What must a train do when it encounters an unattended fusee?

When a train encounters an unattended fusee, the train crew is required to reduce speed to Restricted Speed. This is critical because an unattended fusee typically indicates a warning or potential hazard on the track ahead, such as an obstruction or a condition that requires caution. By reducing speed, the train can ensure safety by allowing the crew enough time to assess the situation and react appropriately if needed.

Restricted Speed is a speed at which a train can stop within half the distance of the range of vision, ensuring that any unexpected obstacles can be addressed adequately. This practice enhances safety, particularly in situations where there might be ambiguity regarding the track ahead and helps prevent accidents.