Audiofrequency track circuit with data transmission/transceiver interface

Abstract From the Canadian patent

A track circuit for a railway system including a track formed by rails having a longitudinal axis and comprising a plurality of successive track segments. The track circuit includes a track segment of preset length which is electrically isolated from adjacent segments by electrical splices at opposite ends thereof. The electrical splices each comprise a splice conductor connecting the rails together at opposite ends of each track segment and having an "S" shape laid flat and extending along the longitudinal axis of the track. Each splice conductor has axially-extending branches arranged along internal sides of corresponding rails. The track circuit comprises a stationary ground transmission …