China has launched the world’s first suspended magnetic levitation line, built with permanent magnets that can keep a “sky train” afloat forever without power supply, the South China Morning Post reports.
The 800-meter experimental Red Railway in South China’s Xingguo County, Jiangxi Province, uses powerful magnets, rich in rare earth elements, to produce a constant propulsion force strong enough to lift a train with 88 passengers into the air, according to a report by state-run China Central Television.
Unlike most existing magnetic levitation lines, the suspended rail operates about 10 metres above the ground. There is no physical contact with the rail as the train moves underneath it at a speed of 80 km/h. One arm of the train surrounds the rail and the permanent magnets on both the arm and the rail repel each other, suspending the train.
According to Interesting Engineering magazine, the train could be ideal for cities with high levels of noise pollution. The train can be seen as accident-proof because the permanent magnetic field can absorb most of the shocks that would damage other trains.
With free-floating and friction-less conditions, only a small amount of electricity is needed to drive the train, according to researchers at Jiangxi University of Science and Technology. The new maglev technology generated little electromagnetic radiation, and its construction cost was about one-tenth the cost of building a subway, they said.
Local transportation authorities said that after some tests, the line would be upgraded to 7.5 km and its maximum operating speed would reach 120 km/h. Many Chinese cities are building or planning magnetic levitation lines. Some trains can go as fast as 600 km/h.
But most of these projects are with electricity, which not only increases energy consumption, but also generates a strong electromagnetic field that can affect the environment and the health of people living nearby. Normal magnets with opposite poles can repel each other, but their magnetic power decreases over time.
Adding rare earth elements to a magnet significantly increases its lifetime. Neodymium, for example, can reduce the loss of magnetism to less than 5 percent in a century. Therefore, magnets with rare earth elements are known as permanent magnets.
With its dominance in the supply of rare earths, China controls more than 80 percent of the world’s permanent magnet production capacity, according to an estimate by industry experts.
China has long planned to build magnetic levitation lines using permanent magnets. Suspended magnetic levitation technology has many challenges, such as maintaining train stability in a floating state without a motor.
The maximum speed of most domestic subway lines is generally capped at 80 km/h, but a permanent magnetic levitation train, powered entirely by Artificial Intelligence, could reach a speed 50% higher.