Weapons · United States · 1942-1945
20mm Oerlikon cannon
shipboard light anti-aircraft autocannon
The Oerlikon 20mm cannon became the US Navy's standard light anti-aircraft weapon from 1942 onward, replacing water-cooled .50 caliber machine guns on ships of every size from landing craft to battleships. Its blowback action gave it a high rate of fire in a comparatively light single or twin mount that could be worked by a small crew, making it easy to proliferate across a ship's deck. By the later stages of the Pacific War its stopping power proved marginal against determined kamikaze attacks, and it was increasingly supplemented and then superseded by the heavier 40mm Bofors, though it remained in widespread service through the end of the war.
| crew | 2-3 |
|---|---|
| rate of fire | 450 rpm cyclic (L70) |
| effective range | ~1.5 km vs aircraft |
| weight | 68-92 kg |
Battle of the Atlantic, Pacific, Mediterranean and North Africa
