As the boom angle decreases, crane capacity _________.

As the boom angle decreases, crane capacity _________.

• A. Increases
• B. Decreases
• C. Remains
• D. Doubles

Answer: (B)

The capacity of a crane is governed by the load moment about the base. When the boom angle is reduced, the load sits farther from the base, increasing the moment for the same weight. To stay inside the rated moment, the allowable load must be smaller, so the crane’s capacity decreases as the boom angle decreases. That’s why the correct idea is that capacity decreases. If you need to lift heavier loads, you’d typically raise the boom or adjust stability factors (outriggers, counterweights) to increase capacity.

The capacity of a crane is governed by the load moment about the base. When the boom angle is reduced, the load sits farther from the base, increasing the moment for the same weight. To stay inside the rated moment, the allowable load must be smaller, so the crane’s capacity decreases as the boom angle decreases.

That’s why the correct idea is that capacity decreases. If you need to lift heavier loads, you’d typically raise the boom or adjust stability factors (outriggers, counterweights) to increase capacity.