What does a long blast on the tower whistle signal to a train operator in the yard?

A long blast on the tower whistle serves as a critical signal to train operators, indicating that all trains must come to an immediate stop. This signal is a safety measure implemented to ensure the safety of personnel and operations within the yard, particularly when there may be a need to address equipment issues, personnel on the tracks, or other potentially dangerous situations.

When this signal is sounded, it is a universal code meant to communicate urgency and requires immediate compliance from all train operators. This is vital in preventing accidents and ensuring the safety of all individuals present in the yard, as well as protecting the integrity of the train operations.

Other signals, such as those for slowing down or continuing movement, serve different purposes and do not convey the same level of urgency associated with a long blast on the tower whistle. Therefore, understanding this signaling system is crucial for maintaining a safe and efficient operational environment in the rail yard.