With the large-scale development of warehousing and freight forwarding, the expansion and new construction of container terminals have also become a trend. Traditional cranes are incompetent for container transportation, so special container gantry cranes need to be selected to improve the efficiency of yard operations.
How do container cranes work
The main working environment of the container gantry crane is the loading and unloading, stacking, and handling of containers. In the construction of rail-mounted container gantry cranes, the gantry cranes will carry out planned container operations according to the orientation and characteristics of the track laying, so the space utilization rate of the operation site is higher. The rail-mounted container gantry crane can stack about 15 rows of containers in the middle of the span in multiple lanes, thereby shortening the working distance and working range and improving the working efficiency.
The rail container gantry crane is dispatched by the central control of modern information technology. The application of information technology makes the positioning ability of the gantry crane more urgent and accurate, and managers can realize convenient and rapid container retrieval and container storage through the central control of the system, thereby improving the automation ability of the terminal container yard. The main power source of the rail container gantry crane is electricity. The built-in battery provides power support for the operation of the unit, which reduces the damage to the environment caused by the emission of pollution sources, and has low emissions and low pollution indicators.
Classification of container cranes:
Also called an integral spreader, it can only handle containers of the same size. It drives the mechanism to rotate in a way of lifting and lowering, does not need to use a special power device, and achieves the purpose of automatic unlocking and locking through the mechanical movement of the wire rope. The fixed container door crane has the characteristics of simple structure and lightweight, but due to the inconvenience of use, it is mostly used for multi-purpose door cranes and general-purpose door cranes.
Because it is composed of upper and lower spreaders, it is also called a combination door crane. Containers of different sizes and types can be lifted and loaded or unloaded during operation. It’s more convenient than the previous one, but it’s a lot heavier.
The mother-child spreader is also called the reload spreader. This kind of door crane is equipped with a special power system on a special crane beam, which can drive the mechanism of the lower module, also called a replaceable door crane. Its deadweight is not high, but it takes more time to replace the sling.
Telescopic door crane
Its working principle is to drive a telescopic chain or an oil cylinder through hydraulic transmission, which can automatically change its length to try containers of different specifications. It is more responsive than its predecessor, and its variable-length makes it versatile and greatly increases its production efficiency.
Container gantry cranes can also be distinguished according to the power supply mode: mainly cabled and cableless. The former supplies power to the door crane via cables and cable reels. The equipment and controlled components used are carried out through sealed electrical cabinets, using special multi-core plugs and other parts, which are not only reliable but also easy to replace. To prevent loose parts, damping pads are also placed in the fixed position of the wiring. The cableless type uses the energy generated by the moving pulley to power other components.
How to operate a container crane
The crane is driven by an operator in the cab sitting on the crane. The trolley runs along rails located on the top or side of the boom and frame. The operator places a trolley on the boat to lift the cargo, usually a container. Once the spreader is locked on the container, the container is lifted, moved on the dock, and placed on a truck bed (trailer) for delivery to the yard. Cranes also lift containers from the dock’s undercarriage to load them onto ships.
A straddle carrier, side lift, reach stacker, or container truck then maneuvers under the crane base and collects the containers, moving them quickly from the dock to the storage yard. A flatbed or well truck can also be mounted directly under the crane base.
Container gantry cranes use electric energy to replace the traditional fuel energy operation method, which can greatly control the cost and improve the operating income. Moreover, due to the high requirements of rail installation, the efficiency and economic value of electric energy are also significantly better than those of traditional fuel in terms of rail planning and operation turnover.