{"id":14,"date":"2009-03-01T17:32:03","date_gmt":"2009-03-01T17:32:03","guid":{"rendered":"\/soundmirrors\/?page_id=14"},"modified":"2018-03-27T19:44:49","modified_gmt":"2018-03-27T18:44:49","slug":"denge","status":"publish","type":"page","link":"https:\/\/www.andrewgrantham.co.uk\/soundmirrors\/locations\/denge\/","title":{"rendered":"Denge sound mirrors"},"content":{"rendered":"

Spectacular remnants of a dead-end technology, the three concrete “listening ears” at Denge near Dungeness in Kent are the best known of the various early warning acoustic mirrors<\/a> built along Britain’s coast<\/a>.
\n<\/em><\/p>\n

\"[Photograph<\/p>\n

\"[Dungeness<\/a><\/p>\n

The only way<\/strong> of seeing the Denge sound mirrors close up is during one of the public open days run by the RSPB. There is no public access<\/strong> to the Dungeness mirrors, which are in the middle of a disused gravel pit. Contact the RSPB for the dates of future open days.<\/p><\/blockquote>\n

A forerunner of radar, the sound mirrors were intended to provide early warning of enemy aeroplanes (or airships) approaching Britain across the English Channel. They did work<\/a>, but the development of faster aircraft made them less useful, as an incoming aircraft would be within sight by the time it had been located. Increasing ambient noise made the mirrors harder to use successfully, and then radar rendered acoustic detection redundant.<\/p>\n

\"Aerial<\/a><\/p>\n

There are three different designs of sound mirror at Denge; the 200′<\/a>, 20′<\/a> and 30′<\/a> sound mirrors.<\/p>\n