When the angle of a crane's boom is between two angles listed on the chart, which angle should be used?

When determining the appropriate angle to use for a crane's boom when it falls between two angles on a chart, the correct approach is to use the next lower angle listed. This is important because using the next lower angle ensures that safety and stability are prioritized in the crane's operation.

Cranes operate based on specific load charts that indicate maximum load capacities at various boom angles. When the actual boom angle is not precisely listed on the chart, selecting the next lower angle is conservative and mitigates the risk of overloading the crane. By doing this, you are accounting for the fact that loading capacity generally decreases as the angle of the boom increases. Using a higher angle, whether that be the highest angle listed or the next higher angle, could lead to exceeding safe operational limits and create unsafe conditions, risking both the equipment and the personnel involved.

Thus, the rationale behind using the next lower angle not only follows best practices in crane operation but also aligns with cautious engineering principles that prioritize safety.