810th History
M-130/Z-130 - Winston-Salem (A-6, A-S/GCI)
Note: The following is based on Wikipedia and other sources.
The 810th Radar Squadron was first established as the 810th Aircraft Control and Warning Squadron by the US Air Defense Command (ADC.) It was one of a planned deployment of forty-four mobile radar stations to support the permanent ADC Radar network in the United States. These were to be located around the perimeter of the country.
The 810th was first activated at Dobbins AFB, GA on 20 June 1953. At this point it existed on paper only. It had neither equipment nor personnel. It moved to Andrews AFB, MD on 1 July 1956. It still had neither equipment nor personnel at that point. On the 9th of October, 1956 what was to become the 810th Aircraft Control and Warning Squadron was directed to move to Winston-Salem, North Carolina. Winston-Salem AFS set up shop in its new home on 1 December 1956 at which point construction and staffing commenced.
This site became operational as Winston-Salem AFS with AN/MPS-11 search radar and AN/FPS-6A height finder radar. Initially the station functioned as a Ground-Control Intercept (GCI) and warning station. As a GCI station, the squadron's role was to guide interceptor aircraft toward unidentified intruders picked up on the unit's radar scopes. The AN/MPS-11 set was replaced by an AN/FPS-8 radar that saw service between 1960 and 1962. In 1962 the 810th began operating its AN/FPS-24 search and AN/FPS-26 height-finder radars along with the previously installed AN/FPS-6 set. The AN/FPS-6A was finally retired in 1968.
In 1962 Winston-Salem AFS joined the Semi Automatic Ground Environment (SAGE) system, initially feeding data to Fort Lee AFS, Virginia. After joining, the squadron was redesignated as the 810th Radar Squadron (SAGE) on 1 March 1962. The radar squadron provided information 24/7 the SAGE Direction Center where it was analyzed to determine range, direction altitude speed and whether or not aircraft were friendly or hostile. On 31 July 1963, the site was redesignated as NORAD ID Z-130.
In addition to the main facility, Winston-Salem AFS operated an AN/FPS-18 unmanned Gap Filler (GATR) site:
The 810th was deactivated on 31 July 1970 as part of a general reduction of Aerospace Defense Command air defense units.
Today some of the former USAF buildings are used as part of a light industrial complex. The large concrete AN/FPS-24 tower structure still stands, though shorn of its once impressive antenna. Many of the support buildings and new barracks also remain. The housing area is in private hands. Some of the buildings are used by ARCA Addiction Recovery Care Association.
Hardware - 1966 to 1969
AN/FPS-24 Search Radar
The AN/FPS-24, such as the unit at Winston-Salem was developed as part of the Frequency Diversity Radar program, a major radar developmental project undertaken at RADC (Rome Air Development Center, Griffiss Air Force Base, Rome, NY). In addition to the AN/FPS-24 this program was also responsible for the AN/FPS-26, AN/FPS-27, AN/FPS-28, and the AN/FPS-35, frequency diversity radars.
This equipment was designed to succeed existing Semi-Automatic Ground Environment (SAGE) radar systems, which had served as the backbone of air defense of the CONUS, in order to provide enhanced electronic counter countermeasures (ECCM) capability.
The AN/FPS-24 at Winston Salem was built by General Electric, and the system was manned by a handful of GE civilian contractors along with an Air Force crew. This radar was designed to operate in the Very High Frequency (VHF) range between 214 and 236 MHz.
A number of problems were encountered with this radar when it underwent initial testing at the test site at Eufaula, Alabama, in 1960. As a result the system underwent many modifications before it was finally deployed.
A total of twelve AN/FPS-24 systems were built between 1958 and 1962. The AN/FPS-24 radar, became operational within the SAGE system on 30 June 1968.
When the radar was initially deployed in 1961, bearing problems often occurred due to the eighty-five ton weight of the antenna. The use of a hydrostatic bearing solved this problem. The development of this bearing was the work of Goodyear Aerospace, under contract with RADC.
The bearing in the AN/FPS-24 at the 810th was not replaced in the 3 plus years I was there. I recall there was a weekly shutdown of the system for preventative maintenance, and one of the tasks performed during these periods was an inspection of the bearing. I was not involved in this, but I was told that some number of rollers were inspected each week, so over some period of time all the rollers would be looked at. I believe this involved jacking up the sail and physically removing the rollers. Individual rollers could be replaced as needed.
A few months before I left a large flatbed tractor trailer truck pulled in delivering a replacement bearing. The single roller bearing arrived in a large wooden crate that extended over the sides of the flatbed! I believe the site was closed before that new bearing was ever installed. I'll bet that part cost the taxpayers a tidy sum and I doubt it had many other applications!
I also recall the 24-tower being shut down for several months while a major retrofit was performed. This would have probably been in 1968. A group of contractors from GE did most of the work. They chopped out a bunch of hardware and piles of cables and added some newer gear. Being a bit of a pack rat I grabbed some of the old parts out of the trash and may still have a few of them in my basement.
Among the electronic components I recall seeing at this time were some capacitors rated in farads. Each of these were about the size of a bathtub! Today you can find caps of similar value on the motherboard of your PC.
AN/FPS-26 Height Finder Radar
Another product of the Air Force Rome Air Development Center [RADC] Frequency Diversity Radar program was the AN/FPS-26. This system was designed to succeed existing Semi-Automatic Ground Environment (SAGE) radar systems, which had served as the backbone of air defense of the CONUS, in order to provide enhanced electronic counter countermeasures (ECCM) capability.
Avco Corporation built this height-finder radar and it entered service on 20 January 1960. RADC accepted the AN/FPS-26 air defense radar from AVCO after stipulating that the contractor must correct certain component deficiencies that were encountered during testing. This radar operated at a frequency of 5400 to 5900 MHz.
Although I did not work directly on this system, a friend who did invited me inside the inflated radome during an extended maintenance shutdown. I recall the scene of the sparkling gray height finder dish under the bright lights under the dome looked like something from a science fiction movie. Unfortunately I didn't bring my Polaroid camera through the air lock. Unlike the electric motor driven AN/FPS-6, the AN/FPS-26 was all hydraulically driven.
AN/FPS-6 Long-Range Height Finder Radar
AN/FPS-6 was a high-power S-Band nodding height-finding radar, developed at RADC (Rome Air Development Center). It was the first long-range height finder radar employed at all Semi-Automatic Ground Environment (SAGE) locations. This system had a maximum range of 200 nautical miles and a height-finding capacity of 75,000 feet within an angle limit of minus 2 to plus 32 degrees.
A couple of things stood out for me on this bit of hardware. The first was that it was mounted on a spindly steel frame work. It was located behind the ops building and quite near the security fence. You could stand in the road outside and watch it operate quite clearly. The antenna rocked back and forth in a nodding fashion using a very simple and mechanically obvious motor driven mechanism. Though it served the same basic function as the AN/FPS-26 it's operating principle was very different.
A Typical AN/FPS-6
The other detail I remember is that the unit's transmitter power amplifier tube was a type called a magnetron. The defining feature of the magnetron is that it has two big horseshoe shaped permanent magnets bolted together around it. Once the tubes reached their end of life and needed to be replaced the old tubes were very popular. Many of us wanted to get them. I was fortunate to get one of the big horseshoe magnets. I gave it to my mom & dad and they used it as a door stop for many years. Unfortunately it disappeared during one of their moves so I no longer have it.
A typical Magnetron
AN/MPS-11 - AN/FPS-8 Search Radars
The AN/MPS-11 was the first search radar at the 810th. Later it was replaced by the AN/FPS-8. The AN/FPS-8 radar was a Medium-Range Search Radar. In 1962 it was replaced by the new AN/FPS-24. By the time I arrived at the 810th only the round metal building that housed the old AN/FPS-8 was still present behind the security fence. We used it as a storage shed for maintenance equipment and supplies along with old out of service parts for the Radar gear. I never saw a trace of the original AN/MPS-11.