each type of gantry crane the company produces all includes all kinds of means of store, carry and work characters of bridge projects, its capability is advanced, framework is reasonable, deadweight is light, rigidity is big, is disassembled and assembled conveniently, as well as equips import or Chinese famous brand electric components to make operation of cranes more simpler and run more safer. Single main beam adopts double-pieces steel truss structure. Combining Character of Beiley Beam, single side main beam is constituted by two vertical parallel chord girder trusses, and two horizon parallel chord girder trusses; web member form of vertical parallel chord girder truss is web member form of diagonal rod. Its character is: summerize and draw on advantage of English System Beiley truss structure, light in weight, low in processing cost, high in utilization ration and big in toughness, easily control and transform during manufacture, increase intension and horizon toughness of beam. The type gantry crane single main beam is designed three units, between each unit adopts pin to joint tightly, two main beams are connected a whole by connection flat and head madetomeasure eight hole support frame. The upper of main beam is equiped recondition flat and guard bar for periodical maintenance, and the frame is of advantage to transportation