| Ordnance QF 4 inch gun Mk V | |
| Origin: | United Kingdom |
| Type: | Naval gun Anti-aircraft gun Coastal defence gun |
| Is Ranged: | yes |
| Is Explosive: | yes |
| Is Artillery: | yes |
| Is Uk: | yes |
| Service: | 1914–1945 |
| Used By: | British Empire |
| Wars: | World War I World War II |
| Number: | 944[1] |
| Weight: | Barrel & breech: 4890lb |
| Part Length: | Bore: 15abbr=onNaNabbr=on (45 cal) Total: 15feet[2] |
| Cartridge: | 31abbr=onNaNabbr=on fixed QF or Separate-loading QF |
| Caliber: | 4sigfig=4NaNsigfig=4 |
| Velocity: | 2350abbr=onNaNabbr=on |
| Max Range: | Surface: 16300abbr=onNaNabbr=on[3] AA: 28750abbr=onNaNabbr=on |
| Breech: | horizontal sliding-block |
| Recoil: | hydro-pneumatic or hydro-spring 15inches |
| Elevation: | mounting dependent |
| Traverse: | mounting dependent |
| Filling: | Lyddite, Amatol |
| Filling Weight: | 5lb |
The QF 4 inch Mk V gun[4] 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 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Mk V was superseded by the QF 4 inch Mk XVI as the HA (i.e. anti-aircraft) gun on new warships in the 1930s, but it continued to serve on many ships such as destroyers, light and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.[5]
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.[6] At the Armistice, a total of 24 guns were employed in AA defences in Britain and 2 in France.[7] 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.[8]
| +Comparison with the other British World War I anti-aircraft guns[9] | |||||||
| Gun | muzzle velocity | Shell (lb) | Time to 5000abbr=onNaNabbr=on at 25° (seconds) | Time to 10000abbr=onNaNabbr=on at 40° (seconds) | Time to 15000abbr=onNaNabbr=on at 55° (seconds) | Max. height[10] | |
|---|---|---|---|---|---|---|---|
| QF 13 pdr 9 cwt | 1990ft/s | 12.5 | 10.1 | 15.5 | 22.1 | 19000feet | |
| QF 12 pdr 12 cwt | 2200NaN | 12.5 | 9.1 | 14.1 | 19.1 | 20000feet | |
| QF 3 inch 20 cwt 1914 | 2500NaN | 12.5 | 8.3 | 12.6 | 16.3 | 23500feet | |
| QF 3 inch 20 cwt 1916 | 2000NaN | 16 | 9.2 | 13.7 | 18.8 | 22000feet[11] | |
| QF 4 inch Mk V World War I | 2350NaN | 31 (3 c.r.h.) | 9.6 | 12.3 | 28750feet | ||
| QF 4 inch Mk V World War II [12] | 2350NaN | 31 (4.38/6 c.r.h.) | 31000feet |
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).[13]