What is the role of the engine whistle in emergencies unless a prohibition is in effect?

The engine whistle serves a crucial role as a warning device in emergencies when there are no prohibitions against its use. When an engine whistle is sounded, it alerts both crew members and nearby individuals of potential danger, allowing for timely responses to avert accidents or hazardous situations. This auditory signal is essential for maintaining safety on the tracks, especially in scenarios where visual communication may be hindered.

In this context, while the whistle can have other functions, such as signaling departure or indicating speed restrictions, its primary purpose during emergencies is to ensure that immediate attention is drawn to a potentially critical situation. Recognizing this function reinforces the importance of the whistle in the overall safety protocols that govern train operations.