A transatlantic telephone cable is a submarine communications cable that carries telephone traffic under the Atlantic Ocean.

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

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. 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. TAT-1 was finally retired in 1978.

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 cables.

Cable Name	Date(s) in service	Type	Initial No. of channels	Final No. of channels	Western end	Eastern end
TAT-1	1956–1978	Galvanic	36	48	Newfoundland	Scotland
TAT-2	1959–1982	Galvanic	48	72	Newfoundland	France
TAT-3	1963–1986	Galvanic	138	276	New Jersey	England
TAT-4	1965–1987	Galvanic	138	345	New Jersey	France
TAT-5	1970–1993	Galvanic	845	2112	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	England
TAT-8*	1988–2002	Fiber-optic	40,000	-	USA	England, 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
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	2000–	Fiber-optic	64 x 10 Gbit/s	-	USA × 2	United Kingdom, France, Netherlands, Germany, Denmark
CANTAT-1	1961–1986	Galvanic	80	-	Newfoundland	Scotland
CANTAT-2	1974–1992	Galvanic	1,840	-	Nova Scotia	England
CANTAT-3	1994–	Fiber-optic	2 × 2.5 Gbit/s		Nova Scotia	Iceland, Faroe Islands, England, Denmark, Germany
PTAT-1	1989–2004	Fiber-optic	3 × 140 Mbit/s?		New Jersey & Bermuda	Ireland & United Kingdom

* first fiber optic cable.

The TAT series of cables constitute a large percentage of all North Atlantic cables. All TAT cables are consortia joint ventures between a number of telecommunications companies, e.g. British Telecom. CANTAT are transatlantic telephone cables terminating in Canada rather than the USA. There are a number of private non-TAT cables.

Cable name	Date(s)	Nominal Capacity	Owner
Gemini (decommissioned)	1998		Cable & Wireless
Apollo	2002	3.2 Tbit/s	Cable & Wireless
AC-1	1998	120 Gbit/s	Global Crossing
Yellow/AC-2	2000		Level 3
FLAG Atlantic	2000		Reliance Communications
VSNL Transatlantic	2001	5.1 Tbit/s	sold by Tyco to VSNL in 2005
Hibernia Atlantic	2001	320 Gbit/s	CVC Acquisition Company

[edit] See also

• Cable layer

[edit] External links

• Aronsson's Telecom History Timeline
• Timeline of Submarine Communications Cables, 1850-2008
• Submarine Cable Landings Worldwide

v • d • e Transatlantic telephone cables TAT series TAT-1 · 2 · 3 · 4 · 5 · 6 · 7 · 8 · 9 · 10 · 11 · 12/13 · 14 · CANTAT-1 · 2 · 3 · PTAT-1 Private non-TAT Gemini · Apollo · AC-1 · Yellow/AC-2 · FLAG Atlantic · VSNL Transatlantic · Hibernia Atlantic Other SAT-2 · SAT-3/WASC/SAFE · ATLANTIS-2 · COLUMBUS III