What is the minimum design factor for standing ropes or pendant lines in boom erection conditions?

The minimum design factor for standing ropes or pendant lines in boom erection conditions is set at 2.5. This standard is established to ensure safety and reliability during crane operations, especially when the crane is being assembled or disassembled, as these conditions can impose additional stresses on the ropes.

A design factor of 2.5 means that the ropes are required to have a breaking strength that is at least 2.5 times greater than the maximum load they are expected to bear during boom erection. This margin is crucial for preventing failure under dynamic loading conditions and ensuring that safety is prioritized.

In contrast, the other proposed factors are designed for different contexts or applications. A lower factor might not provide sufficient strength for the added risks associated with boom erection, while higher factors might be too conservative for such specific scenarios. Therefore, the establishment of a 2.5 design factor reflects a careful balance that accommodates the demands of safety and engineering standards in crane operations.