Upon approaching a dark dwarf signal with a lay-up in a train yard, what should the train operator do?

Upon approaching a dark dwarf signal in a train yard, the most appropriate action for the train operator is to stop and then blow the proper train whistle to attract attention. This response is vital for safety and communication within the rail yard.

When a signal is dark, it indicates that there is no indication provided to the operator, which could mean that the signal is malfunctioning or that there is a need for closer examination of the situation. Stopping allows the operator to assess the environment safely and determine the next steps without risking a collision or other safety mishaps. By blowing the train whistle, the operator is taking an additional precaution to make nearby personnel or other operators aware of the train’s presence, further enhancing safety measures.

This approach also signifies adherence to safety protocols, as operators are trained to respond cautiously to ambiguous signals, particularly in complex areas like train yards where multiple movements and activities are occurring.