What is lost in the train stabling function?

The train stabling function primarily involves ensuring that the train operates safely and efficiently when not in active service, especially when parked or stored. In this context, marker lights are vital for indicating the presence of the train to others, particularly in dimly lit areas or during nighttime. However, when a train is stabled, these lights may be turned off to conserve power or to ensure that they do not cause confusion with other active signals.

The rationale behind focusing on marker lights relates to their operational status while the train is stationary. In stabling mode, operational systems like fuel supply, train speed sensors, and cabin ventilation are typically maintained or can be independently managed, ensuring that essential functions remain active or are switched appropriately for maintenance or inspection purposes. Therefore, the correct choice highlights a specific feature that is deactivated or deemed unnecessary in the stabling process, thereby connecting the function's purpose with real-world operational practices.