What does the yellow zone on the speed dial indicate?

The yellow zone on the speed dial serves a critical function in train operations, specifically indicating that service braking is required to slow down the train. This signal alerts the engineer to reduce speed in preparation for a safe operation, often due to factors such as upcoming track conditions or signals that necessitate a decrease in velocity.

This warning helps maintain safety standards by ensuring that the train can be brought to a stop or slowed appropriately before reaching critical areas such as junctions, switches, or reduced speed zones. Recognizing the significance of the yellow zone is essential for train engineers to manage their speed responsibly and effectively, ensuring not only compliance with operational protocols but also the safety of passengers and crew.

Other signals and zones, such as normal operating speeds or emergency braking, serve different functions and are indicated by distinct markers or colors on the speed dial. Therefore, understanding the specific implications of the yellow zone is vital for safe train operation.