How does a crane's load chart help determine safe lifting capacity for a given boom length and radius?

• A. It provides the actual weight of the crane itself.
• B. It lists the maintenance schedule.
• C. It shows the maximum allowable load for each configuration.
• D. It indicates the target speed of the winch.

Answer: (C)

A crane’s load chart is a rating tool that translates the chosen geometry into a safe lifting capacity. For a given boom length and radius, the chart shows the maximum load that can be lifted without risking instability or structural overload. The radius—how far the load is from the crane’s center—drives leverage, so as the boom length or radius grows, the chart generally shows a smaller allowable load. Many charts also incorporate other configuration details (like jib use, counterweight, and outrigger setup), so the listed capacity reflects the exact combination you’re using.

To use it, you read the maximum allowable load from the chart at your specific boom length and radius, then ensure the actual load (and rigging) stays at or below that number under standard conditions (level ground, proper outriggers, no significant wind). If conditions differ, you adjust downward. The chart is not about the crane’s own weight, maintenance schedules, or winch speeds; it’s specifically the safe load for each configuration.