9-25-15-Route of the first transatlantic telephone cable9-25-15-Transatlantic-telephone-cable-operations-Oban  Scotland

Friday, September 25, 2015

On September 25, 1956 the Chairman of the American Telephone and Telegraph Company (AT&T), in New York, spoke with the Postmaster General of Britain, in London, over the newly-completed, first transatlantic telephone cable. Scientists and engineers had begun to study deep-sea, long-distance submarine cable transmission of telephone calls in the early 1930s. Telegraph cables had successfully carried transatlantic messages since the 1850s, but voice signals were not strong enough to travel across the ocean. Engineers realized that they needed to find a way to increase the strength of the voice signal. They accomplished their goal with the creation of the repeater – an amplifier that could be wired into the cable at intervals.

Planning, designing, manufacturing and installing the system took three years of joint effort by AT&T, Bell Telephone Laboratories, the Canadian Overseas Communications Corporation, and the British Post Office Engineering Department. Two cables were laid, one for each direction of communication. Laying the cables took weeks and was carried out over two summers, to avoid Atlantic winter storms. The cost was $42 million, $367 million in 2014 dollars.

The first cable provided thirty circuits between the U.S. and Britain and six between Britain and Canada. Some of the British circuits were also connected through to systems in Europe.

Before the installation of the cable, international calls by radiotelephone had been possible since 1927, but the cost was so high that, in 1955, only 100,000 calls were made in a year. The first year of cable service, the number of transatlantic calls more than doubled: 220,000 calls were made between the U.S. and Britain and 75,000 between Britain and Canada. Today, residents of the United States place 500,000 transatlantic calls a day.


Route of the first transatlantic telephone cable

Transatlantic telephone cable operations in Oban, Scotland





To commemorate the City of Troy’s 60th Anniversary in 2015, we will publish a different story each day that highlights a person, discovery, or event that occurred locally, regionally, nationally, or even globally between 1955 and 2015 and that helped shape our lives and our community. We will try to post stories on important anniversary dates, but we also realize that dates are less critical than content and context. We will include the facts related to controversial stories, allowing our readers to form their own opinions. We invite you to read and comment on the stories. Your suggestions for topics are also welcome and can be posted on our Facebook page, www.facebook.com/TroyHistoricVillage. You can also email stories or ideas to the 365 Story Editor at ed@thvmail.org.

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