Transatlantic communications cable

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A transatlantic telecommunications cable is a submarine communications cable connecting one side of the Atlantic Ocean to the other. In the 19th and early 20th centuries each cable was a single wire. After mid-century Coaxial cable came into use, with amplifiers. Late in the century, all used optical fiber, and most now use optical amplifiers.


When the first transatlantic telegraph cable was laid in 1858 by businessman Cyrus West Field, it operated for only three weeks; subsequent attempts in 1865 and 1866 were more successful.[1] Although a telephone cable was discussed starting in the 1920s[citation needed], to be practical it needed a number of technological advances which did not arrive until the 1940s[citation needed]. Starting in 1927, transatlantic telephone service was radio-based.[2]

TAT-1 (Transatlantic No. 1) was the first transatlantic telephone cable system. It was laid between Gallanach Bay, near Oban, Scotland and Clarenville, Newfoundland between 1955 and 1956 by the cable ship Monarch.[3] It was inaugurated on September 25, 1956, initially carrying 36 telephone channels. In the first 24 hours of public service there were 588 London–U.S. calls and 119 from London to Canada. The capacity of the cable was soon increased to 48 channels. Later, an additional three channels were added by use of C Carrier equipment. Time-assignment speech interpolation (TASI) was implemented on the TAT-1 cable in June 1960 and effectively increased the cable's capacity from 37 (out of 51 available channels) to 72 speech circuits. TAT-1 was finally retired in 1978. Later coaxial cables, installed through the 1970s, used transistors and had higher bandwidth.

Current technology

All cables presently in service use fiber optic technology. Many cables terminate in Newfoundland and Ireland, which lie on the great circle route (the shortest route) from London, UK to New York City, USA.

There have been a succession of newer transatlantic cable systems. All recent systems have used fiber optic transmission, and a self-healing ring topology. Late in the 20th century, communications satellites lost most of their North Atlantic telephone traffic to these low cost, high capacity, low latency cables. This advantage only increases over time as tighter cables provide higher speed – the 2012 generation of cables drop the transatlantic latency to under 60 milliseconds, according to Hibernia Atlantic, deploying such a cable that year.[4][5]

Some new cables are being announced on the South Atlantic: SACS(South Atlantic Cable System)[6] and SAex(South Atlantic Express) [7]

TAT cable routes

The TAT series of cables constitute a large percentage of all North Atlantic cables. All TAT cables are joint ventures between a number of telecommunications companies, e.g. British Telecom. CANTAT cables terminate in Canada rather than in the USA.

Name In service Type Initial channels Final channels Western end Eastern end
TAT-1 1956–1978 Galvanic 36 51 Newfoundland United Kingdom
TAT-2 1959–1982 Galvanic 48 72 Newfoundland France
TAT-3 1963–1986 Galvanic 138 276 New Jersey United Kingdom
TAT-4 1965–1987 Galvanic 138 345 New Jersey France
TAT-5 1970–1993 Galvanic 845 2,112 Rhode Island Spain
TAT-6 1976–1994 Galvanic 4,000 10,000 Rhode Island France
TAT-7 1978–1994 Galvanic 4,000 10,500 New Jersey United Kingdom
TAT-8 1988–2002 Fiber-optic 40,000 USA United Kingdom, France
TAT-9 1992–2004 Fiber-optic 80,000 USA, Nova Scotia Spain, France, United Kingdom
TAT-10 1992–2003 Fiber-optic 2 × 565 Mbit/s USA Germany, Netherlands
TAT-11 1993–2003 Fiber-optic 2 × 565 Mbit/s USA France
TAT-12/13 1996–2008 Fiber-optic 12 × 2.5 Gbit/s USA × 2 United Kingdom, France
TAT-14 2001– Fiber-optic 3.2 Tbit/s USA × 2 United Kingdom, France, Netherlands, Germany, Denmark
CANTAT-1 1961–1986 Galvanic 80 Newfoundland United Kingdom
CANTAT-2 1974–1992 Galvanic 1,840 Nova Scotia United Kingdom
CANTAT-3 1994–2010 Fiber-optic 2 × 2.5 Gbit/s Nova Scotia Iceland, Faroe Islands, United Kingdom, Denmark, Germany
PTAT-1 1989–2004 Fiber-optic 3 × 140 Mbit/s? New Jersey & Bermuda Ireland & United Kingdom

Private cable routes

There are a number of private non-TAT cables.

Cable name Date(s) Nominal capacity Latency (ms) Landings Owner
Gemini (decommissioned) 1998 Under 100 ms Vodafone (originally Cable & Wireless)
Apollo 2002 3.2 Tbit/s Under 100 ms Vodafone/Alcatel-Lucent (originally Cable & Wireless)[8]
AC-1 1998 120 Gbit/s 65 ms[5] Level 3 Communications (originally Global Crossing)
Yellow/AC-2 2000 640 Gbit/s Under 100 ms Level 3 Communications
FLAG Atlantic 2000 Under 100 ms Reliance Communications
VSNL Transatlantic 2001 5.1 Tbit/s Under 100 ms Sold by Tyco to VSNL in 2005
Hibernia Atlantic 2001 320 Gbit/s, upgraded to 10.16 Tbit/s[9] Under 70 ms CVC Acquisition Company
Emerald Express 2014 (scheduled)[10] 4 × 10 Tbit/s (four strand 100 × 100 Gbit/s) 54 ms Moncton; St. John's; Grindavík, Iceland; Belfast; Dublin; Shirley, New York Emerald Atlantis
Hibernia Atlantic 2012 Unknown (four strand) 59 ms[5] Herring Cove (near Halifax, Canada) CVC Acquisition Company

South Atlantic cable routes

Cable name Date(s) Landing Owner
SACS 2016 Luanda; Fortaleza Angola Cables
SAex 2017 Mtunzini; Yzerfontein; Saint Helena; Fortaleza SimplCom South Africa

See also


  1. Lua error in Module:Citation/CS1/Identifiers at line 47: attempt to index field 'wikibase' (a nil value).
  2. Short-Wave System for Transatlantic Telephony, by Polkinghorn and Schlaack BSTJ, 1935
  3. "Being First Telephone Cable to Connect Hemispheres" Popular Mechanics, March 1954, p. 114.
  4. "Building Networks for High-Speed Stock Trading -". October 9, 2011. Retrieved September 18, 2013.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  5. 5.0 5.1 5.2 "The $300m cable that will save traders milliseconds". The Daily Telegraph. London. September 11, 2011. Retrieved September 18, 2013.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  8. "Submarine Cable Actions Taken PN". FCC. October 4, 2012.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  9. "Hibernia Offers Cross-Atlantic 40G". Light Reading. August 13, 2009.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  10. "About Us | Emerald Networks". Emerald Networks. February 14, 2013.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>

External links