This bunker was part of the Longley Lane Rotor Sector Operations Centre.
The Sector Operation centers were designed to exercise the intermediate control and reporting functions under Fighter Command HQ, Bentley Priory. The UK was divided into 6 sectors, each with an 'SOC'. Fighter Command HQ and the SOC's received raw data from radar stations and ROC Group HQ's; after filtering to remove anomalies this data was retold to the SOC's who were responsible for the actual control and interception via GCI stations. Army AAOR's also received the same information to integrate defences.
During the war the filter room acted as a collecting point for information. Duplicate and irrelevant information could be filtered out here. It was later used for many years as the Preston Armed Forces Headquarters (AFHQ) . The two level bunker has been derelict since 1992. And is currently up for sale. ( 2007 )
