BL 12-inch Mk X naval gun

BL 12-inch gun Mk X
BL 12-inch gun Mk X
	On HMS Dreadnought
Type	Naval gun
Place of origin	United Kingdom
Service history
In service	1906 – 1923
Wars	World War I
Production history
Designer	Vickers
Manufacturer	Vickers
Unit cost	£9800 (1907)
Specifications
Mass	57 tons barrel & breech
Barrel length	45 feet (13.72 m) bore (45 cal)
Shell	850 pounds (385.6 kg) Lyddite, Armour-piercing, Shrapnel
Calibre	12 inches (304.8 mm)
Breech	Welin interrupted screw
Muzzle velocity	2,700 ft/s (823 m/s)
Maximum firing range	22,860 m (25,000 yd)

The BL 12 inch Gun Mark X^{[note 1]} was a British 45-calibre naval gun which was mounted as primary armament on battleships and battlecruisers from 1906. It first appeared on HMS Dreadnought.

History

Ramming shell on HMAS *Australia*, December 1918

The Mk X continued the trend of lengthening gun barrels as far as new construction methods would permit, in order to allow more cordite propellant to be used to attain higher projectile velocities. The Mk X increased the bore length from the Mk IX's 480 to 540 in (12 to 14 metres), increasing muzzle velocity from 2,600 to 2,700 ft/s (790 to 820 m/s).

Subsequent British attempts to further increase the power of 12-inch guns led to failure with the 50-calibre Mk XI and Mk XII guns; the Mk X was the last successful 12-inch British gun.

Naval use

Mk X guns were mounted in the following ships which served throughout World War I:

Lord Nelson-class battleships, laid down 1905, completed 1908
Battleship HMS Dreadnought, laid down 1905, completed 1906
Invincible-class battlecruisers, laid down 1906, completed 1908–1909
Bellerophon-class battleships, laid down 1906, completed 1909
Indefatigable-class battlecruisers, laid down 1909, completed 1911–1913

World War I use ashore

From 1917 several Mk X guns were deployed ashore on the section of the Belgian coast still held by the Allies, near Nieuwpoort. They were part of the "Royal Naval Siege Guns" under the command of Admiral Sir Reginald Bacon, and were used for attacking German heavy gun batteries.

Ammunition


65 lb Cordite Cartridge ¼ charge : i.e. 4 such cartridges were normally loaded to fire the gun	Mk VIIA Common Pointed shell with Cap (CPC) filled with gunpowder, 1912	World War I Shells. Left to Right : Mk XA Capped Armour-Piercing shell filled with Trotyl (TNT) Shrapnel Mk 6A Capped Common pointed shell filled with Shellite 70/30

Notes

^ Mark X = Mark 10. Succeeding versions were Mark XI (11) and XII (12). Britain used Roman numerals to denote Marks (models) of ordnance until after World War II

References

^ "H.M.S. "Dreadnought"—Cost of Armaments. (Hansard, 25 March 1907)". Parliamentary Debates (Hansard). 25 March 1907.
^ "BR 12in 45cal BL Mk X". navalhistory.flixco.info. Retrieved 9 November 2018.
^ 850 lb shells : Treatise on Ammunition, 1915
^ 2700 ft/second : As quoted in "Range Tables for His Majesty's Fleet, 1910. February, 1911"; with 260 lb cordite MD size 45 propellant : Treatise on Ammunition, 1915
^ 22,860 metres quoted at : http://navalhistory.flixco.info/H/76624x53535/8330/a0.htm This is understood to be the maximum possible range at 45° elevation, which was possible for siege mountings on land but not for naval mounts

Bibliography

External links

Tony DiGiulian, British 12"/45 (30.5 cm) Mark X

[6] Mark X = Mark 10. Succeeding versions were Mark XI (11) and XII (12). Britain used Roman numerals to denote Marks (models) of ordnance until after World War II

[1] "H.M.S. "Dreadnought"—Cost of Armaments. (Hansard, 25 March 1907)". Parliamentary Debates (Hansard). 25 March 1907.

[2] "BR 12in 45cal BL Mk X". navalhistory.flixco.info. Retrieved 9 November 2018.

[3] 850 lb shells : Treatise on Ammunition, 1915

[4] 2700 ft/second : As quoted in "Range Tables for His Majesty's Fleet, 1910. February, 1911"; with 260 lb cordite MD size 45 propellant : Treatise on Ammunition, 1915

[5] 22,860 metres quoted at : http://navalhistory.flixco.info/H/76624x53535/8330/a0.htm This is understood to be the maximum possible range at 45° elevation, which was possible for siege mountings on land but not for naval mounts

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[note 1]

v t e British Empire naval weapons of the First World War
Monitor guns	BL 9.2-inch Mk VI BL 9.2-inch Mk VIII BL 9.2-inch Mk X BL 9.2-inch Mk XII BL 12-inch Mk VIII BL 14-inch Mk II (US built) BL 15-inch Mk I BL 18-inch Mk I
Capital ship main armament	Vickers 10-inch 45 cal. EOC 10-inch 45 cal. BL 12-inch Mk VIII BL 12-inch Mk IX BL 12-inch Mk X BL 12-inch Mk XI & XII EOC 12-inch 45 cal. Mk XIII BL 13.5-inch Mk I – IV BL 13.5-inch Mk V BL 13.5-inch Mk VI EOC 14-inch 45 cal. Mk I BL 15-inch Mk I
Armoured cruiser main armament	BL 7.5-inch Mk I BL 9.2-inch Mk X BL 9.2-inch Mk XI
Secondary armament and light cruiser main armament	QF 12-pounder 18 cwt QF 14-pounder Maxim-Nordenfelt QF 14-pounder Mk I & II QF 4-inch Mk III BL 4-inch Mk VII QF 4-inch Mk V BL 4-inch Mk IX BL 5.5-inch Mk I QF 6-inch Mk I – III BL 6-inch Mk VII BL 6-inch Mk XI BL 6-inch Mk XII BL 6-inch Mk XIII-XVIII BL 7.5-inch Mk II – Mk V
Destroyer and small cruiser armament	QF 12-pounder 12 cwt Mk II QF 4-inch Mk III BL 4-inch Mk VIII QF 4-inch Mk IV BL 4.7-inch Mk I
Merchant ship armament	QF 4.7-inch Mk I – IV QF 4.7-inch Mk V*
Submarine guns	BL 4-inch Mk XI QF 4-inch Mk XII
Anti-aircraft guns	QF 2-pounder "pom-pom" Mk II QF 3-inch 20 cwt QF 4-inch Mk V
Light weapons	.303 Vickers machine gun QF 3-pounder Hotchkiss QF 3-pounder Vickers QF 6-pounder Hotchkiss
Torpedoes	18-inch Mk V – VIII 21-inch Mk II 21-inch Mk IV
Mines	Spherical Mk I, II and III Vickers Elia mine Type H mine
Anti-submarine weapons	Type A Depth charge Type B Depth charge Type C Depth charge Type D Depth charge Type E Depth charge Type F Depth charge Type G Depth charge Cruiser Mine 7.5-inch howitzer
Landing guns	QF 12-pounder 8 cwt

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