What should be done if all headlight bulbs fail while on duty?

If all headlight bulbs fail while on duty, the appropriate action is to illuminate all external engine lights that can be illuminated. This measure is essential to ensure visibility and maintain safety on the tracks, particularly in low-light conditions or during operations around other trains or vehicles. By using alternative lighting, the crew can signal their presence and enhance safety despite the headlight failure.

Choosing to notify a supervisor immediately may seem prudent, but it does not address the urgent need for visibility during operations. Proceeding at normal speed neglects the potential hazards associated with a lack of headlights since it can compromise safety for both the crew and others on the track. Stopping the train and waiting for repairs could lead to unsafe situations on the railway since the train would be stationary and could block tracks, leading to delayed operations and potential hazards for other trains.

Hence, illuminating all available external lights helps to mitigate the immediate risk associated with headlight failure while awaiting further instructions or repairs.