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The QF 4 inch Mk V gun[note 1] was a Royal Navy gun of World War I which was adapted on HA (i.e. high-angle) mountings to the heavy anti-aircraft role both at sea and on land, and was also used as a coast defence gun.

Ordnance QF 4 inch gun Mk V
HMAS Sydney 4 inch guns SLV H98.105 3249.jpg
QF 4 inch HA guns aboard the cruiser HMAS Sydney, 1939–1940
TypeNaval gun
Anti-aircraft gun
Coastal defence gun
Place of originUnited Kingdom
Service history
In service1914 - 1945
Used byBritish Empire
WarsWorld War I
World War II
Production history
No. built944[1]
MassBarrel & breech: 4,890 lb (2,220 kg)[2]
Barrel lengthBore: 15 ft (4.6 m)
(45 cal)
Total: 15 ft 8 in (4.8 m)[2]

Shell31 lb (14.1 kg) fixed QF or Separate-loading QF
Calibre4-inch (101.6 mm)
Breechhorizontal sliding-block
Recoilhydro-pneumatic or hydro-spring 15 inches (380 mm)
Elevationmounting dependent
Traversemounting dependent
Muzzle velocity2,350 ft/s (716 m/s)[2]
Maximum firing rangeSurface: 16,300 yd (15,000 m)[3]
AA: 28,750 ft (8,800 m)[2]
FillingLyddite, Amatol
Filling weight5 pounds (2.27 kg)



Naval serviceEdit

LA gun and crew on HMS Galatea, February 1917
LA gun on HMAS Vampire firing circa 1938

This QF gun was introduced to provide a higher rate of fire than the BL 4 inch Mk VII. It first appeared in 1914 as secondary armament on Arethusa-class cruisers, was soon adapted to a high-angle anti-aircraft role. It was typically used on cruisers and heavier ships, although V and W class destroyers of 1917 also mounted the gun.

Mk V was superseded by the QF 4 inch Mk XVI as the HA (i.e. anti-aircraft) gun on new warships in the 1930s, but it continued to serve on many ships such as destroyers, light and heavy cruisers in World War II.[4]

Army anti-aircraft gunEdit

Early in World War I several guns were supplied by the Navy for evaluation as anti-aircraft guns for the home defence of key installations in Britain. They were mounted on static platforms and proved fairly successful after a fixed round was developed to replace the original separate round, and more followed. The AA mounting allowed elevation to 80° but loading was not possible above 62°, which slowed the maximum rate of fire.[5] At the Armistice a total of 24 guns were employed in AA defences in Britain and 2 in France.[6] After World War I the guns were returned to the Navy.

Coast Defence gunEdit

From 1915 to 1928 several guns were mounted in forts to guard the estuary of the River Humber.[7]

Anti-aircraft performanceEdit

The following table[8] compares the gun's performance with the other British World War I anti-aircraft guns:-

Gun m/v ft/s Shell (lb) Time to 5,000 ft (1,500 m) at 25° (seconds) Time to 10,000 ft (3,000 m) at 40° (seconds) Time to 15,000 ft (4,600 m) at 55° (seconds) Max. height (ft)[9]
QF 13 pdr 9 cwt 1990 12.5 10.1 15.5 22.1 19,000
QF 12 pdr 12 cwt 2200 12.5 9.1 14.1 19.1 20,000
QF 3 inch 20 cwt 1914 2500 12.5 8.3 12.6 16.3 23,500
QF 3 inch 20 cwt 1916 2000 16 9.2 13.7 18.8 22,000[10]
QF 4 inch Mk V World War I 2350 31 (3 c.r.h.) 4.4?? 9.6 12.3 28,750
QF 4 inch Mk V World War II [11] 2350 31 (4.38/6 c.r.h.) ? ? ? 31,000


Ammunition for the original low-angle guns introduced in World War I was Separate QF i.e. the shell and cartridge were separate items, but in World War II most guns used Fixed QF ammunition i.e. a single unit. The fixed Mk V ammunition was 44.3 inches (1.13 m) long and weighed 56 pounds (25 kg), while the projectile was 31 pounds (14 kg).[12]

See alsoEdit

Weapons of comparable role, performance and eraEdit

Surviving examplesEdit


  1. ^ Mk V = Mark 5. Britain used Roman numerals to denote Marks (models) of ordnance until after World War II. Mark V indicates this was the fifth model of QF 4-inch gun.


  1. ^ Tony DiGiulian quotes 283 Mk VC built for the navy during WWII; 554 earlier types built for the navy; about 107 earlier types built for the Army in WWI.
  2. ^ a b c d Hogg & Thurston 1972, Page 101
  3. ^ WWI 3 c.r.h. HE shell. Tony DiGiulian, "British 4"/45 (10.2 cm) QF Mark V and Mark XV"
  4. ^ Tony DiGiulian's webpage provides comprehensive information on this gun's Naval service. Tony DiGiulian (January 13, 2008). "British 4"/45 (10.2 cm) QF Mark V and Mark XV". Retrieved 2008-03-29.
  5. ^ Hogg & Thurston 1972, Page 100
  6. ^ Routledge 1994, Page 27
  7. ^ Hogg & Thurston 1972, Page 98
  8. ^ Routledge 1994, Page 9
  9. ^ Hogg & Thurston 1972, Page 234-235
  10. ^ Routledge 1994, Page 13
  11. ^ WWII details from Tony DiGiulian's website
  12. ^ Campbell, Naval Weapons of WWII, p.58.


External linksEdit