Fort Lawton Air Force Station
Fort Lawton Air Force Station (1960-1963) - A Cold War Air Force Radar Station was first established in 1960 in Seattle, King County, Washington. Relocated from McChord Air Force Base in 1960. Named Fort Lawton Air Force Station after the location. Initially assigned a Permanent ID of RP-1 and later a Sage ID of Z-1. Abandoned by the Air Force in 1963 but continued operation as Fort Lawton FAA Radar Site and is still active with updated CARSR radar equipment.
Established in 1960 as Fort Lawton Air Force Station manned by the 635th AC&W Squadron. The site was repositioned from its location on McChord Air Force Base to Fort Lawton in June 1960 as part of a joint FAA/USAF/U.S.Army operation to colocate and integrate long-range radar sites with U.S. Army Nike Missile Master command posts. Fort Lawton was one of six sites where new collocated facilities were to be built and one of three sites where the FAA would provide ARSR-1 search radars.
USAF would provide a SAGE System interface with an FST-2 coordinate data transmitter and two height-finder radars and pending the activation of this SAGE System interface it would install GPA-37 consoles in the Army command post to provide a manual intercept capability.
Initial equipment included the FAA ARSR-1C search radar and two USAF FPS-6A height-finder radars, an FST-2 coordinate data transmission system, and the interim GPA-37 equipment. The U.S. Army NIKE Missile Master complex was located just east of the USAF site and two U.S. Army FPS-6 height-finder radars were placed in the USAF compound to support that operation. A USAF FPS-26A height-finder radar was installed just months before the site was closed.
SAGE System Operation
The site began operation as a SAGE site on 11 Jun 1960 initially feeding the McChord SAGE Direction Center DC-12 at McChord Air Force Base.
The U.S. Army Air Defense Command Post S-90DC became operational in February 1960 for Nike missile command-and-control functions in the Seattle area. The large command post building was located adjacent to the USAF Fort Lawton Air Force Station and initially housed the first production model FSG-1 Missile-Master Nike Radar Direction Center and a USAF GPA-37. It was later equipped with the GSG-5(V) BIRDIE solid-state computer system. The command post shared radar video produced by the FAA ARSR-1 radar with the USAF FST-2 SAGE System coordinate data transmitter. The FST-2 sent target data into the SAGE System computer at the McChord SAGE Direction Center DC-12 at McChord Air Force Base. The SAGE Direction Center provided target assignments back to the NIKE command post.
The command post ceased operation in 1974 as the NIKE System phased out.
Fort Lawton AFS was responsible for the maintenance of one remote unattended gap-filler radar site. The gap-filler sites were placed in locations where the main search radar lacked coverage. These sites sent digitized radar target data directly to a direction center. Maintenance teams were dispatched from Fort Lawton AFS for regularly scheduled maintenance or when fault indicators suggested the site had problems. The Fort Lawton AFS gap-filler site is located on Crego Hill near Chehalis in Lewis County, Washington but little is known about its equipment or operation.
Fort Lawton AFS and the 635th Radar Squadron were deactivated in March 1963. The Fort Lawton Army Air Defense Command Post S-90DC was deactivated in 1974.
A FYQ-47 Common Digitizer was probably placed in service by February 1973 when the USAF/FAA FST-2 to FYQ-47 replacement program was completed. By 1990 the site was still equipped with the ARSR-1E search radar and a CD-2C Common Digitizer. The Fort Lawton CD-2C was scheduled to receive an upgrade kit to implement three-level weather data processing in May 1992.
The nationwide replacement program converting FAA legacy radar systems to the CARSR radar configuration was completed by 17 Aug 2015 and Fort Lawton FAA Radar Site was a part of that program. Legacy FAA radars underwent a Service Life Extension Program (SLEP) that replaced key components in the vintage ARSR-1, ARSR-2, FPS-20, FPS-66 and FPS-67 radars. The CARSR program replaced legacy klystron radar transmitters with a solid-state transmitter as well as renovating the radar receiver and signal processor. The CARSR modification also included common digitizer functionality making a separate common digitizer unnecessary. The Fort Lawton FAA Radar Site is now operating with the CARSR radar. At the time of the CARSR changeout, the legacy radar in place was still the ARSR-1E and the CARSR conversion included a 7172 Antenna. The secondary radar for the site is the ATCBI-6 Beacon set.
The radar site data is now available to the USAF/NORAD Battle Control System-Fixed (BCS-F) operations centers (EADS & WADS) as well as the FAA Seattle ARTCC (ZSE) and adjacent ARTCCs. Other federal agencies have access to the data under the Homeland Security umbrella.
Operating as an unattended FAA CARSR radar site data tied to the FAA center and to the USAF Battle Control System-Fixed (BCS-F). All of the U.S. Army command post buildings were demolished in 2008 and the USAF buildings and towers have also been removed leaving almost no trace. The circular foundation of one USAF FPS-6 tower still exists. The original FAA operations building and tower still exist and are in use.