TAT-8
Encyclopedia
TAT-8 was the 8th transatlantic telecommunications cable,
initially carrying 40,000 telephone circuits (simultaneous calls) between USA
, England and France. It was constructed in 1988 by a consortium of companies led by AT&T
, France Telecom
, and British Telecom. It was able to serve the three countries with a single trans-Atlantic crossing with the use of an innovative branching unit located underwater on the continental shelf
off the coast of Great Britain. The cable lands in Tuckerton, New Jersey
, USA, Widemouth Bay
, England, and Penmarch
, France.
The system was built at a cost of US$335M in 1988 and retired from service in 2002.
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 was reserved as a spare.) The signal on each optical fiber was modulated at 295.6 Mbit/s (carrying 20 Mbit/s traffic) and fully regenerated in equipment placed in pressure housings separated by about 40 km of cable.
There were several problems with the early reliability of this cable during its first 2 years of operation. The cable was laid, not buried, on the continental shelf
. As a result it was snagged and damaged by fish trawling
fleets. Because the cable was the first fiber optic cable and not 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 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. PTAT-1
, the next cable to go in the Atlantic was put in with the shark shielding and it proved much more reliable than TAT-8.
The system was manufactured by a consortium of three established submarine system suppliers: AT&T, STC and Alcatel. The idea was that each manufacturer would manufacture part of the system, so French technology procured by France Telecom 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. Transition between one supplier to another supplier's regenerators was achieved using a "mid-span meet." AT&T was appointed the Integration co ordinator and integration trials were held in Freehold New Jersey.
initially carrying 40,000 telephone circuits (simultaneous calls) between USA
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, England and France. It was constructed in 1988 by a consortium of companies led by AT&T
AT&T
AT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...
, France Telecom
France Télécom
France Telecom S.A. is the main telecommunications company in France, the third-largest in Europe and one of the largest in the world. It currently employs about 180,000 people and has 192.7 million customers worldwide . In 2010 the group had revenue of €45.5 billion...
, and British Telecom. It was able to serve the three countries with a single trans-Atlantic crossing with the use of an innovative branching unit located underwater on the continental shelf
Continental shelf
The continental shelf is the extended perimeter of each continent and associated coastal plain. Much of the shelf was exposed during glacial periods, but is now submerged under relatively shallow seas and gulfs, and was similarly submerged during other interglacial periods. The continental margin,...
off the coast of Great Britain. The cable lands in Tuckerton, New Jersey
Tuckerton, New Jersey
Tuckerton is a Borough in Ocean County, New Jersey, named for founder Ebenezer Tucker , and was a port of entry, but not the third Port of Entry as commonly believed, in the United States As of the 2000 United States Census, the borough population was 3,517.Tuckerton was incorporated as a borough...
, USA, Widemouth Bay
Widemouth Bay
Widemouth Bay is a bay and beach on the Atlantic coast of Cornwall, England, UK, approximately 3 miles south of Bude. This stretch of coast is steeped in the smuggling history of times before, and not far south of Widemouth Bay can be found many little inlets and coves.-Activities:The beach is...
, England, and Penmarch
Penmarch
Penmarc'h or Penmarch is a commune in the Finistère department of Brittany in north-western France. It lies 18 km south-west of Quimper by road.-History:...
, France.
The system was built at a cost of US$335M in 1988 and retired from service in 2002.
This was the first transatlantic cable to use optical fiber
Optical fiber
An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...
s, a revolution in telecommunications. The system contained two working pairs of optical fibers. (A third was reserved as a spare.) The signal on each optical fiber was modulated at 295.6 Mbit/s (carrying 20 Mbit/s traffic) and fully regenerated in equipment placed in pressure housings separated by about 40 km of cable.
There were several problems with the early reliability of this cable during its first 2 years of operation. The cable was laid, not buried, on the continental shelf
Continental shelf
The continental shelf is the extended perimeter of each continent and associated coastal plain. Much of the shelf was exposed during glacial periods, but is now submerged under relatively shallow seas and gulfs, and was similarly submerged during other interglacial periods. The continental margin,...
. As a result it was snagged and damaged by fish trawling
Trawling
Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net that is used for trawling is called a trawl....
fleets. Because the cable was the first fiber optic cable and not coaxial cable
Coaxial cable
Coaxial cable, or coax, has an inner conductor surrounded by a flexible, tubular insulating layer, surrounded by a tubular conducting shield. The term coaxial comes from the inner conductor and the outer shield sharing the same geometric axis...
, the electrical interference shielding for the high voltage supply lines was removed. This removal did not affect the fiber, but it did cause feeding frenzies
Feeding frenzy
In ecology, a feeding frenzy is a situation where oversaturation of a supply of food leads to rapid feeding by predatory animals. For example, a large school of fish can cause nearby sharks to enter a feeding frenzy. This can cause the sharks to go wild, biting anything that moves, including each...
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. PTAT-1
PTAT-1
PTAT-1 was the first privately financed transatlantic fiber optic cable, which was completed in 1989, at a cost of 400 million US dollars.It was maintained by C&W and Sprint/PSI and connected Manasquan, New Jersey, USA with Devonshire, Bermuda and Ballinspittle, Ireland, terminating at Brean,...
, the next cable to go in the Atlantic was put in with the shark shielding and it proved much more reliable than TAT-8.
The system was manufactured by a consortium of three established submarine system suppliers: AT&T, STC and Alcatel. The idea was that each manufacturer would manufacture part of the system, so French technology procured by France Telecom 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. Transition between one supplier to another supplier's regenerators was achieved using a "mid-span meet." AT&T was appointed the Integration co ordinator and integration trials were held in Freehold New Jersey.