bridge gantry crane girder structure according to the classification by primary forms

1 single girder gantry crane
Single Bridge gantry crane cantilever structure is simple, easy to manufacture and installation, small own quality, main beam, mostly off-track box-shaped frame structure. Compared with the double girder gantry crane, the overall stiffness of the weaker. Therefore, when the starting weight Q ≤ 50t, when the span S ≤ 35m, can use this form. Single girder cranes door main gate leg has L and C forms. Facilitate the manufacture and installation of L-type, the forces better, the smaller their quality, but the leg lifting cargo through space at a relatively small number. C-leg formed inclined or curved shape, the purpose is to have a large lateral space for the goods pass feet.
2 double girder bridge crane
Double girder gantry crane carrying capacity, span, good overall stability, variety, but the quality of their starting weight compared with the same single-girder gantry crane to be bigger, the cost is higher. Depending on the structure of the main beam, can be divided into two box girders and trusses form. It is generally use more box-shaped structure.