A steel helmet worn by the Royal Ulster Constabulary (RUC) during World War II. The outbreak of the war in 1939 brought additional duties for the police. The RUC had to enforce black-out restrictions, check the movement of people and vehicles and oversee the Local Defence Volunteers (Home Guard). Rationing in Northern Ireland increased the level of smuggling across the Irish Free State border. A lucrative black market developed and smugglers used guns to defend themselves from capture. An Irish Republican Army (IRA) wartime campaign included bank raids and sporadic attacks on policemen and barracks.

Belfast’s contribution to the war effort made the city a target for enemy bombers. Textile mills produced cloth and uniforms, Harland and Wolff worked on ships, Shorts produced aircraft and engineering firms made tanks and guns. The Northern Ireland government believed that the Luftwaffe (German airforce) could not reach Belfast and left the city poorly protected against aerial bombardment. Belfast had too few air raid shelters, anti-aircraft guns and fire fighting equipment. There was limited radar cover and no search lights or night fighters. Belfast was attacked between April and May 1941 with a barrage of incendiaries and high explosives. The German raids caused widespread damage to industrial and residential premises and resulted in over 900 deaths and more than 2000 casualties. The RUC, Local Defence Volunteers and many civilians joined in the rescue work. Three RUC men won George Medals and two were awarded British Empire Medals for their bravery.

The RUC continued to wear steel helmets during riot duty in the 1950s and 1960s.