How is a light engine defined in railway terminology?

A light engine is defined as an engine that is operating without any cars attached to it. In railway terminology, this term is commonly used to refer to locomotives that are moving independently to either reposition for service, assist in moving trains, or perform other necessary tasks without being coupled to freight or passenger cars.

When an engine is operating in this manner, it often indicates that the locomotive is preparing for its next service or is being moved for maintenance, without the need to carry cargo or passengers at that moment. Understanding this definition is crucial for those working in railway operations, as it helps ensure proper communication and coordination on the tracks, especially when scheduling or dispatching trains.