A simple prefabricated set of fourteen corrugated iron arches which bolted together, plus a front and back wall, the shelter could be assembled in gardens to produce a structure 2 m long and 1.8 m high that could accommodate up to six people. It was recommended that the shelter be placed at least 1 m into the soil and covered with a further 0.5 m of soil or sand bags. The shelter was designed in 1938 by William Paterson and Oscar Carl Kerrison in response to a request from the Home Office and is named after Sir John Anderson, then Home Secretary.
150,000 shelters of this type were distributed from February 1939 to the outbreak of war. They were free to those earning less than £250 a year and cost £7 to others. During the war a further 2.1 million were erected.
The internal fitting out of the shelter was left to the owner and so there was wide variations in comfort. The shelters tended to be cold and damp, as well as prone to flooding.
Compare with Morrison shelter.