Abstract

A railroad track circuit providing for the positive detection of broken rails despite the presence of factors that would otherwise preclude such detection is disclosed. These factors include sneak paths arising from the presence of negative return cross-bonding as applied between parallel tracks in electrified territory. Broken rail detection is ensured through the provision of two track relays, or devices that function as track relays, uniquely arranged so as to render the track circuit immune from these factors.

IPC Classes  ?

• B61L 23/04 - Control, warning or like safety means along the route or between vehicles or trains for monitoring the mechanical state of the route
• B61L 1/18 - Railway track circuits
• B61L 21/10 - Arrangements for trains which are closely following one another