Until recently these defences were considered a fringe interest by many professional archaeologists. Much has been achieved by knowledgeable and dedicated independent groups and individuals, but attention is often confined to specific, often local structures, and few results have been incorporated in county sites and monuments records. Dissemination usually takes the form of regional or local guides and although potentially useful, such initiatives provide little to establish which structures merit protection. The Defence of Britain Project, managed by the Council for British Archaeology and funded through the Monuments Protection Programme is intended to rectify this situation and provide EH with the necessary overview.
A 5-year-programme, to compile a database of 20th-century defence sites in the UK is being undertaken by volunteers who report back to a Field Co-ordinator and all records will be incorporated into the National Monuments Record, and relevant sites and monuments records. This will establish the extent of survival of features but cannot furnish a strategic context, or details of the original numbers of sites arranged by type, their appearance, indications of regional variation (taken from construction specifications), and when they went in and out of use. From a preliminary assessment of the available, it was clear that such an overview was not only possible, but would be of particular value in producing the credible basis required for strategic planning.
The archives project is likely to run for 3 years and in the first year 5 reports have been completed which vary considerably in size (some run to several volumes of text, sources, and gazetteers). Subjects completed to date are anti-aircraft artillery 191446, bombing decoys of WWII, Operations Diver, Overlord, and Anti-invasion. Six reports are anticipated between 199698 covering airfield defence, acoustic detection, civil defence, coast artillery, Cold War remains, and radar. A report on military training and experimental establishments may also be prepared and EH is exploring the feasibility of additional work on defence structures of 16601900.
The scope and volume of the archives for 20th-century defences is huge: all aspects of the defence heritage are documented to some extent and for most site types the coverage is comprehensive. For example, the Diver campaign (England's defence against the flying bomb) is recorded in the day-to-day records of the headquarters, formations, and units who executed the operation. Diver touched many branches of the armed forces and events often moved quickly resulting in a busy network of intercommunication between interested parties. Much was committed to paper and most of these papers are preserved in the files of the War Office and the Air Ministry. The principle War Office sources are the War Diaries of individual army formations and units, and Headquarters Home Forces Papers. Many of the Diaries contain appendices in the form of proforma progress reports, often chronicling the development of each site on a day-to-day basis. Most planning and operational matters appear in the Air Ministry papers, while other important sources are the Cabinet Papers relating to operations at the highest strategic level.
For many types of site we can establish the exact location of every installation that was built, and a chronology refined to weeks or even days. We can present an overview of what was built, how, when, where, by whom, and why. We know, for instance, that 1,003 bombing decoys, were built in the UK (839 in England). 252 (the so-called Q sites) were designed to simulate the flarepath lighting of permanent RAF stations to lure attack by night bombers. We know, from contemporary plans and specification drawings, what the various types of decoy and their component parts looked like. Virtually all Operation Diver sites including 1,190 Heavy (HAA) and Light Anti-Aircraft (LAA) can be precisely located. Recent visits to sites in Kent suggest that some 15% of these now have recognisable remains, and that these are more likely to occur on the HAA sites. Construction hards for the mulberry harbours used in Overlord have also been studied and their original distribution presented. Some 68 sites were identified from the archives, spread along the south coast from Suffolk to Cornwall.
The 2 largest surveys, which have the potential to transform our understanding of England's wartime defence strategy, are of anti-aircraft and anti-invasion measures. The anti-aircraft report covers both World Wars, the intervening years, and those retained as the Nucleus Force after 1946. The report contains an historical framework which provides the context for the development of anti-aircraft defence between 1914 and 1946. Subsequent sections detail site anatomy and site layout, covering the development and typology of each component (command posts, gun emplacements, radar receivers and other buildings. Sections consider domestic sites, including building specifications for the various hut types, and camouflage and ground defence, and based on existing records, a statement is made concerning survival. 2,119 anti-aircraft sites are identified in England (307 belong to WWI and 1,812 to WWII, of which 1,078 are HAA, 705 LAA, and 29 'Z' rocket batteries). It is believed that the figure for HAA sites approaches closely the total originally built and the LAA total represents the greater proportion of those known to have been established. Further work could be undertaken on Z batteries, but as these are known to have been systematically cleared in 1945, little is likely to survive.
Progress on the archives project has exceeded expectations. Not only have gazetteers been produced, but detailed accounts of typology, chronology, and regional diversity also now exist. Sites and site types can be seen in their broader strategic and political context, with local events (seen in Unit Diaries for example) set in the framework of national decision-making (the Cabinet papers). The results of this study have wide appeal. Since the fiftieth anniversaries of VE and VJ days, public interest in recent military history has increased and it is our intention to see the results published in order to meet that demand. It is also our wish to see the field recording programme of the Defence of Britain Project integrated with the results of the archive survey. Finally we must move towards a strategy for the management of 20th-century defence sites. We are often being asked to list and schedule defence structures, especially pillboxes. We are now close to a position where selection can not only be made but fully justified.
