"Anderson Shelter" was one of the most effective and performed well under blast and ground shock as they could absorb a great deal of energy through plastic deformation without falling apart. It was designed by William Paterson and Oscar Carl Kerrison in 1938 in response to a request from the Prime Minister at the time Sir John Anderson in charge of Air Raid Precautions.
Anderson shelters were given for free to poor people. Those who earned more than £5 per week (equivalent to £280 in 2015, when adjusted for inflation) could buy it for £7. Not long after the outbreak of the war about 2 million households had these shelters.
Anderson shelters were designed to accommodate up to six people. The main principle of protection was based on curved and straight galvanised corrugated steel panels.
The shelters were 6 feet (1.8 m) high, 4.5 feet (1.4 m) wide, and 6.5 feet (2.0 m) long. They were buried 3-4 ft (1.2 m) deep in the soil and then covered with a minimum of 15 inches (38 cm) of soil above the roof. The earth banks could be planted with vegetables and flowers, which quikly became the subject of competitions of the best-planted shelter among householders in the neighbourhood.
Because of their robustness, many Anderson shelters could still be found in the backyards.