Container loading and unloading methods mainly include the following five systems:
1. Trainer chassis system
The quayside container loading and unloading bridge is used at the front edge of the terminal to undertake the loading and unloading operations of ships. The imported containers are directly unloaded to the chassis vehicle by the loading and unloading bridge. The container tractor drags the chassis vehicle carrying containers to the storage yard for parking. When leaving the port, the container tractor drags the chassis vehicle carrying containers from the storage yard directly out of the port. For export containers, the container tractor will park the chassis vehicle carrying containers from the port area on the storage yard. When loading, the container tractor will drag the chassis vehicle carrying containers from the storage yard to the wharf apron, and the container will be hoisted onto the ship by the quayside container loading bridge.
2. Straddle vehicle system
The quayside container loading and unloading bridge is used at the wharf apron to undertake the loading and unloading of ships, and the straddle vehicle is used to undertake the horizontal transportation between the wharf apron and the storage yard, as well as the stacking of the storage yard and the loading and unloading of incoming and outgoing vehicles. That is, the "ship arrival" operation is to unload the container from the ship to the wharf apron by the loading bridge, and then transport the container to the designated container position of the wharf yard by the straddle truck; "Site to site", "site to container hauler", "site to freight station" and other operations are undertaken by straddle carriers.
3. Rubber tyred gantry crane system
The quayside container loading and unloading bridge is used at the wharf apron of the tire gantry crane system to undertake the loading and unloading of ships, the tire gantry crane undertakes the loading and unloading and stacking of the wharf yard, and the horizontal transportation from the wharf apron to the yard and the container section in the yard is completed by container trucks. Generally, the rubber tyred gantry crane can span 6 trains and 1 truck lane, and the stacking height is 3 to 5 layers of containers. The rubber tyred gantry crane is equipped with steering device, which can move from one box area to another for operation. The rubber tyred gantry crane system is suitable for wharfs with small land area. Most container terminals in China adopt this process system.
4. Rail mounted gantry crane system
Compared with the tire gantry crane system, the track gantry crane system has larger span and higher stacking capacity. The rail mounted gantry crane can stack 4 ~ 5 layers of containers and span 14 or more columns of containers. The rail mounted gantry crane system is suitable for land and water intermodal terminals with limited site area and large container throughput.
5. Straddle truck gantry crane hybrid system
From the point of view of economy and handling performance, the first four process system schemes have their own advantages and disadvantages. At present, some ports in the world adopt the hybrid system of the above process scheme, the straddle truck gantry crane hybrid system. Its main characteristics are: the loading and unloading at the ship side is undertaken by the quayside container loading and unloading bridge; The horizontal transportation, stacking, delivery and loading of imported containers shall be completed by straddle transport vehicles; The horizontal transportation between the freight yard of the export container and the wharf apron is completed by the container semi-trailer, and the loading, unloading and stacking of the freight yard are completed by the rail gantry crane. Because the hybrid system can give full play to the characteristics of various machinery, develop strengths and avoid weaknesses, and become more reasonable and perfect, this scheme has been adopted by many terminals in the world.
