Common Language Location Identifier: FLKNMDFK


This station is an active AT&T network facility. AT&T Corporate Security has requested that the names and exact locations of such facilities not be published. Accordingly, it is identified on this web page only by its CLLI code, FLKNMDFK.


FLKNMDFK's massive building and tall tower are a striking sight in their rural setting, along a two-lane road and surrounded on three sides by open fields, about 31 miles south of Washington, DC.

The station's windowless blue and white main building is approximately 175 ft. by 160 ft., and about 45 ft. high. Judging from the locations of the loading doors on the side wall, the building appears to have three floors. The asphalt parking lot has marked spaces for 30 cars. The station also features an on-site wastewater treatment plant.

The station's steel-lattice tower supports 12 microwave horn-reflector antennas. A 1970 route map shows the station having microwave paths to :

The following azimuths are uncorrected readings from a hand-held compass aligned by eye, so considerable error is possible and the proposed destinations are very tentative unless noted otherwise:

An AT&T fiber-optic cable runs NNW-SSE through the site. The 1970 route map shows FLKNMDFK having L-carrier coaxial-cable links to Washington No. 1, DC, Richmond, VA a hardened underground main station in Virginia with CLLI code DSVLVADV.

History and Cold War Role

FLKNMDFK was a switching center in two long-distance telephone networks serving the federal government: the Automatic Voice Network (AUTOVON) for the Department of Defense, and the Federal Telecommunications System (FTS) for the civilian agencies. Like AT&T's commercial network, FTS used a hierarchical arrangement of switching centers, in which FLKNMDFK was a top-level (Class 1) switch, also known as a regional center. In contrast, AUTOVON's design was non-hierarchical, to provide the flexibility and redundancy needed for wartime military communications when portions of the network might be disabled.

FLKNMDFK's electromechanical switch, a 4-wire No. 5 crossbar, was partitioned to serve AUTOVON and FTS. The station was dedicated to those federal networks, and handled no calls from AT&T's residential and business customers.

Present Function

FLKNMDFK is still owned by AT&T; its present function is unknown. A small fenced enclosure at one corner of the property is being used for storage of cable, cable-marker posts, and related materials, as well as a conical horn-reflector microwave horn and some lengths of circular waveguide. Recent FCC records show no microwave radio licenses at the facility.

Image Gallery

Photographed November 14, 1999. Select images to view larger version.

Site and surroundings,
looking north

Main building

Rear and south side
of building

looking north

Tower and fuel tanks,
looking south

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Updated on August 4, 2007 at 10:53 by Albert LaFrance