London Calling, on a Beam of Light

By Stephen Koepp.

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.

The huge jump in transatlantic telephone capacity is expected to bring lower prices for both telephone conversations and data transmission (current price of a ten-minute, afternoon Manhattan-to-London call: $7.98, plus tax). The optical cable will also be the first transatlantic line to carry television and other video signals, which now travel only by satellite. The glass-fiber line will be well suited to video transmission because TV signals are densely packed with information and thus require large amounts of cable capacity. The fiber-optic cable will provide another advantage -- security -- for banks and other institutions that send sensitive information. Unlike satellite transmissions, which can be intercepted by outsiders, a glass-fiber line is almost impossible to tap.

While users will take delight in the new form of transmission, it could provide an uncomfortable amount of competition for satellite operators. At least one of them, Washington-based Comsat, is gearing up for a tough marketing battle. "Satellites ain't dead yet," says Joel Alper, president of Comsat's Space Communications Division. "Our fiber-optic competitors will find us a strong and aggressive opponent."

Satellite operators have been eager to point out the drawbacks of fiber optics. Few though they are, one potential problem is cable breakage, which can require six months to locate and repair. AT&T researchers were astonished to discover during testing last year near the Canary Islands that fiber-optic cables emit an electrical signal that attracts a sharp-toothed menace, the alligator shark. On more than one occasion, the small sharks have managed to bite through the cable and knock it out of commission. AT&T hopes it has solved the problem by cladding the cable in heavier armor.

More delicate and brittle than copper cable, the fiber conduit must be laid with painstaking techniques. Perhaps the most difficult stretch will be the first 100 miles off the U.S. coast, where the line will rest on the relatively shallow continental shelf. To protect the line from fishing boats and jagged rocks, the cable will be buried two feet below the sea floor by a robot trench digger. The undersea plow, operated by a specially equipped Canadian ship, will dig the ditch for the cable and then fill in the trench by blowing soil into it with water jets.

The Canadian vessel should complete the first stretch by next autumn, when the AT&T cable ship C.S. Long Lines will pick up the job. Moving across the deep ocean, the cable ship will lay the conduit directly on the seabed at the speedy rate of 6 m.p.h. Oceanographers have plotted a course to avoid sharp peaks or volcanic ranges on the ocean floor.

While 65% of all international calls from the U.S. travel across the Atlantic, the Pacific will be the next ocean to be bridged by fiber optics. Next year AT&T and 22 joint-venture partners plan to begin construction of an 8,600-nautical-mile fiber cable that will link California with the Pacific rim. The cable will reach from Point Arena, Calif., just north of San Francisco, to Hawaii, and then 2,900 miles farther west to a point in the ocean where it will split into separate branches to Japan, Guam and the Philippines. When the Pacific line is completed, a phone call to the other side of the world may sound like one from just around the corner.

With reporting by Steven Holmes/London and Thomas McCarroll/New York