A vehicle-suspension type of permanent magnet-levitation transportation system has an elevated track structure defining a bed with a ferromagnetic levitation track on the underside thereof and a spaced parallel control track composed of ceramic magnetic material having transverse polarity orientation...http://www.google.com/patents/US4307668?utm_source=gb-gplus-sharePatent US4307668 - Transportation system unitizing permanent magnets for levitation of a vehicle
