Truax SAGE Direction Center DC-07

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Truax SAGE Direction Center DC-07 (1957-1967) - A Cold War SAGE System Direction Center first established in 1957 on Truax Field, Madison, Dane County, Wisconsin. Named Truax SAGE Direction Center after the location. Assigned a Sage ID of DC-07. Deactivated as a SAGE Direction Center in 1967.

History of Truax SAGE Direction Center

Established in 1957 and became operational on 15 Feb 1960 as Truax SAGE Direction Center DC-07.

SAGE System Data Flow

Direction center equipment included the duplex FSQ-7 computer system and associated communication equipment. The FSQ-7 computer system assembled digitized inputs from USAF Radar Sites to provide tracking and identification of all aircraft within their sector of responsibility. The digitized radar inputs came from USAF Radar Sites, airborne radar pickets, Texas Towers, Gap Filler Radar Sites and other radar sources. The total picture of aircraft in the sector was assembled and any unknown aircraft were checked out and hostile aircraft were engaged by USAF fighter aircraft, Bomarc missiles or NIKE missiles. The primary defense was against the Soviet threat of a mass nuclear bomber attack on the US. The system evolved before the advent of ICBMs and provided no missile defense against them.

The computer technology was first generation vacuum tube equipment and required significant power and air conditioning. The physical plant of the direction center was enclosed in a large multi-story concrete blockhouse that housed the duplex FSQ-7 computer, communications equipment, a powerhouse, air conditioning systems and operational areas. The operational areas included radar mapping, air surveillance, identification, communications and weapons direction.

The enormous cost of the radar sites, direction centers, personnel, and training caused an immediate reevaluation and almost as quickly as they were built some facilities were closed. The first mass closures began in the 1960s when many radar sites and virtually all the gap filler sites were closed. The first round of direction center closures came in 1963 when six were closed, a second round in 1966 and a third in 1969 that closed a total of 17 out of 23. The remaining six direction centers became SAGE Regional Control Centers (RCCs) still using the massive FSQ-7 vacuum tube computers. As the direction centers and radar sites closed the remaining sites were realigned into ever-increasing sectors.

A new Joint Surveillance System (JSS) evolved as a partnership between the Air Force and the FAA to provide nationwide radar coverage. When completed in 1983 it consisted of only forty-six radar sites feeding into four new Region Operation Control Centers (ROCCs) with FYQ-93 computer systems. With the activation of the four U.S. ROCCs and the two Canadian ROCCs, the last seven of the SAGE direction centers were deactivated and this signaled the end of the SAGE system. Of the remaining forty-six radar sites, thirty-one had FAA-operated search radars and USAF operated height finders. Five sites just had FAA search radars and only ten sites were operated by the Military. With the deployment of forty FAA ARSR-4 3D radar sets in the 1990s, the earlier military and FAA radars were replaced.

The Canadians closed their underground SAGE Direction Center and created two ROCCs (CAN-East and CAN-West) using the FYQ-93 computers in the underground facility.

Truax SAGE Direction Center DC-07
Unit Designation Command From To
Chicago Air Defense Sector ADC 1959-04-01 1966-04-01
20 Air Division ADC 1966-04-01 1967-12-31

The SAGE Combat Center was deactivated on 30 Jun 1966. The SAGE Direction Center was deactivated on 31 Dec 1967.

Truax SAGE Direction Center DC-07 Radar Sites (edit list)
Location Type State Unit ADC NORAD JSS From To GPS Notes
Antigo AFS WI 676th P-19 Z-19 1964-06-01 1967-12-22 45.04833,
Walnut Ridge AFS AR 725th SM-143 Z-143 1961-07-01 1963-09-01 36.13,
Williams Bay AFS WI 755th P-31 1959-06-01 1960-04-01 42.61708,
Moved to
Arlington Heights
Arlington Heights AFS IL 755th RP-31 Z-31 1960-04-01 1967-12-01 42.06431,
Rockville AFS IN 782nd P-53 Z-53 1959-06-01 1966-06-25 39.77528,
Snow Mountain AFS KY 784th P-82 Z-82 1961-06-01
Waverly AFS IA 788th P-83 Z-83 1959-06-01 1967-12-01 42.69,
Kirksville AFS MO 790th P-64 Z-64 1959-06-01 1967-12-01 40.29778,
Hanna City AFS IL 791st P-85 Z-85 1959-06-01 1967-12-01 40.69889,
Belleville AFS IL 798th P-70 Z-70 1961-07-01 1967-12-01 38.47556,

Current Status

Sage Direction Center and the SAGE Combat Center blockhouses still exist and have been modified and repurposed near the present day Madison Dane County Regional Airport in Madison, Wisconsin.

Location: Near Madison Dane County Regional Airport, Madison, Dane County, Wisconsin. Maps & Images

Lat: 43.12667 Long: -89.335

  • Multi Maps from ACME
  • Maps from Bing
  • Maps from Google
  • Elevation: .....'

See Also:


  • Winkler, David F., Searching the Skies: the Legacy of the United States Cold War Defense Radar Program, USAF Hq Air Combat Command, 1997, 192 pages, Pdf.
  • Cornett, Lloyd H. & Johnson, Mildred W., A Handbook of Aerospace Defense Organization (1946-1980), Office of History ADC, Peterson AFB, Colorado, 31 Dec 1980, 179 pages, Pdf.
  • Ulmann, Bernd, AN/FSQ-7:the computer that shaped the Cold War, 2014, Walter de Gruyter GmbH & Co KG, ISBN 978-3-486-72766-1, 272 pages.


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