Royal Ordnance Factory

The three main types of factories were engineering, filling and explosives, and these were dispersed across the country for security reasons.

The emerging threat of aerial bombing prompted the government to consider dispersing its ordnance factories around the country.

[1] A number of Second World War munitions factories were built, and owned, by Imperial Chemical Industries (ICI).

[2] Other filling factories were run by Imperial Tobacco, Courtaulds, the Co-operative Wholesale Society (CWS), Metal Closures and Lever Brothers.

Until 1940, this meant from Bristol, in the south, and then west of a line that ran from (roughly) Weston-super-Mare, in Somerset, northwards to Haltwhistle, Northumberland; and then northwestwards to Linlithgow, in Scotland.

ROFs involved with explosive manufacture or filling needed, on safety grounds, to be located away from centres of population.

They needed access to good transport links, such as railways, the availability of adequate workers within reasonable travelling distance, and a plentiful guaranteed supply of clean process water.

Some ROFs located in Wales and Scotland were the result of political lobbying as these areas had high unemployment rates in the 1930s.

Each ROF tended to be self-contained, apart from its raw materials: with their own coal-fired power stations, for generating steam for heating and process use, and electricity via high-pressure steam turbines if needed; engineering workshops; plumbers and chemical plumbers; leather workers; electricians; buildings and works departments; housing and hostels for workers; canteens; laundries and medical centres.

The design of explosives, propellants and munitions was carried out at separate government-owned research and development establishments such as the Research Department, which was initially based at the Royal Arsenal, Woolwich and then Fort Halstead, in Sevenoaks, Kent; and at PERME Waltham Abbey, Essex, which later moved to become RARDE Fort Halstead.

In 1957, a Defence white paper led to a reorganisation of the aircraft industry, a restructuring of the British Army and a concentration on missile systems.

Some closed ROFs and Admiralty explosive sites, such as the Royal Navy Propellant Factory, Caerwent, were retained by the Ministry of Defence as ammunition storage areas.