What is an gantry crane?

Gantry crane is a deformation of bridge crane, also known as overhead gantry crane. It is mainly used for loading and unloading operations of outdoor cargo yards, material factory cargo, and bulk cargo. The rail mounted gantry crane has the characteristics of high site utilization rate, large operation range, wide application and strong versatility, and is widely used in port freight yards. Its metal structure is like a door-shaped frame. Two legs are installed under the main beam, which can directly walk on the track on the ground. The two ends of the main beam can have overhanging cantilever beams. The classification format of gantry cranes can be classified according to the structure of the door frame, the form of the main beam, the structure of the main beam, and the form of use.

Rolling gantry crane (also known as cantilever gantry crane) is a bridge type crane whose bridge frame is supported on the ground track through outriggers on both sides. Structurally, it consists of a mast, a cart running mechanism, a lifting trolley and electrical parts. Some gantry cranes only have outriggers on one side, and the other side is supported to run on the factory building or trestle, called semi-gantry cranes. The goliath gantry crane is composed of upper bridge frame (including main girder and end girder), outriggers, lower beam and other parts. In order to expand the working range of the crane, the main girder can extend out of the outriggers to one or both sides to form a cantilever. A trolley with a jib can also be used to expand the working range of the crane through the pitch and rotation of the jib.

Motorized gantry cranes can be divided into single-girder gantry cranes and double-girder gantry cranes according to the number of main girders. Single-girder gantry cranes have a simple structure, are easy to manufacture and install, and have low mass. Most of the main girders are off-track box frame structures. . Compared with the double girder gantry crane, the overall rigidity is weaker. Therefore, this form can be used when the lifting weight Q≤50t and the span S≤35m. There are two types of L-shaped and C-shaped gantry legs for single girder gantry cranes. The L-type is easy to manufacture and install, has a good stress condition, and its own mass is small, but the space for hoisting goods through the outriggers is relatively small. The C-shaped leg is made into an inclined or curved shape, and the purpose is to have a larger lateral space so that the goods can pass through the leg smoothly. The double main girder gantry crane has strong bearing capacity, large span, good overall stability and many varieties, but its own quality is larger than that of the single main girder gantry crane with the same lifting capacity, and the cost is also higher. According to the structure of the main girder, it can be divided into two forms: box girder and truss. Generally, a box-shaped structure is used.