The Milwaukee road, working with the servo corporation of America, has developed an automatic railroad crossing protection system designed to provide a maximum of protection at minimum cost, in slow-speed switching areas. The Milwaukee yard in Madison, Wisconsin, is cited as a typical example of what can be accomplished with the system. The new controls will return their original cost in about two years. Transducers sense the movement of engines, railroad cars or trains and in conjunction with associated equipment, determines the direction of movement, provides timing, and actuates crossing controls to permit the movement of vehicular traffic during all safe periods. Audio frequency overlay circuits at the crossings cause the protection equipment to function if railroad cars or locomotives occupy that area. This crossing control system was recommended for low-speed, industrial switching areas where train speeds range from 2 to 25 mph. Tests have indicated that the equipment is reliable at speed up to 80 mph. The equipment operates effectively from -40 f to 150 f.
Abstract