Portal crane is suitable for heavy work at seaports, river ports and freight yards and it equips with hoisting hooks or grab buckets. This product is applicable to various types of cargos and can be used for handling containers. The complete unit consists of three mechanisms. They are lifting mechanism, rotating mechanism and luffing mechanism. These three mechanisms can work separately or jointly. According to the hoisted weight, the strong four-bar derricking system or the single boom pulley block system can be selected.