Wullenweber Antenna Arrays Page 1 ============================================================================================== Circularly Disposed Antenna Array (CDAA), or Wullenweber Antenna Arrays were also popularly known as "elephant cages", "dinosaur cages", and even "missile catchers". ============================================================================================== AN/FLR-9's Contracted in 1959, the Army and Air Force version of the Wullenweber was the AN/FLR-9 "Flare 9". The AN/FLR-9 design was based on the Wollen-Weber antenna used by the German Navy to allow Admiral Donnitz to communicate with his submarines during WW II. AN/FLR-9's were installed in the 1960's and the 1970's, and were located at: Field Station Augsburg, Gablingen, Kaserne, Bararia, Germany (Army) (1970-1993) Deactivated in 1993. Turned over to the Bundesnachrichtendienst, the German Intelligence Service known as the BND, in 1998. RAF Chicksands, England, UK (1st) (USAF) (1962-1996). Dismantled in 1996. Clark AB, Pampanga Province, Luzon, Philippines (USAF) (1964-1991). Decommissioned in 1991. Converted into a 35,000-seat fabric-covered amphitheatre in 1997. Elmendorf AFB, Anchorage, Alaska (USAF) (1966- ) The Elmendorf site may still be operational. Karamursel AB, Izmir, Turkey (USAF) (1966-1977). Dismantled in 1977. Misawa AB, Aomori Prefecture, Honshu, Japan (USAF) (1964- ) The Misawa site may still be operational. Camp Ramasun, Ban Nong Soong, Udorn, Thailand (Army) (1970-1975). Decommissioned in 1975. Dismantled in 1976. San Vito dei Normanni AS, Brindisi, Italy (USAF) (2nd) (1962-1994) Operational in 1963. Deactivated in 1994. Still standing in 2001. In most cases, there was an NSG Activity co-located as a tenant (Augsburg, Clark, Elmendorf, Karamursel, Misawa, Ramasun and San Vito). ============================================================================================== AN/FRD-10's The Navy's version of the Wullenweber was the AN/FRD-10 or AN/FRD-10A. "Fred 10's" were part of the Naval Security Group's Classic Bullseye HFDF Network. Fourteen (14) Navy AN/FRD-10's were installed at NSG sites, two (2) AN/FRD-10 variants (non-NSG) were installed at Sugar Grove, two (2) AN/FRD-10A's were installed at CFS Gander and CFS Masset and two (2) AN/AX-16 Pusher Antennas (miniature wullenwebers) were installed at Diego Garcia and Keflavik. Also contracted in 1959, the Navy AN/FRD-10's (or FRD-10A's) were installed at NSG Activities and Departments between 1962 (Hanza) and 1967 (Imperial Beach); at the following Naval Security Group locations: Adak, Clam Lagoon, Zeto Point, Aleutian Islands, Alaska (1964-1994) AN/FRD-10A CDAA initial phase of construction began in 1962. Operational in December 1964. Ceased operations in December, 1994. CDAA removed. Property remains under Navy control. Edzell, Angus, Scotland, United Kingdom ( -1997) Ceased operations in September, 1997. CDAA dismantled. Property returned to the UK. Finnegayan, Guam, Marianas Island ( -1999) Ceased operations on December 31, 1999. CDAA was abandoned in place, and remains unused on the property of active NAVCOMTELSTA Guam. Galeta Island, Panama Canal Zone (1965-1995) CDAA was operational on October 23, 1965. Ceased operations and transferred to the U.S. Army in 1995. Operated as remote site by a civilian defense contractor, maintained as an automatic U.S. Coast Guard relay station. Transferred to the Panamania government in 1999. All equipment was removed and only the CDAA and Ops building remained. The Panamanian Government gave the site to the Panamanian Technological Insitute. The antenna was not maintained and there are places where the CDAA has fallen. The CDAA has since been abandoned, but was still partially standing in 2006. Located in the center of a mangrove swamp forest. Hanza, Yomitan, Torii Station, Ryukyu Islands, Okinawa (Ryukyu) Prefecture, Japan (1962-2007) 1st Navy AN/FRD-10A installed in 1962. Ceased operations in June, 1998. The Hanza CDAA and Ops Bldg were demolished/removed in June, 2007. Demolition of the Hanza CDAA took place from March 13, 2007 to June 30, 2007. Eyewitness: CTICS David Hughes, USN (retired) (he lives on Okinawa). Link to photo gallery: http://www.navycthistory.com/okihughes01.html. Homestead, Florida ( -1992) Destroyed by Hurricane Andrew in August, 1992. Imperial Beach, California (1967-2007) Last Navy AN/FRD-10A installed in 1967. Ceased opeations on September 9, 1999. CDAA remains abandoned on property of Navy's Silver Strand Training Complex. Scheduled to be dismantled in 2007. Marietta, Washington ( -1972) 1st Navy AN/FRD-10A to be closed. Ceased operations in March, 1972. Dismantled in 1972. Property reverted to Lummi Indian Reservation. Northwest, Chesapeake, Virginia (1964-2001) CDAA accepted from the contractor on October 25, 1963. Activated in July, 1964. Ceased operations on June 1, 2001. CDAA was dismantled. CDAA Property is now an annex to Naval Support Activity, Norfolk, VA. Rota, Andalucia, Spain ( -2005) Ceased operations in 1993. Dismantled in 2005. Sabana Seca, Toa Baja, Puerto Rico ( -1999) Heavily damaged by Hurricane Georges in 1999. Ceased operations and dismantled in 1999. Property sold and being developed by commercial enterprise. Skaggs Island, Sonoma, California ( -????) Ceased operations on June 18, 1993. CDAA was dismantled. Property to be transferred to the U.S. Fish and Wildlife Service. Sugar Grove, West Virginia (1968-1997 & 2005) Two variants of the FRD-10, without goniometers, built side-by-side for general service ship-shore communications, which were completed on November 6, 1968, and were operational in 1969. These two CDAA's were not operated by the Naval Security Group at Sugar Grove. Both CDAA's have been dismantled. The more northern one was dismantled by 1997, and the 2nd was dismantled by 2005. Wahiawa, Lualualei, Oahu, Hawaii ( -2005) Ceased operations on October 4, 1998. Dismantled in 2005. The Wahiawa CDAA was removed in September 2007 to make way for new buildings of the Hawaii Regional Special Operations Center (HRSOC). Winter Harbor, Maine ( -2001) Ceased operations in 1998. CDAA was dismantled in August, 2001. CDAA property officially transferred to U.S. National Parks Service in June, 2002. =========================================================================================== AN/FRD-10A's in Canada Gander (CFS), Newfoundland, Canada (1971- ). Operational in July, 1971. In July, 1997, CFS Gander stood down and was redesignated CFS Leitrim Detachment, Gander. CFS Gander is now under remote control from CFS Leitrim, Ontario. CDAA still operational? Masset (CFS), Graham Island, Queen Charlotte Islands, British Colombia, Canada. (1970- ) AN/FRD-10 completed by December, 1969. Opened on February 13, 1970. In April, 1997, CFS Masset stood down and was redesignated CFS Leitrim Detachment, Masset. CFS Masset is now under remote control from CFS Leitrim, Ontario. CDAA still operational? CFS = Canadian Forces Station =========================================================================================== AN/AX-16's Miniature Wullenweber CDDA AN/AX-16 Pushers: Diego Garcia, British Indian Ocean Territory (BIOT) The Navy maintained a miniature Wullenweber CDDA AN/AX-16 Pusher at Diego Garcia. Keflavik, Iceland (1979-1994) The Navy maintained a miniature Wullenweber CDDA AN/AX-16 Pusher at Keflavik, Iceland Operational in the summer or 1979. Ceased operations in 1994. The AN/AX-16 Pusher is a 2-band Wullenweber Circularly Disposed Dipole Array (CDDA) HFDF collection system, which is a miniaturized version of the Navy's AN/FRD-10 antenna. Used primarily where space is a premium, the outer ring of elements is about 400 feet in diamter, half the diameter of the AN/FRD-10. =========================================================================================== Photo Sources and Links: AN/FLR-9 http://www.fas.org/irp/program/collect/hfdf.gif AN/FRD-10A at CFS Masset http://www.mapability.com/ei8ic/rhombic/wullen.jpg Demolition of the Hanza CDAA. Many more photos at: http://www.navycthistory.com/okihughes01.html Link to: Sabana Seca AN/FRD-10A damaged by Hurricane Georges in 1999: http://www.navycthistory.com/images/Georges.jpg =========================================================================================== Wullenweber Antenna Arrays Page 2 =========================================================================================== The Wullenweber (the original name introduced by Dr. Hans Rindfleisch was Wullenwever) is a type of Circularly Disposed Antenna Array (CDAA) sometimes referred to as a Circularly Disposed Dipole Array (CDDA). It is a large circular antenna array used by the military to triangulate radio signals for radio navigation, intelligence gathering and search and rescue. Because of its immense size and huge circular reflecting screen, the antenna is colloquially known as the elephant cage. Wullenwever was the World War II German cover term used to identify their CDAA research and development program, its name is unrelated to any person involved in the program. Wullenwever technology was developed by the German navy communication research command, Nachrichtenmittelversuchskommando (NVK) and Telefunken during the early years of World War II. The inventor was NVK group leader Dr. Hans Rindfleisch, who worked after the war as a Technical Director for the northern Germany official broadcast (Norddeutscher Rundfunk - NDR). Technical team leaders were Dr. Joachim Pietzner, Dr. Hans Schellhoss, and Dr. Maximilian Wächtler. The latter was a founder of Plath GmbH in 1954 and later a consultant to both Plath and Telefunken. Dr. Rolf Wundt, a German antenna researcher, was one of hundreds of German scientists taken to the U.S. by the Army after the war under Operation Paperclip. He arrived in New York in March, 1947 on the same ship as Wernher Von Braun and his wife and parents. He was first employed by the U.S. Air Force, then by GT&E Sylvania Electronics Systems on Wullenweber and other antenna projects. Although the three men retired in West Germany, some of their second-echelon technicians were taken to the USSR after the war. At least 30 Krug arrays -- the cover term for the Soviet CDAA program -- were installed all over the Soviet Union and allied countries in the 1950s, well before the U.S. military became interested and developed their own CDAAs. Several Krugs were installed in pairs within less than 10 km kilometers of each other, apparently for radio navigation purposes. At least four Krugs were installed near Moscow; just to the north, east and south (55.46408° N 37.3698° E) of the city. The Krugs were used to track the early Sputnik satellites, using their 10 and 20 MHz beacons, and were instrumental in locating re-entry vehicles. The first Wullenwever was built during the war at Skisby (in German: Hjorring), Denmark (coord 57 28 39 N, 10 20 04 E). It used forty vertical radiator elements, placed on the arc of a circle with a diameter of 120 meters. Forty reflecting elements were installed behind the radiator elements, suspended on a circular wooden support structure with a diameter of 112.5 meters. To more easily obtain true geographic bearings, the north and south elements were placed exactly on the North-South meridian. The Soviet Krug arrays also use the 40 radiator Wullenwever configuration. The array in Skisby was extensively studied by the British, then destroyed following the war in accordance with the Geneva Convention. Dr. Wachtler arranged to have a second array built, at Telefunken expense, at Langenargen/Bodensee, for further experimentation after the war. In the years following the war, the U.S. disassembled the Langenargen/ Bodensee array and brought it back to the U.S., where it became known as the "Wullenweber" array. Professor Edgar Hayden, then a young engineer in the University of Illinois Radio Direction Finding Research Group, led the reassembly of the Wullenweber, studied the design and performance of HFDF arrays and researched the physics of HF/DF under contract to the U.S. Navy from 1947 through 1960. His research was used to guide the design and site selection of HFDF arrays. Records of his research are available in the university's archives. Hayden 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 1000 foot diameter circular screen of vertical wires located within the ring of monopoles. Due to their immense size, the location of the Bondville array (40.0494° N 88.3807° W) and the other post-war Wullenweber arrays were clearly visible in high resolution aerial photography available on the internet. The University of Illinois' developmental Wullenweber antenna south of Bondville, IL was abandoned about 1980, partially dismantled in the 1990's, and in 2003, was completely dismantled. In 1959, the U.S. Navy contracted with ITT Federal Systems to deploy a worldwide network of AN/FRD-10 HFDF 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 1967 at NSGA Imperial Beach, CA. A pair of FRD-10s not equipped for HFDF, were installed in 1969 at NAVRADSTA (R) Sugar Grove, WV for Naval HF communications; replacing the NSS receiver site at the Naval Communications Station in Cheltenham, MD. The last two FRD-10 HFDF arrays were installed in 1971 for the Canadian Forces in Gander, Newfoundland and Masset, British Columbia. After the Hanza array was dismantled in 2007, the Canadians now operate the last two FRD-10 arrays in existence. 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 Advanced Information Systems). The first FLR-9 was installed at RAF Chicksands (52.0443° N 0.389182° W), United Kingdom in 1962. The second FLR-9 was installed at San Vito dei Normanni Air Station, Italy also in 1962. The Chicksands array was dismantled following base closure in 1996 and the San Vito array was deactivated following base closure in 1993. In December, 2001 the U.S. Air Force Europe, 31st Contracting Squadron published a solicitation for the removal of the AN/FLR-9 (wullenweber) antennae array at San Vito dei Normanni Air Station. 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. As of 2007, only the Elmendorf and Misawa arrays remain in service, but both are likely to be decommissioned soon due to their age and unavailability of 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 Camp Ramasun in Udorn Thani Province, Thailand. Both were installed in 1970. The Army version has the same design as the Air Force version, but the design of the delay lines in the Beam Forming Networks inside the Central Building are different. The Army used what is called a "Lamp Cluster" delay line design and the Air Force used a "Coaxial" delay line design. The Camp Ramasun array was dismantled in 1975 following base closure. The Augsburg array was turned over to the Bundesnachrichtendienst -- the German Intelligence Service known as the BND -- in 1998, and it is no longer believed to be in service. Aside from the land requirement, the cost was phenominal. The U.S. Government described costs of between $800,000 to $900,000 for a single AN/FRD-10A when they were first being installed in the 1960's. The cost of the AN/FRD-10A installation and Operations Building at CFS Massetcost $11 million in 1970. During the 1970s, the Japanese government installed two large Wullenweber arrays, similar to the FRD-10, at Chitose and Miho. Later in the 1970s, Plessey -- now Roke Manor Research Limited -- of Great Britain developed their smaller, more economical Pusher CDAA array. At least 25 Pusher CDAAs were installed in many countries around the world. Several Pusher arrays were installed in U.S. military facilities, where the array is known as the AN/FRD-13 or the AN/AX-16 Pusher. =============================================================================================== Sources: Wikipedia: http://en.wikipedia.org/wiki/Wullenweber http://en.wikipedia.org/wiki/FLR-9 FAS WebSite: http://www.fas.org/irp/program/collect/an-flr-9.htm http://www.fas.org/irp/program/collect/classic_bullseye.htm http://www.fas.org/irp/program/collect/an-ax-16.htm Global Security: http://www.globalsecurity.org/intell/systems/an-flr-9.htm http://www.globalsecurity.org/intell/systems/classic_bullseye.htm http://www.globalsecurity.org/intell/systems/an-ax-16.htm KB1SG: http://www.mapability.com/ei8ic/rhombic/wullen.html USN CDAAs - End of an Era: http://coldwar-c4i.net/CDAA/history.html JPROC Radio Communications http://www.jproc.ca/rrp/gander.html and Signals Intelligence http://www.jproc.ca/rrp/masset.html in the RCN. =============================================================================================== Article Compiled by: CTOCS Michael R. Morris, USN, Retired CTO SeaDogs WebSite Manager Article First Posted: 08 Jun 07 Most Recently Updated: 27 May 08 =============================================================================================== Downloadable/Printable Text File of the Wullenweber Article On the CTO SeaDogs WebSite (Members only) Wullenweber Article: http://www.msnusers.com/ctoseadogs/Documents/DataBase%2FWullenweber%20Article.txt On Joe Glockner's Navy CT History Site (Accessible to the public domain) WebMaster: CTTCS Joseph A. Glockner (Retired). Wullenweber Article: http://www.navycthistory.com/WullenweberArticle.txt ===============================================================================================