Site of Second World War floodlight, Moulsham Lodge, Chelmsford (EHER 20894)

Now destroyed. The site of a Second World War floodlight and generator building which can be seen in an aerial photograph from August 1946. 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.

1997. Trial trenching. Geophysical survey recorded a small circular feature which was possibly part of the town's defences during the Second World War. The Second World War feature (Feature 27) was recorded in three trenches (G, H and I) and is possibly the remains of a gun replacement or a setting for a search light. <1> January 2005. World War Two Defences in Chelmsford survey: site visit and desktop research. An aerial photograph taken in August 1946 shows an experimental 'floodlight' standing on grassland to the south-east of Moulsham Lodge. The base of its generator building can be seen a few yards away to the west. <1> The greater part of this area has now been built on and clearly nothing of the floodlight site now remains. Its approximate position is where No. 74 Waterson Vale now stands. <2> 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. <3> <4> 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. <5> <6> The project was termed 'Silhouette'. <7> See EHER 20565 for details of the only known remaining example of a Second World War floodlight from this experiment in Essex.