BL 15-inch howitzer


The Ordnance BL 15-inch howitzer was developed by the Coventry Ordnance Works late in 1914 in response to the success of its design of the 9.2-inch siege howitzer.

BL 15-inch howitzer Mk I
In action at Englebelmer Wood, Somme, 7 August 1916
TypeHeavy siege howitzer
Place of originUnited Kingdom
Service history
In service1915–1918
Used byBritish Empire
WarsWorld War I
Production history
DesignerCoventry Ordnance Works[1]
ManufacturerCoventry Ordnance Works
No. built12
VariantsMk I
Mass94 tons

ShellHE 1,450 lb (657.7 kg)[2]
Calibre15 inches (381.0 mm)
BreechWelin interrupted screw
RecoilHydro-spring 31 inches (790 mm) constant[3]
Carriagesiege carriage
Muzzle velocity1,117 ft/s (340 m/s)[3]
Maximum firing range10,795 yd (9,871 m)[3]

The howitzer was cumbersome to deploy, since it was transported in several sections by giant Foster-Daimler tractors.

Service historyEdit

The weapon was operated by Royal Marine Artillery detachments of the Naval Brigade, with one gun per battery. One gun was sent to Gallipoli but not used there. They were later transferred to the British Army. It was used at the Battle of the Somme in September 1916 and at the Battle of Passchendaele, also known as the Third Battle of Ypres, in October 1917.

It operated successfully where it was needed to destroy deep fortifications on the Western Front, but was limited by its relatively short range compared to other modern siege howitzers. The size and weight made it difficult to move and emplace. No further development occurred after the first batch of twelve, and instead Britain continued to develop and produce the 12-inch howitzer and 12-inch railway howitzer.

Image galleryEdit

See alsoEdit

Weapons of comparable role, performance and eraEdit

Notes and referencesEdit

  1. ^ Hogg & Thurston 1972, p. 198
  2. ^ Clarke quotes 1,450 pound shell, Hogg & Thurston quote 1,400 pound shell
  3. ^ a b c Hogg & Thurston 1972, p. 199


  • Dale Clarke, British Artillery 1914–1919. Heavy Artillery. Osprey Publishing, Oxford UK, 2005
  • I.V. Hogg & L.F. Thurston, British Artillery Weapons & Ammunition 1914–1918. London: Ian Allan, 1972. ISBN 978-0-7110-0381-1
  • Winston S. Churchill. The World Crisis, Part 2, 1915. (New York: Rosetta Books, 2013), Kindle.
  • Film clip showing Royal Marine Artillery crew loading and firing the howitzer during the Battle of the Somme
  • BL 15 inch Siege Howitzer at Landships