QF 12-pounder 12 cwt AA gun

The 12 pounder 12 cwt anti-aircraft gun was borrowed for AA use from the QF 12 pounder 12 cwt coast defence gun with the addition of a modified cradle for higher elevation, a retaining catch for the cartridge, and an additional spring recuperator above the barrel and high-angle sights. Writers commonly refer to it simply as "12 pounder anti-aircraft gun". 12 cwt referred to the weight of the barrel and breech (12 x 112 lb = 1,344 lb) to differentiate it from other "12 pounder" guns.

QF 12-pounder 12 cwt AA gun
Class Vehicle
Type Towed Artillery
Manufacturer Elswick Ordnance Company
Origin United Kingdom - UK (Great Britain)
Country Name Origin Year
United Kingdom - UK (Great Britain) 1914
Country Name Operational Year Retirement Year
Italy View
Japan View
United Kingdom - UK (Great Britain) 1914 1918 View
ManufacturerName Production From Production To Quantity
Elswick Ordnance Company View
Vickers Limited View

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.

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 traveling platform, 7 ft (2.1 m) x 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.

It was also deployed on static mountings to defend prominent targets such as dockyards.

While the gun was much lighter than the QF 3 inch 20 cwt dedicated AA gun, for anti-aircraft use it lacked its range and shell weight. Hence the 3 inch 20 cwt gun became the heavy AA gun of choice both on land and ships from 1914 to 1937.

At the end of World War I, 36 guns were still in service in the home air defense of Britain, 10 on the Western Front and 2 in Mesopotamia where it was typically mounted on river barges.

The gun remained in Royal Navy anti-aircraft use, in the form of the new Mk V version, on smaller ships in World War II because of its dual capability of both low and high angle firing.

Type Anti-aircraft gun
Place of origin United Kingdom
Service history
In service 1914 - 1918 (as land AA gun)
Used by UK
Kingdom of Italy
Empire of Japan
Wars World War I
World War II
Production history
Designed 1893
Manufacturer Elswick Ordnance Company
Variants Mk I, Mk II
Barrel length 12 ft
Shell Fixed or separate QF 12.5 lb (5.7 kg)
Calibre 3 inch (76.2 mm)
Breech single-motion screw
Recoil Hydro-spring, constant, 12 inch
Elevation 0° - 85°
Traverse 360°
Muzzle velocity 2,200 ft/s (670 m/s)
Maximum firing range 20,000 ft (6,100 m)

End notes