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QF 4-inch naval gun Mk V

Naval gun

Ordnance QF 4 inch gun Mk V
QF 4 inch HA guns aboard the cruiser HMAS Sydney, 1939–1940
Type	Naval gun Anti-aircraft gun Coastal defence gun
Place of origin	United Kingdom
Service history
In service	1914–1945
Used by	British Empire
Wars	World War I World War II
Production history
No. built	944[1]
Specifications
Mass	Barrel & breech: 4,890 lb (2,220 kg)[2]
Barrel length	Bore: 15 ft (4.6 m) (45cal) Total: 15 ft 8 in (4.8 m)[2]
Shell	31 lb (14.1 kg) fixed QForSeparate-loading QF
Calibre	4-inch (101.6 mm)
Breech	horizontal sliding-block
Recoil	hydro-pneumaticorhydro-spring 15 inches (380 mm)
Elevation	mounting dependent
Traverse	mounting dependent
Muzzle velocity	2,350 ft/s (716 m/s)[2]
Maximum firing range	Surface: 16,300 yd (15,000 m)[3] AA: 28,750 ft (8,800 m)[2]
Filling	Lyddite, Amatol
Filling weight	5 pounds (2.27 kg)

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.

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Mk V was superseded by the QF 4 inch Mk XVI as the HA (i.e. anti-aircraft) gun on new warships in the 1930s, but it continued to serve on many ships such as destroyers, light and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

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.

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

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]

• 
  Fixed QF cartridge for LA (low-angle) gun, 1930s
• 
  Crew storing fixed rounds on the Kingfisher class sloop HMS Widgeon, August 1943

• List of anti-aircraft guns
• List of naval guns
• List of naval anti-aircraft guns

• Cannon 102/45 Italian copy of the QF Mk V made under license
• 10.5 cm SK L/45 naval gun Approximate German equivalent firing slightly heavier shell

• A gun from HMNZS Tutira in front of the Devonport Naval Base, Auckland, New Zealand

• Tony DiGiulian, British 4"/45 (10.2 cm) QF Mark V and Mark XV
• I.V. Hogg & L.F. Thurston, British Artillery Weapons & Ammunition 1914–1918. London: Ian Allan, 1972.
• Brigadier N.W. Routledge, History of the Royal Regiment of Artillery. Anti-Aircraft Artillery, 1914–55. London: Brassey's, 1994. ISBN 1-85753-099-3
• Campbell, John (1985). Naval Weapons of World War Two. Naval Institute Press. ISBN 978-0-87021-459-2.

Wikimedia Commons has media related to QF 4 inch Mk V naval gun.

• Gun drill for 4-inch Q.F. gun mark V (land Service) 1924 at State Library of Victoria