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History of the Atlantic Cable & Undersea Communications
from the first submarine cable of 1850 to the worldwide fiber optic network

1970 TAT-5 / MAT-1 Cables

The fifth in a series of transatlantic telephone cables which began with TAT-1 in 1956, TAT-5 was laid in 1970 between Green Hill, Rhode Island, USA and Conil, Spain, with an extension from Estepona, Spain, to Palo, Italy, designated as MAT-1. TAT-5 had a capacity of 845 telephone circuits and MAT-1 640 circuits.

The type SF cable was manufactured by Standard Telephones & Cables Ltd (1220 nm.), Câbles de Lyon (630 nm.) and Western Electric (1620 nm.) and was laid by AT&T’s cableship Long Lines. 361 repeaters were used, manufactured by Western Electric.

George Craig, who worked for 32 years with AT&T and Ocean Cables, adds this note on an early problem with TAT-5:

Shortly after TAT-5 went into service it failed, and divers found an eight to ten foot trench running as far as they could see, east and west of where the cable was buried, with the cable dangling on both sides of the trench.

A very large Russian factory fishing boat had been reported as being in the area at the time of the cable break. Accompanying the factory ship were several smaller fishing boats, which took their catch to the larger ship to be processed. It appeared that the factory ship had dragged its anchor across the buried cable. Accidentally of course...

I measured the location of the break by powering up the cable and using the voltage output of the power plant and a little math, a very simple procedure. I don't remember exactly how far out the break was, but it was at least ten miles from shore and still on the continental shelf, which extends some 90 miles from the Green Hill cable station.

The extension from Spain to Italy, MAT-1, was 990 nm. in length with 93 repeaters and was laid by CS John W. Mackay.

The cable’s main partners were AT&T (USA), CTNE (Compania Telefonica Nacional de Espana, Spain), CPRM (Companha Portuguesa Radio Marconi, Portugal), and Italcable (Italy). Other authorities leased circuits in the cable.

The TAT-5 system cable length was 3461 nm., with MAT-1 being a further 990 nm. TAT-5 was in operation from 1970 until 1993, when it was withdrawn from service.

This souvenir of TAT-5/MAT-1 has a sample of the transistor
used in the repeaters mounted over a topographic map
of the cable route and encased in acrylic plastic
Overall size 6.5" x 4.5" x 1.25"

The commemorative medal shown below was created by Portuguese sculptor Joao Duarte for Companhia Portuguesa Radio Marconi, the Portuguese telecommunications company. The obverse shows the cable route from the USA to Spain, with the ongoing connection to Italy The reverse has the insignia of the country of each of the main partners in the cable. Other partners were ITT World Communications, RCA Global Communications, and Western Union International.

Sistema de Telecomunicacoes
TAT-5/MAT-1
Abril 1970

Companhia Portuguesa
Radio Marconi

Medal diameter 80mm.

Medal maker Joao Duarte of Portugal

USA

Portugal

Italy

Spain

Another commemorative of TAT-5 - MAT-1 is this bronze plaque mounted on Italian marble, which shows the flags of each of the cable’s main partners. The bronze is signed at the lower right with the maker’s name Orlandini.

Detail of plaque

See also Leo Parrish’s page on the laying of TAT-5

Last revised: 6 July, 2010

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—Bill Burns, publisher and webmaster: Atlantic-Cable.com