On crawler-cranes and truck-cranes, the boom is mounted on the front end of the crane body by means of:

On crawler-cranes and truck-cranes, the boom is mounted on the front end of the crane body by means of:

• A. Hinge joints
• B. Base plates
• C. Pivot bolts
• D. Boom heel pins

Answer: (D)

The main idea is the way the boom is attached at its base to the crane body. On crawler-cranes and truck-cranes, the boom heel is mounted to the front end of the crane body with boom heel pins. These pins form a pivotal connection that lets the boom tilt up and down while safely transferring the loads from the boom into the crane structure. They’re typically sized as a strong, removable pin arrangement, often in pairs, to provide a robust yet serviceable mounting. Other terms like base plates simply distribute loads at the joint, and generic hinge or bolt concepts don’t describe the specific, purpose-built connection used at the boom’s base.

The main idea is the way the boom is attached at its base to the crane body. On crawler-cranes and truck-cranes, the boom heel is mounted to the front end of the crane body with boom heel pins. These pins form a pivotal connection that lets the boom tilt up and down while safely transferring the loads from the boom into the crane structure. They’re typically sized as a strong, removable pin arrangement, often in pairs, to provide a robust yet serviceable mounting. Other terms like base plates simply distribute loads at the joint, and generic hinge or bolt concepts don’t describe the specific, purpose-built connection used at the boom’s base.