Military Wiki
File:No. 23 Post (Skelmorlie) Image 3.jpg

Above ground view of a monitoring post

Royal Observer Corps Monitoring Posts are underground structures all over the United Kingdom and Northern Ireland, constructed as a result of the Corps' nuclear reporting role and operated by volunteers during the Cold War between 1955 and 1991.

In all but a very few instances the posts were built to a standard design consisting of a 14-foot-deep access shaft, a toilet/store and a monitoring room.[1] The most unusual post was the non-standard one constructed in a cellar within Windsor Castle.

A third of the total number of posts were closed in 1968 during a reorganisation and major contraction of the ROC. Several others closed over the next 40 years as a result of structural difficulties i.e. persistent flooding, or regular vandalism. The remainder of the posts were closed in 1991 when the majority of the ROC was stood down following the break-up of the Communist Bloc. Many have been demolished or adapted to other uses but the majority still exist, although in a derelict condition.


The first prototype post was built at Farnham, Surrey, in 1956 and on 29/30 September of that year a trial was conducted to ascertain the usefulness of the underground posts. Of the two crews of four personnel engaged in staffing the post during this trial, the second group of four, two ROC and two Home Office Scientific Advisory Branch, were sealed inside with rations bedding and barrack equipment. With a few minor changes, mainly to the hatch and air ventilation louvres, the posts were built as per the prototype.[2] The protection provided by the concrete roof and compacted earth mounded above the post was estimated to reduce any external nuclear radiation by a factor of 1,500:1.

Construction of the original 1,563 posts was overseen by the Air Ministry Works Department and the ROC and undertaken by local contractors. Once a site was chosen (usually the site of an aircraft observation post) a hole approximately 9 feet deep was excavated. Within this hole a monocoque structure was cast using re-enforced concrete with a floor about twelve inches thick, walls about seven inches thick and a roof about eight inches thick. The whole structure was then bitumen 'tanked' for waterproofing purposes. Soil was compacted over the structure to form a mound leaving the access shaft, doubling as an airshaft, protruding above ground. At the opposite end of the building a further air shaft was formed. Two metal pipes, one 5 inches in diameter and one 1 inch in diameter protruded from the roof and above the four-foot mound to be used with operational instruments.[3] The air vents were covered by downwards sloping louvres above ground and sliding metal shutters below ground to control air flow during contamination by radioactive fallout.

The Home Office wanted 100 posts built in the first year (1957) and 250 a year thereafter. By mid-1958 only 94 posts had been handed over to the ROC with 110 under construction. The cost of building the underground posts was approximately £1000, but rose to nearer £8000 in some instances.[4]


Today most posts lie derelict and abandoned. Approximately half of the posts built have been demolished, either on stand down by the ROC or by private owners in subsequent years. One post, in York, has been incorporated in to a house and forms a handy cellar.[5]

A small number of posts have been purchased and either restored to how they were and usually opened as museums with guided tours by prior arrangement. One such post is the former 20 Group York, 37 Post (Brandsby) post north of York, which has been painstakingly restored to how it was in the final summer of operation in 1991. It is the nearest restored Monitoring Post to the only restored ROC Group Control in Britain, HQ 20 Group York, Shelley House at Acomb, York.[6]

Other known restored posts include Skelmorlie, Scotland, Veryan, Cornwall, Skipsea, Yorkshire, Rushton Spencer, Staffordshire and Portadown County Armagh.[7] Several more are planned or are under development.


  2. Attack Warning Red Derek Wood, MacDonald and James, 1976
  4. Attack Warning Red Derek Wood, MacDonald and James, 1976
  5. subterraniabrittanica
  7. subterraniabrittanica

See also[]

Operational instruments of the Royal Observer Corps

This page uses Creative Commons Licensed content from Wikipedia (view authors).