Counterweight and operator car of tower crane

The vertical tower extends dozens of feet into the air, and the jib rests on top. The longer section of the jib has cables attached to move or position objects below, while the shorter section of the jib extends away from these cables to act as a counterweight. Additional counterweights made from concrete or steel may be hung from the shorter section of the jib to adjust the balance of the crane.

An operator car is typically located where the jib meets the tower. The tower crane operator sits inside of this car and uses a series of controls to swing the jib and move objects. An individual on the ground or within the building oversees the process of fastening objects to the cables of the tower crane. This individual is known as a rigger, and he or she uses radio or hand signals to communicate with the crane operator.