Science: Waves Under the Sea

In the 60-year history of radio, man has learned to send signals over mountains, across oceans, and up to the moon and back. But the search for a radio that could transmit signals beneath the water’s surface was sterner. To receive messages in World War II, subs had to surface or poke up the antenna-bearing periscope and risk detection. Last week word leaked that the U.S. Navy has whipped this underwater communications problem.

On a peninsula jutting from the rocky northern coast near Cutler, Me., the Navy is building a $63 million transmitter complex that, by any measure, will rank as the world’s biggest. Rising 980 ft., its two main antenna masts are almost as tall as the Eiffel Tower (984 ft.). With their flanking arrays of twelve smaller masts, each complex occupies the ground space of eleven Pentagons. Operating at 2,000,000 watts, the station will be 40 times more powerful than the biggest commercial stations and three times more powerful than the mightiest military transmitters known to exist in the U.S. or the Soviet Union.

When it goes on the air in January 1961, the new station will operate on a very low frequency band (14 to 30 kilocycles), sending out radio waves up to one mile long audible to surface ships and shore stations around the world. It may be utilized experimentally to try out the new Tepee scatter-back system for detecting missile firings in Russia. But specifically, it should be capable of sending orders to subs operating under the surface of the North Atlantic and Arctic Oceans. The Navy says that the signals will reach “deep down.” Best estimate is that they will penetrate more than 100 ft. of water.

Cloud on the horizon, no bigger than a boatswain’s hand, as the sun rises on a new era in underwater communication: if radio waves can penetrate water to communicate with submarines, they may eventually be usable with different instrumentation for detection of submarines, which are now immune from anything but surface sighting and chance encounters with short-range sound devices.