Gantry crane for lifting girders of segmental assembly bridge girder launcher is made up of main girder, crane moving wheels group, bottom cross girder, upright, hydraulic bridge girder launcherjacking cylinder for turning direction, fixing device and other parts (gantry crane is a part of the bridge girder launcher).

Gantry crane is important part of the bridge girder launcher, as carrying girders, it separates with main girder to lift girders in the precast yard, it can separates and connects with the main girder fast; lifting trolley lifts the girder moving to the upper part of the bridge girder launcher along main girder and install girders. In the precast girder, when gantry crane changes position from left bridge to the right bridge, use hydraulic jacking cylinder and man power assistance to drive gearbox group to turn direction with no load, realize 90°rail change turning (before and after rail change every time, immediately remove and tighten gearbox and bolts between upright flanges to ensure safety; when it is forbidden for the gantry crane to work, flanges bolts are not needed to tighten, only use gearbox and turning core shaft between upright flanges to fix the position); meet the demand of field arrangement.