If a crane is operating on tires, what percentage of the rated tipping capacity is used?

When a crane is operating on tires, it is important to consider the stability factors involved. A crane's tipping capacity is influenced by its setup and the surface on which it operates. In the case of cranes on tires, they are typically subject to more dynamic forces and stability challenges than cranes on outriggers or tracks.

The correct choice, indicating that 75% of the rated tipping capacity is used, reflects the operational limits of a crane working in this manner. This percentage recognizes that cranes on tires have a reduced stability compared to those that are fully stabilized with outriggers. Therefore, while the crane can still operate efficiently, the caution applied to the rated capacity is necessary to ensure safety and prevent tipping.

While the maximum rated capacity may still be maintained in an ideal situation, accounting for potential instability and lateral forces when on tires leads to this conservative utilization of capacity. Thus, this 75% figure is a standard guideline within the machinery operation context that helps operators make informed decisions regarding safety and operational limits.