Caerwent Training Area
Caerwent, Monmouthshire
West Gate, Caerwent Training Area
Caerwent Training Area Location within Monmouthshire Show map of Monmouthshire Caerwent Training Area Caerwent Training Area (the United Kingdom) Show map of the United Kingdom
Coordinates	51°37′00″N 2°45′53″W / 51.6167°N 2.7648°W / 51.6167; -2.7648
Type	Training Area
Site information
Owner	Ministry of Defence
Operator	British Army
Site history
Built	1939
Built for	War Office
In use	1939–Present

Caerwent Training Area is a British military installation at Caerwent, Monmouthshire, Wales. The large military site is situated north of the A48 road about 5 mi (8.0 km) west of Chepstow and 12 miles (19 km) east of Newport.

Established as the Royal Navy Propellant Factory, Caerwent in 1939, it was originally dedicated to the manufacture and storage of Royal Naval munitions. It has been used as a training area since its closure as an armament works in 1966, and between 1967 and 1993 was RAF Caerwent.

Caerwent Barracks is to be built on the site to house 1st The Queen's Dragoon Guards and 1st Battalion, The Rifles from 2027.^[1] As at 2023, the site is under construction.

In the summer of 1936, the Royal Navy drew up prequirements for a new factory. The main priorities were:^[2]

• the establishment should not be vulnerable to air attack;
• should not be located in an industrial area, but sufficiently close to a populated area to provide an adequate workforce;
• should be close to a railway and to main roads;
• should be located on rough grassland with a gravel on sand subsoil with good natural drainage and a slope of about 1 in 30 to provide maximum safety in the highly dangerous nitroglycerine manufacturing and handling areas;
• the higher part should not have an elevation of not less than 100 ft (30 m) above the lowest part to limit the internal gradients.

Like all explosive factories of this type, a capacious supply of water was required for use in the manufacturing processes. To manufacture 150 tons of cordite per week the factory would need 3 million imperial gallons (14,000 m³) of drinking quality water per day.^[2]

In the latter part of the 19th century, the Great Western Railway (GWR) had undertaken the engineering feat of constructing the Severn Tunnel under the River Severn.^[3] One of the major difficulties encountered underground was the 'Great Spring', which necessitated the pumping of over 9 million gallons (41,000 m³) of water per day, at Sudbrook, from the western end of the tunnel, conveniently located only three miles (5 km) away from the proposed site at Caerwent.^[4] Even during the great drought of 1934 the lowest daily return was 9.1 million imperial gallons (41,000 m³). The GWR used about 1.5 million imperial gallons (6,800 m³) per day themselves, so there was always a guaranteed daily surplus of 7.5 million imperial gallons (34,000 m³).^[4]

Work began to create the propellants factory in 1939.^[2] A total of £4.7 million was spent on buildings and roads, and £2.5 million on plant and equipment.^[2] The site's total area was 1,580 acres (6.4 km²) of land with a total of 1,163 acres (4.71 km²) enclosed within the factory fence. The scale of site consumed the village of Dinham which was located at the northern edge of the RNPF Caerwent.^[2]

By the end of 1940, the Main Office block was complete, and in December of that year the Unit 1 Sulphuric Acid Factory went into production with acid mixing for the Nitrocellulose and Nitroglycerine manufacturing. Five months later, the Pressure Oxidation Plant for the manufacture of Nitric acid came on stream. In August 1941 the Nitrocellulose and Nitroglycerine plants were operational and were soon working 24 hours a day on a three-shift pattern. At the same time, Unit 2 of the factory was almost completed, so RNPF Caerwent was now virtually operational.^[2]

The factory had its own standard gauge railway system, miles of roads and a wide range of buildings, from small earth-banked bomb stores to large four storey built brick buildings.

Since 1993, the former factory site has been used for a variety of military and civil purposes, including military field exercises, car rallying, storage and breakdown of railway vehicles, nature preservation, and leisure activities such as Airsoft.

Between 1955 and 1966, Caerwent produced the Gosling solid rocket booster for the Seaslug missile. This Cold War work began in wartime buildings, the horizontal presses in Press Houses 3 and a longer press in 1, and with other work in a disused blending house and the Tetryl Acetone Recovery building.^[5] From 1957 dedicated buildings, J1...J6, were constructed on the eastern side of the site for the production of guided weapons propellants. Buildings J7...J9 at the northern edge of the site formed a static testing site, where these motors could be test-fired. J7 was an environmental conditioning building where charges could be heated to 70 °C or cooled to -40 °C before testing. These buildings were of typical flat-roofed red brick construction, shielded by large earth traverses.^[5] Testing work was also carried out here on the Magpie, Redtop and Sealyham rocket motors.^[5]

Early in the 1960s, a Parliamentary working party recommended that propellants for the three branches of the armed services should be concentrated at the Royal Ordnance Factory at ROF Bishopton. The decision to close RNPF Caerwent was announced on 25 March 1965. Production continued during the following two-year rundown phase. The last Gosling motor was produced on 14 June 1966, before tooling was transferred to Bishopston.^[5]

RAF Caerwent was transferred to US administration after Charles de Gaulle almost completely expelled United States Department of Defense activities from France in 1967. Caerwent became part of the United States Army European 'theatre reserve stocks' under the command of the United States Army's "47th Area Support Group Reserve Storage Activity", and became known as USADA Caerwent (United States Arms Depot Activity – Caerwent).^[2]

The US Army spent over £4 million constructing 300 magazines and converting some of the former RNPF structures to conform to the required specification. The material stored included small arms ammunition, artillery shells (up to 8"), anti-tank mines, grenades, flares, and the multiple launch rocket system.^[2] The first shipments of shells, rockets, mines, flares and small arms ammo arrived early in 1968 with shipments arriving by rail as far as practicable.^[6]

Circa 1982-83, Caerwent was under the administration of Reserve Storage Activity Caerwent, 47th Area Support Group, 21st Support Command, United States Army Europe.^[7]

At its height, Caerwent was among the larger ammunition depots in Western Europe, storing over 80,000 tonnes of conventional munitions, a substantial fraction of the US Army's European stocks. In 1990 Caerwent shipped 12,000 tons of ammunition to the Middle East and played a critical part in Operation Desert Shield and Desert Storm.^[2]

Following the change in the political climate in Europe and subsequent scaling down of operations, the US Army announced it was to close down their storage operations at the establishment in June 1992. Over 60,000 tonnes of munitions were moved out over a period of less than ten months. The last batch was removed by train on 19 July 1993. The formal closure ceremony took place on 20 August 1993.^[2]

Caerwent is now a major training area covering over 1,500 acres (6.1 km²), capable of sustaining up to 1,000 troops. There are not only over 400 buildings and bunkers on the site, but also a comprehensive road system, for logistics exercises and driver training. Improvements to the site were completed at a cost of £150,000 in November 2015.^[8]

The 1st The Queen's Dragoon Guards and 1st Battalion, The Rifles are scheduled to move to the new Caerwent Barracks when building is completed in 2028.^[9]

The site was connected to the Great Western railway at Caldicot Junction, near Sudbrook by way of a private branch line, sometimes known as the MoD Caerwent siding. There were a number of transfer sidings within the factory.^[10]

After the privatisation of British Rail, RNPF Caerwent like a number of other MOD sites with internal railway sidings, was used as a secure storage area for holding surplus locomotives and rolling stock that might be returned to use. A small number of electric locomotives, particularly in the British Rail Class 86 and British Rail Class 87, were scrapped at RNPF Caerwent.^[11] Between 2008 and 2014, the railway tracks were removed but the trackbeds left in situ. A number of unsafe buildings and redundant acid storage facilities have also been removed since 2014.^[12]

In summer 2022, work began to remove the final stretches of track that remained within the site and on the connecting branch line. The disassembled rails will be transported to the Gwili Railway, a Welsh heritage railway at Carmarthen. The former trackbed is to be converted into a footpath and cycleway.^[13]

Scenes from the Hollywood blockbuster Captain America: The First Avenger were filmed on site in October 2010.^[14] More recently, Caerwent was used in the television series Top Gear.^[15]

• Bowditch, M.R. and Hayward, L., (1996). A pictorial record of the Royal Naval Cordite Factory, Holton Heath. Wareham: Finial Publishing. ISBN 1-900467-01-1.
• Cocroft, Wayne D., (2000). Dangerous Energy: The archaeology of gunpowder and military explosives manufacture. Swindon: English Heritage. ISBN 1-85074-718-0.
• Walker, Thomas A., [1888] (2004). The Severn Tunnel: Its Construction & Difficulties: 1872 – 1887. Republished 2004. Stroud: Nonsuch Publishing. ISBN 1-84588-000-5

• Subterranea site visit with photograph
• Multimap map and aerial imagery
• Aerial photograph 1999
• Orienteering map 2007