Cranes Are Classified According To The Structural Form Of The Main Beam

(a) single main beam gantry crane

Cantilever gantry crane with single main beam has the advantages of simple structure, easy manufacture and installation, small weight, and the main beam is mostly off-track box frame structure. Compared with the double girder gantry crane, the overall stiffness is weaker. Therefore, when the lifting weight Q≤50t, span S≤35m, this form can be adopted. Single main door girder crane door leg has L type and C type two forms. L type is easy to manufacture and install, with good force and small mass. However, the space for lifting goods through the legs is relatively small. The legs of Type C are inclined or bent in order to allow more lateral space for cargo to pass through the legs.

(b) double beam bridge crane

Double beam bridge crane is composed of straight rail, main beam of crane, lifting trolley, power transmission system and electrical control system, especially suitable for large suspension and large lifting plane range material transport.

The double beam bridge crane has strong bearing capacity, large span, good overall stability and many varieties, but its own mass is larger than the single main beam gantry crane with the same weight, and the cost is higher. According to the structure of the main beam, it can be divided into two forms: box beam and truss. Generally, the box structure is adopted.