BL 12-inch railway howitzer

Ordnance BL 12-inch Howitzer Mk I, III, V on truck, railway
Ordnance BL 12-inch Howitzer Mk I, III, V on truck, railway
	Mk. I "Hilda" in action, Ypres, 7 November 1917
Type	Railway howitzer
Place of origin	United Kingdom
Service history
In service	1916–1940
Used by	United Kingdom
Wars	First World War
Production history
Designer	Elswick Ordnance Company
Manufacturer	Elswick Ordnance Company
No. built	81
Variants	Mk I, III, V
Specifications
Barrel length	Mk I: 12 ft (3.7 m); Mk III & V: 17 ft 3 in (5.26 m)
Shell	HE; 750 lb (340 kg)
Calibre	12-inch (305 mm)
Elevation	Mk I & III: 40° - 65°; Mk V: 20° - 65°
Traverse	Mk I & III: 20° L & R; Mk V: 120° L & R
Muzzle velocity	Mk I: 1,175 ft/s (358 m/s); Mk III & V: 1,468 ft/s (447 m/s)
Effective firing range	Mk I: 11,132 yd (10,179 m); Mk III: 15,000 yd (14,000 m); Mk V: 14,350 yd (13,120 m)
Filling weight	83lb 3oz (37.96 kg) Amatol

The British Ordnance BL 12 inch howitzer on truck, railway, a type of railway gun, was developed following the success of the 9.2-inch siege howitzer. It was similar but unrelated to the 12-inch siege howitzers Mk II and IV.

Design and development

Mark I

Mk I was introduced from March 1916. It is identified by its short barrel and recuperator above the barrel.

Mark III

Mk III at Wareham, Dorset, 26 February 1941

The longer-barrelled Mk III soon followed, with a heavier breech to balance the gun. It retained the recuperator above the barrel.

Mark V

One Mk V (foreground) and two Mk IIIs, Catterick UK, 12 December 1940

Mk V, dating from July 1917, moved the recoil buffer and recuperator into a single housing below the barrel, which was common for all new British artillery developed during World War I. It also had a lighter breech with the gun balanced by the redesigned recoil system and altered gun positioning on the cradle.^[2] Mk V also relocated the loading platform from the railway wagon to the revolving gun mounting, which now allowed 120° of traverse, and by overhanging the opposite side provided crew access when the gun fired to the side (90° traverse) and also helped to balance it.^[2]

Combat service

Mk V in action at Soissons, France, 19 May 1918

All 3 versions served on the Western Front in World War I, usually in 2-gun batteries, operated by the Royal Garrison Artillery.

Mk III and MK V were deployed for the home defence of Great Britain in World War II.

Ammunition

Mk V HE shell, WWI
Officer of 444 Siege Battery and kitten, Mk V howitzer, near Arras 19 July 1918

Notes

^ Mk I = Mark 1, Mk III = Mark 3, Mk V = Mark 5. Britain used Roman numerals to denote Marks (i.e. models) of ordnance until after World War II. Hence this article covers the first, third and fifth models of British 12-inch howitzers. Mks II and IV were the unrelated BL 12-inch siege howitzer.

References

^ ^a ^b ^c Hogg & Thurston 1972, page 179, 183, 187
^ ^a ^b Hogg & Thurston 1972, page 186

Bibliography

Dale Clarke, British Artillery 1914-1919. Heavy Artillery. Osprey Publishing, Oxford UK, 2005 ISBN 1-84176-788-3
I.V. Hogg & L.F. Thurston, British Artillery Weapons & Ammunition 1914–1918. London: Ian Allan, 1972.

External links

Newsreel showing 12" Mk I railway howitzer and other heavy weapons in action

[1] Mk I = Mark 1, Mk III = Mark 3, Mk V = Mark 5. Britain used Roman numerals to denote Marks (i.e. models) of ordnance until after World War II. Hence this article covers the first, third and fifth models of British 12-inch howitzers. Mks II and IV were the unrelated BL 12-inch siege howitzer.

[Hogg&Thurston1972page179183187-2] Hogg & Thurston 1972, page 179, 183, 187

[Hogg&Thurston1972page186-3] Hogg & Thurston 1972, page 186

[note 1]

[1]

[2]

v t e British Empire artillery of the First World War
Armoured vehicle guns	QF 3-pounder Vickers QF 6-pounder Hotchkiss QF 6-pounder 6 cwt
Infantry guns	1.59-inch breech-loading Vickers Q.F. gun, Mk II
Field artillery	BL 12-pounder 6 cwt QF 12-pounder 8 cwt QF 12-pounder 18 cwt QF 13-pounder BL 15-pounder BLC 15-pounder QF 15-pounder QF 18-pounder QF 4-inch gun Mk III BL 4-inch gun Mk VII QF 4.5-inch howitzer
Medium & heavy artillery	QF 4.7-inch gun BL 5-inch howitzer BL 5.4-inch howitzer BL 60-pounder gun BLC 6-inch siege gun BL 6-inch gun Mk VII BL 6-inch gun Mk XIX BL 6-inch 26 cwt howitzer BL 6-inch 30 cwt howitzer BL 8-inch howitzer Mk I – V BL 8-inch howitzer Mk VI – VIII
Siege artillery	BL 7.5-inch Mk III naval gun BL 9.2-inch howitzer BL 9.2-inch Mk X naval gun BL 12-inch howitzer BL 12-inch Mk X naval gun BL 15-inch howitzer
Mountain artillery	RML 2.5-inch mountain gun BL 10-pounder mountain gun BL 2.75-inch mountain gun QF 2.95-inch mountain gun QF 3.7-inch mountain howitzer
Mortars	Garland trench mortar 3-inch Stokes mortar Vickers 1.57-inch mortar 2-inch medium mortar Newton 6-inch mortar 9.45-inch Heavy Mortar
Smoke and chemical weapons	4-inch Stokes Mortar Livens Projector Livens Large Gallery Flame Projector
Anti-aircraft guns	QF 1-pounder pom-pom QF 2-pounder "pom-pom" Mk II 75 mm AA gun QF 12-pounder 12 cwt QF 13-pounder 6 cwt QF 13-pounder Mk IV QF 13-pounder 9 cwt QF 3-inch 20 cwt QF 18-pounder QF 4-inch Mk V
Coastal artillery	QF 12-pounder 12 cwt QF 4-inch naval gun Mk I – III BL 6-inch Mk VII naval gun BL 9.2-inch Mk IX – X naval gun RML 9-inch
Railway guns	BL 9.2-inch railway gun BL 12-inch railway gun BL 12-inch railway howitzer BL 14-inch railway gun

v t e British Commonwealth artillery of World War II
Tank guns	QF 2-pounder QF 3-pounder QF 6-pounder QF 75 mm QF 3-inch howitzer QF 17-pounder 77 mm HV QF 95 mm howitzer
Anti-tank guns	QF 2-pounder QF 6-pounder QF 17-pounder
Field guns and howitzers	75 mm Gun M1917 QF 18-pounder 25-pounder Gun-Howitzer 25-pounder Short QF 4.5-inch howitzer
Medium and heavy guns and howitzers	BL 4.5-inch medium field gun BL 60-pounder gun BL 5.5-inch medium gun BL 6-inch howitzer BL 6-inch gun Mk XIX 155 mm Long Tom BL 7.2-inch howitzer BL 8-inch howitzer BL 9.2-inch howitzer 240 mm howitzer M1
Mountain guns	75mm Pack howitzer M1 3.7-inch mountain howitzer
Mortars	SBML 2-inch mortar ML 3-inch mortar ML 4.2-inch mortar
Anti-aircraft weapons	Z Battery 20 mm Oerlikon 20 mm Polsten QF 1½-pounder Mk III QF 2-pounder naval gun Bofors 40 mm QF 3-inch QF 3.7-inch QF 4.5-inch Mk II QF 5.25-inch Mk II
Coast defence	QF 6-pounder 10 cwt QF 12-pounder QF 4.7-inch Mk I–IV BL 6-inch Mk VII & Mk XXIV BL 7.5-inch Mk VI BL 8-inch Mk VIII BL 9.2-inch Mk X BL 14-inch Mk VII BL 15-inch Mk I
Railway artillery	BL 9.2-inch Mk XIII railway gun BL 12-inch Mk V railway howitzer BL 13.5-inch Mk V railway gun BL 18-inch railway howitzer