The BL 12 inch Gun Mark X was a British

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 45-calibres naval gun

Naval artillery

Naval artillery, or naval riflery, is artillery mounted on a warship for use in naval warfare. Naval artillery has historically been used to engage either other ships, or targets on land; in the latter role it is currently termed naval gunfire fire support...

 which was mounted as primary armament on battleship

Battleship

A battleship is a large armored warship with a main battery consisting of heavy caliber guns. Battleships were larger, better armed and armored than cruisers and destroyers. As the largest armed ships in a fleet, battleships were used to attain command of the sea and represented the apex of a...

s and battlecruiser

Battlecruiser

Battlecruisers were large capital ships built in the first half of the 20th century. They were developed in the first decade of the century as the successor to the armoured cruiser, but their evolution was more closely linked to that of the dreadnought battleship...

s from 1906. It first appeared on the revolutionary .

History

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. Mk X increased the bore length from Mk IX's 480 inches (40 calibres) to 540 inches (45 calibres), increasing muzzle velocity from 2,600 to 2,700 feet/second.

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

BL 12 inch Mk XI - XII naval gun

The BL 12 inch Gun Mark XI and Mark XII were British 50-calibres naval guns that were mounted as primary armament on dreadnought battleships from 1910.-History:...

; 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

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

 : of 1906

• The last 3 King Edward VII-class battleships , and , completed in 1906s laid down 1905, completed 1908s laid down 1906, completed 1908 - 1909s laid down 1906, completed 1909s 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 Nieuport. They were part of the "Royal Naval Siege Guns" under the command of Admiral Sir Reginald Bacon

Reginald Bacon

Admiral Sir Reginald Hugh Spencer Bacon, KCB, KCVO, DSO was an officer in the Royal Navy noted for his technical abilities who was described by the First Sea Lord, Admiral Sir Jacky Fisher, as the man "acknowledged to be the cleverest officer in the Navy".-Family:Reginald was born at Wiggonholt in...

, and were used for attacking German heavy gun batteries.

Ammunition

65 lb Cordite Cordite Cordite is a family of smokeless propellants developed and produced in the United Kingdom from 1889 to replace gunpowder as a military propellant. Like gunpowder, cordite is classified as a low explosive because of its slow burning rates and consequently low brisance...  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

See also

• 305mm/45 Modèle 1906 gun
  305mm/45 Modèle 1906 gun
  The 305mm/45 Modèle 1906 gun was a heavy naval gun of the French Navy.The type was used on the s, mounted in two twin turrets. An improved variant, the 305mm/45 Modèle 1910 gun, was installed on the Courbet class.-See also:...
  
   French equivalent
• EOC 12 inch /45 naval gun
  EOC 12 inch /45 naval gun
  The EOC 12 inch 45 calibre gun were various similar 12-inch wire-wound naval guns designed and manufactured by Elswick Ordnance Company to equip ships that the parent company Armstrong Whitworth built and/or armed for several countries before World War I....
  
   Elswick Ordnance Company equivalent
• 12"/45 caliber Mark 5 gun
  12"/45 caliber Mark 5 gun
  The 12"/45 caliber Mark 5 gun was a US naval gun that first entered service in 1906. Initially designed for use with the Connecticut-class of pre-dreadnought battleships, the Mark 5 continued in service aboard the first generation of American dreadnoughts....
  
   US equivalent
• List of naval guns

External links

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