What light indicates a signal has failed on a distant signal subsidiary light?

The signal that indicates a failure on a distant signal subsidiary light is represented by a small yellow light. This signal is important as it informs train operators that there is a malfunction with the associated distant signal, requiring them to approach with caution. The small yellow light serves as a warning, indicating that although the signal is not displaying a standard aspect for movement or stop, there is an underlying issue that must be addressed.

In the context of railway operations, maintaining clear and accurate communications through signal aspects is essential for safety and operational efficiency. The small yellow light alert is a specific feature understood by personnel trained in safeworking practices, ensuring they are aware of the need for vigilance when proceeding past the signal. Understanding these signal communications is crucial for the safe management of train movements, especially in complex railway environments.