Editing TAT-8 (section)

==History==

This was the first transatlantic cable to use [[optical fiber]]s, a revolution in telecommunications. The system contained two working pairs of optical fibers; a third fiber pair (in the AT&T segment only) was reserved as a span-wise spare. The signal on each optical fiber was modulated at 295.6&nbsp;Mbit/s (carrying 280&nbsp;Mbit/s of traffic) and fully regenerated in equipment placed in pressure housings separated by about 40&nbsp;km of cable.

There were several problems with the early reliability of this cable during its first two years of operation.{{citation needed|date=February 2024}}<ref>R.K. Stix, et al, Private Communication, 1989</ref> The cable was buried on the continental shelf on the European and the American side of the ocean. The burial was largely effective, and the cable issues were primarily related to manufacturing defects. AT&T laid a trial optical cable in the [[Canary Islands]] in 1985. This cable did not have an electrical screen and was attacked by sharks. It was never proved whether these attacks were due to the sharks sensing the electrical radiation from the cable or the vibration of the cable moving on the sea floor where it might have been suspended, or a combination of both. TAT-8 did not have the screen conductor over the vast majority of its length, as the threat of shark attack was deemed to be small over the majority of the route. Because the Canary Island cable was the first fiber-optic cable and not a [[coaxial cable]], the electrical interference shielding for the high voltage supply lines was removed. This removal did not affect the fiber, but it did cause [[feeding frenzy|feeding frenzies]] in sharks that swam nearby. The sharks would then attack the cable until the voltage lines killed them. This caused numerous, prolonged outages. Eventually, a shark shielding was developed for the cable and was available for TAT-8. [[PTAT-1]], the next cable to go in the Atlantic was put in with the shark shielding across its entire length; the added reliability provided by this shield has not been fully evaluated.

The system was manufactured by a consortium of three established submarine system suppliers: AT&T, [[Standard Telephones and Cables]] and Alcatel. The idea was that each manufacturer would manufacture part of the system, so French technology procured by France Télécom would land in France, US technology in America procured by AT&T and British technology procured by BT in the UK. The systems were designed to interoperate although the regenerator supervisory systems were all proprietary. The transition between one supplier to another supplier's regenerators was achieved using a "mid-span meet". AT&T was appointed the integration coordinator and integration trials were held in [[Freehold Borough, New Jersey|Freehold, New Jersey]].