Mobile gantry for bridge underside maintenance - is mounted on lorry or railway wagon and has three parts which are extended to locate third part under bridge

摘要

The vehicle is driven onto the bridge above the section which is to be inspected and parked. An additional support is then deployed to one side of the vehicle. The three part gantry which is folded together is then swung out to jut out horizontally over the edge of the bridge, with the middle and end parts at right angles, parallel to the bridge edge. - The tubular first part is then rotated so that the second and third parts hang downwards. The third part then folds out horizontally below the underside of the bridge. The second part is then rotated to bring the third part under the bridge directly below the vehicle. The third part is then extended to bring the maintenance workers to the required point under the bridge.(0/3)