Call-on signals are displayed on which type of signals?

Call-on signals are used specifically to instruct a train to proceed under certain conditions, typically when the main signal displays a stop indication. These signals are primarily associated with home signals, which are located at various points along the railway to control train movements.

A call-on signal permits a train to enter an occupied block when it is safe to do so, usually providing guidance for a movement that would otherwise be restricted or prohibited by a stop signal. When a call-on signal is displayed, it indicates to the operator that they may pass the signal and proceed into an area where a train is already occupying the track, often requiring the operator to proceed cautiously.

This is particularly important in scenarios where a signal is displaying a stop indication that cannot be cleared due to track occupancy or other operational reasons. Understanding the functionality and application of call-on signals is critical for train operators to ensure safety and efficient train movements along the railway.