You're welcome, Clickclick.
The underground posts evolved from the aircraft-spotting role of the 1920s, 30s, 40s, fast jets of the 50s to a nuclear monitoring role and a UK-wide network of subterranean bunkers were built, quietly and without fuss, in the 1960s and '70s, located at roughly fourteen-mile intervals across the UK, and in groups of three: one of each group being a 'cluster station' equipped with VHF radio.
Serious Civil Defence cuts in October 1968 by Prime Minister Harold Wilson and his Labour Government left only 873 posts, most of which remained until 'Stand-Down' in the early 1990s. The UKWMO was disbanded rather unceremoniously, to the annoyance of many members, who felt badly let down.
Here's a gratuitous plug for my website (rather old-fashioned by today's standards!
) where you'll find a little more. The link takes you to the bunker in my home-town, but you can navigate to the index page where you'll find more. Many of the bunkers went on the market (guide-price typically £50,000 - £70,000 UKP) as wine-cellars, bolt-holes for solitude, etc... Many were filled in and / or sold to mobile phone comanies as they made ideal bases for radio towers. But one national broadcasting chain got its fingers burned when it bought them and subsequently put them back on the market.
Workington U/G ROC Post