How should a train proceed if delayed in an interlocking?

When a train is delayed within an interlocking, it is essential for safety and operational efficiency to proceed in a controlled manner. The proper course of action is to operate at Restricted Speed and in accordance with the last signal indication. This means that the train must travel at a speed that allows it to stop short of any obstruction or signal, which ensures that the crew has adequate time to respond to any unforeseen circumstances such as another train or equipment in the area.

Restricted Speed allows for safe movement through the interlocking area where the potential for conflicting train movements exists. By adhering to the last signal indication, the crew is also following signal indications that are critical in managing traffic and ensuring safe passage through the interlocking.

In contrast, if a train were to proceed at Normal Speed until the last signal or return to the previous station, it could result in safety hazards or traffic conflicts. Moreover, contacting the Dispatcher may not be necessary if the last signal indication is clear and there is a protocol that allows the train to move safely at Restricted Speed. Thus, option B ensures that operations are conducted safely and in compliance with established railroad safety practices.