QF 2 Pounder Naval Gun - Wartime Use

Wartime Use

An advanced weapon when introduced, by the outbreak of World War II advances in aircraft would have made it obsolete but for the introduction of a high-velocity round and new director designs. It was intended that the curtain of fire it threw up would be sufficient to deter attacking aircraft, which it did, but was hampered by the ineffective Mk III director. The MK IV Director with a Gyro Rate Unit and Type 282 radar was a great advance and was introduced on the King George V-class battleships. In January 1941, HMS Illustrious′s Mk VIII (HV) mountings performed flawlessly firing 30,000 rounds with very few stoppages. When HMS Prince of Wales was attacked and sunk by Japanese aircraft near Singapore, the subsequent report judged that a single 40 mm Bofors gun firing tracer was a more effective anti-aircraft weapon than a multiple pom-pom in director control, as the pom-poms did not have tracer ammunition and the pom-pom ammunition had deteriorated badly in their ready use lockers, while the Type 282 radar units also failed in the equatorial heat. In the same action, the Commissioned Gunner of HMS Repulse spent the whole action running from one pom-pom mount to another trying to keep them operational due to the faulty ammunition. The pom-poms on Repulse shot down two of the four confirmed kills made by Force Z, while Prince of Wales′ pom-poms did record hits on enemy aircraft. The Royal Navy judged the pom-pom's effectiveness to range from about half that of the Bofors, per gun, against torpedo planes to about equal against Kamikaze attackers. It was a ubiquitous weapon that outnumbered the Bofors gun, in Commonwealth naval service, up to the end of World War II and shot down many Axis aircraft. Later innovations such as Remote Power Control (RPC) coupled to a radar-equipped tachymetric (speed predicting) director increased the accuracy enormously and problems with the fuses and reliability were also remedied. The single mountings received a reprieve toward the end of the war as the 20 mm Oerlikon guns had insufficient stopping power to counter Japanese kamikaze aircraft and there were insufficient numbers of Bofors guns to go round.

• 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: 2,040 ft/s (622 m/s) or 2400 ft/s (732 m/s) for HV

For more extensive technical data, see 2-pdr Mark VIII at Navweaps.com