Site of Second World War searchlight emplacement, South of Sudbury Road, Downham (EHER 20869)

Now destroyed. The site of a Second World War floodlight and generator building, the concrete base of which can be seen in an aerial photograph from June 1960. The floodlight was probably constructed between 1936 and 1940 as part of an experiment to light up the night sky with a grid of large, fixed 'floodlights', as a defence against German bombers. The experiment, termed 'Silhouette', failed as the network of floodlights acted as a navigational aid for the enemy aircraft, and it was subsequently terminated in March 1940. When visited in 2005, nothing of the floodlight or the generator building remained.

January 2005. World War Two Defences in Chelmsford survey: site visit and desktop research. An aerial photograph taken in June 1960 shows the outline of the base of an experimental 'floodlight' in a field to the south of Sudbury Road. The base of its generator can be seen to its south-west. The experiment was abandoned in 1940 and by this time the steel superstructure had clearly been dismantled, leaving just the concrete bases. The site is further identified in a letter to 'Essex Countryside' dated May 1992. <1> <2> Nothing of it now survives, however, and the area is an open, grassy field. <3> During the late 1930s/early 1940s (probably 1936-1940), an experiment was conducted to light up the night sky with a grid of large, fixed 'floodlights', as a defence against German bombers. Each installation consisted of a steel enclosure, 50 feet across, in which the floodlight was mounted, surrounded by twelve large mirrors angled towards the sky. Information on the experiment is still scarce; an enquiry to the Imperial War Museum has been unsuccessful. Enquiries by Mr F. Plume at the Public Record Office (PRO) in 1992/1993 have resolved some of the questions. <4> <5> A map drawn by Mr Plume in 1999, from his earlier investigations, shows 50 sites in Essex, located in an area from Little Leighs in the North to Eastwick in the South. It is not known whether this was the complete grid (although one floodlight is known to have been sited at Dovercourt, EHER 10715) or whether the experiment overlapped to other counties. The experiment was not a success - it is said that the light reflecting from the clouds lit up the countryside as a perfect navigational aid for the bombers, and the work was terminated in March 1940. <6> <7> The project was termed 'Silhouette'. <8> See EHER 20565 for details of the only known remaining example of a Second World War floodlight from this experiment in Essex.