Many people in addition to Churchill’s ‘Few’ worked to defend Britain. Ground crew – including riggers, fitters, armourers, and repair and maintenance engineers – looked after the aircraft. Factory workers helped keep aircraft production up. The Observer Corps tracked incoming raids – its tens of thousands of volunteers ensured that the 1,000 observation posts were continuously manned. Anti-aircraft gunners, searchlight operators and barrage balloon crews all played vital roles in Britain’s defence. Members of the Women’s Auxiliary Air Force (WAAF) served as radar operators and worked as plotters, tracking raids in the group and sector operations rooms. The Local Defence Volunteers (later the Home Guard) had been set up in May 1940 as a ‘last line of defence’ against German invasion. By July, nearly 1.5 million men had enrolled.