese decision to construct a conventional high speed system rather than a Maglev Shanghai to Beijing.

10. "Banking" and grades are usually limited by factors other than the operating characteristics of the full speed train. Superelevation is usually limited to 4 inches on must US railroads out of respect to the high center of gravity of piggybacks, auto racks, and double stack containers. This is not for normal running at speed, but in consideration of the forces on a stopped or low speed train on the curve. On passenger only lines, it is usually limited to between 6 and 7.5 inches, again due to consideration of passenger comfort and safety in case the train stops on the curve. This is the same logic used to limit the maximum speed and the reason that the speed limits on curves can be raised with tilt systems. The TGV has grade of up to 3.5%, Saluda hill was about 4.5% and heavy coal trains ran over that, and some transit systems go over 6%. Given high power factors and entering speeds there is no problem with steeper on the railway, except that it is a serious problem for the maintenance forces and in case a train stops on the grade.

11. "Skip-stops" can be and are used in current high speed railways. It is probably easier to do so on a railway than a Maglev. The Germans have standard turnout designs usable with diverging speeds of up to 220 km/h (136m mph) and the same design principles could be used to develop higher speed turnouts if needed. Usually a turnout good for 130 to 160 km/h (80 to 100 mph) is quite sufficient as it is placed at a position where the speed of the stopping / accelerating train will be below the turnout's allowable speed. Therefore, this is not a property of the Maglev system, but an operating plan applicable to either propulsion system.

12. The statement that "the Japanese send out thousands of workers every night to push the tracks back into place" is a major exaggeration. They do a 100% inspection of the Shinkansen track every night. But for the most part, it is exactly that, an inspection. The original sections are on ties and ballast, and yes, that part is very precisely maintained using a huge input of manpower. As for the slab track portions, it is doubtful that much is really done in the maintenance effort except check the fastenings. At 280 km/h your main sensations is that the countryside is going by very fast.

13. The acceleration rate dnsommer quotes is impractical unless you are going to have people strap in for acceleration and braking. It is 8.8 ft/sec^2 = 27% of gravity. For comparison, normal transit vehicle set maximum acceleration at about 3 ft/sec^2 = about 10% of gravity. Usual passenger train accelerations are about one-half of that or less, maximum. In the higher speed ranges, acceleration is power limited.

14. Saw the Discovery program on the tube under the Atlantic. Probably possible, but many technical, financial, political problems. Unlikely in our lifetimes. Vacuum tube railway lines / pneumatic tube people mover system ideas go back to the mid 19th century.

I have seen nothing in any discussion on train control systems, crashworthiness of vehicles, evacuation, other safety-related issues, etc.

In sum, I am always skeptical about anyone who touts their system wholely or in part by saying how bad the alternative is. Before we blow billions on maglev, we need to be very sure it is the best use of the money.

Posted by George Harris (Member # 2077) on :

found an article I was looking for: Following are quotes from the Canadian Press, January 10, 2004. All the following is concerning the Japanese system. How well it applies to the German system I do not know.

Begin quotes:

Experts concede that the trains aren’t “greener” than existing electric-railway technology, notably the Shinkansen bullet trains that traverse the mountainous countryside and connect major cities at up to 300 kilometres an hour. Japan also uses monorails, trains and subways for intra-city transit. “The maglev is less efficient than the Shinkansen. It consumes about three times more energy,” said Satoru Sone, an engineering professor at Tokyo’s Kogakuin University.

But Sone said the maglev could someday replace airplanes for shuttling passengers around Japan because they emit one-fourth of the harmful greenhouse gases of a passenger jet. “Bullet trains are too slow to compete with planes. But the maglev might one day replace domestic air travel along some routes,” he said.

Central Japan Railway . . . wants to build a maglev line from Tokyo to Osaka, linking the two countries’ largest cities in just one hour, the same as commercial flights. Its bullet trains require 2½ hours to make the 500-kilometre trip. But the experts said the project’s costs are still too high and they would reassess the situation in 2005.
Building the train’s electromagnetic guideway could set back taxpayers $85 billion. That’s three times what it costs to lay bullet-train tracks. Maglev trains would tack on another $6.48 billion.