Usually, many people like to admit that a gantry crane is made up of 3 parts: metal structure, mechanism (including lifting mechanism, luffing mechanism, slewing mechanism and traveling mechanism) and electrical system.

       Fig 30-2 is a picture about some types of gantry cranes.

Multi-purpose gantry crane is one kind of gantry cranes .It is a transforming product of common gantry crane. Its structure is almost the same as the later. With different handling accessory, it can handle container, general cargo and bulk cargo. It can also be equipped with magnetic chuck, if it is wanted to handle scrap iron and steel. It is mostly used in middle and small type terminals whereas the quayside container crane is mostly used in large scale port.

Multi-purpose gantry crane also has lifting mechanism, luffing mechanism, slewing mechanism and traveling mechanism .Fig30-3 is the structure diagram of multi-purpose gantry crane.

In most cases, we can classify the multi-purpose gantry crane on the basis of types of the handling cargo and structure type of the boom. From the former angle, multi-purpose gantry crane is usually classified into two kinds. One kind mainly deals with container, heavy cargo and general cargo. The other kind is designed for handling container, heavy cargo, general cargo and bulk cargo. (The main job of these two kinds is container handling. From the latter angle, we can get four-bar combination jib multi-purpose gantry crane and single-beam multi-purpose gantry crane.