Abridgment of power supply for railway signals and automatic train control

This paper deals, in a general way, with the several systems of automatic block signaling, particularly the a-c. system, and the apparatus commonly used to insure continuity of power supply. It covers briefly the older phases of the subject and more specifically the later applications. The most modern system of continuous inductive train control, the code system, has required the development of frequency-converting apparatus for this use. Within the past three years, a number of frequency-converting automatic substations has been installed by the railway companies. The class of apparatus used in these stations is discussed, including some details of installations on the Pennsylvania and Long Island Railroads.