Novel traction system for railway applications

Traction systems employing the simple and rugged a.c. induction motor have long been the dream of railway engineers. Variable-frequency solid-state inverters have made that dream a reality, and many railway authorities and manufacturers around the world are developing such systems using conventional polyphase induction motors driving the wheels through gears. The Research & Development Division of British Rail has succeeded in building an induction motor entirely within a tubular axle and driving the wheels directly, and so the problems of mounting the motor and its gears which arise with conventional arrangements are eliminated