Genghis the Engineer
24th Aug 2002, 18:32
A couple of days ago I was on my way into Lydd for lunch, a first visit (and I recommend the German sausages on the menu).
Under the downwind leg, which was to the South of the runway were two rather strange parabolic concrete structures, sat on an island in the middle of a lake. One was 2-dimensional (constant in the vertical plane), the other was 3-dimensional. Both were pointed out to sea, approximately in the direction of what is now Dungeness power station.
Being a nosey so and so, and also fancying a stroll after my lunch, I asked in the club about them. It turns out that these devices date back to WW1 and were listening stations for Zeppelins - the parabola focussed sound onto one spot, where an observer could hear the distinctive drone of the engines in plenty of time to alert coastal defences.
Sadly, the local geography (and the fact that they're apparently within the airfield perimeter) prevented me walking out to them to take a look more closely. But, they have rather grabbed my imagination, so a couple of questions for the history buffs amongst you...
(1) Are these the only ones, or are there more on the coast somewhere?
(2) If there are any more, can they be visited?
(3) Can anybody point me at any published history on the subject?
Below is a picture I managed to take of the device.
G
http://www.btinternet.com/~guy.gratton/Lydd_s.jpg
Postscript: After a web search, I now know that the devices are called "Sound Mirrors", and there's a write-up about them at http://www.ttforumfriends.com/historysoundmirrors.htm Still fascinating, and anything anybody can add, I'll be interested anyway.
Under the downwind leg, which was to the South of the runway were two rather strange parabolic concrete structures, sat on an island in the middle of a lake. One was 2-dimensional (constant in the vertical plane), the other was 3-dimensional. Both were pointed out to sea, approximately in the direction of what is now Dungeness power station.
Being a nosey so and so, and also fancying a stroll after my lunch, I asked in the club about them. It turns out that these devices date back to WW1 and were listening stations for Zeppelins - the parabola focussed sound onto one spot, where an observer could hear the distinctive drone of the engines in plenty of time to alert coastal defences.
Sadly, the local geography (and the fact that they're apparently within the airfield perimeter) prevented me walking out to them to take a look more closely. But, they have rather grabbed my imagination, so a couple of questions for the history buffs amongst you...
(1) Are these the only ones, or are there more on the coast somewhere?
(2) If there are any more, can they be visited?
(3) Can anybody point me at any published history on the subject?
Below is a picture I managed to take of the device.
G
http://www.btinternet.com/~guy.gratton/Lydd_s.jpg
Postscript: After a web search, I now know that the devices are called "Sound Mirrors", and there's a write-up about them at http://www.ttforumfriends.com/historysoundmirrors.htm Still fascinating, and anything anybody can add, I'll be interested anyway.