The QF 4-inch gun Mk IVMk IV = Mark 4. Britain used

Roman numerals Roman numerals are a numeral system that originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. Numbers are written with combinations of letters from the Latin alphabet, eac ...

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 The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against F ...

and

British Empire The British Empire was composed of the dominions, colonies, protectorates, mandates, and other territories ruled or administered by the United Kingdom and its predecessor states. It began with the overseas possessions and trading posts esta ...

destroyer In naval terminology, a destroyer is a fast, manoeuvrable, long-endurance warship intended to escort larger vessels in a fleet, convoy or battle group and defend them against powerful short range attackers. They were originally developed in ...

s in

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

. 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 World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

. 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 destroyer The Yarrow M class was a class of ten destroyers built for the Royal Navy that saw service during World War I. They were generally similar to the standard , but were instead designed by the builder, Yarrow & Company. Generally, they had two ins ...

s laid down 1912 - 1915 *

Admiralty M-class destroyer The M class, more properly known as the Admiralty M class, were a class of 85 destroyers built for the Royal Navy of United Kingdom that saw service during World War I. All ships were built to an identical – Admiralty – design, hence the c ...

of 1913 * Thornycroft M-class destroyers laid down 1913 - 1915 *

Hawthorn M-class destroyer The Hawthorn M (or Mansfield) Class were a class of two destroyers built for the Royal Navy under the pre-war 1913-14 Programme for World War I service. They were similar to the Admiralty M class, but completed to a modified design by Hawtho ...

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 destroyer The Yarrow Later M class were a class of seven destroyers built for the Royal Navy that saw service during World War I. They were based on the preceding and successful Yarrow M class with minor alterations; notably reduced beam to compensate for ...

s 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 East Falkland ( es, Isla Soledad) is the largest island of the Falklands in the South Atlantic, having an area of or 54% of the total area of the Falklands. The island consists of two main land masses, of which the more southerly is known as La ...

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 Imperial War Museums (IWM) is a British national museum organisation with branches at five locations in England, three of which are in London. Founded as the Imperial War Museum in 1917, the museum was intended to record the civil and military ...

File:QF 4 inch Mk IV gun IWM.jpg, Back of QF 4 inch Mk IV gun at

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

QF 4 inch Mk XII gun on T class submarine AWM 306479

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 The National Museum of the Royal Navy was created in early 2009 to act as a single non-departmental public body for the museums of the Royal Navy. With venues across the United Kingdom, the museums detail the history of the Royal Navy operating o ...

, Portsmouth (on loan from the

). * A Mk IV gun on a 1945 Mk XVI mounting is on display at the Heugh Gun Battery Museum in

Hartlepool Hartlepool () is a seaside and port town in County Durham, England. It is the largest settlement and administrative centre of the Borough of Hartlepool. With an estimated population of 90,123, it is the second-largest settlement in County ...

County Durham County Durham ( ), officially simply Durham,UK General Acts 1997 c. 23Lieutenancies Act 1997 Schedule 1(3). From legislation.gov.uk, retrieved 6 April 2022. is a ceremonial county in North East England.North East Assembly �About North East E ...

. * A Mk IV gun on a pedestal mounting is still in situ at Ordnance Point in the

Falkland Islands The Falkland Islands (; es, Islas Malvinas, link=no ) is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and about from Cape Dubouzet ...

, 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 Sidney is a town located at the northern end of the Saanich Peninsula, on Vancouver Island in the Canadian province of British Columbia. It's 1 of the 13 Greater Victoria municipalities. It has a population of approximately 11,583. Sidney is l ...

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