Individual mirrors

Modern technology at Maghtab

Posted on by Andrew Grantham

Maltese telecoms firm GO has updated the kit at its Maghtab site, by the sound mirror:

In comments, [Prime Minister] Dr Gonzi said the Maghtab headend site was symbolically important because of the sound mirror, a primitive radar built some 70 years ago to detect and amplify the sounds of air and sea vessels nearing Malta.

This is the only sound mirror built outside England but became outdated within three to seven years since being built because it was replaced by radars.

Dr Gonzi said that even nowadays, major investment in technology became outdated quickly and companies needed to continue investing consistently.

GO fully equipped to transmit English and Italian football, Annaliza Borg, The Malta Independent

Hythe sound mirror walk

Posted on by Andrew Grantham

As well as the walks to the Denge mirrors, there is one to the Hythe sound mirror this year.

Sunday 4th July 2.00pm
SOUND MIRRORS AT HYTHE

A chance to walk up the steep grassy escarpment to the 30ft Concrete Mirror or Sound Dish on The Roughs at Hythe. One of the Mirrors has fallen down and the other is surrounded by fencing, but the views are wonderful. Donation appreciated.

Full details at the Romney Marsh Countryside Project website.

Photos of 2004 Denge sound mirror guided walk

Posted on by Andrew Grantham

Hywel Williams took some photographs on a guided walk to the Denge sound mirrors on 4 August 2004: Denge Sound Mirrors – “The Listening Ears”.

I could hear the little steam train pass across in front of me off the sound mirror, GREATLY magnified in sound and apparently in the mirror direction it was traveling. Clearly not a demonstration of aeroplane detection, but also a clear demonstration that these concrete mirrors still work, nearly 80 years after their experimental construction!

Ooo, I’m in one of the photos!

Hywel also has a rather good site about Disused stations on London’s Underground.

Denge mirrors at Exploring Kent’s Past

Posted on by Andrew Grantham

“Acoustic Sound Mirrors at Greatstone-on-Sea, Lydd” at Kent County Council’s Exploring Kent’s Past.

The remains of three large concrete structures, formerly an anti-aircraft Acoustic Detection installation. Microphones were attached to the three reinforced concrete structures in order to pick up the sound of approaching enemy aircraft. The smallest ‘sound mirror’ was found to be fairly ineffective so it was superseded by a larger dish, 12 m in diameter. This in turn was replaced by a 70m long ‘sound wall’. The structures were built by the RAF between 1930-4. They were rendered obsolete by the introduction of radar in 1935, and by advances in aerial technology.
Source: Exploring Kent’s Past

Kent History Forum photos

Posted on by Andrew Grantham

Sound mirrors on the Kent History Forum. There is lots of other good stuff on the site, too.

  • Abbot’s Cliff. Including an aerial photo.
  • Denge. on the last official walk … there was round 300 hundred of us.
  • Fan Hole, near Dover.
  • Hythe.
  • Joss Gap (Kingsgate). Joss bay had two sound mirrors one being a slab, this was cut into the cliff near by the castle keep hotel , now replaced by flats.a slight indentation can still be seen near the top of the cliff. Checking the site where the round mirror was, which was a timber frame rendered. a few years ago the telephone cable blocks were still in place.
  • Warden Point. With a good 1978 photo of it about to go over the cliff.