Semi Gantry Crane can be divided into Three types, single girder semi gantry crane, double girder truss type semi gantry crane, and double girder box-type semi gantry crane. This kind of crane is composed of gantry frame, main girder, legs (two sets), slide sill, lifting mechanism, travelling mechanism, and electric box. Widely used in workshop, storage, port and hydroelectric power station and some other outdoor place. This type of crane is equipped with has CD1, type and MD1 type hoist Its lifting capacity is 5-75 tons, span is 18-35 meters, and working temperature is -20–+40℃. Its working class is A5, A6, and A7. Semi gantry crane has two control method, wireless control and cabin control.