Which factors are considered on the load chart to determine rigging capacity?

• A. Color of the sling and operator experience.
• B. Wind speed and temperature only.
• C. Configuration, angle, radius, and number of legs.
• D. Length of the lifting strap is the only factor.

Answer: (C)

Load charts are built to show how the geometry of the lift changes the forces the rigging must carry. The factors that show up on these charts—configuration, angle, radius, and number of legs—all describe how the load is shared and how the sling engages with the load and any sheaves or edges.

Configuration tells you how the sling or slings are arranged around the load. A single leg, a two-leg bridle, or a basket hitch each transfer weight differently. Some arrangements spread the load more evenly across the sling, increasing capacity when done correctly, while others concentrate forces in a way that lowers the safe rating.

Angle matters because it directly affects tension in each leg. When the sling legs form a shallow or acute angle with the load, each leg must hold more of the load, reducing the overall capacity. The chart derates capacity as the angle changes to account for this increased tension and potential instability.

Radius, or bend radius, is about how sharply the sling or strap bends around edges or pulleys. A small or sharp radius increases wear and local forces on the sling, so the rated capacity is reduced. A gentler bend radius preserves more of the sling’s strength and the chart reflects that with higher allowable loads.

Number of legs indicates how many strands are sharing the load. More legs can distribute load more evenly and allow greater overall capacity, assuming the rigging is arranged so the load is actually shared. The chart provides different ratings based on how many legs are used and how they’re arranged.

Other factors like wind speed, temperature, or the sling length do not determine the load rating shown on the chart. Those elements influence safe operation or setup, but the chart’s capacity is driven by the lift geometry and distribution described above.