Transatlantic communications cable

When the first transatlantic telegraph cable was laid in 1858 by Cyrus West Field, it operated for only three weeks; a subsequent attempt in 1866 was more successful.{{Citation needed|date=May 2024}} On July 13, 1866 the cable laying ship Great Eastern sailed out of Valentia Island, Ireland and on July 27 landed at Heart's Content in Newfoundland, completing the first lasting connection across the Atlantic. It was active until 1965.{{Cite journal|last=Guarnieri|first=M.|title=The Conquest of the Atlantic |journal=IEEE Industrial Electronics Magazine|date=March 2014 | volume=8 | issue=1 |pages=53–55/67|doi=10.1109/MIE.2014.2299492}}

Although a telephone cable was discussed starting in the 1920s,{{cite web |last1=Elmore |first1=Bart |title=January 2017: From the Transatlantic Telephone to the iPhone |url=https://origins.osu.edu/milestones/january-2017-transatlantic-telephone-iphone |website=Origins |publisher=Ohio State University |access-date=28 May 2021}} to be practical it needed a number of technological advances which did not arrive until the 1940s.{{Citation needed|date=September 2012}} Starting in 1927, transatlantic telephone service was radio-based.[http://alcatel-lucent.com/bstj/vol14-1935/articles/bstj14-3-489.pdf Short-Wave System for Transatlantic Telephony, by Polkinghorn and Schlaack] BSTJ, 1935

TAT-1 (Transatlantic No. 1) was the first transatlantic telephone cable system. It was laid between Gallanach Bay, near Oban, and Clarenville, Newfoundland between 1955 and 1956 by the cable ship Monarch.[https://books.google.com/books?id=nNwDAAAAMBAJ&pg=PA115 "Being First Telephone Cable to Connect Hemispheres"]. Popular Mechanics, March 1954, p. 114. 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. The Moscow–Washington hotline was initially connected through this system.

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

There has 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 bandwidth – the 2012 generation of cables drop the transatlantic latency to under 60 milliseconds, according to Hibernia Atlantic, deploying such a cable that year.{{cite web|url=https://www.wsj.com/articles/SB10001424052970204524604576610860386189444 |title=Building Networks for High-Speed Stock Trading - WSJ.com |publisher=Online.wsj.com |date=October 9, 2011 |access-date=September 18, 2013}}{{cite news |url=https://www.telegraph.co.uk/finance/newsbysector/mediatechnologyandtelecoms/8753784/The-300m-cable-that-will-save-traders-milliseconds.html |archive-url=https://web.archive.org/web/20110911194258/http://www.telegraph.co.uk/finance/newsbysector/mediatechnologyandtelecoms/8753784/The-300m-cable-that-will-save-traders-milliseconds.html |url-status=dead |archive-date=September 11, 2011 |title=The $300m cable that will save traders milliseconds |newspaper=The Daily Telegraph |location=London |date=September 11, 2011 |access-date=September 18, 2013}}

Some new cables are being announced on the South Atlantic: SACS (South Atlantic Cable System){{cite web|url=http://www.nec.com/en/press/201411/global_20141104_04.html|title=Angola Cables to build the world's first submarine cable across the South Atlantic: Press Releases - NEC}} and SAex (South Atlantic Express).{{cite web|url=http://www.techcentral.co.za/16tbits-saex-cable-deal-signed/35811/|title=16Tbit/s SAEx cable deal signed}}

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 US.

There are a number of private non-TAT cables.

• Cable layer
• List of international submarine communications cables

{{reflist}}

• {{cite journal|first=Jeremiah|last=Hayes|title=A history of transatlantic cables|journal=IEEE Communications|date=September 2008|volume=46|issue=9|pages=42–48|doi=10.1109/MCOM.2008.4623705}}
• [https://web.archive.org/web/20130724101651/http://aronsson.se/hist.html Aronsson's Telecom History Timeline]
• [http://www.atlantic-cable.com/Cables/CableTimeLine/index.htm Timeline of Submarine Communications Cables, 1850–2024]
• [http://www.kidorf.com/DBLandings.php Submarine Cable Landings Worldwide]

{{Transatlantic telephone cables}}

{{Submarine communications cables in the Atlantic Ocean}}

{{DEFAULTSORT:Transatlantic Telephone Cable}}

Category:History of the telephone

Category:History of telecommunications in the United States

Category:History of telecommunications in the United Kingdom