TheDigger
16-01-2008, 08:38
The Standard Anti Aircraft Gun of the Royal Navy during WW2 was the QF 2 Pounder Naval Gun.
The 2-pounder gun, officially designated the QF 2-pounder (QF denoting "quick firing") and universally known as the pom-pom, is a large calibre British machine-gun, used famously as an anti-aircraft gun by the Royal Navy. The name came from the sound that the original models were reported to make when firing. The name 2 pounder is derived from the size of the projectile which weighed 2 pounds.
The Royal Navy had identified the need for a rapid-firing, multi-barrelled close-range anti-aircraft weapon at an early stage. The design and eventual continued use of this weaopon was in part due to the the enormous stocks of 2-pounder ammunition left over from World War I.
Known as the QF 2-pounder Mark VIII, it is usually referred to as the multiple pom-pom. The initial mounting was the enormous, 16-ton, eight-barrelled mounting Mark V (later Mark VI), suitable for ships of heavy cruiser and aircraft carrier size upwards.
From 1935 the quadruple mounting Mark VII, essentially half a Mark V or VI, entered service for ships of destroyer and cruiser size. These multiple gun mounts required four different guns. The mount had 2 rows each of 2 or 4 weapons. Guns were produced in both right and left hand and "inner" and "outer" so that the feed and ejector mechanisms matched.
An advanced weapon when introduced, by the outbreak of World War II advances in aircraft had effectively made it obsolete. It was intended that the curtain of fire it threw up would be sufficient to deter attacking aircraft but lack of a suitable tracer round meant that the barrage was unseen and so the deterrence factor was prevented from being effective.
It had a low velocity due to the relatively short barrel and small charge, the fuse mechanism was unsatisfactory, the weapons were extremely complex and prone to jamming, and the mountings were enormously heavy and complicated and could not be produced quickly enough or fitted widely enough.
When HMS Prince of Wales was attacked and sunk by Japanese aircraft near Singapore the subsequent report judged that the single 40 mm Bofors gun, mounted on the quarterdeck, had been a more effective anti-aircraft weapon than the entire battery of multiple pom-pom mounts.
Apart from many of the issues noted above it was never entirely displaced by the Bofors gun during during WW2
Calibre: 40 mm L/39
·Shell Weight: 2 lb. (980 g) or 1.8 lb. (820 g) for High-Velocity (HV) round
·Rate of Fire: 115 rpm fully automatic
·Effective Range: 3,800 yards (3,475 m) or 5,000 yards (4,572 m) HV
·Effective Ceiling (HV): 13,300 feet (3,960 m)
·Muzzle Velocity: 1,920 ft/s (585 m/s)
The 2-pounder gun, officially designated the QF 2-pounder (QF denoting "quick firing") and universally known as the pom-pom, is a large calibre British machine-gun, used famously as an anti-aircraft gun by the Royal Navy. The name came from the sound that the original models were reported to make when firing. The name 2 pounder is derived from the size of the projectile which weighed 2 pounds.
The Royal Navy had identified the need for a rapid-firing, multi-barrelled close-range anti-aircraft weapon at an early stage. The design and eventual continued use of this weaopon was in part due to the the enormous stocks of 2-pounder ammunition left over from World War I.
Known as the QF 2-pounder Mark VIII, it is usually referred to as the multiple pom-pom. The initial mounting was the enormous, 16-ton, eight-barrelled mounting Mark V (later Mark VI), suitable for ships of heavy cruiser and aircraft carrier size upwards.
From 1935 the quadruple mounting Mark VII, essentially half a Mark V or VI, entered service for ships of destroyer and cruiser size. These multiple gun mounts required four different guns. The mount had 2 rows each of 2 or 4 weapons. Guns were produced in both right and left hand and "inner" and "outer" so that the feed and ejector mechanisms matched.
An advanced weapon when introduced, by the outbreak of World War II advances in aircraft had effectively made it obsolete. It was intended that the curtain of fire it threw up would be sufficient to deter attacking aircraft but lack of a suitable tracer round meant that the barrage was unseen and so the deterrence factor was prevented from being effective.
It had a low velocity due to the relatively short barrel and small charge, the fuse mechanism was unsatisfactory, the weapons were extremely complex and prone to jamming, and the mountings were enormously heavy and complicated and could not be produced quickly enough or fitted widely enough.
When HMS Prince of Wales was attacked and sunk by Japanese aircraft near Singapore the subsequent report judged that the single 40 mm Bofors gun, mounted on the quarterdeck, had been a more effective anti-aircraft weapon than the entire battery of multiple pom-pom mounts.
Apart from many of the issues noted above it was never entirely displaced by the Bofors gun during during WW2
Calibre: 40 mm L/39
·Shell Weight: 2 lb. (980 g) or 1.8 lb. (820 g) for High-Velocity (HV) round
·Rate of Fire: 115 rpm fully automatic
·Effective Range: 3,800 yards (3,475 m) or 5,000 yards (4,572 m) HV
·Effective Ceiling (HV): 13,300 feet (3,960 m)
·Muzzle Velocity: 1,920 ft/s (585 m/s)