Union CTC Logo Shirt Printed on Front 100% Cotton Shirt Color - Sagestone Please allow 10 business days to ship! US&S built the first power interlocking system in the United States, a pneumatic design, in 1882 at East St. Louis, Illinois. Within several years the company developed an electro-pneumatic system, which was widely adopted by railroads across the country.[11]In 1901 US&S developed the first electro-pneumatic automatic train stop system for the Boston Elevated Railway. This system was later adopted by the New York City Subway and other transit systems.[12] In 1908 the company introduced an electrically-controlled highway crossing gate.[13]In 1923 US&S developed the first inductive train control system. (See also pulse code cab signaling.) The company developed coded track circuits, supporting bi-directional cab signaling, in 1934.[4]The first digital rail yard control system was built by US&S in 1970, for the Atchison, Topeka & Santa Fe railway at Kansas City, Kansas