Object Title

Breech Loading 18-inch Howitzer Mark 1 on Railway Proof Mounting

Breech Loading 18-inch Howitzer Mark 1 on Railway Proof Mounting

The First World War was expected to be mobile, fast moving and soon over. Notoriously, the Western Front instead became a gigantic siege. To break this stalemate, heavier artillery was constantly demanded. This railway howitzer is the only survivor of the British Army's biggest guns.

Artillery was the most destructive weapon of the First World War and caused the most casualties. Heavier and heavier guns were required to support the infantry trying to achieve the elusive breakthrough against an enemy dug in ever more stubbornly on the Western Front. The heaviest artillery could only be deployed by rail.

Just four 18-inch railway howitzers were built. They were not brought into action before the Armistice in 1918. However, one was stationed at Dover during the Second World War. The original 18-inch railway mounting was much longer than this Victorian proof sleigh, which was used for range trials until 1959.

I remember there was an elderly couple standing by their cottage near where we were shooting and every time we fired their roof lost a few more tiles...
A lump of (German) shrapnel went through the ammo wagon...we picked up some pieces and worked out that they were 15" shells.

David Collyer on 'Boche Buster' in about 1941, from "Somewhere in England..." in Bygone Kent, 1982


The idea of bringing artillery and rolling stock together seems to have initially been undertaken during the American Civil War (1861-1865) when a 13-inch Mortar was mounted on a flatcar. During the Anglo-Egyptian War (1882), Admiral Sir Percy Scott placed naval landing guns on railway wagons to help protect troop trains and 4.7-inch guns similarly mounted were used during the Boer War in 1900.

During the First World War railway artillery seemed to be the answer to the glutinous mud that affected the Western Front and all the belligerents deployed some form of it. The British were able to draw on reserve naval and coast defence guns with the 9.2-inch being the first in 1915: others included the 12-inch Howitzer and 14-inch. Indeed A 14-inch Mark III gun mounted on the carriage 'Boche-Buster', firing in the presence of King George V in 1918, scored a direct hit on a German troop carrying train at Douai Railway junction at his suggestion and becoming known as the King's Shot. As the German subterranean defences of the Hindenburg Line became deeper and more robust , General Headquarters in France in 1917 requested a heavier more penetrative projectile which meant larger, weightier artillery.

The Elswick Ordnance Company of Newcastle started work on an 18-inch Howitzer barrel in 1918 but of the five earmarked (L1-L5) none were completed before the end of the war and did not enter British service until 1920.

Use and Effect

In the inter-war period, one of the barrels was selected for periodic ballistics trials and found either at Shoeburyness, Salisbury Plain or at the Royal Arsenal, Woolwich. Later, in 1940, during the early part of the Second World War, the threat of a German invasion focussed Winston Churchill's attention an apparent weakness in the coast defences of the south-east. He hit upon the brilliant idea of contacting the surviving King's Shot detachment commander, Major Monty Cleeve to scour the country for any surviving heavy artillery that might be used to make good any deficiencies especially around Dover in Kent. This proved very successful with an 18-inch Howitzer barrel being mounted on one of the converted 14-inch carriages and railed to Kent. Another surviving 18-inch barrel (L1) placed upon a Victorian converted Railway Proof Carriage was retained at Shoeburyness for trials into the penetration of concrete commencing in 1943. This was of particular interest to the Royal Air Force and quite probably Barnes Wallis of 'Bouncing-Bomb' fame who was keen to develop an air-dropped super-bomb of 10 tons and able to destroy viaducts or penetrate 20-feet of reinforced concrete soon to become known as 'Grand Slam'. It was of course far simpler to undertake a test of this kind using artillery rather than having to modify a Lancaster and take a crew from front-line duty.

L1 and its Victorian mounting were eventually purchased by the Royal Artillery Historical Trust in 1991 and displayed at the Rotunda, Woolwich and the Royal Artillery Barracks, Larkhill before coming to Fort Nelson on loan in 2013.


Action / Operating system Cordite propellant
Barrel length 16.47 m (648.4 in)
Calibre 347 mm (18 in)
Country of manufacture Britain
Crew 24
Date entered service 1920
Length of Sleigh 7 m
Manufacturer Elswick Ordnance Co. Newcastle
Muzzle velocity 570 m/s (1880 fps)
Primary operator Britain
Projectile weight 1135 kg
Range 20.92 km (13 miles)
Rate of fire (rounds per hour) 2
Weight 87,075 kg


Philip Magrath