QF 4-inch naval gun Mk V

The QF 4 inch Mk V gun 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.

Service

Naval service

File:4-inch Mk V gun and crew on HMS Galatea Feb 1917 LAC 3398106.jpg

LA (Low Angle) gun and crew on , February 1917

File:4 inch gun on HMAS Vampire 1938 SLV.jpeg

LA (Low Angle) gun on 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 s, was soon adapted to a high-angle anti-aircraft role. It was typically used on cruisers and heavier ships, although s 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Mk V was superseded by the QF 4 inch Mk XVI as the HA (i.e. anti-aircraft) gun on new warships in the 1930s, but it continued to serve on many ships such as destroyers, light and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.

Army anti-aircraft gun

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. At the Armistice, a total of 24 guns were employed in AA defences in Britain and 2 in France. After World War I, the guns were returned to the Navy.

Coast Defence gun

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

Anti-aircraft performance

Comparison with the other British World War I anti-aircraft guns

Gun	muzzle velocity	Shell (lb)	Time to at 25° (seconds)	Time to at 40° (seconds)	Time to at 55° (seconds)	Max. height
QF 13 pdr 9 cwt		12.5	10.1	15.5	22.1
QF 12 pdr 12 cwt		12.5	9.1	14.1	19.1
QF 3 inch 20 cwt 1914		12.5	8.3	12.6	16.3
QF 3 inch 20 cwt 1916		16	9.2	13.7	18.8
QF 4 inch Mk V World War I		31 (3 c.r.h.)		9.6	12.3
QF 4 inch Mk V World War II		31 (4.38/6 c.r.h.)

Ammunition

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).

• Fixed QF cartridge for LA (low-angle) gun, 1930s Script error: No such module "Check for unknown parameters".
  Fixed QF cartridge for LA (low-angle) gun, 1930s
• Crew storing fixed rounds on the Kingfisher class sloop HMS Widgeon, August 1943 Script error: No such module "Check for unknown parameters".
  Crew storing fixed rounds on the Kingfisher class sloop HMS Widgeon, August 1943

See also

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

Weapons of comparable role, performance and era

• 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

Surviving examples

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

Bibliography

• 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. Template:ISBN

External links

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