This site has its origins in the World War Two Royal Ordnance Factory, most of which is now an industrial estate. The factory employed 40,000 people at its peak and supplied and filled naval shells. It connected to the Barry Railway via a siding and served underground magazines built into Brackla Ridge, for secure storage.
At some time after the 1960s, two of the tunnels were taken over by the Home Office and converted to become SRHQ 8.2 and later RGHQ 8.2. In the absence of a bunker for North Wales, Brackla covered the whole principality.
The site, which is one of the most unusual RGHQs, was extensively re-fitted in the early 1980s. The accommodation comprised two adjacent tunnels, each consisting of two parallel passageways 8ft wide and 250ft long, lined with metal sections like the London tube tunnels. The passageways were linked by eight chambers which gave the bulk of the space. At the entrance to each tunnel was a plant room with diesel and water tanks and a 169 bhp 6-cylinder diesel generator. An oddity of the site was an enclosed concrete passageway connecting the two tunnels, allowing protected access between them no doubt much more cheaply than by digging a connecting bore. Above the tunnels on the ridge was an escape exit and a standard mast. The site was sold in 1995.
