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Site E Tysons Tower
Tysons Corner, VA

The Site E Tysons Tower is a large and prominent communications relay tower centrally located in Tysons Corner. The facility is apparently associated with the Suitland Tower, and the Warrenton complex. It seems that the facility was originally built as a major communications link to the big FEMA installation at Mount Weather, but has become primarily a shared host for remote VHF communications equipment for multiple federal entities. In fact it may be of primarily historical rather than current interest.

The tower itself is rather unusual, because of its broad footprint and large deck on top. This suggests that it was originally intended to hold of bulky and/or heavy antennas, such as microwave dishes and horns; its construction is certainly big-time overkill for the existing crop of antennas. It is also unusual in that it has a stairway, rather than a ladder. It might mean that the tower was intended to be climbed often and/or by many people. In fact, the overall appearance of the tower is a bit like a forest-fire lookout tower without the enclosed cab.

Another noteworthy part of the tower are the two vertical components, several feet apart, that extend from a point maybe 20-30 feet above the ground, up to near the top of the tower. They appear to be built of structural steel angle stock, almost like elevator guide rails. They might have been supports for heavy rigid waveguides, or maybe nothing more than innocuous structural elements.

The buildings are all of a similar style -- 1950's vintage with a Cold War military look to them - though it is said they were built in the early 70s. The large main building has several doors, and a couple of very small outbuildings. No windows - just glass blocks.

As for the antennas, the current population consists almost entirely of a large number of what appear to be ordinary VHF vertical antennas, such as are used for mobile radio systems. There are also two microwave dishes. One goes to the Vienna Technology Park. The other is a little larger, and much higher on the tower, which appears to go to the Defense Communications installation at Fort Myer.

Over the past few years, a lot of microwave antennas have been removed from the tower. In particular, two large "kettle-drum" type dishes, aimed in the general direction of Mount Weather, have disappeared - possibly replaced by satellite or fiber-optic cable links. Other dishes, of various sizes, including some pointed towards Langley.

A CBD announcement, dated 8-12-96, solicited bids for "...unarmed guard services for COMMUNICATIONS TOWERS at Suitland, Maryland, and Site 'E' Tysons Corner, Virginia". The contract was being advertised by the Fort Myer Military Community, Directorate of Contracting. It has been suggested that "Site 'E'" may not necessarily be the name of the facility; it could be, for example, just the name of the facility's guard station. Visible security consists of a chain-link fence topped with three strands of barbed wire. There are a number of light poles around the perimeter, linked by a gravel path. Some or all of the poles have key stations for logging on a watchman's mechanical round recorder. The site seems to be constantly under the protection of a single unarmed private security guard, who parks his/her car near the main building.

The street address of the facility is 1744 Pinnacle Drive. The Fairfax County tax assessments office lists the proprerty owner as, not surprisingly, the United States of America. The land is valued (as of 1-1-97) at $4,099,655, and the "improvements" at a $195,270. There is a USGS horizontal/vertical control station, called "PEACH GROVE", on the site, and another nearby, outside the fence.

Electrical power comes from ordinary lines, which serve other nearby customers. A three-phase transformer bank is on a pole inside the fence. There appears to be an emergency generator in the building, and an environmentally-correct (and, unfortunately, quite vulnerable) above-ground fuel tank outside.

A telephone cable and a fiber-optic cable go up the outside of the building.

Overall, the facility includes:

  1. Approx. 50 VHF and UHF antennas, of the type commonly used for mobile two-way radio systems.
  2. A Bell Atlantic cable containing an unknown number of copper phone lines.
  3. A private (LSI) fiber-optic cable.
  4. Two microwave dishes.
  5. One shiny, gold, UHF/VHF TV receiving antenna on the main building's roof.
Some reasonable working assumptions (not the only possibilities, of course) are:

The small microwave dish, fairly low on the tower, is apparently pointed toward the Vienna Technology Park CIA facility.

However, it is puzzling that the FCC microwave database includes no entries for the two dishes at Tysons. The only station licensed to the tower's geographic coordinates is for a link between the Tysons tower and a station called ELMER in Elmer (Montgomery County), Maryland, about 20 miles northwest of Tysons Corner. ELMER, in turn, communicates with PARIS EAST, in Paris, Virginia, about 28 miles to the southwest of Elmer, in the vicinity of the Mount Weather facility. The owner is listed as Contel Federal Systems. Whatever the connection, it no longer exists, at least from Tysons to Elmer, because there's no corresponding dish on the Tysons tower. It would seem that the link has been replaced by a satellite channel and/or fiber-optic cable. Since the tower had many more microwave antennas in the past, it is probable that the owners turned in the licenses or let them expire as the links became obsolete, so the license information was purged from the database during periodic updates. As for the lack of licensing information on the two existing dishes, that could mean that the FCC database isn't current, that the dishes are not in service, or that the licensing data are exempt from the public release.

However, there *are* two microwave stations licensed to the exact latitude of the tower, but 10 seconds of longitude to the east. That works out to about 800 feet, which would put them at the Holiday Inn. In addition to the Holiday Inn, locations named or identified by coordinates are Independent [Hill] (just north of the Quantico USMC base, and a known site for civilian antennas), Building 27540 at the Quantico base, a site near the intersection of Chain Bridge Road and Pohick Road in Fairfax Station, and an office building at 8150 Leesburg Pike, near the intersection with International Drive. The Fairfax Station site is in a pretty direct line between Tysons Corner and Independent Hill/Quantico, and all three fall within the large margin of error in the estimated bearing of the lower dish on the Tysons tower, but the licenses are not for the tower site .

To make things even more confusing, while the ground-level elevation for the "Holiday Inn" site looks about right (500 ft., vs. 520 ft. at the tower location), the structure height listed (300 ft.) is the same as given for the tower, though the hotel isn't that tall.

There is apparently a communcations link between the CIA buildings on Westbranch Drive, and the CIA facilities in the Remingtion/Warrenton area. The communications seem to travel via the LSI fiber optic cable to the Tysons tower, from there via microwave to the Overseas Telecommunications facility at Quantico, and again by the Lightwave Spectrum (LSI) fiber-optic cable to the CIA facilities in Fauquier County.

There are some faded orange (indicating a comm line) Miss Utility paint markings on the Pinnacle Dr. sidewalk, identified by the characters "LSI" or "LS1". The marks began with a north-pointing arrow in the west side of Pinnacle, near the northeast corner of the outer fence. They cross the public sidewalk then turn south, along the narrow strip of grass between the sidewalk and the fence. They continue along that line across the driveway, to a point approximately 10 feet beyond the south side of the driveway. Here, the line turns west, under the fence. At this point there was a marking "H-H" ["hand-hole"]. The marks continue across the lawn, parallel to and a few feet outside the north side of the inner fence, to the southeast corner of the building. At that point a cable with a yellow plastic tag can be observed running up the side of the building and along the top of the east wall, to the northeast corner of the building, near where the copper telephone cables also enter. In addition, those phone cables are marked. From the junction box pedestal near the northeast corner of the site, they run in a more-or-less straight line to the point mentioned above.

Nonetheless, the FCC database gives the location of the Tysons Corner antenna as being 10 seconds (about 800 ft.) east of the tower's actual coordinates. This would seem to put it at the Holiday Inn, which has no dishes except for satellite TV antennas and is far shorter than the 300 ft. structure height given in the FCC file. Furthermore, the antenna site elevation listed is different from the tower's and looks more like that of the hotel. There's also the confusing presence of a Fairfax Station path for the link.

Consequently, the exact nature of this facility remains unclear.

Sources and Methods


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Updated Monday, April 06, 1998 12:51:05 PM