Bedford Borough archaeological survey to National Mapping Programme standards
There are proposals and plans for major changes and developments in Bedford Borough, including large-scale strategic housing allocations, aggregate extraction, waste management, renewable generation sites and areas identified for large-scale landscape regeneration. A better understanding of the historic environment will inform decisions on these plans at a strategic level. The Bedford Borough project will bring together information from recent aerial photographs, airborne laser scanning (lidar) and historic aerial images into an interpreted archaeological map. This will show details of the form and extent of subsurface archaeological sites revealed as cropmarks, and also archaeological remains seen as earthworks, structures and buildings. This will be incorporated into the Bedford Borough Historic Environment Record where it can be used with information from other sources.
Discoveries new and old - cropmarks
Oblique aerial photography by Historic England in Bedfordshire recorded significant numbers of previously unrecognised archaeological features visible as cropmarks. The cropmarks mainly indicate the buried remains of ditches defining settlement enclosures, fields, tracks and boundaries. Most are thought to date to the Iron Age or Roman periods although some may have earlier origins, and others almost certainly continued into the post Roman period. By mapping these remains we can provide a framework for a better understanding of the date and function of these extensive and complex remains over large areas. Our systematic approach also provides information on geographic and thematic gaps in our knowledge and where we may need to apply other survey techniques.
New discoveries were also found on the older aerial photographs in the Historic England Archive. Bowells manor is known from documentary sources to be near Bromham village. RAF vertical aerial photographs taken in 1947 show cropmarks of the buried remains of a subrectangular moat, in a field known as Bowells Close, almost certainly associated with the site of the manor house. This was the clearest image of this rediscovered moat compared to aerial photographs taken in subsequent decades, highlighting the importance of looking at the historic aerial photo collection.
The benefits of lidar
It is good practice to include as many sources as possible in aerial investigation projects. The ready availability of airborne laser scanning data (lidar) and free software for processing mean it is a standard part of the archaeologist’s toolkit. Where available, Environment Agency lidar was a major source of accurate georeferenced information for archaeological earthworks.
For example, the earthworks of an Iron Age hillfort and a medieval moat were recorded on lidar within the heavily wooded Mowsbury Hill north of Bedford. The image below shows how processed lidar data has stripped away the tree cover to show the Early Iron Age fortifications and overlain by the medieval moat. The earthworks of tees, greens and bunkers of the adjacent golf course are also recorded by the lidar data. This moat is one of over 200 hundred examples known in Bedfordshire and demonstrate how important this expression of manorial power was in the medieval period. Use of lidar data in the Bedford Borough survey identified and mapped several previously unrecognised moats.
Conventional aerial photography continues to play a major role in recording and illustrating archaeological earthworks. In the right conditions, the shadows cast by the sun at low angles reveal even the most subtle surviving ‘lump and bump’. Aerial photographs also give us a good idea of land use, helping us to understand land use and how this affects how we see the archaeological remains. At Medbury Farm, an aerial photograph taken in what appears to be warm evening sunshine, highlights the earthwork remains of medieval ridge and furrow cultivation (part of the former common open-field system), trackways, house enclosures (tofts) and accompanying crofts that suggest a deserted settlement (NRHE 1603127). Most medieval ridge and furrow in the survey area has been ploughed level within reorganised post medieval fields, but small pockets survive particularly around villages and farmsteads, such as at Medbury Farm.
Contemporary and immediate post-war aerial photographs are a great source for Second World War defences. The extensive collection at Historic England’s archive in Swindon provides a detailed pictorial record of Bedford during and after the conflict.
Here is an excellent example of the earthwork defences from a triple searchlight battery, along with its locator and generator posts, a light anti-aircraft gun emplacement and the adjacent military camp for use by its personnel, at Putnoe Farm. These types of Second Word War military installations are often not visible with such clarity, due to being short lived, ephemeral in nature and not being photographed while in use. Post-war residential housing expansion means that most of these features have now been built upon.
The former London Brick Company brickworks at Stewartby included an unusual wartime site. Known as ‘Field 99’, this was an experimental facility to test the effectiveness of air raid shelters and the potential effects of bomb blasts on their human occupants, through the use of unfortunate livestock and other animals. Notable in this vertical aerial photograph is the ring of air raid shelters, startlingly reminiscent of Stonehenge, and the numerous bomb craters around the field.
The noted war artist John Piper captured these same rather dramatic experiments in his 1943 watercolour ‘shelter experiments near Woburn, Bedfordshire’, now held in the Imperial War Museum, London. The artist’s watercolour painting portrays a rather more brooding and sombre location than the sunny aerial photograph suggests, though perhaps not for the hapless doomed livestock.
The project was begun in February 2016 and is scheduled for completion in February 2018.
The images used on this page are copyright Historic England unless specified otherwise. For further details of any photographs or other images and for copies of these, or the plans and reports related to the project, please contact the Historic England Archive.