In general, the term design load can refer to two distinct concepts: These interpretations represent fundamentally different aspects of system performance.
Structures and pressure vessels have design loads of the first type.
Electric motors, compressors and heaters have design loads of the second type.
The minimum breaking load (MBL) for the combined capacity of reeves of a steel wire hoisting rope required on this size of crane is, (p 68)[1]
This factor of safety has been shown to be required when a failure could be catastrophic, such as a crane dropping its load or collapsing entirely.