Web Databases
Without the use of databases, a project of this scope would be almost impossible. Databases are a means by which data can be stored in a structured format and retrieved, and it is they that do the real processing work of the project.
Several databases have been created to store and process the information collected:
Documentary Evidence database
Documentary Evidence was created to store data extracted from documentary sources. Although broadly similar to Concrete Evidence (see below), the latter proved inadequate for this task, but its basic structure provided a starting point. Documentary Evidence will not be publicly available until a later stage in the project.
The database is being compiled through the meticulous scanning of documents for mention of anti-invasion defences in order to identify their location and how they fitted into the overall scheme. The intention is to cross-reference each defence between documents as much as possible to build up a picture from construction through to use, creating a 3-dimensional picture of how East Sussex was to be defended in the event of invasion.
At this point in time, for a defence work to be included in the database, there must be at least one piece of documentary evidence that mentions it. The extract that provides evidence of the defence work is quoted in the database record, and multiple documents can be associated with each defence. The reason this seemingly lengthy process is utilised is so that for each record, it is known how we know that defence work existed and what we know about it. In this way we trace the history and use of individual works.
Each record has a Historian's Comments field, in which discrepancies between sources or other points of note can be discussed.
Each record consists of the following fields:
- Record ID number
- Type of defence work
- Location (placename)
- Cassini Grid reference (can have multiple)
- National Grid reference (can have multiple)
- Historian's Comments
- Document references (can have multiple)
- Parent/child relationships (can have multiple)
Problems in compiling Documentary Evidence
The largest problem is that of location; many defence works mentioned in the documents do not give a map reference but just a place name, making it hard to extablish exactly where the feature was. In some cases it has been possible to speculate the most likely grid square, in which case the Historian's Comments will indicate this.
There is also the potential for duplication of sites in the database. For example, a R.E. war diary may give a grid reference for a completed pillbox (say 123 456), but a later defence scheme may list a pillbox at a reference which is perhaps one digit different (perhaps 124 456). Now, are these documents describing the same pillbox (such discrepancies are common), or two different ones? This illustrates the need for careful and multiple references; another source (perhaps an aerial photograph) may be able to disentangle the confusion. In the meantime, two database entries are made to record the possibility that another defence may have existed.
Documentary Evidence as a processing machine
The database currently contains 1280 records and work is ongoing to input data; at least another 500 potential sites have been identified from documents awaiting the full extraction process.
Although the database cannot process the data and make historical judgements, it is an invaluable part of the analysis.
The sheer number of sites that it is anticipated will be contained within the database make it beyond normal human ability to store and retrieve the information in an efficient way.
The database has been set up to display individual records (that of a defended locality is shown at right).
At top left is an image of the appropriate grid square with a 'drag and drop' map romer that allows a grid reference to be judged on-screen. The four black arrows allow neighbouring grid squares to be searched.
On the right hand side, the database lists all of the other features that are recorded as being within the same grid square; this information, coupled with the romer and map extract, allow a picture to be built up without cluttering up a small map image with numerous symbols.
Below the map is information relating to the feature's heirarchy in the defences, if appropriate; the defended locality in question has a Company Locality as a parent, and defended buildings and other features as children. All references to other defences are hyperlinked to provide quick access to them.
Below the parent/child box we have the grid references in both Cassini and National Grid, the latter having been converted from the former using the formula discussed on the maps page. An extra stage in the data entry process automatically runs the Cassini reference through the formula and posts the resulting National Grid Reference directly into the database.
Finally, at the bottom of the page we have the actual information that tells us how we know this particular defence existed and how much we know from the available source material. Without the database to automatically process this information and present it conveniently on a single screen, the task of analysing the data would be very much harder.
Documentary Evidence is not publicly available, although some statistics are available.
Concrete Evidence database
Concrete Evidence was the original database for this website when it was conceived in 2006.
It was designed solely to record the surviving defence works that I had visited; its importance, in its current form, is secondary now that the emphasis of my research (and, therefore, this website) has broadened.
Designing the database was a useful exercise, however, and the experience gained proved invaluable when Documentary Evidence was being considered.
In light of the latter, Concrete Evidence is actually too complex, in that defences have a parent/child relationship which is perhaps best described in a database that attempts to reconstruct the entire defence system, not just those that still remain.
The parent/child relationship has been reconstructed in Documentary Evidence, but whether abstract defences such as Sub-sectors will be removed from Concrete Evidence has not yet been decided, neither has the ultimate fate of those listed defences not in East Sussex.
Concrete Evidence is publicly available, and although I have no definite plans to keep developing it, its relevant data will eventually be merged with Documentary Evidence.
War Diary database
War Diary is an ambitious side-project to transcribe anti-invasion-related entries from the war diaries of units stationed in East Sussex from May 1940.
The database began as a concept, but grew into a project in itself, and currently contains 591 entries, although work on the database is irregular while Documentary Evidence is being initially compiled.
Each entry basically follows the structure of a printed war diary, containing date and time fields alongside the event details. Additional fields link the diary entry with its originating unit, its branch of service (e.g. infantry, artilery, engineers etc) and the diary's National Archive document reference. The latter are also incidentally forming the foundation of an archive document bibliography database.
The diaries processed thus far are mainly those of units belonging to 45 Division, although by no means all of them; those that were typed have proved the easiest to transcribe. Entries relating to anti-invasion activities and training are included, as are those mentioning enemy action and aircraft crashes.
The legwork of compiling the database is eased by the use of voice recognition software, which, though not perfect, significantly speeds up the transcription process.
Although the database has proved of enormous value so far; there are currently no immediate plans to make it publicly available, although once I have extracted all of the research potential from it, I may open it up to all.