What is single girder launching gantry?

As one of bridge construction machinery, the single girder launching gantry is set with one box girder suspension arm extending forward and one folded column (made up of left and right support legs)at its front.

The launching gantry with no load could move forward automatically, then unbend the front column to stand on the front pier. As the erected girder moves along the suspension arm, the suspension arm is near in simply supported beam condition.

As constructing bridge, the pre-cast girder must be transferred to special girder carrier with special gantry crane, then girder carrier carries the girder to the rear part of launching gantry, two trolleys lift the girder to move along the suspension arm to reach proper position, drop girder.

To suit for construction of curved bridge, the suspension arm of launching gantry could sway a little in the horizontal plane. Single girder launching gantry advantages: cancel the balanced weight, it is unnecessary to push the launching gantry with haulage motor, feeding girder could be done without branch line at bridgehead, high degree of mechanization and better safety performance.