Following its humble beginnings in the early 19th century, the train has evolved into a high-tech marvel capable of speeds in excess of 360 mph.
Such unheard-of velocity is made possible through magnetic levitation, or maglev, and trains are the first practical use of the technology in transportation. Anyone who has ever handled magnets knows that opposite poles attract and similar poles repel, which happens to be the fundamental basis of electromagnetic propulsion.
Magnetic levitation falls into two categories: electromagnetic suspension (EMS) and electrodynamic suspension (EDS). In electrodynamic suspension, superconducting magnets on both the track and the railcar exert opposing magnetic fields and the repelling forces suspend the railcar. Electromagnetic suspension works the opposite way, using the attraction of electromagnets beneath the rail to keep the train elevated above the track. In each case, the railcars are suspended on a magnetic cushion about a half-inch above the tracks.
A major difference between magnetic levitation trains and conventional locomotives is that maglev trains do not have anything resembling an internal combustion engine. Rather than using fossil fuels, these trains are propelled by varying shifts in the horizontal magnetic fields that alternately attract and repel along the rails.
In the 1960s, the concept of magnetic levitation began to move from the theoretical stage to the practical level, with Great Britain taking the lead. Scientists at Imperial College built a functional maglev railcar capable of carrying four people. Tests were done on a one-mile stretch of track, but funding cuts stalled further progress.
At about the same time, while stuck in New York City rush hour traffic, James Powell had the idea of using some form of magnetic levitation as an alternative to traffic congestion. A scientist at Brookhaven National Laboratory, he laid out a system using magnets fixed to a moving vehicle to provide lift and guidance over a specially designed roadway. Powell was awarded a patent in 1969.
However, it was back overseas in England that the first commercial mode of maglev transportation became operational. Opening in 1984, the track stretched about 2,000 feet from the Birmingham airport to a railway station and provided service for 11 years before problems with the electronics system led to its being replaced by more conventional transportation.
More recently, Japan, China and Germany have taken the lead in maglev train service, adding new routes, and upgrading existing structures. With further refinements, it is estimated that speeds of up to 600 mph may one day be possible.
The high cost of building maglev rail systems is a major factor inhibiting their widespread development. For example, in China it costs approximately $25 million per kilometer of track. Moreover, in Los Angeles, the estimated cost of a proposed maglev route is $8.5 billion, nearly four times as much as the cost of a freeway. In addition to the higher cost, maglev trains have another major disadvantage. Because they are not compatible with traditional railroad tracks, a complete infrastructure must be built for their entire route.
On the other hand, magnetic levitation trains have a number of advantages. Because the train glides with no contact with rails or the ground, there are no moving parts, which means lower operational and maintenance costs, as well as far less noise. In addition, unlike conventional trains, it is more economically viable for maglev trains to travel at very high rates of speed. Furthermore, the absence of a combustion engine means no pollution, making these trains one of the more environmentally sound methods of transportation.
Over the course of their relatively short history, there has been one serious accident involving a maglev train. In September 2006, a train crashed into a service vehicle in Germany killing 23 and injuring 10. Investigators cited human error as the cause of the collision.