The knuckle boom system consists of a main boom and a three-part telescopic jib.
Mounted on the jib is a rotatable load hook with a safety catch. The boom and jib are
actuated by the lift, the jib and the three telescopic extension hydraulic cylinders.
The crane incorporates an overload protection shut-off system. In the event of any
overload situation, however caused, the system prevents any further movement of the
crane boom, which will increase the load moment. This system only allows
movements that reduce the load moment and continued operation within the rated
capacity of the crane.
Figure 2. 18 Crane Nomenclature