Archie to SAM: A Short Operational History of Ground-Based Air ...

ANTIAIRCRAFT DEFENSE THROUGH WORLD WAR II
Figure 4. 3.7-inch gun on a Pile mattress. Here it is mounted on a “Pile
mattress” used during the V-1 campaign and named for antiaircraft
artillery commander Gen Frederick Pile. (Reprinted from Imperial War
Museum.)
fense against night attacks, as night fighters were in their infancy.
By the end of 1940, AAA defenses claimed 85 percent of
the British night kills.
British AAA defenses had a number of problems. One continual
air defense difficulty that is seldom discussed is “friendly
fire.” In fact, the first British kill, three days after the declaration
of war, was unfortunately a friendly aircraft that had even
given the correct recognition signal. The British gunners claimed
the first German aircraft over a month later on 19 October 1939.
Retention of the older three-inch guns until 1943 was another
factor that inhibited the British air defenders. Perhaps most
significant was the reliance on visual aiming. It was not until
October 1940 that the British began to equip their forces with
gun-laying radar. Radar made a big difference—the number of
rounds fired per destroyed claim at night fell from 30,000 in
September (when German night bombing began) to 11,000 in
October and to 4,087 in January 1941. 11
Personnel problems hampered British antiaircraft defenses
throughout the war. The British sent their regular antiaircraft
units overseas and relied on territorial forces similar to the
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