What is the purpose of a locomotive's horn?

The primary purpose of a locomotive's horn is to alert others of the train's presence, especially at railroad crossings. This warning system is essential for safety, as it helps prevent accidents by notifying pedestrians, vehicles, and other trains that a train is approaching. The sound of the horn serves as an auditory warning to individuals who may be unaware of the train's approach or its speed, allowing them to take necessary precautions.

While signaling to other trains or railway staff might be important in specific contexts, the horn's main function is centered around ensuring safety in areas where trains and other entities interact, particularly at crossings where the risk of collision is significant. This proactive alert system is crucial for reducing the likelihood of accidents and protecting lives.