National Commission for the Certification of Crane Operators (NCCCO) Mobile Crane Practice Exam

Counterweights should be installed before raising the boom because their primary purpose is to provide stability and balance to the crane during operation. When a boom is raised, it creates a significant load moment which can lead to tipping or instability if not properly counterbalanced. By installing counterweights beforehand, you ensure that the crane has adequate support while the boom is being lifted, maintaining its center of gravity within safe limits. This proactive approach minimizes the risk of accidents and enhances overall safety during the assembly process. Timing is crucial in crane assembly; therefore, installing counterweights before any lifting actions aligns with recommended practices to safeguard both the equipment and personnel involved.