Self-extending mobile bridge for spanning gap is cantilevered out from support on near side of gap with succession of short girder elements unrolling toward far side of gap

摘要

The self-extending mobile bridge is cantilevered out from a support on the near side of a gap. It consists of a succession of identical short girder elements with their top webs hinged together and their bottom webs butted together under compression to form a rigid cantilever structure. The end of the bridge remote from the cantilever support has a ramp structure and is folded back toward the cantilever support. The end rests on a carriage which moves outward, unrolling the bridge toward the far side of the gap. Finally, the ramp is unfolded and the carriage is returned toward the cantilever support.