What is a "master switch" used for in locomotive operation?

A "master switch" in locomotive operation is primarily used to control the flow of power to the locomotive's systems. This switch is crucial for managing the electrical systems within the locomotive, as it allows the operator to turn on or off power to various components such as lights, horns, and other critical equipment.

Being the central means of powering up the train's systems, the master switch ensures that all electrical operations are initiated properly before departure, contributing to both safety and functionality. Proper operation of the master switch is essential for ensuring that the locomotive is ready for service while also being able to deactivate systems when necessary for maintenance or emergencies. Each locomotive can have different protocols for using this switch, but its primary function remains consistently related to managing electrical power.