What are door hold backs used for in containers?

Door hold backs are devices used to secure the doors of a container in the fully open position. This is particularly important during loading and unloading operations, allowing for easy access to the interior of the container without the doors swinging shut unintentionally. By maintaining the door in an open position, it enhances both safety and efficiency, enabling workers to handle cargo without obstruction.

The other options do not accurately describe the function of door hold backs. While keeping doors locked during transit might involve different locking mechanisms, hold backs specifically do not serve that purpose. Similarly, preventing leaks during rainfall is unrelated to the operation of door hold backs, which focus solely on door positioning rather than sealing. Additionally, providing extra weight is not relevant, as the primary role of door hold backs relates to the management of the doors rather than influencing the weight distribution of the cargo.