QF 12-pounder 12 cwt AA gun
Ordnance QF 12 pounder 12 cwt anti-aircraft gun | ||
---|---|---|
Breech single-motion screw | | |
Recoil | Hydro-spring, constant, 12 in (300 mm) | |
Elevation | 0° - 85° | |
Traverse | 360° | |
Muzzle velocity | 2,200 ft/s (670 m/s) | |
Maximum firing range | 20,000 ft (6,100 m)[1] |
The 12 pounder 12 cwt anti-aircraft gun was borrowed for AA use from the
History
When World War I began Britain had no anti-aircraft artillery and had given little thought to it. Hence in 1914 when Germany occupied parts of Belgium and northern France, it faced the risk of air attack, and various medium calibre guns were adapted to high-angle mountings, including the 12 pdr 12 cwt. All QF 12 pounder ammunition at the time was "Separate loading QF" i.e. the propellant came in a brass cartridge case with primer ready installed, but the shell was loaded separately. For anti-aircraft firing, Fixed QF rounds were quickly developed i.e. with the shell already attached to the cartridge case. This allowed slightly faster loading.
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Combat use
For home air defence the gun was typically mounted on a high-angle mounting with an additional spring recuperator above the barrel, on a 2-wheel towed travelling platform, 7 ft (2.1 m) × 5 ft 4 in (1.63 m) The 4 stabilising arms at the corners were swung out, rods at the ends screwed down to lift the platform off the wheels which were then removed and the platform lowered to the ground.[2] It was also deployed on static mountings to defend prominent targets such as dockyards.
While the gun was much lighter than the
Gun | Muzzle velocity | Shell weight | Time to 5,000 ft (1,500 m) at 25° (seconds) | Time to 10,000 ft (3,000 m) at 40° (seconds) | Time to 15,000 ft (4,600 m) at 55° (seconds) | Max. height[4] |
13-pdr 9 cwt
|
1,990 ft/s (607 m/s) | 12.5 lb (5.7 kg) | 10.1 | 15.5 | 22.1 | 19,000 ft (5,800 m) |
12-pdr 12 cwt | 2,200 ft/s (670 m/s) | 12.5 lb (5.7 kg) | 9.1 | 14.1 | 19.1 | 20,000 ft (6,100 m) |
3-inch 20 cwt 1914
|
2,500 ft/s (760 m/s) | 12.5 lb (5.7 kg) | 8.3 | 12.6 | 16.3 | 23,500 ft (7,200 m) |
3-inch 20 cwt 1916
|
2,000 ft/s (610 m/s) | 16 lb (7.3 kg) | 9.2 | 13.7 | 18.8 | 22,000 ft (6,700 m)[5] |
At the end of
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Ammunition
Mk II & Mk III cartridges, 1914 - original separate QF
|
Mk IV
Common Lyddite AA shell, 1914 |
See also
- List of anti-aircraft guns
- QF 12 pounder 12 cwt naval gun
Surviving Examples
There are no surviving examples
Notes and references
Bibliography
- ISBN 978-0-7110-0381-1
- Brigadier NW Routledge, History of the Royal Regiment of Artillery. Anti-Aircraft Artillery, 1914-55. London: Brassey's, 1994. ISBN 1-85753-099-3