The railways were important during the First World War for supply line reasons which included the redistribution of munitions and heavy arms, as well as of troops, medical staff, and general supplies. These technical details, produced by the South Eastern and Chatham Railway, note particulars for various railway companies.
Both the Great Western Railway (GWR) and Midland Railway (MR) used specific wagons for the moving of guns. The GWR used Pollen B wagon sets 48979-48982, 48999-48900 to carry 12-inch BL guns Marks 8-10 for the moving of heavy guns, 45-58 tons. The MR used wagon set 9696 carrying 12, 13.5, 14, and 15 inch guns, these were even heavier at 67-97 tons. These technical drawings for both companies include side elevations showing basic dimensions, weights, and axle loads. Guns were moved both within Britain and on the Continent to position them for battle or strategic defence. The largest artillery was actually held by the Royal Navy for their dreadnaughts, the 'monster' guns moved by MR were most likely for this purpose.