Tucked away on the southern coast of Rhode Island is the Green Hill Site.  Now home for Worldcom, MCI, Bell Atlantic? and AT&T communication facilities.  It was at the end of a L-4 route originating at Cheshire, CT.  The tower sports a pair of TD2's (unknown if working), Cellular antennas and a Combat Cider GEP set of antennas.  Green Hill is/was also a US end of one of the Transoceanic Cables (TAT-6 a SG system)  This SG system, was installed in 1976.  The other end is at St. Hilaire de Reis, France.  The SG system was developed a few years after the L-5 coaxial system and had a bandwidth of 30 mhz.  The SG system is similar to the L-5 system except the terminals on each end supplied power at plus and minus 5070 volts for operating the repeaters and some of the equalizers were shore controlled.  Needless to say repeaters were much smaller and had greater spacing.  The SG system was the last major analog submarine system before the introduction of optical digital systems (fiber).

NOTES:

Update on trans Atlantic cables at Greenhill by John Manock -  "Before TAT-6 was installed, another copper transatlantic cable (TAT-5) was landed in Green Hill in 1970.  It ran to Conil, Spain.  Both are now out of service.  More recently, three fiberoptic cables have been brought into Green Hill.  TAT-10 (1992), which runs to Germany and the Netherlands; TAT-12/13 (1995) linking Green Hill, NewJersey, the U.K., and France; and Gemini, which is being installed right now and has landing points in Green Hill, Long Island, and the U.K."

Green Hill is also mentioned in James Bamford's book "Puzzle Palace" (pg. 174).  Bamford points out that in 1982 over 90% of all trans-Atlantic traffic terminated at Green Hill, where upon they were routed over the TD-2 microwave to Montville or L-4 coaxial cable system to  Cheshire.  Bamford alludes to the fact that NSA or any other foreign power could intercept trans Atlantic phone traffic by setting up a covert intercept station somewhere in the path between Greenhill and Montville (coincidently the Naval Submarine Base at Groton, CT is in this pathway).  Currently the L-4 and TD-2 paths have been replaced by fiber.
 
 

Northeast view of site showing additional buildings, including cellular hut to rear and open open picnic style structure to the left of the tower.

View of top of tower showing four Combat Cider antennas.  Also small Combat Cider?? antenna on same plane but to the right of the four main antennas.

 Return to L-4 Home page