London Calling, on a Beam of Light

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The cable is only the size of a large garden hose, and its route across the marshlands of New Jersey is not particularly breathtaking. But AT&T workers are taking extraordinary care in handling and splicing this slender conduit as they work their way inch by inch toward the ocean. This is no routine telephone line going in. When it reaches its final destination -- Europe -- in 1988, the $335 million cable will be the first telephone line to carry voices and data across the Atlantic on beams of light.

The fiber-optic cable will be able to handle the equivalent of 40,000 simultaneous telephone conversations, more than twice the number of transatlantic phone lines now available on the three operating copper-core cables. Together with a $700 million transpacific fiber-optic cable scheduled to be completed in 1989, the new undersea phone lines should provide better connections and lower prices for millions of U.S. consumers and businesses who regularly reach out and touch someone across an ocean.

Callers will hear a noticeable improvement in transmission quality, AT&T promises. The current undersea cables are often overcrowded and frequently suffer from static. And satellite connections, which now carry about 60% of transatlantic phone calls, typically produce an echoey sound and an annoying half-second delay because signals must be sent 22,300 miles up to a communications satellite and back down again. Fiber-optic technology, by contrast, delivers a comparatively pure sound. The ultrathin glass fibers in the cable carry information on laser beams of light, which travel with virtually no susceptibility to electronic interference. Long-distance telephone companies have already installed more than 20,000 miles of fiber- optic cables to connect major cities in the U.S., but the undersea phone lines represent a big leap forward.

Transatlantic cables have been in operation since 1858, when the first working telegraph line was laid between Newfoundland and Ireland after many failed attempts. But radio was the only means of transmitting telephone calls across the ocean until 1956, when the first voice-carrying cable was completed. Dubbed TAT-1, for transatlantic, the $49.5 million telephone cable connected Newfoundland with Scotland and could carry 52 telephone calls. More cables followed, but the number of available wires remained well below demand until recent years. The last conventional cable to be installed, TAT-7, was built in 1983 for $191 million and carries up to 9,000 calls.

The optical cable will be jointly owned by 29 separate North American and European communications companies, among them AT&T, RCA, MCI, ITT and Western Union. AT&T, which has a 37% stake in the venture, is in charge of building the first 3,161 nautical miles of the cable, to a point in the Atlantic Ocean near Continental Europe. There the cable will fork into two lines, one each to Britain and France, which will be built by communications firms from those countries.