Throughout World War II Air raid shelters were installed across the UK. These varied from large public shelters built with bricks and reinforced concrete through to small private shelters using corrugated steel panels*. Many of these were removed after the war, however, others remain buried and are often encountered during construction works.
*In 1938, Anderson shelters were given free to families earning less than £5 per week. If you earned £5 or more it would cost you £7. Within months, one and a half million Anderson shelters were distributed to people living in areas expected to be bombed.
Whether a small back garden or a large brown field site, SUMO can conduct a geophysical survey to locate these buried structures before any construction work takes place.
The most suitable method to locate the position of a shelter, depends as much on the site conditions as it does upon the shelter construction itself. If the search area is large, it would be necessary to narrow this down, to allow the targeting of smaller areas with detailed methods. This may be achieved by carrying out a rapid magnetic survey, which is quick and cost-effective, and then targeting magnetic anomalies with Ground Penetrating Radar (GPR), a high-resolution technique which gives depth information to the top of the shelter, as shown in the examples below.
Above: Example GPR radargram (section view). The planar feature at the end is representative of an air raid shelter.
Above: Interpretation of GPR data with probable air raid shelter marked with an in green hatch and possible further shelters marked in brown hatch.
Above: GPR Timeslice (plan view) showing an air raid shelter in the south east of the site at c. 0.75m depth. A pipe or service is also seen running through the site.
Geophysical Engineering Surveys
Air Raid Shelters
Cellars & Basements
Post Tension Cables
Underground Storage Tanks
Air Voids
Chimney Flues
Rebar
Water Engineering
Badger Setts
Earthing Installations
Sinkholes
Burials
Geological Application
Soil Thermal Resistivity Testing
Buried Foundations
Landfills
Structural Investigations
Buried Manholes
Mineshafts
