Clarenville, N.L., became the North American gateway to the world’s first transatlantic telephone service on Sept. 25, 1956, when engineers in New York, Ottawa and London opened cable system TAT-1 with a live three-way call, according to the History of the Atlantic Cable and Submarine Telegraphy archive and the IEEE Engineering and Technology History Wiki.
The system, formally called Transatlantic No. 1, linked Oban, Scotland, to Clarenville by way of twin submarine cables running roughly 1,950 nautical miles across the North Atlantic seabed, each fitted with 51 repeaters spaced about 37 nautical miles apart to boost the signal, the IEEE wiki says. From Clarenville, the connection continued overland across Newfoundland to Terrenceville before crossing the Cabot Strait by cable to Sydney Mines, N.S., and joining the continental telephone network, according to atlantic-cable.com, a specialist archive of submarine cable history.
At the Sept. 25 opening, Cleo F. Craig, chairman of American Telephone and Telegraph, declared the line open for service between the United States and the United Kingdom from a gathering in New York. In Ottawa, George C. Marler, Canada’s minister of transport, and Douglas F. Bowie, president of the Canadian Overseas Telecommunications Corporation, announced Canada’s part in the venture, while Dr. Charles Hill, Britain’s postmaster general, confirmed the British Post Office’s role from London, according to atlantic-cable.com’s account of the ceremony. Hill remarked to Craig during the call that he sounded “as if you’re speaking from somewhere in London,” despite being roughly 4,000 miles away, the archive says. About 250 guests watched the ceremony on television screens and through individual earphones.
Before TAT-1, transatlantic calls travelled by high frequency radio, a method vulnerable to static, weather and limited capacity. The new cable initially carried 35 simultaneous telephone conversations plus one channel that could be split into 22 telegraph circuits, the IEEE wiki says. On its first day of commercial service, the line handled 588 calls between London and the United States and 119 between London and Canada, according to atlantic-cable.com.
Laying the Newfoundland leg was itself an engineering challenge. Crews trenched cable through bog, rock and ponds across the island’s interior between Clarenville and Terrenceville, a stretch of about 55 nautical miles, using portable equipment and X-ray inspection gear to check splices, atlantic-cable.com reports. The full project cost about 120 million pounds, split roughly 40 per cent British, 50 per cent American and 10 per cent Canadian, according to the same archive.
TAT-1’s capacity grew over time. Bell Laboratories’ Time Assignment Speech Interpolation technology, introduced in June 1960, allowed the cable to carry the equivalent of 72 speech circuits by filling the silent gaps in ordinary conversation, the IEEE wiki notes. The cable carried the Moscow to Washington hotline starting July 13, 1963, a direct result of communication delays during the Cuban Missile Crisis the previous year, and in May 1957 singer Paul Robeson used it to perform live from New York for an audience in London, according to the same source.
Wikipedia’s entry on TAT-1 says the system remained in service until 1978, when newer cables and satellite links made it obsolete, and the Institute of Electrical and Electronics Engineers designated it a milestone achievement in 2006. Newfoundland, which had joined Confederation only seven years earlier, in 1949, was by 1956 the physical link connecting North America’s telephone network to Europe’s, a role its cable stations would keep playing into the satellite era.
