The BL 6 inch Gun Mark XI 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...

 50 calibres high-velocity 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 cruiser

Cruiser

A cruiser is a type of warship. The term has been in use for several hundreds of years, and has had different meanings throughout this period...

s and secondary armament on pre-dreadnought battleships.

History

The gun with its increased length of 50 calibres gave improved firepower over the current 6-inch Mk VII gun

BL 6 inch Mk VII naval gun

The BL 6 inch Gun Mark VII was a British naval gun dating from 1899, which was mounted on a heavy traveling carriage in 1915 for British Army service to become one of the main heavy field guns in the First World War, and also served as one of the main coast defence guns throughout the British...

 of 45 calibres. However, its increased length and weight made it unwieldy in the current manually-operated shipboard mountings on light cruisers, which did not provide a steady platform. Britain reverted to 45-calibres guns in new warships from 1914 onwards with the BL 6 inch Mk XII

BL 6 inch Mk XII naval gun

The BL 6 inch Gun Mark XII was a British 45 calibres naval gun which was mounted as primary armament on light cruisers and secondary armament on dreadnought battleships commissioned in the period 1914 - 1926, and remained in service on many warships until the end of World War II.-Design:This was a...

 gun.

Naval gun

Guns were mounted in the following ships :

• The last 3 King Edward VII class battleships Britannia
  HMS Britannia (1904)
  The sixth HMS Britannia of the British Royal Navy was a pre-dreadnought battleship of the King Edward VII class. She was named after Britannia, the Latin name of Great Britain under Roman rule.-Technical characteristics:...
  
  , Africa
  HMS Africa (1905)
  HMS Africa was a pre-dreadnought battleship of the Royal Navy. She was the penultimate ship of the King Edward VII class. Like all ships of the class , she was named after an important part of the British Empire, namely Africa....
  
   and Hibernia
  HMS Hibernia (1905)
  HMS Hibernia was a King Edward VII-class predreadnought battleship of Britain's Royal Navy. Like all ships of the class she was named after an important part of the British Empire, namely Ireland....
  
   laid down 1902 - 1904
• Armoured cruisers: HMS Duke of Edinburgh
  HMS Duke of Edinburgh (1904)
  HMS Duke of Edinburgh was the lead ship of the armoured cruisers built for the Royal Navy in the mid-1900s. She was stationed in the Mediterranean when the First World War began and participated in the pursuit of the German battlecruiser and light cruiser...
  
   and Black Prince
  HMS Black Prince (1904)
  HMS Black Prince was a armoured cruiser built for the Royal Navy in the mid-1900s. During the First World War she served in the Mediterranean before joining the Grand Fleet...
  
   laid down 1903
• Bristol class light cruisers laid down 1909
• Weymouth class cruisers laid down 1910
• Chatham class light cruisers laid down 1911
• Birmingham class light cruisers laid down 1912
• Monitor HMS Marshal Ney
  HMS Marshal Ney
  HMS Marshal Ney was a Royal Navy Marshal Ney class monitor constructed in the opening years of the First World War. Laid down as M13, she was named for the French general of the Napoleonic Wars Marshal Michel Ney....
  
   as re-gunned in 1918

Coast defence gun

The Mk XI gun was emplaced for coast defence in South Africa and particularly in Australia leading up to World War II, and remained in service until the 1950s. Guns in Australia came from the decommissioned World War I cruisers HMAS Sydney

HMAS Sydney (1912)

HMAS Sydney was a Chatham class light cruiser of the Royal Australian Navy . Laid down in 1911 and launched in 1912, the cruiser was commissioned into the RAN in 1913....

, HMAS Melbourne

HMAS Melbourne (1912)

HMAS Melbourne was a Town class light cruiser operated by the Royal Australian Navy . Commissioned in 1913, the cruiser served during World War I. She was paid off in 1928, and broken up for scrap in 1929.-Design and construction:...

 and HMAS Brisbane

HMAS Brisbane (1915)

HMAS Brisbane was a Town class light cruiser of the Royal Australian Navy . Built in Sydney between 1913 and 1916 to the Chatham subtype design, Brisbane operated in the Indian Ocean, Pacific Ocean, and Australian coastal waters during World War I.Following the end of the war, the cruiser was...

 and were emplaced in northern Australia and Torres Strait

Torres Strait

The Torres Strait is a body of water which lies between Australia and the Melanesian island of New Guinea. It is approximately wide at its narrowest extent. To the south is Cape York Peninsula, the northernmost continental extremity of the Australian state of Queensland...

 to defend against possible attack by Japan, and also on Rottnest Island WA, Brisbane and the Sydney harbour

Sydney Harbour defences

Sydney Harbour was protected by coastal batteries and other fixed defences from the early 19th century until the 1960s. These defences were constructed to protect the Australian city of Sydney from attack by enemy warships and submarines....

 and Port Kembla

Illowra Battery

Illowra Battery was an Australian Army coastal battery at Port Kembla, New South Wales, Australia during World War II. It was also known as Hill 60 Battery.-History:...

 defences.

See also

• 15 cm/50 41st Year Type
  15 cm/50 41st Year Type
  The 15 cm/50 41st Year Type gun was a naval gun used by the Imperial Japanese Navy. It was first used in single casemates on the battleships of the Kongo and Fuso classes and later in the Agano class light cruisers in twin mountings.-External links:...
  
   : Imperial Japanese Navy equivalent gun
• List of naval guns

Surviving examples

• RGF gun No. 2035 of 1905, and 1 other gun at Malgaskop, Saldanha Bay
  Saldanha Bay
  Saldanha Bay is a natural harbour on the south-western coast of South Africa, north west of Cape Town. The town that developed on the northern shore of the bay, also called Saldanha, was incorporated with five other towns into the Saldanha Bay Local Municipality in 2000. The current population of...
  
  , South Africa
• VSM gun No. 2305 of 1912 formerly at Port Wakefield
  Port Wakefield, South Australia
  Port Wakefield was the first government town to be established north of the capital, Adelaide, in South Australia.Port Wakefield is situated approximately 98.7 kilometres from Adelaide and lies on the Port Wakefield Road section of the A1 National Highway...
  
   Proof Range, north of Adelaide, and since 2006 at B42 gun emplacement at Lower Georges Heights, Sydney Australia
• A coast defence gun at East Point Military museum
  East Point Military museum
  The Darwin Military Museum was originally established as an artillery museum by the Royal Australian Artillery Association Inc to exhibit photographs and artefacts from Darwin's history during World War II. The Museum now has a large exhibits of items from the war, including Navy, Army and Air...
  
  , Darwin, Australia
• EOC gun at Leighton Battery, Fremantle, Western Australia

External links

• Tony DiGiulian, British 6"/50 (15.2 cm) BL Marks XI and XI*