When are locomotive safety devices not required to be operating?

Locomotive safety devices are not required to be operational when locomotives are being hauled in tow. This scenario involves a locomotive that is not actively in operation but is being transported by another locomotive or vehicle. Since the primary function of safety devices is to ensure safe operation while the locomotive is in service, this requirement does not apply when the locomotive is not being operated under its own power.

In other situations, such as when the locomotive is at full speed or before a brake test is performed, safety devices must be operational to ensure the safety of the locomotive and crew. Additionally, scheduled maintenance usually requires that safety devices be functional to conduct necessary tests or inspections on the equipment being serviced. Therefore, the context of being transported without active operation is what makes this answer accurate.