More than 100 years ago acoustic mirrors along the coast of England were used to detect the sound of approaching German zeppelins.
Joe Pettet-Smith set out to photograph all the remaining structures following a conversation with his father, who told him about these large concrete structures dotted along the coastline between Brighton and Dover.
Source: The concrete blocks that once protected Britain, BBC News, 7 January 2019
An article about sound mirrors by the security and defence editor of the Financial Times.
Forgotten, dilapidated and, in one case, buried by the local council as an eyesore; these smooth, spherical concrete structures known as acoustic mirrors provided the UK with its first early warning system against German air attack during the first world war.
Source: Joe Pettet-Smith’s photographs of the UK’s early warning air defence system, David Bond, Financial Times, 20 July 2018.
It even quotes this website!
Thank you to all 350 visitors who came to support our open day. Good turn out considering this weekends sporting events… The next one is on the 1st September! @RSPB_SouthEast @concreteear pic.twitter.com/ADyMvmMAt4
— Louise Kelly (@LouiseK1192) July 7, 2018
— David Bonney (@isetta_windsor) July 7, 2018
Today they’re usually called ‘sound mirrors’ or ‘listening ears’ – and to a certain sort of person they are one of the holy grails of aircraft surveillance.
The ‘big ears’ of Kent built to keep Blighty safe from European invaders, Sophie Campbell, The Telegraph, 17 April 2018.
There will be two open days at the Denge sound mirrors this year. The open days are scheduled for 10:00 to 15:00 on Saturday 7 July 2018 and Saturday 1 September 2018.
There will be a cash-only charge of £5 per adult, £2.50 per child (RSPB members free).
The open days are generally the only way for the public to access the Denge listening ears close up, although there have also been some photography days, so it might be worth keeping an eye out, if you are seriously interested.
(Please note that andrewgrantham.co.uk has no connection to the open day, the RSPB or anything else! Please check the details with the RSPB before visiting)
A pair of Richter Spielgeräte concrete sound mirrors in a small park on the banks of the River Thames at Kew in west London. Photographs taken on 11 March 2018.
This tweet about the Sunderland sound mirror was a little bit popular!
Delighted to discover Sunderland's sound mirror hidden behind the VW garage in Fulwell. It was built around 1917 to detect Zeppelins after deadly airship attacks on the city in 1916. More info athttps://t.co/Qn1K2qXZ2R pic.twitter.com/H9Wvbwd48d
— Birmingham 81 (@Birmingham_81) January 22, 2018
Kent, UK. Between the World Wars, before the invention of radar, parabolic sound mirrors were used experimentally as early-warning devices by military air defence forces to detect incoming enemy aircraft by listening for the sound of their engines. #drone #dji pic.twitter.com/ncSkWVMcww
— Bryan Bruner (@Therobotarmy1) January 3, 2018
Acoustic Mirror – sketchbook drawing of an acoustic mirror for a current project, also known as a sound mirror, there’s lots of lovely stuff on them here: https://t.co/8Ro14bdA7z #wip #workinprogress #soundmirrors https://t.co/0xTjf86FoM pic.twitter.com/HYovst5Muw
— Brian McHenry (@lostcont) January 20, 2018