Site Records

Site Name: Dean Hill Royal Naval Armaments Depot (RNAD) - later known as Defence Munitions Dean Hill

West Dean
Wiltshire
Location: OS Gris Ref: SU2626

Sub Brit site visit 5th December 2003

The Dean Hill Royal Naval Armament Depot (RNAD) was opened in 1941 for the storage, inspection and maintenance of naval armaments. Munitions would be sent from Dean Hill to the forward RNAD's at Priddy's Hard (now a museum) and Gosport from where they would be issued to ships.

The primary task of the depot has always been the storage of munitions in a series of 24 underground magazines excavated in the chalk hillside 'Dean Hill', at the rear (south) of the 583 acre depot at West Dean near Salisbury in Wiltshire. There have never been any explosives manufacturing on the site.

There was a standard gauge connection to the Southampton - Salisbury railway line west of Dean Station with a substantial marshalling yard and two transfer sheds for transferring munitions to the extensive 2' 6" gauge railway network that serviced all the magazines and workshops around the dispersed site. The connection to the main line was severed in 1988 with the entire standard gauge track including the marshalling yard being lifted by the mid 1990's.

As well as storage, a major function of the depot was the inspection, maintenance and repair of munitions. This was carried out in a series of light and heavy traverse laboratories located towards the middle of the site. General inspection and examination of armaments returned from sea or after long term storage took place in the light traverse laboratories. These consisted of a series of brick buildings surrounded by concrete traverses that would have limited the damage caused by an explosion to one building. The buildings were in a single block each with its own narrow gauge railway siding and loading platform. Each of the buildings were fitted with overhead gantry cranes for moving munitions around. At the rear (north) of the block a passage or 'clean way' ran through the traverses giving access to each of the buildings.

Repair and refurbishment took place in the heavy traverse laboratories. These buildings were more substantially protected with the buildings mounded over with earth. To facilitate safe handling of explosives the arrangements were similar to explosives magazines with a 'shifting lobby' where workers could change into safe magazine clothes, safe lighting and a 'clean way' through the traverses at the rear of the laboratories. There was a facility for dismantling unusable munitions and for steaming out explosives.

It's unlikely that nuclear weapons were ever stored long term at Dean Hill; the depot was however used for overnight stabling of nuclear materials and weapons. Nuclear bombs were manufactured at Aldermaston & Burghfield with plutonium and other nuclear materials coming from the MOD reactors at Calder Hall and Chapelcross. This was processed at Sellafield and moved by road to Aldermarston. The completed weapons were then transported in convoys to specials munitions depots across the country. In southern England there was only one such depot, RNAD Frater near Gosport. (Now Defence Munitions Gosport). Nuclear depth charges used by the Royal Navy are stored there.

These convoys always travel in daylight accompanied by a police escort and two vans full of armed Royal Marine commandos with a fire engine and communications vehicle traveling half a mile behind. If delayed the convoys normally stop over night at a suitably equipped military base. In Southern England this was RNAD Dean Hill. No 1 magazine was refurbished for this purpose and enclosed within a secure compound with a small observation 'tower' with a searchlight alongside the magazine. There was also a protected accommodation block within the compound which was totally self sufficient including its own ventilation plant and stand-by generator.

In January 1987 a 20-ton lorry believed to be carrying nuclear weapons slid off an icy country road and overturned near the depot.

During later years munitions stored at Dean Hill represented less than 4% of munitions stored for the three services at depots around the country. Although initially opened as a storage facility for the Navy the depot was also shared by the other services. Before closure was announced, only 48% of munitions stored were held in support of the Navy with 52% in support of the RAF.

One building close to the centre of the site was used for the maintenance of the Paveway III laser-guided bomb (LGB). Paveway was the most successful air-to-ground weapon system employed during the first Gulf War. Over half of all air-to-ground precision guided weapons expended were Paveways. They were used to destroy the full spectrum of targets including aircraft shelters, runways, command bunkers and SCUD missile launchers. Paveway LGB's refurbished at Dean Hill were used by Tornado aircraft from RAF Marham.

Further information and pictures about this site continues here

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