The mobile girder rail gantry crane consists of the main beam, rigid and flexible door legs, operating trolley, lifting mechanism, cart operating mechanism, electrical system, operating cab, etc. According to the yard operation process, the cantilever can be extended in the direction of the single door leg or the double door leg to become a single cantilever or double cantilever model, and if it is not extended, it will be a non-cantilever model. According to the location, container storage and transportation process, and loading and unloading vehicles (container trucks or railway vehicles), confirm the selection of different structural methods without cantilever, single cantilever, and double cantilever.

Shipyard cranes are the main equipment for manufacturing ships. Currently, crane trolleys generally use rimless wheels and are designed with a guide device (horizontal wheel) added to one side of the track. This structural form reduces the manufacturing deviation and the impact of track gauge changes on the trolley operation under trolley load conditions. Rolling friction replaces sliding friction between the horizontal wheel and the side of the track, and the frictional resistance endured by the operating mechanism is greatly reduced.

The light tire-type container gantry crane for ports can meet the loading and unloading needs of existing cargo types, and has functions such as customs declaration, inspection, foreign trade, and storage. Moreover, its operation efficiency is high and it can take into account the company's subsequent container development. Light tire-type container gantry crane has the following characteristics:

In recent years, with the increasing use of offset rail beam structures (square steel welded rails located inside the box-shaped main beam), the manufacturing requirements have become higher. Let's take this structure as an example to improve it from the manufacturing aspects such as component manufacturing and processing.