What does 1 long buzz indicate when communicated by the conductor?

A long buzz from the conductor serves as a clear signal to stop the train. In train operations, auditory signals like buzzes are crucial for maintaining communication between the conductor and the crew, especially in situations where visual contact may be limited. This specific signal alerts the engineer to halt the train's movement, ensuring safety and allowing for necessary actions to be taken, such as addressing an obstacle on the track or preparing for station stops. Understanding and responding to such signals is fundamental in maintaining safe train operations.

The other choices represent different actions or responses that are not communicated by a long buzz. For example, starting the train or proceeding with caution would require different signals, reflecting the importance of recognizing various auditory cues in operational practices.