It's "What's This?" Time Again

Perhaps the top of a missile silo or of a farm silo.

Reckon you've got it.

Probably somewhere along the Kent coast.

Nice call. I was thinking something acoustic too but I never would have guessed they were used for plane detection. Really cool.

Out west somewhere I remember a natural formation that had the same effect. The Indians considered it to be sacred because of all the things they could hear in it.

You nailed it.

Some additional information. http://www.damninteresting.com/?p=12

and http://www.24hourmuseum.org.uk/nwh_gfx_en/ART17649.html

Dan W.

http://www.castlekas.freeserve.co.uk/sound_mirrors.htm

Interesting. I never found out how effective they were. All the books or articles say was that radar made them obsolete but no mention of the success rate. If they were built beginning in the 1920s up until World War II (20 years later), they must have had some usefulness to have lasted that long.

Actually, they weren't that great at all. The Germans experimented extensively with these devices, and realised they were of limited value too. But the British, being the very smart bastards that they are, kept this program alive, even after the advent of radar, (top secret program). For a while, they fooled the the Germans into thinking their early warning system was based on these listening devices. So the Germans would bomb them. The rest is history. Sneaky freeking British.

The US gave it a try too, in stereo:

With some gear like that, and a good diet of carrots, hostile aircraft had no chance!

Wow! That's one big hearing aid!

Sort looks like the "stretch" stereo version of the hearing aid that the villian used in the movie The Wild Wild West ( Will Smith & Kevin Kline )

There was a program on BBC a couple of months ago (ish), where they tried one out, I think it was this one:

... with a prop plane flying across the Channel from France. It certainly works!

I tried a few quick searches, but couldn't find it - I'll try again later if I get a chance (up to the eyeballs at present).

Yup, they did give them a precious few minutes warning.

If interested, check out this site:

http://www.dself.dsl.pipex.com/MUSEUM/COMMS/ear/ear.htm

That looks like the one at Denge in Sussex, just up the coast from me. There's a website about them here. There's also a new one on the Military canal outside Rye with an ear & a speaking place so that visitors can experience th effect. The science park at the old Royal Greenwich Observatory at Herstmonceux has a large parabolic reflector to demonstrate the same thing.

Someday these might be listed alongside Stonehenge as "mysterious" artifacts from a lost empire.

Along the same vein...

This dish was part of the microwave based inter-station communication system that used to link the stations of the D.E.W. line to each other. This equipment has been replaced by satellite technology.

That brings back many memories. I was stationed at Ft Yukon AFS, Alaska, in 1974-75. We had a couple of these. They relayed all our comunications. It was part of what was called the WHITE ALICE system. I have no idea what WHITE ALICE stood for.

I think White Alice was a series of radio communication antennas rather than acoustic devices. Wiki has a page here.

Maybe they can be recycled for the X Games. Leapin' motorcycles!

Build a ramp leading in, and maybe you could barrel-roll the bike out the top edge, hitting the ground heading back the way you came in. That would put that new wall-climbing sport (can't remember the name for some reason) on a whole new footing.

And be a WAY cool way to kill yourself, to boot.

Mike

Deleted by author

I once saw one on Malta, listening towards Sicily.

It was flat, around 1 or 2 m high and 20 or so meter long.

Situated in a region with "no" disturbing noise it was said to have detected the starting planes 200km away.

RHABE

I feel that it might be one of the various acoustic locator dishes set up in the UK. It looks similar to the one somewhere in Kent, built in 1928... a sort of pre runner to Radar......never seen them, but I have read about them....There is a web site with pictures at:-

Acoustic Locators

Having looked at a picture of the one in Kent on the web site, it is similar but not the same.

How far from the truth am I?

True, but I only read #4 after I had posted. Also surely great minds think alike?

..........just a big ear!!!!!

EARLY RADAR TYPE LISTENING DEVICE FROM WW 2 IN ENGLAND

I'm sure I already answered this one, Bricky. If it wasn't so cold, I'd walk over and get you another pic. Rear view or side view ?