Mag-lev Trains

[Anonymous]

I don't get here nearly as often as I'd like so I don't know if this has been posted but... what do you think of maglev technology? Do you think if it becomes economicaly viable for a high-speed passenger train that it could replace diesels? I know that would require an isolated mainline with no grade-crossings but is that the future? What are your thoughts?

[Anonymous]

It's real expensive, and would require completely new rail lines.
It's an awsome idea, but it's not likely to take over here in North America, that is if it ever even makes an appearance.

Forget what country (china perhpas?) but they just decided against installing a maglev line, and went for a regular high speed rail line instead.

Still very expensive infastructure, making it in many cases impractical.

[daveklepper]

I have been following this for years and believe that conventional 2-rail can outperform Maglev, particularly if track structure is changed for: (1) continuous support of rails, and (2) continous guard rails for ultimate safety at very high speeds. Dave

[Hugh Jampton]

Having been to the maglev test track near Lathen in Germany I can say that the technology is very impressive, the acceleration and braking rates can never be matched by conventional rail. Also, the power being delivered by the infrastructure means that there can never be a head on collision.
The big problem with maglev is that it needs completely new infrastructure, whereas high speed lines can be constructed cross country and link into the low speed network in cities to allow access to existing stations (as in France and Germany)
Part of the decision by the Chinese to construct a high speed line instead of a maglev is political in nature, as the Chinese have developed a method to construct the track at a price not that much more than that required to build a conventional high speed line.

[TH&B]

I agree with Dave in that 2 rail can probably out perform maglev, if it can't now it will in the future. But I now wonder if todays hi-speed rail even uses gaurd rails, even on bridges, I'll have to check because I doubt that they bneed a gaurd rail.
Hugh; it still possible for a maglev to strike a stopped maglev vehicle parked on the track head on. It was a wise choice of the Chinease to choose rail instead of maglev, less cost and most of the performance and using Chinas own rail technoligy. The one maglev line China built already runs almost empty every day now.

[BNSFNUT]

With high speed conventional rail working well and being made better with research using Maglev seens like reinventing the wheel.

[Anonymous]

Didn't I hear somewhere that the magnets can damage items such as Cell phones & laptops as well? that would keep a few intercity bussiness men & women away at least.

[RudyRockvilleMD]

For Train Hearted Guy
Magnetic fields can damage cell phones, lap tops, and floppy disks; they can also damage audio or video tapes and watches. However, i doubt if the magnetic field in a passenger compartment of a maglev would be strong enough affect cell phones and the like.

[Rick Gates]

I don't think we will have the chance to see one here any time soon, if at all. I know Balto. - Wash. was trying to get it sold in their area to attract the Olympic Games. I sure would sign up to run one tough! [^]

[Hugh Jampton]

QUOTE: Originally posted by 440cuin

I agree with Dave in that 2 rail can probably out perform maglev, if it can't now it will in the future. But I now wonder if todays hi-speed rail even uses gaurd rails, even on bridges, I'll have to check because I doubt that they bneed a gaurd rail.
Hugh; it still possible for a maglev to strike a stopped maglev vehicle parked on the track head on. It was a wise choice of the Chinease to choose rail instead of maglev, less cost and most of the performance and using Chinas own rail technoligy. The one maglev line China built already runs almost empty every day now.

No, the maximum acceleration that a train can have is limited by the friction between the wheel and the rail and the load upon them. If you take the theoretical maximum friction of 0.5 (which never happens in real life) and a maximum axle load of 35 metric tonnes (77,000 lbs) then the maximum force that can be transferred between the wheel and the rail is 172 kiloNewtons (38,500 lbs of force). Now, Sir Issac Newton (inventor of the catflap) says the acceleration is equal to the force divided by the mass, so this gives 172,000/35,000 = 4.9 metres per second squared (16.1 feet per second squared), or about one half g. A maglev, on the otherhand, is only limited by the power available to the track, and searching the internet for maglev acceleration rates gives figures between 2g and 10g. In practice, train acceleration is usually around the 0.1g mark due to variations in the adhesion, passenger comfort issues, the number of powered axles and installed power limitations. whereas the German maglev ramps up to a maximum acceleration of 0.75g.
It is not possible for one maglev train to strike a parked train because as soon as the track is energised for the moving train the stopped train will start to move, just like a train set,, er,, model railway. The vehicles are completely passive, the control desk consists of a single red button that the "driver" (who doesn't actually drive the thing) can push in case of emergency which sends a signal to the control center, and the control center de-energises the track, which stops the train.
I would be happy to entertain contrary argument provided they are backed up by scientific facts.
Love and kisses:
Hugh

[Anonymous]

QUOTE: Originally posted by BNSFNUT

With high speed conventional rail working well and being made better with research using Maglev seens like reinventing the wheel.

As an example, vacuum tubes work well, are still being made better, but the fact that people now use solid state for most applications doesn't sound like reinventing the wheel. In my humble opinion, the only limiting factor for a maglev would be the source of electricity used to power it. Be it coal-fired, gas-fired, oil-fired, nuclear, or solar power, it's got to come from somewhere and cost is going to be the big issue.

The School of Engineering and Sciences at Old Dominion University has built a working maglev on the campus. It is designed to carry students from the west end of campus to the east end, running overhead between buildings and across one major thoroughfare.

With maglev, what parts are there to wear out? Since the train rides above the rail, there's no friction to speak up, no axles, no bearings, no wheels, all of which contribute to friction. There is friction with the air that the train passes through, but with the speeds we want to use, friction is neglible. I don't think we'll be trying to run trains at Mach 3 (at least, not for a while), and as the technology gets better, the cost should come down. That's SHOULD, not will, since nobody can predict the cost of the energy required to generate the electricity.

Hugh, I am amazed. I didn't know Sir Isaac invented the catflap! I guess this brings into play the third law of emotion - the amount of amazement is inversely proportional to the amount of obfuscation in the description.

[Anonymous]

QUOTE:
In my humble opinion, the only limiting factor for a maglev would be the source of electricity used to power it.

Don't forget the other limiting factor....COST.

There just isn't enough money floating around to support a new technology like Maglev on a federal scale. It would cost billions of billions of billions to even start changing regular rail lines to maglev lines.

Perhpas the technology has it's place on the smaller scales, but I'll be damned if it takes over for regular rail in my life time.

[Anonymous]

for macguy: I realize there would be a significant outlay of monies to build the infrastructure, right-of-way, overheads, terminals, etc. My intention wasn't to say it would be cheaper to run maglev, but as far as operating it once the infrastructure was in place, then I believe the major limiting factor (yes, I am amending my previous opinion) would still be cost of generating electricity. Other factors would be maintenance and upkeep of infrastructure, rolling stock, wages, etc., etc., etc.

I believe that unless the population of the U.S. decides that it's too expensive to drive or fly to their destinations, they will not support maglev. Since most of us are in love with the car, and compared to the rest of the world, our gas prices are fairly low, I doubt that train travel will become popular. But, that's another discussion somewhere on this forum.