Trench railways
Trench railways represented military adaptation of early 20th century railway technology to the problem of keeping soldiers supplied during the static trench warfare phase of World War I. The large concentrations of soldiers and artillery at the front lines required delivery of enormous quantities of food, ammunition and fortification construction materials where transport facilities had been destroyed. Reconstruction of conventional roads (at that time rarely surfaced) and railways was too slow, and fixed facilities were attractive targets for enemy artillery. Trench railways linked the front with standard gauge railway facilities beyond the range of enemy artillery. Empty cars often carried litters returning wounded from the front.
France had developed portable Decauville railways for agricultural areas, small scale mining and temporary construction projects. France had standardized 600 mm (1 ft 11 5⁄8 in) narrow gauge Decauville military equipment and Germany adopted similar feldbahn of the same gauge. British War Department Light Railways and the United States Army Transportation Corps used the French 600 mm narrow gauge system. Russia used Decauville 600 mm narrow gauge and 750 mm (2 ft 5 1⁄2 in)narrow gauge systems.
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