Military Wiki
BL 12-inch howitzer
12-inch howitzer Mk IV manned by Newfoundlanders, UK, 1942
Type Heavy siege howitzer
Place of origin  UK
Service history
In service 1916 - 1945
Used by UK and Commonwealth
Wars World War I, World War II
Production history
Designer Vickers
Number built 14 (Mk II); 43 (Mk IV)
Variants Mk II, Mk IV[1]
Barrel length 160 inch (Mk II)
207.6 inch (Mk IV)[2]

Shell HE 750 lb (340 kg)
Calibre 12 inches (304.8 mm)
Recoil Variable hydropneumatic
Carriage siege carriage
Maximum range 11,340 yd (10,370 m) (Mk II)
14,350 yd (13,120 m) (Mk IV)[2]

The Ordnance BL 12-inch howitzer was a scaled-up version of the successful 9.2-inch siege howitzer.


Following the success of their BL 9.2-inch howitzer, Vickers designed an almost identical version scaled up to a calibre of 12 inches, the Mk II entering service on the Western Front in August 1916.[3]

It was similar but unrelated to the 12 inch railway howitzers Mk I, III and V produced by the Elswick Ordnance Company at the same time.

The Mk IV was a more powerful version with longer barrel produced from 1917.

Later models were used for British home defence in World War II.

Combat use

Shell marked "For Fritz" is readied for loading, bombardment of Thiepval September 1916, Photo by Ernest Brooks.

As with other large-calibre weapons, it was operated by the Royal Garrison Artillery in World War I.

The 12-inch was dismantled and transported in 6 loads mounted on traction engine wheels. It was then reassembled on its static siege mounting on top of a steel "holdfast", with 22 long ton of earth in a box sitting on the front of the holdfast in front of the gun, to counteract the kick of firing.

Surviving examples


BL 12 inch Howitzer Shell Mk V Diagram.jpg
Mk V HE shell, World War I

See also

Weapons of comparable role, performance and era

Notes and references

  1. Mk II = Mark 2, Mk IV = Mark 4. Britain used Roman numerals to denote Marks (i.e. models) of ordnance until after World War II. This article covers the second and fourth models of British 12-inch howitzer.
  2. 2.0 2.1 Hogg & Thurston 1972, page 181, 184
  3. Hogg & Thurston 1972, Page 180. 8 complete equipments are reported as arriving in August 1916 and being in action in France shortly afterwards.


  • Dale Clarke, British Artillery 1914-1919. Heavy Artillery. Osprey Publishing, Oxford UK, 2005 ISBN 978-1-84176-788-8
  • I.V. Hogg & L.F. Thurston, British Artillery Weapons & Ammunition 1914-1918. London: Ian Allan, 1972. ISBN 978-0-7110-0381-1

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