page_title: Wullenweber
section_title: 1960s & 1970s construction boom and subsequent demolition
hierarchical_section_title: Wullenweber / History / 1960s & 1970s construction boom and subsequent demolition
caption_attribution_description: AN/FLR-9 Circularly Disposed Antenna Array or Wullenweber antenna (popularly referred to as an "Elephant Cage") at Elmendorf AFB, Alaska. It is used for radio direction finding.
context_page_description: The Wullenweber is a type of Circularly Disposed Antenna Array sometimes referred to as a Circularly Disposed Dipole Array. It is a large circular antenna array used for radio direction finding. It was used by the military to triangulate radio signals for radio navigation, intelligence gathering and search and rescue. Because its huge circular reflecting screen looks like a circular fence, the antenna has been colloquially referred to as the elephant cage. The term wullenwever was the World War II German cover term used to identify their secret CDAA research and development program; its name is unrelated to any person involved in the program.
context_section_description: In 1959, the U.S. 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.
  The FRD-10 at NSGA Hanza, Okinawa was the first installed, in 1962, followed by eleven additional arrays, with the last completed in 1964 at NRRF Imperial Beach, CA. (Silver Strand) which was demolished in 2014. Due to their immense size, the location of the Bondville array (40.0494°N 88.3807°W) and the other post-war Wullenweber arrays are clearly visible in high resolution aerial photography now available on the internet.
  Also in 1959, a contract to build a larger Wullenweber array — the AN/FLR-9 antenna receiving system — was awarded by the U.S. Air Force to GT&E Sylvania Electronics Systems (now General Dynamics Mission Systems).
  The first FLR-9 was installed at RAF Chicksands (52.0443°N 0.389182°W) in the United Kingdom in 1962. The second FLR-9 was installed at San Vito dei Normanni Air Station (40.64700°N 17.83900°E), Italy also in 1962. The Chicksands array was dismantled following base closure in 1996 and the San Vito array was dismantled following base closure in 1993.
  A second contract was awarded to Sylvania to install AN/FLR-9 systems at Misawa AB, Japan; Clark AB, Philippine Islands; Pakistan (never built); Elmendorf AFB, Alaska; and Karamursel AS, Turkey. The last two were completed in 1966. The Karamursel AS was closed and array was dismantled in 1977 in retribution for the suspension of U.S. military aid to Turkey. The Clark AB array was decommissioned after the Mt. Pinatubo volcano eruption in 1991. It was later converted into an outdoor amphitheater. Demolition of the Misawa FLR-9 began in October 2014.
  A pair of FRD-10s not equipped for HF/DF were installed in 1969 at NAVRADSTA(R) Sugar Grove, WV (38.5129°N 79.2790°W), for naval HF communications, replacing the NSS receiver site at the Naval Communications Station in Cheltenham, MD.
  The Elmendorf array was decommissioned in May 2016 due to its age and unavailable repair parts.
  The U.S. Army awarded a contract in 1968 to F&M Systems to build AN/FLR-9 systems for USASA Field Station Augsburg, Germany, and Ramasun Station in Udon Thani, Thailand (17.2919°N 102.8682°E). Both were installed in 1970. The Ramasun Station array was dismantled in 1975 following base closure.
  During the 1970s, the Japanese government installed two large Wullenweber arrays, similar to the FRD-10, at Chitose and Miho.
caption: FLR-9 Wullenweber array at Elmendorf Air Force Base, Alaska, USA, completed in 1966.
exif: {}