Also known as a bateau bridge or a pontoon bridge, a floating bridge is a type of bridge design that makes use of barges or pontoons to create a span across a body of water. In many instances, a floating bridge is constructed for temporary use and can be dismantled and transported for reassembly at a different location, making the design ideal for use by military operations. The floating bridge design can also be used to create more permanent solutions when it is not considered feasible to invest the time and money that is involved with constructing other types of bridges.
The main function of a floating bridge is to create a means of spanning a waterway without investing a great deal of time. A series of pontoons or barges are connected so that individuals and equipment can pass over the expanse with relative ease, and then disassemble the bridge to prevent others from making use of the device. Used since ancient times, this type of temporary bridge has been used by armies as a means of crossing rivers. The armies then destroyed or dismantled the bridge so that others could not follow and attack from the rear.
While the floating bridge has often been employed as a short-term strategy to cross waterways, it can also be used as a permanent solution. Typically, the use of this particular bridge design is viable when the cost or difficulty in sinking supports, erecting pylons or building a suspension system to support other bridge designs cannot be justified. Since a floating bridge can be created in sections, it is also possible to structure the design so that one or more partitions of the bridge can be moved to one side, making it possible for boats or ships to pass through if necessary.
While a basic floating bridge works best on calm waters, there is technology available that aids in stabilizing the sections of the bridge in the event that the water should become choppy, such as during some sort of storm. At other times, the design makes it possible to retract the bridge when severe weather is looming, a measure that can sometimes mean fewer repairs after the storm. This aspect can be especially important for a small community that may rely on the floating bridge as a direct link to a community across a river, and wishes to avoid an extended period of losing that easy access due to a damaged bridge.