Bailey Bridge
Sir Donald Coleman Bailey (1901–1985) was a civil engineer.
1928 Bailey joined the War Office as a civil engineering designer at the Military Engineering Experimental Establishment in Christchurch.
1936 Bailey conceived the idea of a simple bridge structure based on standard rectangular, trussed welded units (10 ft × 5 ft) connected in combinations to suit the job in hand. Each unit could be lifted by six men and fitted a standard 3 ton lorry. The panels were built up from small components, which could be subcontracted to a large number of small engineering firms. The War Office showed no interest.
Another engineer, Archibald Milne Hamilton, successfully demonstrated that the Bailey bridge breached a patent on the Callender-Hamilton bridge, though the Bailey bridge was generally regarded as being superior for temporary use.
1941 Bailey was ordered to produce a suitable design and quickly resurrected his earlier scheme. The modular, light but strong and versatile steel bridge system proved to be one of the greatest inventions of WWII and played a significant part in the allied victory.
First production units reached the Army in December 1941.
1941 The Bailey Bridge was adopted as the standard Military Bridge and used extensively throughout the European campaign and in the Far East.
650 firms were involved in the manufacture of The Bailey Bridges including Thomas Storey (Engineers) who went on to make a post-war business building the bridges.
By 1947, around 2,000 Bailey Bridges had been built with more than 1,500 bridges being constructed in North West Europe alone.
Postwar: both second-hand and new bridge panels found a ready civilian market and many Bailey bridges remained in use around the world. Mabey Bridge purchased second-hand Bailey bridges to expand its business rapidly[1]
1946 article in the Military Engineer here.