City of Light: The Story of Fiber Optics

15
Submarine Cables
Covering the Ocean Floor with Glass
(1970–1995)
In the much more difficult case of the sub-ocean routes, it
may take up to about 20 years to produce repeaters with
long enough average lives to give complete cables 5000
km long that will operate without maintenance for an average
period of 20 years—but it can be and certainly will
be done.
—Alec Reeves, 1969 1
In the 1960s, it took a wild-eyed optimist like Alec Reeves to see a future
for fiber optics in one of the toughest jobs for any cable—crossing the ocean
depths to link continents. Yet by the mid-1970s, optical fibers were the last
hope of salvaging an aging submarine cable industry besieged by rapid advances
in satellite communications.
Submarine cable engineers had made considerable progress since TAT-1,
the first telephone cable, crossed the Atlantic in 1956. They had multiplied
capacity of coaxial cables a thousandfold, cramming 4000 voice circuits
through the latest in the series. But there coaxial cables ran into a technological
stone wall while satellites charged ahead. Only fiber optics offered any
hope for a new generation of submarine cables.
The Submarine Cable Business
Ocean-spanning cables are unique parts of the global telecommunications
network. The vast network on land is composed of many comparatively small
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