ROF Glascoed (today BAE Systems Munitions Glascoed) was initially a UK government-owned, Royal Ordnance Factory (ROF). It was designed as one of 20 munitions filling factories. It was planned as a permanent ROF with the intention that, unlike some other similar facilities, it would remain open for production after the end of World War II. After privatisation of the Royal Ordnance Factories in the 1980s it became part of Royal Ordnance plc and later a production unit of BAE Systems. It was served by the Great Western Railway's Coleford, Monmouth, Usk and Pontypool Railway from its opening in April 1940 until 1993. Early history In the late 1930s leading up to the outbreak of war in 1939, the British government developed a strategy to disperse armaments and munitions production away from major cities and the southeast part of England which were felt to be especially vulnerable to bombing from the air. As a result the Ministry of Supply built a number of Royal Ordnance Factories and satellite factories. A munitions-filling factory was sited at Glascoed in a valley between Pontypool and Usk in Monmouthshire. The site was chosen for its seclusion and sheltered topography surrounded by hills and its damp micro-climate was suited for the handling of explosives. Mostly agricultural land was acquired by compulsory purchase. In addition, the large workforce needed would benefit a region of the UK hit by particularly heavy unemployment in the 1930s Great Depression. The new factory was designed at the Royal Arsenal, Woolwich (Woolwich Arsenal), based on its long experience in munitions production. Safety considerations were paramount. The design, style and spacing of individual production buildings meant that they were separated by wide open spaces as well as approx 20 feet (6 m) high grassed embankments and extremely thick reinforced concrete walls and overbridges, called traverses. The purpose of these earthworks was to deflect any explosion skyward rather than outward to any adjacent buildings or structures. The site was built with extensive underground magazines, comprehensive lightning protection and individual buildings linked by paths, roads and railways. Building work on the 1,000 acre (4 km²) site started in February 1938, with the Ministry of Works acting as agents; and was undertaken by a construction company from Cardiff. The factory was officially opened in April 1940 and full production was achieved in 1941-1942. World War II and Korean War activity At its peak, ROF Glascoed boasted