In a multi-crane lift, each crane should be loaded to no more than what percentage of its rated capacity?

• A. 50%
• B. 75%
• C. 90%
• D. 100%

Answer: (B)

Distributing the load safely among multiple cranes requires leaving a solid margin for dynamic effects and rigging variance. Keeping each crane loading to about three-quarters of its rated capacity gives room for sway, acceleration and deceleration, slight miscalculations in load share, and any small inefficiencies in crane synchronization. That extra capacity acts as a safety buffer so if the load shifts or one crane takes a tad more than planned, no crane hits its limit. Loading closer to full capacity leaves little room for these uncertainties and raises the risk of overload or instability. So, the practical choice is to limit each crane to 75% of its rated capacity. Loading at 50% would be unnecessarily conservative and slow things down, while 90% or 100% leaves insufficient margin for dynamic factors and contingencies.