TP corresponds to which term?

• A. Time element relay
• B. Train Stop
• C. Time element unit
• D. Track repeater relay

Answer: (D)

TP corresponds to the Track Repeater Relay. In signaling diagrams, two-letter codes name specific devices, and TP is used for the component that duplicates the status of a track circuit so it can be observed at a remote location, such as another panel or interlocking. This repeater relay ensures the same track condition is visible wherever needed, helping maintain correct interlocking logic and safe operation. The other options refer to different kinds of devices: timing-related elements (which manage delays or time-based logic) and a Train Stop (which actively enforces a train to halt). The Track Repeater Relay is the one that simply repeats the track status, matching the TP designation.