Maglev: over a century of floating trains, yet only six in service
Trains that hover on magnets instead of rolling on wheels have been patented since 1902, and a Japanese test train touched 603 kilometres an hour in 2015. Even so, just six maglev systems carry passengers today, four of them in China, because the guideways are costly to build and cannot share ordinary rail lines.
Levitation comes in two main flavours, electromagnetic and electrodynamic suspension, and a linear motor usually supplies the push. Lifting the train takes surprisingly little power; fighting air resistance consumes most of it, which is why sealed low-pressure vactrain tubes have been suggested. The payoff is faster acceleration, easier climbing, quieter running and less maintenance. Shanghai's airport link, built on German Transrapid technology, held the record for scheduled passenger speed from 2002 until 2021 at 431 kilometres an hour, covering 30.5 kilometres in 7 minutes and 20 seconds.
Early dreamers were plentiful. Albert C. Albertson's patent of 2 December 1902 used magnets merely to lighten the load on wheels. In 1908 Cleveland mayor Tom L. Johnson ran a wheel-less car nicknamed Greased Lightning along a 90-foot track in his basement, and in 1912 Émile Bachelet demonstrated a levitating model in Mount Vernon, New York, taking it to London in 1914. Hermann Kemper collected German patents between 1937 and 1941, and in 1961 James Powell of Brookhaven, stuck in a traffic jam, began the superconducting concept he later patented with Gordon Danby.
In Britain, Eric Laithwaite built the first full-size working linear induction motor in the late 1940s and, in the early 1970s, found a magnet layout he called the magnetic river that delivered lift and thrust together. That work fed the first commercial maglev, a 600-metre shuttle between Birmingham Airport and the nearby railway station that opened in 1984, floated 15 millimetres up, topped out at 42 kilometres an hour and closed in 1995 over reliability problems. Germany's Transrapid 05 carried more than 50,000 riders on a 908-metre track in Hamburg in 1979.
Japan pursued two systems. Superconducting work began in 1962, and test trains at Miyazaki routinely hit 517 kilometres an hour by 1979, while the slower HSST design, started in 1974, entered service in 2005 as the 8.9-kilometre Linimo in Aichi. Construction of the Chūō Shinkansen between Tokyo and Nagoya, 285.6 kilometres, began in 2014 with a 2027 target, but delays and resistance from Shizuoka governor Heita Kawakatsu have pushed opening to no earlier than 2036.
Source: Maglev
