When determining the number of hand brakes needed, which factor is considered?

The number of hand brakes required for a train is primarily determined by factors such as the grade of the track and the adhesion characteristics of the rail and wheels. The grade refers to the steepness of the track; steeper grades require more hand brakes to ensure that the train remains securely in place and does not roll backward or forward unintentionally. Adhesion involves the friction between the train wheels and the track surface, which can vary based on environmental conditions like weather or rail material.

If the track is wet, icy, or made of a material that has lower friction, additional hand brakes may be needed to compensate for that reduced grip. Therefore, understanding both the grade and the level of adhesion is vital for keeping the train safely restrained on a slope.

While other factors, such as the weight of the locomotive or crew operational hours, might influence overall train handling and safety protocols, they do not directly determine the specific number of hand brakes necessary in the same way that grade and adhesion do.