Editing Transatlantic communications cable (section)

==History==
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 layer|cable laying ship]] ''[[SS Great Eastern|Great Eastern]]'' sailed out of [[Valentia Island]], [[Ireland]] and on July 27 landed at [[Heart's Content, Newfoundland and Labrador|Heart's Content]] in [[Newfoundland]], completing the first lasting connection across the Atlantic. It was active until 1965.<ref>{{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}}</ref> 

Although a telephone cable was discussed starting in the 1920s,<ref>{{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}}</ref> 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.<ref>[http://alcatel-lucent.com/bstj/vol14-1935/articles/bstj14-3-489.pdf Short-Wave System for Transatlantic Telephony, by Polkinghorn and Schlaack] BSTJ, 1935</ref>

[[TAT-1]] (Transatlantic No. 1) was the first transatlantic telephone cable system. It was laid between Gallanach Bay, near [[Oban]], and [[Clarenville]], [[Newfoundland and Labrador|Newfoundland]] between 1955 and 1956 by the [[cable ship]] ''[[CS Monarch (1945)|Monarch]]''.<ref>[https://books.google.com/books?id=nNwDAAAAMBAJ&pg=PA115 "Being First Telephone Cable to Connect Hemispheres"]. ''Popular Mechanics'', March 1954, p. 114.</ref> 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 [[transistor]]s and had higher bandwidth. The [[Moscow–Washington hotline]] was initially connected through this system.