Magnetic levitation, or maglev for short, is a technology that allows moving objects without wheels, tracks, or another form of physical contact with the object. Instead, maglev uses powerful magnets to create a magnetic field that lifts and propels objects, like trains, along a track.
The basic principle behind maglev is that opposite magnetic poles attract and like poles repel each other. This means that if you have two magnets with opposite poles facing each other, they will attract and move towards each other. At the same time, two magnets with like poles will move away from each other.
Controlling magnetic power
To lift objects using magnetic levitation, you need to control the magnetic power of the magnets. Magnetic force cancels out the downward pull of gravity on the object you are trying to lift. Whether it is a train moving humans or skids moving goods, the weight is never the same, meaning the upward force needed to lift the train or skid varies. For that reason, electromagnets are used.
An electromagnet is a type of magnet that is created by running an electrical current through a wire. When electricity flows through the wire, it creates a magnetic field around it. If you coil the wire around a metal core, like iron, the magnetic field becomes stronger and more focused, creating a stronger magnet.
How magnets lift and move trains
While Maglev trains don’t have wheels, they still have rails to guide them. The difference is they don’t touch the rails. There are magnets in the rails and magnets at the bottom of the train. These magnets are placed with the same poles towards each other. Because they push each other away, the train is lifted.
Once the train is lifted, it can be propelled forward by magnetic fields that pull it along the track. This is done by managing the electricity flowing through the magnets so that the train is pulled forward—the magnets causing the forward motion work based on opposite poles. The train is pulled forward by powerful magnets that are activated in sequence.
The benefits of magnetic levitation
One of the main benefits of magnetic levitation is the lack of friction. Because there is no physical contact between the train or skid and the rails guiding it, it can travel at high speeds. Because of the lack of contact, there is also no wear and tear.
Another benefit is energy efficiency. Next to the fact that you don’t need a locomotive to pull the train forward, the lack of friction also saves a lot of energy. Maglev trains are powered by electricity, and you can use many sustainable energy sources.
One of the best-known examples of magnetic levitation used in transportation is the bullet trains in China and Japan.
Header image courtesy of CRRC Corporation