Electromagnetic suspension and levitation

The phenomenon of levitation has attracted attention from philosophers and scientists in the past. Recent advances, notably in power electronics and magnetic materials, have focused this attention within the last decade on the application of electromagnetic suspension and levitation techniques to advanced ground transportation. Regardless of the fact that there is, in effect, a separate technology involved for each electromagnetic method, the whole subject is given a blanket title of `maglev¿¿. There is also a very wide range of industrial applications to which magnetic suspension techniques could be profitably applied, particularly in the area of high-speed bearings to reduce noise and to eliminate friction, and yet it is only high-speed ground transportation that has caught the imagination of the media. The review deals with the physics and engineering aspects of the four principal contenders for advanced ground transportation and describes the most up to date developments in Germany, Japan, the USA and the UK in this field. The review also describes some of the very recent challenging developments in the application of electromagnetic suspension and levitation techniques to contactless hearings. A fairly comprehensive bibliography is given to enable the more interested reader to pursue the topic further in any one of the technologies dealt with in the paper.