What component allows the boom to lift or lower loads?

The component responsible for lifting or lowering loads in a crane's boom is the winch assembly. The winch assembly typically includes a drum that winds the hoisting cable, allowing for the vertical movement of the load. When the cable is wound onto the drum, the load is lifted; when the cable is unwound, the load is lowered.

The fly section is an extension of the boom that can provide additional reach and support for the load but does not inherently lift or lower it. The base section provides stability and support for the entire structure but does not directly interact with the load itself. Counterweights are used to balance the crane, especially when lifting heavy loads, but they do not contribute to the actual lifting mechanism. Understanding the function of each component is crucial for safe and effective crane operation.