Head-end power

Head-end power is a process used by railways to maintain the electric power during a train's journey. It works by using a generator on the train (called a "head-end power unit") to provide electricity to the train. The head-end power unit takes power from the locomotive's main engine and converts it into a form of electricity that can be used by the train systems, like lighting and air conditioning. This process makes sure that the train has power throughout its journey, even when the train is at a station and the main engine is turned off.