A crane's main boom length is 40 meters. The load chart lists capacities for working radii of 10m, 12m, 14m, and 16m. An operator needs to lift a load at a 13-meter radius. Which of the following is the correct approach?

Question: A crane's main boom length is 40 meters. The load chart lists capacities for working radii of 10m, 12m, 14m, and 16m. An operator needs to lift a load at a 13-meter radius. Which of the following is the correct approach?

Answer options: ✅ Use the capacity listed for the next LONGER radius (14m) or interpolate if allowed by the manufacturer.

• Use the capacity listed for the next SHORTER radius (12m).
• Always use the lowest capacity given on the chart for that boom length.
• Estimate the capacity by averaging the 12m and 14m values without further verification.

Correct answer: Use the capacity listed for the next LONGER radius (14m) or interpolate if allowed by the manufacturer.

Explanation: When the exact radius is not listed, the general rule is to use the capacity for the next LONGER radius to ensure safety, or to interpolate the capacity if the manufacturer's load chart specifically permits interpolation between values. This provides a more conservative and safe capacity rating. This is consistent with ASME B30.5 and CSA Z150 principles.