One or two beam is supported on steel legs, on beam, there is a trolley to lift and move across, and the whole structure seems like a big gate, we call it Gantry Crane.
This gantry crane travels on rail on ground, mainly used in outdoor yard, storage, dock, power station, port, railway station and so on. Its function is to lift heavy thing and move to other place, load & unload truck, train, ship, and install some equipment.
According to differenets standards, gantry cranes can be grouped in to different types. Geneally the types of gantry cranes are as following:
First, normally, gantry cranes are divided into full gantry crane, semi-gantry crane, gantry crane with cantilever, gantry crane without cantilever. Their functions are as below:
Second, according to the main beam form
The single girder gantry crane has a simple structure, is easy to manufacture and install, and has a small mass of its own. The main beam is mostly an off-track box-shaped structure. Compared with double-girder gantry cranes, the overall stiffness is weaker. Therefore, when the weight Q≤50t and the span S≤35m, this form can be used. Single-gantry gantry cranes have L-shaped and C-shaped door legs. The L-shape is easy to manufacture and install, and the stress conditions are good. The quality of the L-shape is small. However, the space for lifting cargo through the legs is relatively small. The C-shaped legs are made to be inclined or curved so as to have a large lateral space for the cargo to pass through the legs.
Double girder gantry cranes have strong bearing capacity, large span, overall stability, and many varieties, but their own quality is larger and their cost is higher compared with single-girder gantry cranes with the same weight. According to the different main beam structure, it can be divided into two forms of box beam and truss. At present, generally more box-shaped structure.
Thirdly, according to girder design, the gantry cranes can be grouped into truss gantry crane type and box girder gantry crane types.
The structural form welded by angle steel or I-beam has the advantages of low cost, light weight, and good wind resistance. However, because of the large number of welding points and the defects of the trusses themselves, the truss beams also have the drawbacks of large deflection, low rigidity, relatively low reliability, and frequent detection of welding spots. Suitable for sites with low safety requirements and low lifting weight.
Truss type gantry crane - Dongqi types of gantry crane
The use of steel plates welded into a box structure, with high safety, stiffness and other characteristics. It is generally used for gantry cranes with large tonnage and oversized tonnage. As shown in the right figure, MGhz1200 has a lifting capacity of 1,200 tons and is the largest gantry crane in China. The main beam adopts a box girder structure. The box girder also has the disadvantages of high cost, heavy self, and poor wind resistance.
Box girder gantry crane - Dongqi types of gantry crane
Fouth, types of gantry cranes also can be grouped in terms of gantry designs, including:
Adjustable Gantries
Adjustable gantry cranes is designed for warehousing applications, where the movement of materials is required to go through aisles, doorways, around obstacles, and over or under obstructions. Adjustable gantry crane is often used to lift parts and equipment into position in welding shops, fabrication shops and etc.
Adjustable gantry crane - A type of crane of Dongqi Crane
Portable Gantries
Portable gantry crane is flexible, which can be replaced and relocated, which is featured as fast, easy movement to and from a work site.
Portable gantry crane and movable gantry crane - Gantry crane type
Rail Mounted Gantries
Rail mounted gantry crane is used for transferring heavy loads, manually or motorized, over a fixed route.
Rail mounted gantry crane - A type of gantry crane of Dongqi Crane
Fifth, according to the use and application environment, the types of gantry cranes is classified as following:
Common type gantry crane refers to the gantry crane used for common application environment where no special requirement is needed. This gantry crane is most popular which can lift heavy item and material, with lifting capacity no less than 100 ton, span length 4~35m. If the gantry crane is equipped with grab, its work duty is higher.
Hydropower station gantry crane is used to lift and start sluice gate, also can perform installing work. Lifting capacity of hydropower station gantry crane is 80~500 ton. But span length is shorter among 8~16m with lower lifting speed is 1~5m/min.
Ship building gantry crane is used to maintenance and assembly ship. It usually is equipped with two trolleys: one traveling on top flange of on rail, the other is on the rail under flange, used for turning over the large object. The lifting capacity of the ship building gantry crane is up to 100~1500 Ton. The span length can reach 185m with lifting speed 0.1~0.5m/min.
Container gantry crane is used on container port. Truck delivers container from ship to container yard, and the container gantry crane will stack the containers or load onto truck to transport it, which can speed up the entire work cycle.
Container gantry crane can stack containers onto 3~4 layers and 6 rows wide. This kind of gantry cranes include tyre type and rail mounted type. Its lifting speed is 8~10m/min. Its span is depend on containers size. Max. span is 60m.
How to select gantry crane for your application? Select the right type of gantry crane, it will largerly reduce the gantry crane price. On gantry crane selection, there are several factors that needs to be considered.
Usually for 50 ton or lighter capacity, span is within 35m, no other special function, single girder gantry crane is suitable and enough. If working condition require wider leg clearance space and higher working speed, and often to lift heavy and big object, double girder is much better to choose.
The span of gantry crane is important factor affecting the quality of the crane. When you choose crane type, if it can meet the equipment using and in standard span conditions, you’d better to reduce the span.
During work, there should be a safe space between crane’s external size and cargo and vehicle path, so that enough space for loading &unloading work. If truck is working in span, it should far from crane leg about 0.7m away. When crane don't work, the hook should be 0.5m higher to vehicles; cargo is 0.5m away from legs when it is though out from legs.
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