What factors determine the minimum number of hand brakes to apply?

The minimum number of hand brakes to apply is determined primarily by the weight of the train and the grade conditions. When considering safety and compliance with regulations, these two factors are critical in ensuring that the train remains stationary and stable when stopped, particularly on gradients.

The weight of the train influences how much braking power is needed to counteract gravitational forces when the train is on an incline. Heavier trains require more hand brakes to prevent rolling or movement. Moreover, the grade conditions, meaning whether the train is on a flat surface, ascending, or descending, further dictate the braking requirements. On steeper grades, additional hand brakes may be necessary even for lighter trains to ensure stability.

Although other factors such as crew availability or the length of the train can play roles in operational decisions, they do not directly relate to the technical requirements for safely securing a train. The primary focus should be on weight and grade, as they directly impact the forces at play and the effectiveness of the hand brakes in preventing movement.