Bailey bridge
It was designed by a British engineer, Donald Bailey. The British army tested different bridge designs in 1941–1942, including a suspension bridge and a stepped arch bridge. The flat truss bridge was the most successful. An early test model of the Bailey flat truss bridge is still in place over Mother Siller's Channel in Dorset. The Bailey bridge was first used by the army in Tobruk in 1942. The US Army built many of the bridges for use after the D-Day landings in France.