QF 3.7-inch AA gun
| QF 3.7-in heavy anti-aircraft gun | |
|---|---|
A 3.7-inch gun on a travelling carriage in London in 1939 | |
| Type | Anti-aircraft gun |
| Place of origin | United Kingdom |
| Service history | |
| In service | 1937–present (the Nepalese Army still has 45 in service) |
| Used by | UK & other Commonwealth countries |
| Wars | World War II Indo-Pakistani War of 1947–1948 |
| Production history | |
| Designer | Vickers |
| Designed | 1937 |
| Produced | 1937–1945 |
| No. built | approx. 10.000 |
| Specifications | |
| Mass | 20,541 lb (9,317 kg) |
| Length | 28 ft 3 in (8.6 m) |
| Barrel length | Mk I–III:
15 ft 5 in (4.7 m) L/50 Mk VI: L/65 |
| Width | 7 ft 10 in (2.4 m) |
| Height | 8 ft 2 in (2.5 m) |
| Crew | 7 |
| Shell | Mk I–III: Fixed QF 94 x 675mm R Mk VI: 94 x 857mm R |
| Shell weight | 28 pounds (13 kg) |
| Calibre | 3.7 in (94 mm) |
| Breech | Horizontal sliding-wedge |
| Recoil | Hydro-pneumatic |
| Carriage | Mobile and static versions |
| Elevation | −5 to +80 degrees |
| Traverse | 360 degrees |
| Rate of fire | 10–20 rpm |
| Muzzle velocity | Mk I–III: 2,598–2,670 ft/s (792–814 m/s) Mk VI : 3,425 ft/s (1,044 m/s) |
| Maximum firing range | Horizontal: 3.5 mi (5.6 km) Slant: 7.5 mi (12 km) Ceiling Mk I–II: 30,000 ft (9 km) Ceiling Mk VI: 45,000 ft (13.7 km) |
The QF 3.7-inch AA was Britain's primary heavy anti-aircraft gun during World War II. It was roughly the equivalent of the German Flak 8.8 cm and American 90 mm, but with a slightly larger calibre of 3.7 inches, approximately 94 mm. Production began in 1937 and it was used throughout World War II in all theatres except the Eastern Front. It remained in use after the war until AA guns were replaced by guided missiles beginning in 1957.
The gun was produced in two versions, one mobile and another fixed. The fixed mounting allowed more powerful ammunition, Mk. VI, which gave vastly increased performance. Six variants of the two designs were introduced. The gun was also used as the basis for the Ordnance QF 32-pounder anti-tank gun variant used on the Tortoise heavy assault tank.