Magnetic suspension, also called magnetic levitation, is a concept developed in the United States during the late sixties and early seventies. Its uses are at this time somewhat limited, but it shows incredible promise in areas such as transportation.

The basic principle behind magnetic levitation is simple. It is nothing more than using electromagnets repelling or attracting each other in order to make an object float in the air. In transportation, this principle is used to make a vehicle, typically some form of train, float above a kind of track called a guideway. Strategically timed positive and negative electromagnetic pulses in the track propel the vehicle. Due to the lack of friction with the rail and the efficiency of the electric power, these trains can attain great speeds. A low-speed maglev has been in use in Birmingham, England since 1984 as a commuter train between the airport and the city train station. High speed tracks exist in Miyazaki, Japan and Emsland, Germany which operate at 321 and 270 miles per hour, respectively.

There are two ways to approach magnetic levitation. The first is called electro- magnetic suspension, or EMS. The basic operations in an EMS system involve the vehicle being wrapped around the guideway like a monorail and using conventional electro- magnets to lift the train off of the track. The magnets, which are located on the very bottom of the vehicle are attracted to laminated iron rails in the bottom of the guideway. This lifts the train off of the rail. The train in Germany operates on this principle. The primary problem is that the distance between the track and train is a mere ten millimeters so the track must be maintained intensely to avoid uneven or loose tracks that would catch on the train. This makes an EMS train very high maintenance and in need of constant monitoring.

The second method is called electrodynamic suspension, or EDS, and is much more stable. Instead of using magnets to attract, it uses them to repel the train from the guiderail and make it float. The clearance of 100 to 150 millimeters significantly reduces the chance of track snags and makes maintenance much less complicated. The track in Japan has found that this is a relatively worry-free and efficient system. The only drawback to the EDS is that it is more expensive than the EMS because of expensive cooling for the superconducting magnets, which are also high cost.

The advantages of using maglevs for mass transportation are staggering. By using electricity as a power source, the trains use no petroleum and significantly reduce pollution and the production of poisonous gases like carbon monoxide. They are very efficient, using about half of the energy per passenger as the typical commercial aircraft. Tracks and cars alike are very low maintenance and the potential speed for travel is astounding. Maglevs are capable of greater climbing angles than conventional trains and are even capable of vertical climbs or traveling upside-down. The ground clearance also allows for enhanced operations in inclement conditions such as snow, ice, or heavy rain.

Unfortunately, the advantages of magnetic levitation transit are also incredibly expensive. While the system itself is not expensive to operate, it involves laying down new tracks, retraining employees and technicians, and producing the powerful electromagnets. It is believed by many supporters of maglevs that soon even the financial disadvantages will be overcome by necessity, much as happened with highways and airports.

Despite its financially laborious downfalls, plans for a track connecting Miami, Orlando, and Tampa have just been approved by the Florida government. It will run through the everglades, a wildlife preserve, and over a drinking water reservoir. German Parliament has also approved a 175 mile track which will be ready for commercial operations in 2005. Japan is constructing a 27 mile track in Yamanshashi Prefecture, 62 miles west of Tokyo. After testing, the track will be extended to Tokyo and Osaka. The U.S. military is using maglev rocket sleds to test the performance of new missiles which reach incredible speeds. Plans are even being made to use maglev technology to make model trains. As you can see, magnetic suspension is an ever-growing field.

Magnetic levitation, a science developed three decades ago is just now getting recognition for its endless possibilities. A technology with as many possibilities for growth as this definitely deserves its time of fame. Let’s hope that its fifteen minutes is not yet up.