What is the protocol at a stop indication in automatic interlockings?

At a stop indication in automatic interlockings, the established protocol is to work the box and move at restricted speed if the signal remains. This approach recognizes that automatic interlockings are designed to manage train movements safely, yet there may be conditions requiring a train to proceed even when facing a stop signal.

When a train encounters a stop indication, working the box often means that the crew will take necessary actions, such as verifying routes or receiving permission from a dispatcher if applicable. Moving at restricted speed allows the train to proceed cautiously, being prepared to stop within half the range of vision or within the limits of any signal indication, thus ensuring safety while potentially allowing for a continuation of movement as needed.

The other options do not align with established practices for managing stop indications at automatic interlockings. The need for immediate contact with the control operator, waiting for the next scheduled signal, or proceeding slowly without proper actions are not part of the protocols designed to ensure safe and efficient train operations in these scenarios.