A Century of Service: The U.S. Navy on Cape Henlopen



Terminal Equipment Building of the Navy

Sound Surveillance System (SOSUS)

Naval Facility (NavFac) Lewes



This page describes the Terminal Equipment (TE)Building of NavFac Lewes and the equipment employed for underwater surveillance of enemy submarines.

































































































































































































































































































































Delaware Senator Thomas Carper

toured the site of

the TE building, to read the news article, go here___.










The Terminal Equipment (TE) building was the location from which the SOSUS operations of the NavFac were conducted.


NavFac Lewes was established in 1962 to replace NavFac Cape May which had been isolated and flooded by the Ash Wednesday Nor'easter.  To preclude such a reoccurance of such and event, the TE building was built on top of the high dune well behind the beach at Herring Point, in front of the former Coast Artillery Battery Herring, and the earthen cover was removed from that battery. 


From the TE building a cable with 40 hydrophones at its end, ran into the sea. 


From the TE Building the cable was buried underground on the top of the dune and ran to a concrete anchor at the top edge of the dune. At that point it was spliced to an armored cable which ran to the sea.  As it ran under the dune and beach it was also placed inside a split pipe for additional protection.

The cable gradually became exposed over the years as the dune was eroded.  This is how it looked in 2006-2008.

The cable ran to the edge of the Continental Shelf about 100 miles off shore to a point designated as Area George (G).  The hydrophones were placed at a depth of more than 1000 fathoms (6000 feet) close to the "deep sound channel", a layer of ocean water in which a balance of temperature and pressure causes the low frequency sound from submarine engines and other machinery to be trapped and travel great distances.

The hydrophones  were  equally  spaced  in  the  final  1800 feet "stub" end of the cable. When low frequency sound waves struck a diaphram on the hydrophone, a coil was sympathetically caused to move generating a low voltage current. The fluctuations of that current created "signals" that represented the duration and strength of all the low frequency sounds in the sea detected by the hydrophone.  The  small currents from each hydrophone were carried back to the TE building by two insulated copper wires.  The wires from a pair of hydrophones were wrapped together into a "quad". The twenty quads for the hydrophone pairs plus a quad for the environmental sensor were carried to shore within the  "21 quad" armored cable.  

Over the course of the cable run, the "21 quad" cable was protected by 4 different sizes of armor, depending on the distance from land and, therefore, the likelihood that the cable would be damaged by anchors, fishing gear or sea bottom disturbances. Type AA cable had two bands of heavy wire wrapping, Type A (see above) had one band of the same size wire wrapping, Type B had one band of smaller wire wrapping and Type D had one band of even smaller wire to protect it. Despite that protection, the cable was damaged and had to be repaired 11 times during its active service. 

As the signals moved along the cable back to the TE building, to maintain the "bandwidth" (i.e., the low frequencies of interest) which would be distorted by the capacitance created by the copper wire conductors of the cable, an impedance matching device, known as a "load coil" was spliced into each pair of conductors in the cable.  These load coils were inserted about every three miles in order to compensate for the distortion.  While each load coil by itself was rather small, due to the large number of conductors (i.e., two wires for each hydrophone; 80 wires or 40 pairs for the 40 hydrophones)   the "loading coil packages" which contained the individual loading coils were large.  Each package was on the order of 152 feet long and about 2,000 pounds in weight.  There were 37 of these huge "packages" between the hydrophones and the TE building.

When the  cable entered the TE building it went into the Equipment Room  where the weak  signals  it carried were amplified, summed and "formed" into 40 "beams". Each  beam represented the ocean sounds as if they had been detected by a "virtual" hydrophone oriented toward a different small two to five degree sector of the ocean. Thus, the 40 beams represented the sounds from a wide arc of the ocean.  These beams were further processed to eliminate signals that represented random noise and to reinforce steady signals.  They then went to a "spectrum analyzer" to eliminate signals except those in the narrow low frequency bandwidth of interest for submarine detection. 

The output of each beam was sent to a separate low frequency analyzer-recorder (LOFAR) or "gram writer".  This was a stand with a sloping face on top, over which a roll of specially electrically sensitized paper was pulled beneath an "actuator" into which the electrical signals flowed.  As the paper was continually moving forward in time, a stylus in the actuator moved across it on a frequency scale, marking the paper with a black dot to represent each signal, lighter or darker depending on the signal strength.  Thus, a constant time versus frequency versus strength graph or "lofargram" was continually being created. 

Those LOFARgrams could be interpreted by well-trained Navy Ocean Technicians to detect, from among the many random signals created by the sounds of the ocean, those strong, persistent, regular, non-environmental signals that might represent submarine noises.

If a possible non-environmental detection appeared on one LOFARgram from one 2-5 degree sector of the ocean, it was compared to grams from other sectors, analyzed for validity based on frequency, persistence, strength and other characteristics.  If it were accessed as a possible submarine, it was plotted and the position and characteristics were forwarded to the central processing facility for comparison with information from other NavFacs.


Those functions were performed by the senior NCO and officer watchstanders of the Operations Department under the supervison of the Operations Officer.

The first award was given to NavFac Lewes as part of ASW Task Group 84---Atlantic Fleet SOSUS---for outstanding operational performance during a period of high level Soviet submarine activity in the Atlantic.  The second award was given for improving the physical conditions on the base and enhancing the Navy's image with the civilian community in Delaware.  As shown by these two awards for an overlapping period, responding to a demanding operational situation did not preclude increased efforts to improve the  command environment.  

The entrance mat is all that remains of the TE building today.

The building was torn down in 2004.

The site of the TE building today.

Photo Credits


-TE Building in 2000: Courtesy of Ron Scarborough.

-Cape exposed on dune: Author's photo 2004.

-USNS Neptune (ARC-2): U.S. Navy photo.

-21 quad cable: Author's photo and annotation. 

-LOFARgram writers: Edward Whitman, "SOSUS: The Secret Weapon of Undersea Surveillance,"  Undersea Warfare Winter 2000, vol. 7, no. 2.

-Operations Department floor mat: Author's photo.  Mat is owned by Ms Kay Scanlon, formerly of Supply Department, NavFac Lewes.

-TE Building wreckage: Author's photo.

-TE Building today: Author's photo.

-Illustrations of cable run on dune, of cable run to sea, of Area George, and TE Building floorplan: Department of the Navy, Bureau of Ships, Installation Techniques for Sonar Set AN/FQQ-1  (V), Cable Laying, NavShips 92962. Courtesy of the Office of Chief of Naval Operations (N-87). Declassified 20 October 2009.

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