Acoustic early warning systems, spectacular remnants of a dead-end technology on the British coast
Following from an open day on 8 July 2012, there is a free non-booking guided walk out to the Denge sound mirrors on the afternoon of Sunday 12 August.
The RMCP events are the only way to visit the Denge mirrors. The walks are very popular, and well worth doing.
Full details from the Romney Marsh Countryside Partnership website. Anyone planning to attend should confirm details with the RMCP before travelling.
At the weekend I went to see some new sound mirrors in a park at Kew in west London.
Kent-based science fiction and fantasy gaming supplier Brigade Models is producing some 1/1200 models inspired by the Denge sound mirrors.
They are designed for Aeronef, a form of wargaming based on “an alternate history in the late 19th Century when the aircraft has been invented several decades earlier than the Wright Brothers actually managed. The nations and empires of the world battle for supremacy of the skies in giant aerial ships known as Aeronefs, lighter-than-air dirigibles (‘Digs’) and small fighter and bomber aircraft.”
Tony Francis of Brigade Models tells me that while the models are based on the Denge sound mirrors they are are not exact replicas; he worked from photos and satellite images to produce something that looked roughly right. “Although they are really First World War technology rather than late 19th century, we’ve appropriated them as being ideal for our Victorian science-fiction alternate history games”, he explains.
The 200 ft mirror comes out at about 50 mm long, while the two small ‘ears’ are about 10 mm. They are produced in pewter from masters which were created using a 3D modelling package and 3D printing.
For more details of availability and how to order, see the Brigade Models website.
“Vergessene Technologien – Riesenohren aus Beton” (Forgotten technologies – Giant ears of concrete) is a 23 May 2011 German-language article by Solveig Grothe on the website of Spiegel. It has a history of sound mirror development between the wars, and features some photos of sound mirrors from the Sound Mirrors Flickr group (used with the permission of the photographers).
With reinforced concrete shells the size of a house, the British listened in the 20s and 30s for enemy aircraft. The acoustic experiments along the coast gave the island extraordinary architectural monuments – and an interception technique to which was used to the outbreak of World War II.
Und jetzt, die artikel auf Englisch: Listening for the Enemy, Giant Ears on the British Coast
Planned dates for public access to the Denge sound mirrors in 2011 have been announced on the Notice Board section of the Romney Marsh Countryside Project website.
There is one open day this year, and two guided walks. These events don’t need to be booked and are free, but rely on donations to cover the costs with at least £2 per person suggested.
More information at the RMCP website. Anyone planning to attend these events should obviously confirm details with the RMCP before travelling.
Remember, the RMCP events are the only way to visit the Denge mirrors. The walks are very popular, and well worth doing.
A sound mirror installation neat Slaithwaite in Yorkshire. Some pictures of it.
Commissioned by the River Colne Sculpture Trail and Huddersfield Contemporary Music Festival
A Sound Installation by Matthew Sansom
About
Colne Valley Listeners employs active listening, both as metaphor and as practice, to explore and enhance the relationship between the valley’s beauty and significance with people past, present and future. The project combines a sculptural installation of two acoustic mirrors at the Rotcher Picnic Site and a guided soundwalk with accompanying audio.
The River Colne Acoustic Mirrors are parabolic dishes fashioned in aluminium: one dish eavesdrops on the approach from the picnic site and the other listens out towards the trees and across the valley. Close-up, these devices focus and subtly amplify the soundscape at a focal point a short distance from the centre of the dish. Interaction with the acoustic mirrors helps direct awareness towards the surrounding soundscape, leaving a subtle perceptual imprint on the listener.
The River Colne Soundwalk explores the location of the sculptural installation. It combines material from local children’s sonic explorations of the area, sound archive material and location recordings made along the walk.
Sound effects is a 20 August 2010 posting about the Kilnsea sound mirror at Mike Higginbottom’s Interesting Times website.
Among the First World War fortifications that protected eastern England from the German threat is a curious lump of concrete in a field north-west of the Godwin Battery on the coast at Kilnsea on the way to Spurn Point. This enigmatic piece of concrete is an acoustic mirror …
Sounding Out Liverpool
Artist: Matthew Sansom
Location: St James’ Mount, Anglican CathedralGiant ‘sound mirrors’ tempt viewers to listen to the city through the artwork, which amplifies the continual flowing soundscape of the city and its inhabitants.
This artwork invites you to entertain and play, bounce your own stories, jokes or poems off the sound mirror, or recite extracts from the films, books and entertainers of Liverpool, whose words are etched on the surrounding ground.
It is open 14th-18th February 2011 (11.00-3.00pm) and 21st–25th February 2011 (11.00-3.00pm).
Sound and Vision at Walking Class Hero: These other worldy concrete structures are the remains of part of an acoustic early warning system that was designed to detect engine sounds from approaching aircraft. ‘Staccato signals of constant information‘ as Paul Simon sings from another time
Another very popular walk, it seems: I stopped estimating at 150
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Listening Vessels consists of two large parabolic reflectors set at least 50 feet apart which act as mirrors to reflect sound from one to the other. Two people sit opposite each other at approximately the focal point for each reflector, so that the sound coming from each reflector is focused at this point, allowing each visitor to clearly hear the other’s voice, even at a very low decibel in spite of the distance separating the vessels.
Source: The Exploratorium