QF 4 inch Mk V naval gun

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.

Country Name Origin Year
United Kingdom - UK (Great Britain) 1914
Country Name Operational Year Retirement Year
United Kingdom - UK (Great Britain) 1914 View

Naval service

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Mk V was superseded by the QF 4 inch Mk XVI as the HA (i.e. anti-aircraft) gun on new warships in the 1930s, but it continued to serve on many ships such as destroyers, light and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

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.

Type Naval gun
Anti-aircraft gun
Coastal defence gun
Place of origin  United Kingdom
Service history
In service 1914 - 1940s
Used by British Empire
Wars World War I
World War II
Production history
Number built 944
Weight Barrel & breech: 4,890 lb (2,220 kg)
Barrel length Bore: 15 ft (4.6 m)
(45 cal)
Total: 15 ft 8 in (4.8 m)
Shell 31 lb (14.1 kg) fixed QF orSeparate-loading QF
Calibre 4-inch (101.6 mm)
Breech horizontal sliding block
Recoil hydro-pneumatic or hydro-spring 15 inches (380 mm)
Elevation mounting dependent
Traverse mounting dependent
Muzzle velocity 2,350 ft/s (716 m/s)
Maximum firing range Surface: 16,300 yd (15,000 m)
AA: 28,750 ft (8,800 m)
Filling Lyddite, Amatol
Filling weight 5 pounds (2.27 kg)

End notes