QF 4-inch Naval Gun Mk IV, XII, XXII

The QF 4-inch gun Mk IVMk IV = Mark 4. Britain used Roman numerals to denote Marks (models) of ordnance until after World War II. This was the fourth model of 4-inch QF naval gun. Variants Mk XII = Mark 12, Mk XXII = Mark 22. was the main gun on most Royal Navy and British Empire destroyers in World War I. It was introduced in 1911 as a faster-loading light gun successor to the BL 4 inch Mk VIII gun. Of the 1,141 produced, 939 were still available in 1939.Campbell, ''Naval Weapons of WWII'', p.59. Mk XII and Mk XXII variants armed many British interwar and World War II submarines.

Mk IV gun

Mk IV armed many British destroyers and some cruisers in World War I.
It was used to arm merchant ships in World War II.

The guns armed the following warships :
* ''Forward''-class scout cruisers as re-gunned in 1911
* ''Sentinel''-class scout cruisers as re-gunned 1911-1912
* ''Pathfinder''-class scout cruisers as re-gunned 1911-1912
* ''Adventure''-class scout cruisers as re-gunned 1911-1912
* ''Acasta'' (K)-class destroyers of 1911
* ''Laforey'' (L)-class destroyers of 1913
* Yarrow M-class destroyers laid down 1912 - 1915
* Admiralty M-class destroyer of 1913
* Thornycroft M-class destroyers laid down 1913 - 1915
* Hawthorn M-class destroyer of 1914
* s of 1914
* s of 1914
* ''Faulknor''-class leaders of 1914
* s of 1914
* ''Parker'' class leaders of 1915
* Yarrow Later M-class destroyers of 1915
* R-class destroyers of 1916
* S-class destroyers of 1917
* s of 1938 (guns from decommissioned Canadian S-class destroyers)

File:QF 4 inch Mk. IV.jpg, Rusted QF 4 inch mk IV gun without a gun shield on East Falkland
File:QF 4 inch Mk. IV back.jpg, Back of rusted QF 4 inch mk IV gun without a gun shield
File:QF 4 inch Mk IV gun IWM May 2009.jpg, Front of QF 4 inch mk IV gun in Imperial War Museum
File:QF 4 inch Mk IV gun IWM.jpg, Back of QF 4 inch Mk IV gun at Imperial War Museum
File:QF 4 inch Mk IV gun & crew 1942 LAC 3572367.jpg, British sailors loading a QF 4 inch Mk IV gun in 1942
File:QF4inchMkIVGunCartridge5lb1oz12drMkII.jpg, Diagram of a QF 4 inch Mk IV gun cartridge.

Mk XII and XXII submarine gun

The Mk XII variant was developed for arming submarines from 1918, Mk XXII was developed to arm submarines during World War II. These submarine guns fired a heavier projectile from late 1944. Shortly after the end of hostilities, the Mk XXII was superseded in new British submarines by the lighter QF 4 inch Mk XXIII.

Mk XII and XXII equipped submarines

* L class
* ''Odin'' ("O") class
* ''Parthian'' ("P") class
* River (or ''Thames'') class
* ''Grampus'' (or ''Porpoise'') class
* ''Triton'' ("T") class
* S class
* Some of the ''Amphion'' ("A" or ''Acheron'') class

Surviving guns

* The Mk IV gun from which fired the first British shot of World War I on 5 August 1914 is on display at the National Museum of the Royal Navy, Portsmouth (on loan from the Imperial War Museum).
* A Mk IV gun on a 1945 Mk XVI mounting is on display at the Heugh Gun Battery Museum in Hartlepool, County Durham.
* A Mk IV gun on a pedestal mounting is still in situ at Ordnance Point in the Falkland Islands, where it is believed to have been installed in 1943.
* A First World War 4-inch naval gun, tentatively identified as a Mk IV, stands outside the Army, Navy and Air Force Veterans Hall in 4th Street, Sidney, British Columbia.

See also

* List of naval guns

Weapons of comparable role, performance and era

* 10.5 cm SK L/45 naval gun : German WWI equivalent
* 10.5 cm SK C/32 naval gun : Slightly more powerful German equivalent WWII submarine gun
* 4"/50 caliber gun : US Navy equivalent

Notes

References

Sources

* Tony DiGiulian
British 4"/40 (10.2 cm) QF Marks IV, XII and XXII
*

{{DEFAULTSORT:QF 04-inch Mk 04
Naval guns of the United Kingdom
100 mm artillery
Coastal artillery
World War I naval weapons of the United Kingdom
World War II naval weapons of the United Kingdom