How do you determine the crane’s stable working radius for a lift?

• A. Consult the load chart for the current configuration and confirm the load does not exceed the charted capacity at that radius and boom length.
• B. Estimate based on prior lifts without checking the chart.
• C. The radius is the same for all configurations.
• D. Use the operator's seat position to judge distance.

Answer: (A)

The key idea is that the stable working radius comes from the crane’s load chart specific to the current setup. The chart links radius, boom length, and the exact configuration (outriggers deployed, counterweights, attachments) to the maximum load the crane can safely lift at that radius. To determine stability, you identify the crane’s current configuration, find the corresponding section of the chart, and verify that the load you plan to lift does not exceed the charted capacity at that radius and boom length. If the load is greater, you must reduce the radius, shorten the boom, lighten the load, or adjust the setup until the chart shows sufficient capacity.

Relying on memory from previous lifts isn’t reliable because every configuration changes the stability, and the chart reflects those precise conditions. The radius isn’t the same for all configurations, so you can’t assume a universal value. The operator’s seat position doesn’t change the actual distance to the load. Using the chart ensures a true, configuration-specific assessment of stability.