Under the 1926.1400 standard, assembly of a crane boom requires which competent person?

• A. Qualified rigger
• B. Crane operator
• C. AD director
• D. Site supervisor

Answer: (C)

When a crane boom is being assembled, a competent person with authority to direct and oversee the work must be on site. This person ensures the assembly follows the crane manufacturer’s instructions, verified procedures, and all safety controls, coordinating rigging, pins, lubrication, and any testing steps so nothing is done without proper authorization and understanding of the hazards.

The designated AD director is the one who holds that authority on the jobsite and brings the necessary knowledge to supervise the entire process. This role coordinates with riggers and operators, confirms that the boom assembly sequence is correct, and ensures that each step is performed safely and in accordance with the manufacturer’s instructions and the project’s safety plan.

A qualified rigger focuses on rigging the loads, which is critical but does not by itself oversee the entire assembly process. The crane operator runs the equipment once it’s assembled, but cannot supervise the assembly steps. A site supervisor may oversee work in general but may not have the specialized authority and technical oversight required for crane assembly per the standard.