What are three short horn signals used to indicate?

Three short horn signals are utilized primarily to indicate the need for a Road Car Inspector (RCI). This specific signal is crucial in the context of rail operations, as it alerts personnel who may be stationed along the tracks or in nearby areas that an inspection is required. The use of sound signals, like the three short horn blasts, is essential for communication in situations where visibility may be limited or where visual signals would not be effective.

The choice of this signal highlights the importance of safety and maintenance in rail operations. If an inspector is needed, it typically indicates that there may be an issue with the condition of the rolling stock or fixed infrastructure that requires immediate attention. This ensures prompt action for safety checks and regulatory compliance, which plays a significant role in the overall operation and maintenance of railway systems.