“Keep Mum - The World Has Ears”

“Keep Mum - The World Has Ears”. . , When World War II broke out in Europe, the Pole Farm's international telephone service was used by world leaders as one of the few means of direct, voice-to-voice communication. British Prime Minister Winston Churchill was able to call President Franklin D. Roosevelt at once, upon learning of the Japanese attack on Pearl Harbor., The Germans built an eavesdropping station in the North Sea off the Dutch coast to intercept the transmissions from Lawrenceville. The Allies always assumed that the transmissions were bugged, and it was a good thing because after the war it was confirmed that the Germans had intercepted and decoded many calls., Rhombic Antennas , In 1931, AT&T installed a new kind of antenna, the rhombic, which with its tall supporting timber poles would come to define Lawrenceville as the “Pole Farm.” By the end of the 1930s, the rhombics had completely replaced the original Sterba antennas and towers., Rhombic means “diamond-shaped” and in horizontal view the wires were in the shape of a diamond with the four corners supported by poles., Rhombic antennas had several advantages over Sterba antennas. First, they were highly directional and focused the shortwave beam on its target receiver. Second, they were much less expensive to build and maintain. And, third, they could be used across a greater range of frequencies allowing for the handling of a greater number of calls., Security in the Pre-Digital Age , Lawrenceville's signals were scrambled during World War II to deter enemy eavesdropping but the non-digital technology was not considered secure for highly classified information. Instead, specially trained Allied operators listened to every call and interrupted any conversation that strayed into classified information., During 1943, the U.S. Army built its own secure shortwave facilities, and the Pole Farm was used only for non-classified diplomatic and civilian calls. The Pole Farm also served as a training facility for radiomen from Fort Monmouth, the headquarters of the U.S. Army's Signal Corps., ( Photo Captions ) , , World leaders used Lawrenceville’s telephone circuits to communicate. Given the distances and dangers of travel, face-to-face meetings were very rare. From left, Stalin, Roosevelt and Churchill. , , At Lawrenceville, radiomen used a primitive non-digital scrambling system to encode transmissions. , , A soldier with telephone operators at a USO facility. Lawrenceville was the hub for non-classified overseas calls, offering a precious few minutes to connect with family or friends. , , In this rare photo, both the original Sterba London Tower Array (foreground) and the Bermuda rhombic antenna (background) are visible, c. 1935. Building One is located between the two antenna arrays.