The Anderson shelter was basically a steel trench shelter that could house a typical family of four (it could accommodate six at a pinch). It was perhaps the greatest reflection of the change in attitude as a result of the Munich Crises – the decision to offer the Anderson shelter free of charge to poorer families or at a subsidized cost for others.
The shelter consisted of an arch shaped trench lining constructed of heavy corrugated steel sheet which could be bolted together. A blast plate entrance protected the arched ‘tunnel’. It was to be semi-sunken in a trench, the spoil being used to cover the shelter.
The shelter performed remarkably well, capable of protecting its inhabitants from very near misses. It functioned better than other trench linings due to being constructed of a ductile material – i.e. could absorb the shock of blasts by stretching without a reduction in strength.
However it was still a trench shelter and suffered the same problems of all trenches – cold, damp and often flooded in wet weather. Although bunks were provided so people could spend the night in them, they were unlikely to do this especially in the winter months in such conditions. In fear of rising casualties and a resulting drop in morale due to people deciding not to spend the night in their Anderson Shelter, Churchill demanded an indoor shelter (the result was the Morrison Shelter).
After the war, steel was in short supply and Anderson and Morrison shelters were collected from households and collection of the accumulated stocks arranged by The Ministry of Supply. A letter from The Eastern Civil Defence Region issued to Clerks of various Local Authorities on 12th February 1949 asked for details of any further shelters returned since the Local Authority deemed the work of collection complete, such was the need for steel in post-war Britain.
Enterprise versus Bureaucracy – The Development of Structural Air-Raid Precautions during the 2nd World War, Lord Barker of Windrush, O.B.E., Sc.D.,F.R.S., C.Eng, Pergamon Press 1978
Aldeburgh air raid shelter papers, SRO