By now, most people have read about Magnetically Levitated trains of the future traveling along at 300 Miles per hour from city to city! MagLev technologies have been around since the the 60's. The question is if it's so great, how come none have ever been put into use?

Cost! Cost! Cost!
In this country, companies have been pushing MagLev mostly for a Miami to Orlando, Florida route and a Los Angeles, California to Las Vegas, Nevada route. So far it has been unsuccessful. Why? Probably because of the multi-billion dollar costs involved. The Japanese and French have steel wheeled trains that roll on steel tracks that are running all day at 125 MPH and occasionally reach 180 MPH speeds in certain sections. (The difference in making a 200 mile trip at 180 MPH versus 300 MPH is 27 minutes.)

In California, a few years back there was a push to build a Los Angeles to San Francisco 125 MPH High Speed Rail Line at a price tag of $12.6 billion. They never mentioned what a ticket might end up having to cost. Could they ever come close to competing with $39 fares from Southwest Airlines? AND their planes travel between the cities at 550 MPH! Probably another reason it was dumped.

Who cares about cost? Just take more from the taxpayers!
Worse, in Los Angeles, they have their ongoing $5.3 Billion Subway project - a sad expensive joke for only 23 miles of usefulness. Those vehicles max out at 70 MPH and maybe average 33 MPH because of all the stopping and starting and waiting (while some people get off and new people get on) at each and every station along the route - boring! It's one of those wonderful systems that all the taxpayers who never use it get to involuntarily chip in their hard earned dollars to subsidize its costs of operations - forever!

It's as bad as most city bus operations, whom are actually proud if they even earn 28% of their annual out-of-pocket costs (let alone ever paying a cent towards the purchase of the equipment). Wish I could get away with running a business as stupidly and could then force others legally to pay for my losses year after year after year! Folks, you are in an awful rut! Use your brains and get out of it!

Is it the speed or the cost?
Time for some more math! Why do airplanes spend all that fuel climbing up to 30,000 feet? Why not save all that fuel and time wasted climbing and just level out at 3,000 feet. There must be a logical reason? Basically, when the plane climbs up to 30,000 feet the atmosphere's density is down to 37% of what it is at sea level. This directly means the power consumed by air resistance at any speed is 37% of what it is at sea level (a linear relationship). It turns out that aerodynamic drag is especially important for vehicles like Trains and SkyTran that are stuck operating on the earth's surface and cannot climb up high to take advantage of less dense air.

Power consumed by Aerodynamic Drag depends on speed, size, shape and air density.
It takes a lot of power to travel fast in thick, sea level air! Simply slowing down from 300 MPH to 100 MPH cuts the power required to overcome air resistance by 27 times (because power varies in proportion to the cube of the speed ratio). Two other factors effect the amount of power consumed by air resistance, but they are linear like air density, not cubic like velocity. These are the size of an object (frontal area is the simple reference) and its shape factor (how streamlined it is). A SkyTran vehicle is very teeny compared to a typical train and is shaped like the front end of a soaring glider to minimize air drag. The power consumed by 2.3 hair dryers can keep a Pod traveling along at a steady 100 MPH! I feel that it is essential to be able to exceed the best possible speed of automobile traffic and use an absolute minimum amount of energy at the same time! Why not 90 Mph or 112 MPH, instead? Don't know - 100 MPH just has a nice ring to it!

Power is also used up in the rolling resistance of steel wheels on steel track (or in the case of an automobile of the rubber tires rolling on the pavement). How much power does it take to magnetically levitate an object? This is a super interesting topic and is one of the most exciting aspects of MagLev transportation. Yes, it takes electrical power to levitate the vehicle, even when parked and standing still. Levitation power also goes up slightly as the vehicle moves faster and faster. This variation happens to look quite similar to a typical pneumatic rubber tire rolling resistance power vs speed graph!

Tires LEVITATE your car!
The analogy is to simply think of tires on your car as an independent levitation device that supports your car and keeps the main body from contacting the ground. It's just that tires are not an invisible support, whereas Magnetic Levitation Suspension is. There are four different type of MagLev systems that we have researched. Some of the basic properties are compared in the table shown here:

Levitation Method	Basic Levitation Power Requirement	Levitation Power Req'd for a 600 pound SkyTran	Feature Comparisons
German TransRapid (Electromagnetic Attraction)	1 Kilowatt per Metric Ton (2,205 lbs)	270 Watts	Active Control Expensive track
Japanese RTRI (Superconducting Electrodynamic)	0.1 Kilowatt per Metric Ton.	27 Watts	Passive Track. Needs wheel support until 60 mph speed attained
Russian MPV (Superconducting Magnetic Well Potential)	0.01Kilowatt per Metric Ton	2.7 Watts!	Levitates at zero speed. Requires no "training wheels"
Electromagnetic Rail Gun (Levi & Zibar)	Unknown at this time	Unknown	Uses 60 Hertz AC

(For comparison, a 1,500 Watt rated hair dryer consumes 1.5 Kilowatts of electrical energy)

Carrying the analogy of tires being the levitation device for an automobile further, we can calculate that a 600 pound SkyTran riding on low rolling resistance tires (say a .015 Rolling Coefficient) would be be spending a continuous 1.44 Horsepower (= 1,075 Watts or 1.1 Kilowatts) just to overcome rolling resistance at 100 MPH. (A typical 3,000 pound car would use 5.3 Horsepower overcoming rolling resistance forces at 60 MPH and 8.8 Horsepower at 100 MPH.)

The WORST of the MagLev systems applied to SkyTran uses 270 watts to levitate the same weight at zero speed, whereas rubber tires at zero speed consume no energy whatsoever. However, according to the magnetic drag formulas, the magnetically supported SkyTran vehicle would only consume another 513 Watts at a 100 MPH speed! Thus, the total power needed at 100 MPH, then becomes 783 Watts. This is 73% of the wheeled version and simply another reason to consider MagLev over wheeled vehicles. (The magnetic drag formulas were developed for 100,000 pound MagLev monster trains. We are assuming the formulas scale down and are still valid for these mini machines.)

What about Electromagnetic Radiation from a MagLev causing cancer?
I can't believe the controversy and hysteria all stirred up by one, non-technical, news reporter. My solution - don't read the books he is selling. At the same time don't read what the Electrical Power Research Institute (EPRI) is telling you (as they also MAY be biased in the other direction) and don't bother researching it all on the Internet either. Instead, just go out and buy an EMF meter which measures electromagnetic field strengths and measure it for yourself and be done with it! ($65 when I bought one a couple of years ago, when I was concerned because of all the media hype and because I live near power lines. Little LED's light up starting at 2 Milligauss)

First, find some high tension power lines to walk around and under with the instrument. THEN compare those readings to what you find inside your house. Check the wall switches (flip on and off), your Microwave, the TV, your computer and monitor, electric blanket, electric razor, blow dryer, Cell phone, portable phone, the little black plug-in-the-wall transformer/rectifiers, etc. Gee, if the idiot's premises about the dangers of EMF had any practical validity we would all be dying of cancer from the other stronger local EMF fields all around us! Duh! It's inverse square law, just like the physics people always said! Yikes - drives me nuts! Enough said.

The other parts of the 100 MPH vs. 300 MPH question
The second is noise. A 100 MPH Pod should be no louder than a pedal bicycle going through your neighborhood and the noise would come and go much quicker than a bike. At 300 MPH, acoustic noise equations tell us that the same Pod would make 3.8 times the sound (per Lighthill's formulas). This would not be as acceptable, but still would be extremely quiet compared to 80 MPH Amtrak passenger trains that both disturb the air and shake, rattle and roll the ground as they go by.

The third is deceleration and acceleration. To get off at a station, the pod has to drive off the main, non-stop freeway track onto a parallel deceleration lane without slowing down and at minimum sideways "jerk" (rate of change of acceleration per unit time) during that transition. Then it can start to decelerate. At 100 MPH, it takes about 1,000 feet of extra roll formed track to get your pod smoothly transitioned off the main track and stopped at a rate of 1/2 g deceleration. At 300 MPH it takes 9 times longer to stop at the same deceleration rate. I rejected the 300 MPH option because of 1) the 9 times factor of energy consumed per trip (27 times the power, but for 1/3rd of the time enroute) and 2) the cost for all that extra deceleration and acceleration side track we would have to install. [Note that a typical trip on a grid involves one turn to get to any given final destination. To minimize the radius of the turn (and cost of track) we plan to first slow down off-line to 20 MPH or so.]

Normal public transportation has laws that limit braking to 1/8th g. That is logical when people are standing in aisles and it doesn't take much to toss them around. SkyTran vehicles, however, are too streamlined to fully stand up. Passengers will sit in sport car-like reclined seats and must wear seat belts and shoulder harnesses. In fact, your Pod will not be allowed to even move until the seat belt/shoulder harness electrical interlock circuit is complete. (From what I have been reading most of these "Air Bag" deaths happen to people who did not have their seat belts attached.)

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Copyright©1999-2003, Douglas J. Malewicki, AeroVisions, Inc.