A Rapidly Deployable Bridge System

Rapidly deployable mobile bridges are of direct relevance to military and civilian agencies. The US Army uses such bridges in a broad range of applications including assault, tactical, and general communication. Civilian use extends from temporary infrastructure improvements during natural disasters to planned situations that are equally critical. This paper describes a modular bridge system developed primarily for use in assault scenarios where rapid deployment is vital, but this design concept is also relevant in civil applications. The robust metallic design of the bridge is based on an aluminum trussed arch reinforced by steel cables. The segmental form of the structure allows it to be folded into a compact package for transportation in a standard 40 ft container, which facilitates shipping by road, rail, sea, or air (C-130 transport aircraft). The bridge segments also facilitate adaptation of the bridge to different spans ranging from 8m to 32m. The load rating for these spans varies between 100T and 40T respectively. The preferred deployment approach for the assault configuration uses a scissor method in conjunction with a winching mechanism mounted on an auxiliary bridge guide. Compared to more conventional techniques, this method reduces the demands on the bridge launcher. The complete system provides an integrated solution to cover a broad spectrum of bridging applications. Extensive computer analysis was used to refine and optimize the components in the bridge. Structural testing of components during the design stage also helped guide the design process, and operational and load testing of a prototype system using strain gauging confirmed the integrity of the final design.