MANUFACTURER(S): State Arsenals - UK
OPERATORS: United Kingdom
Detailing the development and operational history of the Ordnance BL 12-inch Gun Mk IX Railway Gun.
Entry last updated on 5/2/2017.
Authored by Staff Writer. Content ©www.MilitaryFactory.com.
Many of the primary players of World War 1 (1914-1918) fielded some sort of railway artillery - this included the French, British, and the Germans among others. Rail guns were some of the heaviest artillery pieces witnessed in the conflict and provided extremely-long-range in-direct fire support capabilities for ground offensives. In some cases (such as with the German "Paris Gun"), they also enacted a certain psychological terror upon recipients, primarily in civilian areas, where large shells could fall on busy centers without warning. Initial work on railway artillery was handled through French experiments in 1914 but it was only a matter of time before the other powers found the value in these massive guns. By the end of the war, the available designs proved more dedicated for the role than those initially seen in service.
The British Army eventually moved on a railway gun program all their own which produced the "BL 12-inch Railway Gun". This system took a stock of unused 12" Mk IX naval guns (originally forged in 1906 by the Woolwich Arsenal) and found new homes atop railway carriages. The carriages appeared in two distinct marks as Mk 1 and Mk 2. The Mk 1 was manufactured by Vickers while the Mk 2 was from the Elswick Ordnance Company. A total of four BL 12-inch Railway Guns were produced. The Mk 1 carriage models were delivered for service during 1915 at which point the originally-fluid war had bogged down into the bloody business of trench warfare. The Mk 2 carriage model systems followed in 1916.
The guns fired an 850-pound High-Explosive (HE), Amatol-filled shell from a 304.8mm caliber gun tube that measured 40 feet long. The tube was breech-loaded and featured a Welin screw design. Initial recoil was handled by way of a Hydro-spring design though the forces were so severe that the remainder of the recoil action was the train car simply allowed to roll back a distance along the tracks (the Elswick carriage used locked brakes to reduce this effect). The gun tube's mounting allowed the barrel to be elevated from a span of 0 to 30-degrees though traverse left or right was severely restricted. Muzzle velocity of the outgoing shells reached 2,610 feet per second with a maximum firing range out to 32,700 yards.
Railway guns were ultimately limited by the extent of an existing railway network and a true lack of traversal for the gun element reduced their tactical usefulness. Due to their size, the units were not easy to quickly move about the battlefront and required much planning, material, and manpower to successfully field. The sheer forces at play could also lead to shortened barrel lives due to fracturing. Luckily for the Allies, western Europe featured an very established and modern rail network which benefitted railway guns like the BL 12" Railway Gun. Its group of four fought on through to the end of the war in November of 1918 with the last example believed to have not been given up until 1930.