Llanymynech ROC Post

The Royal Observer Corps (ROC) was formed in 1925, the role of its volunteers to identify enemy aircraft. In the 1950s the ROC was additionally charged with reporting on nuclear blasts. 1,563 underground posts were built throughout the UK, often at the same sites as the earlier aircraft identification, or Orlit, posts. Each post had an entrance shaft (top), giving access to two concrete-built rooms, one about 15 feet by 7 feet 6 inches, containing bunk beds, table, chairs and cupboard; and the other a chemical toilet. Ventilation was provided via louvred vents alongside the access shaft, and to a separate air shaft (below) giving on to the other end of the underground chamber.

Crude instrumentation provided for determination of the bearing and elevation of nuclear bursts, level of radiation, and mega-tonnage. The absurdity of nuclear civil defence is indicated all too strongly by these posts: the air vents would have allowed the ingress of radiation; and the telegraph poles and lines on which communications largely depended would have been flattened.

In 1968 more than half the posts were closed. The remaining posts, including this, were closed in 1991, with many of the sites sold off to mobile phone companies, to whom their positions on high ground made them desirable locations for masts. At this site above Llanymynech the brick-built observation post still contains the wooden mounting for the observation instrumentation and chart.