Maglev Trains

Maglev trains (short for magnetic levitation trains) are modern trains that leverage electromagnets. These trains are faster, quieter, smoother, and more efficient than their wheeled counterparts. Maglev trains are common in many Asian and European countries, and are becoming popular in airports as well. Today's fastest Maglev train can speed along at 581 mph, about the speed of a commercial airplane. While Maglev trains with passengers travel much slower, they still can travel twice as fast as their wheeled counterparts. As Maglev trains become more and more efficient, they may rival airplanes for land travel.

All Maglev trains rely on the attraction and repulsion of magnetic poles. There are two main systems in use today, the EMS and EDS systems. The EMS system is used mostly in Germany, while the EDS system is used in Japan's Maglev trains.

Electromagnetic Suspension (EMS)

The EMS system uses one set of electromagnets to float the train, and uses another set to propel it.

In the EMS system, the entire track is connected to a large power source, which supplies the electromagnets. The sides of the track contain coils of wire, which make a strong electromagnet. This repels the magnets on the bottom of the train, causing it to float. Once the train is floating, the tracks uses a different system for forward motion. The coils are supplied with an alternating current (AC), which causes the coils to switch polarity. By spacing the coils with gaps, the train's magnets are first attracted to the magnets in front but later repelled by them as the train passes over.

Electrodynmic Suspension (EDS)

The EDS system is very similar to the EMS system, except the former uses superconducting magnets. These magnets are cooled to incredibly low temperatures. As a result, they continue conducting electricity even after their power source is shut off. This allows for less energy to be used to run the train. Unfortunately, the standard EDS system uses very strong magnets which may conflict with the magnets inside pacemakers.

Because of this, a newer, theoretical EDS system called the Inductrack has been developed. This system uses permanent, non-electric magnets. A power source is used to lift the train into the air, at which point it is propelled without any electric power. Originally, it was thought that "normal" (permanent) magnets were to weak for Maglev trains, but the Inductrack uses a special system called the Halbach array. The Halbach array creates a magnetic field that is strongest above the magnets, which is perfect for the Maglev train.