Bridges are overhead structures with carrying capacity for railroads, highways, pipelines, etc., to crossing rivers, valleys, or other obstacles. The gantry and girder cranes provide the mechanical foundation for the construction of the bridge, which can improve the efficiency of transporting heavy loads and building the bridge. In particular, the girder machine is specially designed for bridge construction. The members are connected by high-strength bolts, which is easy to disassemble and transport. It can be hoisted at the same time by two sets (the maximum lifting weight of a single set is 450T) or by a single set (the maximum lifting weight of a single set is 900T).