ROF Glascoed 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 nearly 700 separate buildings , each designated for a particular process and used as required . It still has in excess of 10 miles ( 16 km ) of roads , an 8 - mile ( 13 - kilometre ) perimeter fence and , until more recent years , its own 17 mile ( 27 km ) standard gauge railway system . This included a dedicated passenger station and freight marshalling yards . It was linked to the Great Western Railway ( GWR ) branch line that ran between Pontypool Road and Monmouth . This rail link enabled the three - times daily movement of up to 13 , 000 workers in and out of the site as well as the receipt of raw materials and components and the despatch of finished munitions . A small housing estate was built close - by to accommodate managers and staff who had to respond quickly in emergencies . Initially it was intended that ROF Glascoed would produce sea - mines for the Royal Navy . However as well as these , heavy bombs and pyrotechnics ( such as target indicators and skymarkers ) were supplied to the RAF . Among the weapons filled and assembled by ROF Glascoed were the bouncing bomb , designed by Barnes Wallis and delivered to the Ruhr area of Germany by the Dambusters , RAF 617 squadron . Contemporary ARP planning was largely based on Stanley Baldwin ' s assertion that " the bomber will always get through " . So , near Glascoed , the local Folly Tower on a hill top at nearby Pontypool was seen as an aiming - off point for the Luftwaffe to attack the ROF factory . The Tower was demolished at the start of the war and not rebuilt until 1994 when it became a minor tourist attraction . As it was , ROF Glascoed was bombed only twice during the war . On one occasion , a worker was killed and several injured by a lone bomber which caused minor damage . Post - war debriefing records show that the bomber ' s crew were convinced they had bombed Filton aerodrome in Bristol , some forty miles ( 65 km ) away . As demand for weapons and ammunition declined with the end of the war , many Royal Ordnance Factories were closed . ROF Glascoed was retained and supplemented its output by manufacturing concrete building products and by scrapping surplus munitions . The growing hostility of the Cold War as evidenced by the Korean War saw a much wider range of munitions filled , assembled and packed at ROF Glascoed . These included munitions for field guns and howitzers , tanks and other fighting vehicles , mortar and aerial bombs , warhead s for missiles and torpedoes , flares , pyrotechnics and smoke bombs . Post - war survival . The Royal Ordnance Factories were part of a government department until they were privatised in 1987 . Today Glascoed is operated by BAE Systems Global Combat Systems Munitions . With the closure of other ROFs , Glascoed remains the only ammunition filling facility in the UK and exports its products , as well as supplying the British Ministry of Defence ( MoD ) . Glascoed now employs about 400 people and is investing heavily in R & D and improved production facilities . In recent years , Glascoed has developed an expertise with Insensitive Munitions in artillery shell s and other warheads . These employ PBX compositions such as Rowanex 3601 ( booster ) and Rowanex 1100 ( main charge ) designed to minimise the risk of accidents e . g . inadvertent detonation by dropping , heat , friction or impact . One such accident occurred on the USS Forrestal in 1967 . Until the mid - 1990s , in the interests of security , British Ordnance Survey maps omitted the details of all ROF sites ; and showed the sites as they existed before the ROF ' s construction , although it was sometimes possible to identify the site boundaries . More recent editions show the detail of the buildings , internal roads , and rail links , labelled simply as " Depot " or " Works " . On the 20 August 2008 the Ministry of Defence ( United Kingdom ) announced a 15 year £2bn contract with BAE Systems to supply British forces with medium calibre and small arms ammunition .