Indian Army officers inspecting a railway gun, 1918.

During World War One the demand for heavy field artillery was never-ending. To meet this need, both the Allies and Germans moved large numbers of static coastal guns and naval guns to the front, but these were typically unsuitable for field use and required some kind of mounting. The railway gun provided the obvious solution. By 1916, both sides were deploying railway guns. The most famous railway gun of the war was the German Paris Gun. From an album of 24 photographs, World War One, Western Front (1914-1918), August to December 1918.