In September 1935, the British prime minister, Stanley Baldwin, published a circular entitled Air Raid Precautions, inviting local authorities to make plans to protect their people in event of a war. Some towns responded by arranging the building of public air raid shelters. These shelters were built of brick with roofs of reinforced concrete. However, some local authorities ignored the circular and in April 1937 the government decided to create an Air Raid Wardens' Service and during the next year recruited around 200,000 volunteers. In August 1938 Adolf Hitler began making speeches that suggested he was going to send the German Army into Czechoslovakia. The British government now began to fear a war with Nazi Germany and Neville Chamberlain ordered that Air Raid Precautions (ARP) volunteers to be mobilized. Cellars and basements were requisitioned for air raid shelters and trenches were dug in the parks of large towns. The government also ordered the flying of barrage balloons over London and quickly made plans for the evacuation of children from Britain's large cities. In November 1938, Chamberlain placed Sir John Anderson in charge of the ARP. He immediately commissioned the engineer, William Patterson, to design a small and cheap shelter that could be erected in people's gardens. Within a few months nearly one and a half million of these Anderson Shelters were distributed to people living in areas expected to be bombed by the Luftwaffe. Made from six curved sheets bolted together at the top, with steel plates at either end, and measuring 6ft 6in by 4ft 6in (1.95m by 1.35m) the shelter could accommodate six people. These shelters were half buried in the ground with earth heaped on top. The entrance was protected by a steel shield and an earthen blast wall. Anderson shelters were given free to poor people. Men who earned more than £5 a week could buy one for £7. Soon after the outbreak of the Second World War in September 1939, over 2 million families had shelters in their garden. By the time of the Blitz this had risen to two and a quarter million. When the Luftwaffe changed from daylight to night bombing raids, the government expected people to sleep in their Anderson shelters. Each night the wailing of the air raid sirens announced the approach of the German bombers and ensured that most people had time to take cover before the raid actually started. The Anderson Shelters were dark and damp and people were reluctant to use them at night. In low-lying areas they tended to flood and sleeping was difficult as they did not keep out the sound of the bombings. Another problem was that the majority of people living in industrial areas did not have gardens where they could erect their shelters. Demonstrating the new bunk designed Anderson Shelter In March 1940 the government began to build communal shelters designed to protect around fifty people living in the same area. Made of brick and concrete they provided more protection than garden shelters. However, within a couple of months there was a severe shortage of cement and this slowed down the building of these shelters. There were also accidents that persuaded people not to use these shelters. On one occasion all the occupants of a purpose-built shelter in London drowned when it was "filled to the brim" by a burst water main. The government passed legislation that attempted to control people's behaviour in air raid shelters. If someone was found to "wilfully disturb other persons in the proper use of an air raid shelter" he could be sent to prison. In December 1941, fifty-three-year-old George Hall was sent to prison under this legislation. In fact, he was guilty of snoring in a shelter. He had been warned by the shelter marshal but continued to snore and was eventually arrested by the police for the offence. When the judge sentenced him to 14 days in prison he replied "I can't help what I do when I'm asleep". During the Blitz the deep trenches dug in parks in 1938 were lined and covered with concrete or steel. These trenches could normally hold some fifty people. They were impossible to keep waterproof and were very uncomfortable during air raids. Some people left the city every night. Special trains were run from London every night to Chislehurst in Kent where people slept in the caves in the area. Some people set up home in the caves and others established shops to serve the growing number of people seeking safety in Chislehurst. Music concerts and church services were also held in the caves. Another popular place to go in London during air raids was the Tilbury Arches in Stepney. The local council took over this collection of cellars and vaults and turned them into a large public shelter for 3,000 people. However it is estimated that on some nights there were over 16,000 people sheltering in the Tilbury Arches. People in London also used tube stations during the Blitz. People would buy platform tickets for a penny halfpenny and camped on the platforms for the night. They were popular because they were dry, warm and quiet. The government, fearing that the overcrowded platforms would hamper troop movements, attempted to stop the public from using the tube stations as shelters. The people refused to give them up and the government was forced to back down. In some cases underground stations were closed down and given over to the public to use during air raids. The tube stations were not as safe as people thought. High explosive bombs dropped by the Luftwaffe could penetrate up to fifty feet through solid ground. On 17th September 1940, a bomb killed twenty people sheltering in Marble Arch station. The worst incident took place at Balham in October 1940 when 600 people were killed or injured. The following year 111 people were killed while sheltering at the Bank underground station. One night 178 people suffocated at Bethnal Green station after a panic stampede. A census held in November 1940 discovered that the majority of people in London did not use specially created shelters. The survey revealed that of those interviewed, 27 per cent used domestic shelters, 9 per cent slept in public shelters whereas 4 per cent used underground railway stations (4 per cent). The rest of those interviewed were either on duty at night or slept in their own homes. This picture shows two young boys entering Britain’s largest shelter, it was the disused electric railway tunnel at Southwark, it could hold 11,000 people. The actual entrance to the shelter seen here adding the finishing touches before it was opened to the public.. In March 1941 the government began issuing Morrison Shelters. Named after the Home Secretary, Herbert Morrison, the shelters were made of very heavy steel and could be put in the living room and used as a table. One wire side lifted up for people to crawl underneath and get inside. Morrison shelters were fairly large and provided sleeping space for two or three people. Eventually the government decided to build eight shelters, far below ground, in central London. Each one of these shelters could house 8,000 people. Although these shelters provided excellent protection, they fulfilled no practical purpose as they were not finished until the Blitz was over.