The world’s first submarine transatlantic telephone cable system was inaugurated.
Known as Transatlantic No. 1 or TAT-1, the £120 million system actually consisted of two identical cables to allow transmission in each direction. Prompted by the successful installation of a submarine cable between Florida and Cuba in 1952, a consortium of the UK’s General Post Office, the American Telephone and Telegraph Company, and the Canadian Overseas Telecommunications Corporation agreed to investigate the feasibility of a transatlantic cable.
It was already possible to make a transatlantic telephone call when the 1,950 nautical mile long cable began to be laid in 1955. However, this involved numerous radio links to be booked in advance and was consequently an expensive method of communicating that required significant advance planning.
Stretching from Oban in Scotland to Clarenville in Newfoundland, TAT-1 was able to carry 35 simultaneous telephone calls while a 36th channel provided an additional 22 telegraph lines. Calls from the UK were charged at £1 per minute, a significant reduction from the cost of the radio alternative.
Having gone into operation almost as soon as the two ends were connected, TAT-1 went on to carry over 600 transatlantic calls in the first 24 hours of public service. In 1963, following the de-escalation of the Cuban Missile Crisis, TAT-1 also carried the Moscow-Washington hotline that linked the Kremlin to the White House.
TAT-1 was eventually retired in 1978 having been superseded by other transatlantic cables that were capable of transmitting a greater number of concurrent signals.