Cable underwater

A underwater cable is a cable posed on the Sea-bed, or ensouillé at a shallow depth, intended to convey Communication S or to transport electrical energy.

The underwater cables are set up and maintained by ships cable-laying ships, after bathymetric recognition to locate the ideal way (shortest, but without risk for the cable); by low depths, and when the nature of the bottom allows it, the cables are generally ensouillés using a system resembling a Charrue: this makes it possible to minimize the risks of damage, in particular by the Chalutier S.

Transport of energy

underwater cables can connect islands to the continent, or inter-connect distinct networks; they are also used to at sea convey the electricity produced in the wind farms (“parks Offshore ”). These cables make it possible to transport energy (alternative course or continuous) under tensions ranging between 30 Kv and more than 400 Kv; they generally comprise one or more fiberoptics allowing the simultaneous transmission of information of exploitation (wind farms) or telecommunications.

Communications

The underwater cables of communication are used to convey telephone calls, or to inter-connect data-processing networks (Internet); traditionally composed of coaxial cables, they generally contain from now on Fiberoptics. To compensate for the progressive attenuation of the signals, of the Répéteur S can be established with regular intervals.

The first underwater cables of communication were cables intended for the Télégraphe, then the cables intended for the phone lines appeared and finally today the cables make it possible to transport numerical data. Currently the latter all are composed of fiberoptics to transport payloads, which are then used to as well transport the telephone traffic as data-processing (Internet) and of the private networks.

In 2005, the underwater cables connect all the continents, except for the Antarctic.

Transatlantic cables

A transatlantic cable is a cable of telecommunication connecting the Europe to the America.

Characteristics of the 1st cable

3.200 km of distance
4.200 km of cable of a weight of 7.000 tons.

a heart made up of a pure strand of seven copper wires sheathed of three layers of Gutta-perched (12,2 mms diameter)
a thin layer of tarpaulin armed with 18 formed strands each of 7 iron wire
Départ in Europe: Valentia an Irish small island 11 km length
Departure in America: Trinity Bay with the Canada
maintenance is carried out by raising of the cable
Transmission speed in Morse: 2,75 words per minute.

History

1839, first ideas
In August 1850, the Goliath tug boat poses the underwater cable between the Cape Gray-Nose, in France, and the Cape Southerland, in England.
In 1860, a connection is established between London and the Indian continent.
1857, the first cable is drawn but at the end of 10 days, the cable breaks by 3700 m basic, the project is abandoned for one year.
1866, the Great Eastern succeeds in posing the cable
July 27th 1866, the first message transmitted by the queen Victoria to the US president James Buchanan:

"Glory to God in the highest, one earth and good will to all men"
" Glory with God with highest of the skies, on the ground and with the men of good volonté"

1950, the first underwater telephone link between Key West and Havana.
1956, the first telephone cable (TAT1), 48 telephone ways
1988, the first cable with fiberoptics. (TAT8), 40.000 telephone ways
2002, the Apollo cable, of Cable & Wireless, made up of two cables (Apollo North and Apollo South), of four pairs of fiberoptics. Each cable has a line capacity of 3,2 Terabits a second

Owners and cablers

TYCO
ASN Navy
Elettra;
FT Marine
Marine Systems Limited
NTT World Engineering Marine Corporation (NTT-WEM)
S.B. Submarine Systems
YIT Primatel Ltd.

List underwater cables of communication

See also: List of the underwater cables of communication

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