The Perfect Synthesis
by Joshua Zev Levin, Ph.D.
A proposal to mate GM's AUTOnomy Skateboard vehicle concept with MagLev train technology.
How fast does a jet airliner fly? The conventional answer is about 560 m.p.h., which is, after all, pretty fast.
Now, how fast is a jets passengers average speed, from door to door, for the entire trip? Well, that can be much slower.
If youve ever flown for business, especially as a consultant, does this sound familiar? You get up very early in the morning, drive to the airport, fighting morning rush hour, try to find a good parking space, maybe take a bus or underground train to the terminal, wait in two or three long lines (including security) before you get to your gate, maybe wait some more before the plane loads its passengers, and sit in the plane for half an hour before it takes off. Then, the plane is airborne only a few hours, and lands several hundred to over a thousand miles away. Youre not done yet. You have to claim your luggage, get your rental car, figure out the controls on your rental car, and drive to your destination. By the time you get there, youre too tired for any creative thought, except maybe for filling out your previous weeks expense report. Driving to a vacation with your family can be even worse, with all those kids in tow.
Now, how long does this all take you? My experience as a consultant, traveling from the northern suburbs of Philadelphia, PA, to the southside of Jacksonville, FL, made total travel time to be over six hours for a distance of about 750 miles, as the crow flies. Of course, the crow doesnt have to deal with airport security or rental cars. This is an average speed of less than 125 m.p.h., less than one-fourth of the airplanes maximum speed while in flight. This is not so fast. No wonder a lot of people prefer to drive this distance, rather than fly!
Wouldnt it be wonderful if you could combine the convenience of a private car with the door-to-door speed of a jet airliner, without all the hassles of changing vehicles? There is a way
A couple of years ago, General Motors introduced a modular concept car called AUTOnomy. A thin chassis contains the power-and-propulsion system, plus ventilation and other systems. The passengers and their luggage are in a separate body, mounted atop the chassis, and secured with eleven docking connectors. A version called "Hy-Wire" used hydrogen fuel cells to power in-wheel electric motors, plus the "X-Drive" drive-by-wire system, using a joystick instead of a steering wheel. This new automotive architecture has many advantages, with fewer fluids, fewer things to break down, easier servicing, and more flexibility in how they are used.
Also, there is a frictionless monorail technology called MagLev (short for "Magnetic Levitation") that allows land vehicles to travel as fast as 325 m.p.h. on controlled monorail tracks. Power is supplied by stationary sources, which are easier to run from "green" energy.
Now, putting the body from an AUTOnomy car on a special chassis for the MagLev system can combine the best features of both. I prefer to call this special chassis a "bogie", from a standard railroad term for a wheeled undercarriage that supports rail cars. The same MagLev monorails can be used for standard MagLev passenger and freight trains, and for this system of private car bodies mounted in MagLev bogies, which I like to call the "LeviCar" system.
Picture how your trip would be much simpler. You would, as before, start by packing your car and driving - not to an airport that might be twenty to fifty miles away or more, but to a MagLev station within ten miles. Then, instead of taking your bags out of the car and schlepping them from one place to another, you leave them in the car. You might even stay in the car yourself. What happens is that the lower part of your car, the road chassis, is removed, and the upper part is placed on a MagLev bogie, which is on a spur of MagLev monorail. If needed, a streamlined fairing or dome can be placed over the car body. After a few automated safety checks, including a wind-tunnel check, the combined vehicle, or LeviCar, glides towards its destination on the MagLev system.
Your car will now travel to another MagLev station within ten miles of your final destination, at speeds up to 300 m.p.h., or maybe more. There, it would removed from the MagLev bogie, and placed on another road chassis, similar to the one you left behind at the MagLev station near home. You can then drive to your final destination. From a business standpoint, this would be easier if the road chassis are leased from an agency that would also be responsible for chassis maintenance. The car bodies may be owned by the users, or leased.
Sitting still for a long time can lead to a life-threatening condition call deep-vein thrombosis, so it would be good to have a rest stop every two hours or so to stop and get out of your LeviCar, walk a bit around and use the facilities. The rest stop might have an automatic parking facility that would drop you off at an entrance, give you a magnetic card to be used to retrieve your vehicle, and automatically park it. When you are done, simply put the card in a reader, and your vehicle will come to you. If you dont want to slow your trip with a rest stop, you could have an on-board "honey pot", with the commode seat and privacy curtains in the car body, and the waste tank in the chassis.
In the further future, there may be whole resorts or resort areas that are completely LeviCar compatible. You would never need to drive or use a road chassis - just simply tell the system where you are going. You might even park your car in your hotel suite, making unpacking and repacking that much easier.
All in all, your trip will be less tiring than current travel by road, rail or air.
How will this be accomplished?
To save on energy costs and increase speed by reducing wind resistance, several LeviCars will travel together as a convoy. This is like a train, but there are no physical links between the units, although there would be electro-magnetic couplings. Each individual LeviCar would join a convoy near the beginning of its trip, and may switch convoys a few times within a trip.
A LeviCar may join a convoy at its front, traveling slightly slower until the front car of the convoy is magnetically linked to it. At times, a LeviCar may have to leave its convoy. The magnetic links to the cars in front and back are broken, and the cars in front speed up slightly, and those in back slow down slightly. The now-broken convoy travels through a switch, and the LeviCar in question is switched off to another track. Then, the two remaining segments of the convoy rejoin, the front cars slowing down, and the rear cars speeding up, until they meet.
In order for this to work, the switches have to be very fast. In railroads, a switch, also called a "switching point" or "point", is where a track splits in two, and it must be set to send the train in one direction or the other. In the other direction, it is where two tracks come together. In a conventional two-track system, this means that there are slight breaks in the rail, which can cause noticeable bumps when you go over them.
In a monorail system, the track is a lot heftier, and might take some time to move from one position to another. It is unlikely such a monorail could switch fast enough to switch a single LeviCar out of a convoy at operating speeds of 300 m.p.h. or more, unless the gaps between cars are very large.
Fortunately, one MagLev architecture permits short segments where the monorails disappears, and the cars travel on two "virtual" tracks, which are defined by their magnetic fields. This was developed by the original inventors of MagLev, Gordon T. Danby and James R. Powell. The switching is done electro-magnetically, which is, for our purposes, instantaneous.
This is possible, in part, because the Danby-Powell system architecture used a repulsive system, whereby the magnets on the rail repel the ones on the vehicle. In contrast, most MagLev systems use attracting magnets, but this has two major disadvantages. First, of the magnets get too close, they will attract each other even more, and would collide, if it werent for the automatic control system, which keeps them a certain small distance apart - a fraction of an inch. Also, the attracting system requires the magnets to be below the rails, which means that the vehicles not only overhang the rails, but must surround it, top, left, right, and part of the bottom. In contrast, the Danby-Powell architecture use repelling magnets on the bottom of the vehicle and the top of the rail, so that the closer they get, the stronger the magnetic force becomes, and they are pushed away. If the magnets get too far apart, gravity will gently move them closer together. An automatic control system is still needed, but the distance between the magnets can be far greater, a few inches, allowing for better tolerance of any debris that might get on the rails. Without the vehicle surrounding the rail on all four sides, switching would be easier. Using virtual rails makes switching easier yet.
All this will not be built in a day. In fact, it will take many years to build this, and over a trillion dollars. Also, the proper algorithms to efficiently and safely handle all those LeviCars are yet to be devised. It would be best to first build a freight system. Standard containers, currently used in multi-mode transportation systems, could be mounted on MagLev bogies and covered with aerodynamic fairings, and then sent, individually, on MagLev rails. (Later, aerodynamic containers can be built that would not need fairings.) After certain problems are worked out, we could start using convoys to make things more efficient. The convoy algorithms could be real-world tested this way, before they are used for passenger vehicles. When a certain level of safety and reliability is reached, small passenger trains can be introduced. (As a computer programmer, I am very much aware of the limitations of computer simulations. After all - look at the massive blackout in 2003.)
In the mean time, there would be increased use of modular automobiles because of the many advantages they have, other than their use in a LeviCar system. There are far fewer fluids to leak, and, once the body is removed from the chassis, service is a snap. If the chassis breaks down on the road, a flat-bed truck can come with a new chassis, perform a chassis swap, and let the driver continue to trip with much less delay than taking the whole car in for service. Regular service would likewise be much simpler, except that the chassis swap would be done at a repair facility. Modular cars also have some disadvantages, being heavier than conventional cars, but they are bottom-heavy, improving handling. Hopefully, the improved fuel economy from using a hydrogen fuel-cell, pure electric, or other "green" technology will make up for the increased weight. The car body could also be combined with a boat hull (displacement, speed, or hydrofoil) to make a marine craft, or with aerodynamic surfaces and engines to make an airplane. Business-wise, it would be advantageous to have the chassis leased out by companies that would take responsibility for maintenance. Thus, the chassis lease is not so much a lease of the chassis as a physical unit, but rather of the service that it provides. A chassis would be regularly returned to the leasing company for repair and maintenance, and replaced with another chassis of the same sort, while the original chassis is later given to another customer.
Finally, as many people get modular cars, and as the system grows and matures, we could have LeviCars, smaller mass-transit vehicles (LeviVans and LeviBuses), passenger trains, and freight all moving on the same system. However, since the heavier vehicles might move somewhat faster than the lighter ones, there might be separate monorails. A typical line might have five monorails, two for heavy vehicles (especially freight), two for light vehicles, and one spare. Smaller lines might have only two or three monorails, while the most-used lines might have seven or even nine monorails. When one monorail is undergoing maintenance, the others in its line might be reassigned as to what vehicles they carry.
All travel would be under automatic control. When entering the MagLev system, you enter your destination and how many rest stops you want, and the system will do the rest until you get to a station near your final destination.
This would lead to more efficient ground transportation for freight, and a speedier system for passengers for distances of up to a thousand miles or more, reducing our need for foreign oil, and all the implications that has for our foreign policy. Perhaps its privacy and added convenience will make people want to use it for even longer trips. This will be an important part of a coming revolution in how we travel.
Note: For details on a similar concept (called HiLoMag) devised by Francis D. Reynolds , click HERE.
Last modified: September 15, 2004