Maglev
The world's first commercial maglev system was a low-speed maglev shuttle that ran between the airport terminal of Birmingham International Airport and the nearby Birmingham International railway station between 1984 and 1995. Its track length was , and trains levitated at an altitude of , levitated by electromagnets, and propelled with linear induction motors. It operated for 11 years and was initially very popular with passengers, but obsolescence problems with the electronic systems made it progressively unreliable as years passed, leading to its closure in 1995. One of the original cars is now on display at Railworld in Peterborough, together with the RTV31 hover train vehicle. Another is on display at the National Railway Museum in York.
Maglev
The drag force can be used to the electrodynamic system's advantage, however, as it creates a varying force in the rails that can be used as a reactionary system to drive the train, without the need for a separate reaction plate, as in most linear motor systems. Laithwaite led development of such "traverse-flux" systems at his Imperial College laboratory. Alternatively, propulsion coils on the guideway are used to exert a force on the magnets in the train and make the train move forward. The propulsion coils that exert a force on the train are effectively a linear motor: an alternating current through the coils generates a continuously varying magnetic field that moves forward along the track. The frequency of the alternating current is synchronized to match the speed of the train. The offset between the field exerted by magnets on the train and the applied field creates a force moving the train forward.