MAGLEV TRAINS

ABOUT: Maglev (magnetic levitation) trains were first invented in the early 1900s by an American professor and French-American engineer. The first commercially used maglev train was installed in an airport Great Britan, however, it only traveled around 600 meters. There are currently six operating passenger maglev trains all existing in Korea, Japan, and China, but, many cities are planning on installing more in the future. Maglev trains have many advantages over traditional trains. Due to the fact that there is no rolling friction, maglev trains are much less expensive to operate as parts do not have to be replaced as frequently. The lack of friction also allows the trains to travel at speeds up to 370 mph. Comparatively, a traditional passenger train travels at around 80 mph. The design of the tracks allows for the trains to be wider, increasing passenger capacity, and the chance for derailment is very unlikely. One of the most important benefits in our current environmental status is that the trains produce little to no air pollution. Additionally, the trains can travel on steeper slopes which eliminates the need to damage the earth through excavation. These trains allow for a more enjoyable ride for passengers as they are smoother and quieter than traditional trains. One downside to maglev trains is that they require rare earth metals to create a strong magnetic field, these metals are often expensive and increase the costs of construction. To build a maglev system costs around 50-200 million dollars per mile.

HOW THEY WORK: There are currently two types of maglev trains in operation, electromagnetic suspension (EMS) and electrodynamic suspension (EDS). EMS trains wrap around the bottom of a guideway; an electromagnetic attraction between the guideway and the bottom side of the train levitate the train about 1cm off of the track and keeps the train constantly levitated.  This system is called Transrapid and was engineered and is currently used in Germany. EDS is similar to EMS, however, in this system electromagnets repel the train instead of attracting it. This system uses supercooled and superconducting magnets that operate even when the power is turned off. The magnetized coils repel the charged train levitating it 1-10cm. Differing from the EMS, EDS trains are slow to raise and require wheels when traveling under 62mph. When the train is levitated the guideway coils constantly change polarity propelling the train forward.

SOURCES: Britannica   How Stuff Works