What two factors affect the digger derrick's ability to lift an object within its maximum lift capacity?

The ability of a digger derrick to lift an object within its maximum lift capacity is primarily influenced by the hook radius and sheave height. The hook radius refers to the distance from the center of the rotation point (usually the base of the boom) to the line of lift. This distance plays a crucial role in the amount of leverage applied, affecting the vertical lifting capacity, as the farther the load is from the base, the more force is required to lift it.

Sheave height is the vertical distance from the ground to the point where the lifting line passes over the sheave (a wheel on which a rope runs). This height can alter the mechanical advantage of the system and also impact the stability of the load during the lift. Both the hook radius and sheave height must be taken into account to ensure that the digger derrick operates within its designed limits, as they directly affect the lifting capability and the mechanical dynamics involved in the operation.

Understanding these factors is essential for safe and effective lifting operations, enabling operators to maximize the digger derrick's lifting ability while minimizing the risk of overloading or loss of stability.