What must the train operator do to warn shop employees of the approaching train?

Blowing two blasts of the whistle is a standard protocol used by train operators to alert individuals in the vicinity, including shop employees, of an approaching train. This method is effective because sound travels over distances and can be heard by people who may not be able to see the train. The two blasts specifically are recognized signals indicating that the train is approaching, creating awareness for people in the area to remain safe and take necessary precautions.

In many train systems, audible signals are a crucial part of safety procedures, as they provide immediate warnings to anyone who may be working on or near the tracks. This practice helps to minimize the risk of accidents and ensures that everyone is informed of the train's approach in a timely manner.