Crane (machine)

Cranes are commonly employed in the construction industry and in manufacturing heavy equipment.

Construction cranes are usually temporary structures, either fixed to the ground or mounted on a purpose-built vehicle.

Cranes may either be controlled from an operator in a cab that travels with the crane, by a pushbutton pendant control station, or by infrared or radio control.

Where a cab operator is employed, workers on the ground will communicate with the operator through a system of standardised hand-signals or, in larger installations, radio systems; an experienced crew can position loads with great precision using only these signals.