If one rail joint becomes short-circuited, how many track signal circuits will be affected?

When one rail joint becomes short-circuited, it affects two track signal circuits. This occurs because each rail joint serves to connect two sections of the railway track that are monitored by the signal system.

In a typical signaling system, the track is divided into segments that are detected by signal circuits. A short circuit at a rail joint disrupts the electrical continuity and alters the conditions in the circuits that are using that section of the rail to determine the presence or absence of a train.

The first circuit is affected on one side of the joint, where the short circuit directly inhibits the signaling functionality. The second circuit is affected on the opposite side of the joint, as it also relies on the integrity of the electrical connection through the track. Therefore, with one rail joint short-circuited, both of the circuits linked to that joint would experience disruptions, leading to the conclusion that two track signal circuits will be impacted.