An electric system for monorail rapid transit

SURFACE traffic congestion and the high cost of subway construction have caused renewed interest in elevated mass transit. The necessity to eliminate noise and to avoid shutting off light and air, both of which have been characteristic of the old elevated lines has focused interest on the monorail, or suspended railway, form of transportation. Modernization of the monorail type of transportation led to research for ways to simplify, lighten, and minimize the required space of all components of the equipment. One outstanding result, incorporated in a recently completed report to the Los Angeles Metropolitan Transit Authority, was adoption of the squirrel-cage induction motor working in combination with a torque converter drive as the propulsion equipment, in place of the d-c series motor and its involved rheostatic voltage control. The resulting performance characteristics are the equal of the most recent series motor equipment proposed for comparable service. Besides weight and space advantages on the rolling stock, a substantial reduction in power supply apparatus costs results from the direct use of usual 3-phase 60-cycle electric energy without the expense and the complication of special conversion to direct current.