Rail mounted container gantry cranes are mainly used for container loading, unloading, handling, and stacking in container railway transfer yards and large container storage and transportation yards. The rail type container gantry crane consists of a main beam, rigid and flexible door legs, a running trolley, a lifting mechanism, a crane running mechanism, an electrical system, and an operating cab.

According to the yard operation process, extending the cantilever in the direction of single or double door legs becomes a single cantilever or double cantilever model, and not extending becomes a non cantilever model. Determine the different structural forms of non cantilever, single cantilever, and double cantilever based on the site, container storage and transportation process, and loading and unloading vehicles (container trucks or railway vehicles).