Friday, April 10, 2009

The "elephant cages"

The "elephant cages":
Elephant cages are what they called or in normal terms the Wullenwebers or the FLR-9 antennas (the original name introduced by Dr. Hans Rindfleisch was Wullenwever). I talk about the circularly disposed antenna arrays built by the United States during the 1960s. These are large circular antenna arrays used by the military to triangulate radio signals for radio navigation, intelligence gathering and search and rescues. Because of the immense sizes (370 meters in diameter and 40 meters high) and huge circular reflecting screens, the antennas are colloquially known as the elephant cages. In total there are 8 of these huge FLR-9 antennas build, spread over the world. They were constructed at:

-Augsburg, Germany. This one is not in use anymore:



-Chicksands, United Kingdom ( not in use anymore):



-Clark AFB, Philippines. As you can see in the picture below this elephant cage has been converted to a 35,000-seat fabric-covered amphitheatre:


-Elmendorf AFB, Alaska. This one is still operational:


- Karamursel, Turkey. This one is already overgrown by vegetation and is the least visible one. It looked identical as the other ones.

- Misawa, Japan. This antenna is still active also:


-Ramasun, Thailand (This one is not visible in google maps in highress).

-San Vito dei Normanni, Italy:



As you can see in the pictures above all of these antennas excist of two major rings of HF antennaes. The outer ring is for monitoring shorter HF wavelengths and is is about 370 meters in diameter and contains some 120 sleeve monopoles. The inner ring is for monitoring Longer wavelength signals, and is typically some 100 meters in diameter with some containing 40 folded dipoles. A horizontal ground screen about 400 meters in diameter surrounds the entire site. The station's intercept operators work in an operations building in the center of the array.

1 comment:

  1. There is one on the beach in San Diego right by the Mexican border. I just saw it. News reports it will be disassembled soon.

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