View source for AN/FPS-35

{{Use dmy dates|date=June 2025}}
{{More citations needed|date=April 2009}}
The '''AN/FPS-35''' frequency diversity radar was a long range [[search radar]] used in the early 1960s. It was one of the largest air defense radars ever produced, with its antenna and supporting structure mounted on one of the largest [[rolling-element bearing]]s in the world (with a ball pitch of 12&nbsp;ft 7 inches in diameter.).<ref>{{cite journal |last=Blatter |first=Francis P. |url=https://books.google.com/books?id=KsAiAQAAMAAJ&q=FPS-35+largest |title=Mechanical Considerations in Antenna Design |journal=Sperry Engineering Review |year=1960 |pages=55, 58}}</ref> 

In accordance with the [[Joint Electronics Type Designation System]] (JETDS), the "''AN/FPS-30''" designation represents the 30th design of an Army-Navy electronic device for fixed ground search radar.<ref>{{cite book|last=Winkler|first=David F.|title=Searching the Skies: The Legacy of the United States Cold War Defense Radar Program|chapter=Radar Systems Classification Methods|page=73|publisher=United States Air Force Headquarters Air Combat Command|location=Langley AFB, Virginia|year=1997|lccn=97020912|url=https://nuke.fas.org/guide/usa/airdef/1997-06-01955.pdf}} {{source-attribution}}</ref><ref>{{cite book|author=Avionics Department|title=Electronic Warfare and Radar Systems Engineering Handbook|edition=4|chapter=Missile and Electronic Equipment Designations|pages=2–8.1|publisher=Naval Air Warfare Center Weapons Division|location=Point Mugu, California|year=2013|url=https://apps.dtic.mil/sti/tr/pdf/ADA617071.pdf}}</ref> The JETDS system also now is used to name all [[Department of Defense]] electronic systems.

==Overview==
[[Sperry Corporation]] built 12 long range radars (picking up objects 200 miles away) in the 1960s to succeed existing [[Semi Automatic Ground Environment]] (SAGE) to provide enhanced electronic countermeasures (ECM). The systems operated at 420 to 450&nbsp;MHz. The antennas weighed {{convert|70|to|80|ST}} and had numerous problems. The concrete tower bases were {{convert|84|ft|6|in}} high, with 5 floors, and {{convert|60|ft|3|in}} square in side dimensions.

The prototype was developed at the Thomasville Aircraft Control and Warning Station in [[Thomasville, Alabama]].<ref name="FPS35">{{cite web |title=AN/FPS-35 |work=Radomes.org |url=http://www.radomes.org/museum/equip/fps-35.html |accessdate=2008-01-08}}</ref>

The {{convert|85|foot}} enclosed radar towers that supported all 12 of the FPS-35 antennas were prominent landmarks. All these radar towers were of the same basic design with 10 made primarily from concrete and two based on a steel frame structure (Baker and Finley).  Only the  radar tower at Baker has been demolished.<ref name="FPS35" />

The 23 radar towers used by the AN/FPS-24 and the AN/FPS-35 radar sets were of similar designs (concrete or steel frame) and were designed under the direction of the Rome Air Development Center (RADC).  The radar tower at Thomasville has an RADC plaque next to the one from the Sperry Corporation.  Only the AN/FPS-35 tower at Baker included a radome to protect the antenna.  This radome was attached to a separate steel tower called a Radome Support Structure (RSS) that surrounded the radar tower to its full height of {{convert|85|feet}}.<ref name="FPS35" /> With the antenna, the structure's total height is {{convert|150|feet}}.

==Montauk tower==
{{Infobox NRHP
| name         = AN/FPS-35 Radar Tower and Antenna
| nrhp_type    =
| image        = Montauk1.jpg
| caption      = The AN-FPS-35 Radar at [[Camp Hero State Park]] in [[Montauk, New York]]. The radar rises well above its surrounding trees.
| nearest_city = [[Montauk, New York]]
| coordinates  = {{coord|41|3|44.81|N|71|52|28.24|W|display=inline,title}}
| area         =
| built        = 1960
| architect    =
| added        = June 4, 2002<ref name="nris">{{NRISref|2007a}}</ref>
| refnum       = 02000615
}}
All of the radars have been dismantled except for the one at [[Camp Hero State Park]] on the eastern tip of [[Long Island]] in [[Montauk, New York]]. It was the last to operate (January 1981) and the radar tower is the only one that still has an antenna on the roof and contains some of the radar set equipment and cabinets. The antenna was repaired with parts from the Sault Ste. Marie station after it closed in October 1979. The Montauk antenna is very corroded and can not be rotated.<ref name="FPS35" />

The structure was listed on the [[National Register of Historic Places]] in 2002.<ref name="nris" /><ref name="nrhpinv_ny">{{cite web|last=Warren|first=James|date=February 2002|title=National Register of Historic Places Registration: AN/FPS-35 Radar Tower and Antennae|url=http://www.oprhp.state.ny.us/hpimaging/hp_view.asp?GroupView=9069|url-status=dead|archive-url=https://web.archive.org/web/20120304035134/http://www.oprhp.state.ny.us/hpimaging/hp_view.asp?GroupView=9069|archive-date=2012-03-04|publisher=[[New York State Office of Parks, Recreation and Historic Preservation]]|accessdate=2008-07-28}} ''Note:'' This includes {{cite web|title=Accompanying 11 photos, undated|url=http://www.oprhp.state.ny.us/hpimaging/hp_view.asp?GroupView=9073}} and {{cite web|title=Accompanying nomination correspondence|url=http://www.oprhp.state.ny.us/hpimaging/hp_view.asp?GroupView=9068}}</ref> Fishermen on the [[Atlantic Ocean]] and [[Block Island Sound]] lobbied to save it since the massive [[radar tower]] was a better daytime landmark than the [[Montauk Point Lighthouse]].<ref>{{cite news|last=Drumm|first=Russell|date=December 23, 1999|title=Rally Round The Radar|newspaper=The East Hampton Star|url=http://easthamptonstar.com/DNN/Archive/1999/991223/news4.htm|accessdate=2009-10-12}}{{dead link|date=June 2017|bot=InternetArchiveBot|fix-attempted=yes}}</ref>

The 150-foot tower dominates the environs and can be seen from as far away as [[Charlestown, Rhode Island]], to the east (22 miles) and [[Orient Point, New York]] (20 miles) to the west.

The Montauk radar has worked its way into an [[urban legend]] that it was used in time travel experiments called the [[Montauk Project]].

==List of towers==
* AL Thomasville {{coord|31.9382|-87.7502|display=inline}}
* CA Boron {{coord|35.0823|-117.5823|display=inline}}
* MI Sault Ste. Marie {{coord|46.4565|-84.3878|display=inline}}
* MI Selfridge {{coord|42.6275|-82.8300|display=inline}}
* NV Fallon {{coord|39.4054|-118.7224|display=inline}}
* NY Montauk {{coord|41.0622|-71.8740|display=inline}}
* ND Finley {{coord|47.5161|-97.8687|display=inline}}   (steel tower, present)
* ND [[Fortuna Air Force Station|Fortuna]] {{coord|48.9042|-103.8665|display=inline}}
* PA Benton {{coord|41.3574|-76.2930|display=inline}}
* VA Manassas {{coord|38.6288|-77.4385|display=inline}}
* WI Antigo {{coord|45.048333|-89.233889|display=inline}}
* OR Baker {{coord|44.586389|-117.787222|display=inline}}   (steel tower, demolished)

==See also==
{{Portal|Electronics}}
*[[List of radars]]
*[[List of military electronics of the United States]]

==References==
{{Reflist}}

==External links==
{{Commons category}}
*[http://www.fas.org/nuke/guide/usa/airdef/an-fps-35.htm FAS.ORG list of radars]
*[http://www.radomes.org/museum/equip/fps-35.html Radomes.org Article on the Radar]

{{AN/FPS}}

{{DEFAULTSORT:AN/FPS-035}}
[[Category:Montauk, New York]]
[[Category:Ground radars]]
[[Category:Military radars of the United States]]
[[Category:Radars of the United States Air Force]]
[[Category:Military facilities on the National Register of Historic Places in New York (state)]]
[[Category:Buildings and structures in Suffolk County, New York]]
[[Category:National Register of Historic Places in Suffolk County, New York]]
[[Category:Military equipment introduced in the 1960s]]
[[Category:Military electronics of the United States]]