When must trains operating on "track and time" be granted verbal authority at signals displaying stop indication?

When trains are operating on "track and time," it is crucial to maintain clear communication and authority regarding their movements, especially in situations where signals are displaying a stop indication. The correct answer emphasizes that verbal authority must be granted to enter the limits of "track and time" at either end.

This requirement is significant because the "track and time" authority allows a train to occupy a section of track that may be used by other trains, and entering that territory without proper authorization could lead to dangerous situations, including collisions. When a signal displays a stop indication, it signifies that the train cannot proceed without explicit permission. Therefore, granting verbal authority to enter the limits ensures that all safety protocols are observed, and that the dispatcher has the necessary situational awareness to manage train movements effectively within that established zone.

This careful protocol is essential in mitigating risks and maintaining operational safety on the rail network.