The Wullenweber Array (CDDA): An Era Of Intelligence Gathering

The Wullenweber was a monster sized antenna invented by Dr. Hans Rindfleisch, which was informally called the elephant cage. The elephant cage or Circularly Disposed Dipole Array (CDDA), was circular and was used for spying. Was the elephant cage antenna the predecessor of HAARP?

The elephant cage was used by the US military for intelligence, but was originally developed by the German Navy. It was very large, expensive, and impractical for the average amateur radio operator.

“Professor Edgar Hayden, then a young engineer in the University of Illinois Radio Direction Finding Research Group, led the design and development of a large Wullenweber array at the university’s Bondville Road Field Station, a few miles southwest of Bondville, IL. The array consisted of a ring 120 vertical monopoles covering 2-20 MHz. Tall wood poles supported a 1,000-foot-diameter circular screen of vertical wires located within the ring of monopoles. Due to their immense size, the location of the array (40.0494°N 88.3807°W) and the other post-war arrays are clearly visible on the internet.”

Edward C. Jordan participated in nine books and published numerous articles. His popular textbook, Electromagnetic Waves and Radiating Systems, was first published in 1950.

Jordan’s follow-up book was Electromagnetic Waves and Radiating Systems Second Edition.

Wullenweber research lasted for more than 25 years and the US Navy constructed systems around the world.

“The ring of poles is an elaborate radio antenna system that was developed for the US Navy in the 1950’s and 60’s by the Electrical Engineering Department of the University of Illinois in the farmland a few miles southwest of Bondville, about five miles west of Champaign, Illinois. Following the completion of the University’s development work, the Bondville installation, known as the Bondville Road Field Station (BRFS), was abandoned in approximately 1980, partially dismantled in the 1990’s, and in 2003, was completely dismantled.”

The Elephant Cage Timeline

  • In the early 1940’s,  the first Wullenweber was built in Skisby, Denmark (57°28′39″N 10°20′04″E).
  • In 1947, Dr. Rolf  Wundt, another German antenna researcher, arrived in New York to work for the US Air Force, and afterwards the GT&E Sylvania Electronics Systems. He was one among hundreds of German scientists taken to the US after the war, under a special US program called Operation Paperclip.
  • In the 1950’s, at least 30 Krug (Russian for circle) arrays were installed all over the Soviet Union and allied countries, before the US developed its own. At least 4 were installed near Moscow (55.46408°N 37.3698°E).
  • In 1959, the US Navy contracted with ITT Federal Systems to deploy a worldwide network of AN/FRD-10 HF/DF arrays based on lessons learned from the Bondville experimental array.
  • In 1959, a contract to build a larger Wullenweber array—the AN/FLR-9 antenna receiving system—was awarded by the US Air Force to GT&E Sylvania Electronics Systems, which is now General Dynamics.
  • In 1962, the FRD-10 at NSGA Hanza, Okinawa was the first installed (followed by eleven additional arrays).
  • In 1962, the first FLR-9 was installed at RAF Chicksands (52.0443°N 0.389182°W) in the UK. (Dismantled in 1996.)
  • In 1962, the second FLR-9 was installed at San Vito dei Normanni Air Station, Italy (40°38′46″N 017°50′25″E). (Dismantled in 1993.)
  • In 1964, arrays were installed at NRRF in Imperial Beach, CA.
  • In 1966, the AN/FLR-9 was installed in Elmendorf AFB, Alaska.
  • In 1966, the AN/FLR-9 was installed in Karamursel AS, Turkey.
  • In 1968, US Army to build AN/FLR-9 system at USASA Field Station in Augsburg, Germany.
  • In 1968, US Army to build AN/FLR-9 system at Camp Ramasun in Udon Thani Province, Thailand.
  • In 1969, a pair of FRD-10s (not equipped for HF/DF) were installed at NAVRADSTA(R) Sugar Grove for naval HF communications, replacing the NSS receiver site at the Naval Communications Station in Cheltenham, MD.
  • In the 1970’s, the Japanese government installed two large Wullenweber arrays at Chitose and Miho.
  • In 1971, the last two FRD-10 HF/DF arrays were installed for the Canadian Forces in Gander, Newfoundland and Masset, British Columbia.
  • In 2006, the Hanza array was decommissioned.