TAT-1

TAT -1 (Transatlantic No. 1.) Was the first transatlantic telephone cable system. It was between Oban, Scotland and Clarenville in Newfoundland. It was put into operation on 25 September 1956.

History

The first transatlantic cable was laid in 1858 by Cyrus West Field. After just one month of operating time it was replaced in 1866. With these cables but only telegraphic connections were possible. The telephone connection via radio was taken in 1927 in operation. The call charge for three minutes was 9 pounds (then about $ 45, according to today's purchasing power $ 550 ). The technology for such a long submarine telephone cable ( electron tubes for amplifiers, polyethylene instead of gutta-percha for insulation, carrier frequency) was available only in the 1940s. The cost of 120 million pounds was paid by the British postal authority, AT & T, as well as to 10% of VSNL Canada.

Technology

It was given a separate cable for each direction of speech. The cable consisted of two armored shallow-water sections as well as a 1,500 -mile deep-water part. All 37 nautical miles was a tube amp (each a total of 51 pieces) inserted. By the carrier -frequency technology speech circuits 36 were possible. The cable was taken out of service in 1978.

Laying

The cables were deployed in the summers of 1955 and 1956 mainly from the British cable ship Monarch. The end points were in the Gallanach Bay in Oban in Scotland and Clarenville, Newfoundland. On opening day, September 25, 1956, 707 calls were communicated. The capacitance of the cable was increased by reducing the voice bandwidth soon to 48 channels. In the 1960s, three voice channels have been added yet.