Monument record 4133 - Royal Observer Corps Monitoring Post at Preston-on-Hill

This was a site occupied by the Royal Observer Corps. The Corps originally monitored aircraft during World War 2, however at the end of the war they were disbanded. In 1947 they were reformed and initially monitored aircraft, with raised 'Orlit posts' being the most characteristic structure. Structures of this period are normally little more than re-enforced huts and could be semi-sunken, at ground level or raised. However as aircraft got faster and Radar got more advanced this side of their job was phased out. Instead they were assigned to detect nuclear fallout in the event of a nuclear war, to warn the population of the fallout and to monitor the fallout. It was for this purpose that the later underground monitoring posts were constructed. On the surface there would be an entrance hatch, ventilator and fixings for survey probes. Underground there were usually two chambers, one with a chemical toilet and another with the monitoring equipment and bunks. Many of these sites survive as small fenced off enclosures in semi rural areas.