Mobile Crane Assembly and Disassembly Flashcards

When assembling a mobile crane, in what position should the superstructure typically be before installing counterweights?

Answer: Slewed directly over the rear of the carrier

For most mobile cranes, the superstructure must be slewed over the rear of the carrier for counterweight installation. This position provides maximum stability and correctly aligns the counterweight tray or hydraulic pinning system with the counterweights on the ground or transport vehicle.

When assembling a lattice boom, what is the most critical step after connecting two sections with pins?

Answer: Ensuring all connection pins are fully inserted and secured with keepers

The structural integrity of a lattice boom depends on the secure connection of its sections. After inserting the main connection pins, it is absolutely critical to ensure they are fully seated and that all retaining clips, cotter pins, or other keepers are properly installed to prevent the pins from backing out during operation.

Before beginning any assembly or disassembly procedures, what must be ensured regarding the crane's outriggers?

Answer: They are fully extended as required, set on pads, and the crane is level with tires clear of the ground

A stable foundation is the first principle of safe crane operation and assembly. Before lifting any components, the outriggers must be extended to the manufacturer's required configuration, placed on blocking or pads sufficient to support the load, and used to level the crane until the tires are clear of the ground.

What is the only authoritative source for the correct sequence and procedures for assembling or disassembling a specific mobile crane?

Answer: The crane manufacturer's operator/assembly manual

Every crane model has unique assembly and disassembly procedures designed by the engineers who built it. The manufacturer's manual is the only authoritative source for the correct sequence, required tools, and safety precautions. Failure to follow these specific instructions can lead to component damage or catastrophic failure.

When assembling a luffing jib on the ground, what is a primary hazard the crew must control?

Answer: The potential for uncontrolled movement due to the jib's center of gravity

Luffing jibs and other long attachments often have a center of gravity that can cause them to become unstable and swing or 'flop' unexpectedly during assembly if not properly blocked and supported. The assembly plan must account for this and ensure the component is stable at all times before lifting.

During disassembly, an assist crane removes the main boom. What must the lift director's calculation of the boom's weight include?

Answer: The total weight of the boom, including all rigging, wire rope, and the hook block

To safely lift the boom, the lift director must calculate the total weight of the 'pick'. This includes not just the boom structure, but also the weight of the main hook block, any auxiliary blocks, all the wire rope spooled on the drum, and the rigging used to connect the boom to the assist crane.

What is a key element of a good site layout plan for mobile crane assembly/disassembly?

Answer: Having a designated, level, and firm area with sufficient space for all components and assist cranes

A well-planned assembly/disassembly area is critical for safety and efficiency. The area must be large enough to lay out the boom, jib, counterweights, and other components without being crowded. Most importantly, the ground must be firm and level to ensure the stability of the main crane, assist cranes, and the components themselves.