BL 9.2-inch Mk XI naval gun

Naval gun

BL 9.2-inch Mk XI gun
Agamemnon fires her 9.2-inch secondary guns at Ottoman Turkish forts at Sedd el Bahr on 4 March 1915
Type	Naval gun
Place of origin	United Kingdom
Service history
In service	1908 – 1920^[1]
Used by	United Kingdom
Wars	World War I
Production history
Designer	Vickers
Designed	1902^[2]
Specifications
Mass	28 tons barrel & breech
Barrel length	38 ft 4 in (11.68 m) bore (50 cal)

Shell	380 pounds (172.4 kg) Lyddite, Armour-piercing, Shrapnel^[3]
Calibre	9.2 inches (233.7 mm)
Muzzle velocity	2,875 ft/s (876 m/s)^[4]

The BL 9.2-inch Mark XI gun^{[note 1]} was a British 50 calibre high-velocity naval gun which was mounted as primary armament on armoured cruisers and secondary armament on pre-dreadnought battleships.

History

The gun with its increased length of 50 calibres was an attempt to extract a higher velocity, and hence more range and armour-piercing capability, from the 9.2-inch gun. Like other British 50-calibre guns of the period, it was relatively unsuccessful and was the last model of 9.2-inch gun Britain built.

Guns were mounted in the following ships :

Minotaur-class armoured cruisers laid down 1905 & completed 1908–1909: 2 twin mounts.
Lord Nelson-class battleships laid down 1905 & completed 1908: 4 twin mounts and 2 single mounts.

After the scrapping of these ships, these guns and mountings were retained in storage. There was the intention, at one point, early during World War Two, to use them as armament for small monitors which would have been reduced versions of the Roberts-class monitors; this however never advanced beyond the planning stage.

Notes

^ Mark XI = Mark 11. Britain use Roman numerals to denote Marks (models) of ordnance until after World War II. Hence this was the eleventh model of BL 9.2-inch gun.

References

^ 1908–1920 : Dates of commissioning and scrapping of the ships. The guns were not used again after removal.
^ The National Archives of the United Kingdom, Kew. SUPP 6/61
^ 380 lb shells : Treatise on Ammunition, 1915
^ 2875 ft/second : As quoted in "Range Tables for His Majesty's Fleet, 1910. February, 1911"; with 130 ½ lb cordite MD propellant : Treatise on Ammunition, 1915