Concrete Evidence Database

Concrete Evidence is the main Project database of defence works and related features extracted from original documents and other sources.

Restricted online access has been granted for 131 records, but the full database, (currently 3369 records) will not be released for the time being.

The database is being compiled through the meticulous scanning of War Diaries, Defence Schemes and Operation Orders for mention of anti-invasion defences in order to identify their location and how they fitted into the defences. The intention is to cross-reference each defence between documents and other sources 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.

More information about the history and design of Concrete Evidence can be found in the Databases page of the Methodology section.

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Concrete Evidence Help

The sections below will guide you through the important parts of a Concrete Evidence record; you're advised to give them a quick scan now, but you can always come back to a particular section on this page by clicking the help icon on any section.

Serial numbers/identifiers

This section contains known identification names/numbers.

DESPro: This is the unique ID number for the Defence of East Sussex Project

Defence of Britain Project: This is the unique Site Reference Number (UORN) assigned to this defence work by the Defence of Britain Project (1995-2002). This number can be used to find the record using the search facility available from: http://ads.ahds.ac.uk/catalogue/specColl/dob/.

Wartime Serial/Post No.: Many pillboxes and defence works were assigned post numbers for identification purposes; these are listed where known.

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Location

This box provides map references for the site; please note that they may not be accurate!

Map references

The unit of location in the database is the Cassini Grid reference (or Modified British System), the predecessor of the National Grid Reference system in use today. It is the Cassini reference that applies to the map images.

Cassini Grid is used for several reasons; it was the system in use at the time and is obviously that used in the documents and on contemporary military maps. National Grid and modern maps are therefore sidelined, as the Cassini maps are the same that the Army was using.

Crucially, as this is a study of a past landscape, contemporary maps provide a far better idea of that landscape as it was, than is often the case on a modern map.

Grid Reference conversion

A National Grid reference is provided for each listed Cassini reference, generated by one of two methods. Where an area is given a Cassini Grid square (such as Hailsham Nodal Point at wR 02 28) then the National Grid square that best fits the feature according to visual comparison is given.

Where a 6- or 8-figure Cassini reference is available, the National Grid Reference is derived using an automated calculation only - THE NGR HAS NOT BEEN VERIFIED OR CORRECTED BY FIELDWORK! It is not intended to actually provide 12-figure references, although some GPS readings are used for works that are not documented but still survive. DESPro, however, is not intended to solely be a guide to what still survives and how to access it; the aim is to interpret strategy and use of the landscape according to the documents. Therefore, data input according to cassini grid references takes priority and the inclusion of NGRs is simply a convenient by-product made possible by the use of technology.

Ex-Situ Features

Some features may flag a warning about being ex-situ; this applies to moveable structures such as cylinders and buoys that were part of roadblocks. This occurs in records where such features still survive but no roadblocks are documented at that location. The 1941 Roadblock Report lists 473 locations, but numerous others are known to have been established prior to and after the report and some features regarded as ex-situ may coincide with these.

Proposed Features

Documents regularly indicate unbuilt structures; some features may only have been proposed and never built, for example, roadblocks. Sometimes the records subsequently confirm the construction went ahead, but in other cases missing documents and/or lack of other evidence means we can only guess as to whether the feature was actually built. In such cases, database records will carry the 'proposed' status until such time (if ever), the question is resolved. These cases are always entered into the database because, even if they were never built, they provide an extra insight into policy and perhaps other factors such as labour and materials.

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Access

The Defence of East Sussex Project DOES NOT condone trespassing or invasion of privacy - always ask for the landowner's permission first!

DESPro cannot accept responsibility for any damage or injury that results from use of the information on this website.

Access information is based on common sense, respect for property and pivacy, the presence of fences, signage and footpaths - you should always make your own enquiries before visiting any site and not rely on this information being correct. This information does not imply any right of way or access to any site.

Please remember that although a roadblock site may be on a public road, associated obstacles may be on private property!

The default text "Assumed private property until otherwise known" appears when no specific details are known.

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Defence Hierarchy

This box describes the hierarchy of defence works in terms of 'Parent' and 'Child' where known or reasonable to extrapolate.

The example at right shows how Pevensey Castle has the nodal point as a parent, and has numerous pillboxes and other features as its children.

This information can be onerous to record, but is vital in establishing relationships between defence works. In such a large database, it is also an efficient means of working your way down to pillbox/slit trench level from, say, a Company Locality.

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Neighbouring Features

An important aspect of the Project is not to list and view defence works in isolation, but to interpret them in relation to the landscape and each other.

Therefore, when viewing any record in the database, any other features that are listed as being in the same grid square are returned in order to indicate what else is going on in the locality. The grid references listed can be used in conjunction with the mapping tools.

Dating features

It should be noted that the Age column is simply the date of the earliest source that mentions the feature.

For example, some roadblocks are dated 1943, but this is only because they are first mentioned in documents that describe their removal; most were probably erected in 1940.

Where surviving evidence only applies, a question-marked date of 1940 is used.

All of these dates will change as more sources are added to the database.

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Incident Log

Part of the Project is to summarise War Diary entries; this is an ongoing exercise but many events such as air raids, bomb incidents, aircraft crashes, training exercises, road traffic accidents etc. are being assigned location data where known. This allows them to appear in the Incident Log for the current grid square.

It should be noted that where only a town is given, e.g. "Incendiary bombs dropped on Bexhill", the incident will be repeated across multiple squares that cover the town. Unfortunately, the incidents may contain military jargon and abbreviations for which it is not yet possible to provide a glossary.

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Map Tools

This section looks complicated, but it is actually quite simple! Every record will display a map tile containing the grid square in question. Above it is a movable Romer, which is a graduated scale that aids more accurate map-reading.

The eight main compass points are links that allow you to jump into neighbouring squares to see if there's anything there.

The romer allows you to read on the map where the current feature or other defences listed in the Neighbouring Features box are located.

The image at right should help explain how to use the romer; simply click and drag it until it is over the map. The romer will remain wherever you leave it; refreshing the page will return it to its starting location.

The current grid square is the most complete one visible; at this time the image is generated using a rough formula so the actual square may not be fully visible. The formula is being developed to reduce the chances of this happening.

The Romer has been dragged over the main square and is carefully positioned at grid reference wR 085 233. Note how the '5' and the '3' coincide with the easting and northing lines respectively. The red triangle points to the feature in question.

Accuracy

It should be noted that at this scale, six-figure grid references are not very accurate and that references given in documents are sometimes calculated using a romer and sometimes simply judged by eye.

The accuracy of six-figure references is shown in the example; wR 085 233 is the correct reading for the railway halt (orange circle in centre), even though the red triangle on the romer is not actually on it. This is because references are supposed to be given to the nearest line to the west and south of the feature. An eight-figure reference for the halt would be wR 0855 2335. However, while some documents would give the halt's location as wR 085 233 (correctly), in others the same feature might be given as wR 086 234, as this is seemingly closer. This however, puts the triangle on top of the feature, and not pointing to it.

An example of an inaccurate reference is seen at left: the red triangle in the sea is actually the given location of a roadblock!

It should actually be 100m further north on the road itself. It is ironic that this reference was actually included in the Roadblock Report, part of the purpose of which was to check grid references and provide more accurate ones!

This gives an indication of the looseless with which some grid references you may encounter are recorded. In some cases I have corrected transcription errors, but most will be as given in the documents. I'm aware that they're not all very accurate, but I have no plans to undertake a large-scale revision of them.

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