Bailey bridge is a modular prefabricated steel bridge, which is connected by steel Bailey panels through bolts and other fasteners. Its simple structure makes it especially suitable for scenarios requiring rapid bridge construction. Bailey Bridge, also known as a prefabricated road steel bridge, was invented by British engineer Donald Coleman Bailey in 1938. It uses high-strength steel as a material and is manufactured into a lightweight standardized bridge unit construction, including beams, longitudinal beams, bridge decks, bridge seats, and connectors. The site can be quickly assembled into a Bailey bridge of various spans and loads with only dedicated installation equipment. The Bailey bridge was originally used in the military bridge field, and it has been widely promoted in the civilian field since the 1960s. Common models include the compact 100 Bailey bridge and the compact 200 Bailey bridge.

Compared with Bailey bridge technology, traditional bridge-building technology occupies a large area, has high manufacturing costs, consumes more manpower, and has a long construction period. The biggest feature of Bailey bridge technology is the assembly type, which means that it can be assembled and disassembled on-site, which is convenient and flexible. The components can be production standardized in the factory in advance, which greatly improves the production efficiency of bridge building, is safe and efficient, and reduces costs. Because of standardized production, the quality is more stable and reliable.

The smallest modular unit in the Bailey bridge is the Bailey panel, which is a rectangular Bailey structure welded from steel frames. It can be used to splice and assemble Bailey bridges of different structures. According to the different types of Bailey panels, their size also changes. The Bailey beam is a truss beam composed of Bailey panels. The Bailey panels are fixed by bolts and cooperate with other structural parts for rapid bridge erection. The Bailey bridge is not only fast to erect, but also very fast and convenient to dismantle and has strong mobility. Therefore, it is often used in simple bridges and temporary constructions, as well as permanent bridges.

Advantages of Bailey Bridge:
The Bailey bridge has a simple structure, lightweight components, convenient transportation, flexible combination, fast erection, convenient disassembly and assembly, and reusable components;
Bailey bridge also has the advantages of large carrying capacity, strong structural rigidity, and long fatigue life;
The Bailey bridge can also be combined into bridges of different spans, types, and uses according to the design requirements of the factory.

Bailey bridge is a technological revolution in the history of the development of bridge technology. Because the Bailey bridge has obvious advantages over traditional bridges, so it is widely used in traffic engineering, railway engineering, and water conservancy projects. The supporting structure composed of Bailey panels can also be used for construction brackets such as cast-in-place beams or crane towers.