ARP (air raid precaution) wardens supervised the Blackout.
Air Raid Precautions (ARP) were organised by the national government and delivered by the local authorities. The aim was to protect civilians from the danger of air-raids.
In September 1935, four years before WW2 began, British prime minister, Stanley Baldwin, published a circular entitled Air Raid Precautions (ARP) inviting local authorities to make plans to protect their people in event of a war. Such plans included building public air raid shelters.
In April 1937 the government decided to create an Air Raid Wardens' Service and during the next year recruited around 200,000 volunteers. These volunteers were know as Air Raid Precaution Wardens.
Their main purpose of ARP Wardens was to patrol the streets during blackout and to ensure that no light was visible. If a light was spotted, the warden would alert the person/people responsible by shouting something like "Put that light out!" or "Cover that window!".
The ARP Wardens also reported the extent of bomb damage and assess the local need for help from the emergency and rescue services.
They were responsible for the handing out of gas masks and pre-fabricated air-raid shelters (such as Anderson shelters, as well as Morrison shelters), and organised and staffed public air raid shelters. They used their knowledge of their local areas to help find and reunite family members who had been separated in the rush to find shelter from the bombs.
There were 1.4 million ARP wardens in Britain, most of who were part time volunteers who had full time day jobs.
They wore helmets with a big W on the front.