Load Charts and Capacity Flashcards

A load chart shows a gross capacity of 20,000 lbs at the working radius. The hook block weighs 500 lbs and rigging weighs 300 lbs. What is the net capacity available for the load?

Answer: 19,200 lbs

Net capacity = 20,000 − 500 − 300 = 19,200 lbs available for the actual load.

A lift requires picking a 15,000 lb load. With deductions the net capacity is 16,000 lbs. The load utilization is closest to:

Answer: About 94%

15,000 ÷ 16,000 ≈ 0.94, or roughly 94% of available capacity.

If a load weighs more than the net capacity at the current radius, the operator should first try to:

Answer: Reduce the radius by booming up so a higher capacity column applies

Bringing the load closer (shorter radius) generally raises the rated capacity available.

A crane is rated at 30,000 lbs at 10 ft radius and 12,000 lbs at 30 ft radius. This illustrates that capacity is most sensitive to:

Answer: Changes in load radius

The large drop from 30,000 to 12,000 lbs shows how strongly radius affects rated capacity.

When two chart values bracket your actual radius (e.g., your radius falls between listed 25 ft and 30 ft rows), you should:

Answer: Use the capacity for the next larger (longer) radius

Always round to the longer radius, which gives the more conservative, lower capacity.

A load handling device weight of 800 lbs is forgotten in the calculation. The likely consequence is that the operator:

Answer: Underestimates the true load and may exceed rated capacity

Omitting device weight makes the load appear lighter than it is, risking an overload.

A wire-rope load line on a multiple-part reeving system shares the load across the parts. Increasing the parts of line primarily:

Answer: Increases the lifting capacity of the hoist line

More parts of line distribute the load across more rope sections, raising the line's effective capacity.