Royal Navy Propellant Factory, Caerwent
The
Royal Navy Propellant Factory, Caerwent,
Monmouthshire, (later
RAF Caerwent) UK was associated with the manufacture or storage of ammunition components from
1939 to
1993. It is now used for a variety of military and civil purposes, including field exercises, car rallying, storage and breakdown of railway vehicles, and nature preservation.
The site of about 6 square kilometres measures 2
miles (3 km) by 1.5 miles (2 km), with its own
railway system (linked to the national network), many private roads and a wide range of buildings, from small earth-banked stores to large four
storey lightly-built
brick buildings. The perimeter road inside the security fence, is on its own, over seven miles long.
The site was created as a
Royal Navy propellants factory in 1939.
Note: The Royal Navy Propellant Factory, Caerwent, like the
Royal Navy Cordite Factory, Holton Heath, were never part of the
Ministry of Supply /
Royal Ordnance Factory management chain; they were controlled by the
Admiralty. However, they were functionally very similar to
Explosive ROFs.
In the summer of
1936 the site requirements for a new factory were drawn up. The main priorities were that the establishment should not be vulnerable to air attack; it should not be located in an industrial area, but sufficiently close to a populated area to provide an adequate workforce; the site should be close to a railway and to main roads; it 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
nitroglycerin manufacturing and handling areas. The higher part should not have an elevation of not less than 100
ft. (30
metre) 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
ton of
Cordite per week the factory would need 3 million imperial gallons (14,000 m³) of
drinking quality water per day. In the final quarter of
19th Century the
Great Western Railway (GWR) had undertaken the impressive engineering feat of constructing the
Severn Tunnel. 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. 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).
The total area acquired was 1,580
acres (6.39 km²) of land, a total of 1,163 acres (4.7 km²) were enclosed within the factory fence. It was connected to the Great Western railway near Sudbrook via a private branch line, sometimes known as the
MoD Caerwent sidings; and a number of transfer sidings were laid out inside the factory fence. The site is situated north of the
A48 road 4 miles west of
Chepstow and 12 miles (19 km) east of
Newport. It is about 2 miles (3 km) east-west, and 1.5 miles (2 km) north-south. The site was and still is one of the largest military sites in Britain.
The site consumed the village of Dinham which was located within the boundary of the RNPF Caerwent.
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.
A total of £4.7 million was spent on buildings and roads, and £2.5 million on plant and equipment.
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
Bishopton. The decision to close RNPF Caerwent was announced on the
25 March 1965. Production continued during the following two year rundown phase.
RAF Caerwent was transferred to US administration after
De Gaulle expelled the US military from France in
1967. Caerwent thus became part of the
US Army European 'theatre reserve stocks' under the command of the United States Army's "47th Area Support Group Reserve Storage Activity", with an
RAF Liaison Party also present.
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. The first shipments of
shells, rockets, mines, flares and small arms ammo arrived early in
1968. Maintenance facilities were added in
1971.
In the early
1970s the site's capacity was expanded substantially, which allowed the closure of three other munitions bases in the
West Midlands (Bramshall, Ditton Priors and Fauld) in
1973. One of the reasons Caerwent was retained was its proximity to
Barry Docks where many of the armaments entered the United Kingdom.
At its height Caerwent was the largest
ammunition supply depot in Western Europe, storing over 80,000
tonnes of conventional munitions. 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.
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 the
19 July 1993. The formal closure ceremony took place on the
20 August 1993.
The base is now maintained by a small army staff as a 'Training Area' for troops from
Beachley barracks and further afield. A 'representative sample' of the bomb storage and processing structures of this vast site can now be seen on the latest
Ordnance Survey map showing roughly 200 structures. Previous editions showed the site as completely blank, but serviced by a railway line.
Caerwent is now a major training area covering over 1,500 acres (6 km²), capable of sustaining up to 1,000 troops. There are not only over 400 buildings and
bunkers on the site, but also an operating railway and a comprehensive road system, for logistics exercises and driver training.
The site has been used for military training and public order training by various
police forces. Local farmers are allowed to graze their
livestock on the convenient areas of
pasture that separate the former factory buildings.
Parts of the site have also been let for civilian usage, including driver training and
car rallying.
Since the
privatisation of
British Rail, RNPF Caerwent like a number of other
MOD sites with internal railway sidings, has been 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, have been scrapped at RNPF Caerwent.
*
'The Factory' A history of the Royal Navy Propellant Factory, Caerwent by Medwyn Parry
*
Subterranea site visit with photographs*
Multimap map and aerial imagery*
Aerial photograph 1999
