TAT-1 (Transatlantic No. 1) was the first submarine transatlantic telephone cable system. It was laid between Kerrera,Oban, Scotland and Clarenville, Newfoundland. [1] Two cables were laid between 1955 and 1956 with one cable for each direction. [1] It was inaugurated on September 25, 1956. [2] The cable was able to carry 35 simultaneous telephone calls. [3] A 36th channel was used to carry up to 22 telegraph lines. [3]
The first transatlantic telegraph cable had been laid in 1858 (see Cyrus West Field). [4] It only operated for a month, but was replaced with a successful connection in 1866. [4] A radio-based transatlantic telephone service was started in 1927, charging £9 [5] (about US$45, or roughly $550 in 2010 dollars) for three minutes and handling around 300,000 calls a year. Although a telephone cable was discussed at that time, it was not practical until a number of technological advances arrived in the 1940s.
The developments that made TAT-1 possible were coaxial cable, polyethylene insulation (replacing gutta-percha), very reliable vacuum tubes for the submerged repeaters and a general improvement in carrier equipment. Transistors were not used, being a recent invention of unknown longevity.
The agreement to make the connection was announced by the Postmaster General on December 1, 1953. The project was a joint one between the General Post Office of the UK, the American Telephone and Telegraph company, and the Canadian Overseas Telecommunications Corporation. The share split in the scheme was 40% British, 50% American, and 10% Canadian. The total cost was about £120 million.
There were to be two main cables, one for each direction of transmission. Each cable was produced and laid in three sections, two shallow-water armored sections, and one continuous central section 1,500 nautical miles (2,800 km) long. The electronic repeaters were designed by the Bell Telephone Laboratories of the United States and they were inserted into the cable at 37-nautical-mile (69 km) intervals – a total of 51 repeaters in the central section. The armored cables were manufactured southeast of London, at a factory in Erith, Kent, owned by Submarine Cables Ltd. (owned jointly by Siemens Brothers & Co, Ltd, and The Telegraph Construction & Maintenance Company, Ltd). [6]
The cables were laid over the summers of 1955 and 1956, with the majority of the work done by the cable ship HMTS Monarch. At the land-end in Gallanach Bay near Oban, Scotland, the cable was connected to coaxial (and then 24-circuit carrier lines) carrying the transatlantic circuits via Glasgow and Inverness to the International Exchange at Faraday Building in London. At the cable landing point in Newfoundland the cable joined at Clarenville, then crossed the 300-mile (480 km) Cabot Strait by another submarine cable to Sydney Mines, Nova Scotia. From there the communications traffic was routed to the US border by a microwave radio relay link, and in Brunswick, Maine the route joined the main US network and branched to Montreal to connect with the Canadian network.
Opened on September 25, 1956, TAT-1 carried 588 London-US calls and 119 London-Canada calls in the first 24 hours of public service.
The original 36 channels were 4 kHz. The increase to 48 channels was accomplished by narrowing the bandwidth to 3 kHz. 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. [7]
TAT-1 carried the Moscow-Washington hotline between the American and Soviet heads of state, although using a teleprinter rather than voice calls as written communications were regarded as less likely to be misinterpreted. [8] The link became operational on 13 July 1963 and was principally motivated as a result of the Cuban Missile Crisis where it took the US, for example, nearly 12 hours to receive and decode the initial settlement message that contained approx. 3,000 words. By the time the message was decoded and interpreted, and an answer had been prepared, another – more aggressive – message had been received. [9]
In May 1957, TAT-1 was used to transmit a concert by the singer and civil rights activist, Paul Robeson performing in New York to St Pancras Town Hall in London. [10] Due to McCarthyism, Robeson's passport had been withdrawn by the United States authorities in 1950. Unable to accept numerous invitations to perform abroad, he stated "We have to learn the hard way that there is another way to sing". [11] The 15 minute connection, which required a music quality circuit, cost £300 (~£6,500 as of 2015). Robeson performed this way again in October 1957 when he linked up to the Grand Pavilion, Porthcawl, Wales, fulfilling an invitation to the eistedfodd there. A 10-inch record featuring selections from the event entitled Transatlantic Exchange was issued by South Wales area of the National Union of Mineworkers as a fundraiser and protest at Robeson's treatment. [12] [13]
After the success of TAT-1, a number of other TAT cables were laid and TAT-1 was retired in 1978.
The TAT-1 was named an IEEE Milestone in 2006. [14]
In telecommunications, a repeater is an electronic device that receives a signal and retransmits it. Repeaters are used to extend transmissions so that the signal can cover longer distances or be received on the other side of an obstruction. Some types of repeaters broadcast an identical signal, but alter its method of transmission, for example, on another frequency or baud rate.
The T-carrier is a member of the series of carrier systems developed by AT&T Bell Laboratories for digital transmission of multiplexed telephone calls.
In telecommunication, a time-assignment speech interpolation (TASI) was an analog technique used on certain long transmission links to increase voice transmission capacity.
TAT-2 was AT&T Corporation's second transatlantic telephone cable. It was in operation from 1959 to 1982, initially carrying 48 telephone circuits on two cables between Penmarch, France and Clarenville, Newfoundland. It was operated by AT&T and the national operators of Germany and France.
TAT-5 was AT&T Corporation's 5th transatlantic telephone cable, in operation from 1970 to 1993, carrying 720 3kHz channels, between Rhode Island, United States and Conil de la Frontera, (Cádiz), Spain. It had 361 repeaters.
TAT-6 was the sixth transatlantic telephone cable. It was in operation from 1976 to 1994, with a bandwidth of 12MHz between Green Hill and Saint-Hilaire-de-Riez, Vendée, (France).
TAT-8 was the 8th transatlantic communications cable and first transatlantic fiber-optic cable, carrying 280 Mbit/s between the United States, United Kingdom and France. It was constructed in 1988 by a consortium of companies led by AT&T Corporation, France Télécom, and British Telecom. AT&T Bell Laboratories developed the technologies used in the cable. The system was made possible by optical amplifiers acting as repeaters with advantages over the electrical repeaters of former cables. They were less costly and could be at greater spacing with less need for associated hardware and software. It was able to serve the three countries with a single transatlantic crossing with the use of an innovative branching unit located underwater on the continental shelf off the coast of Great Britain. The cable lands in Tuckerton, New Jersey, USA, Widemouth Bay, England, UK, and Penmarch, France.
TAT-10 was AT&T Corporation's 10th transatlantic telephone cable, in operation from 1992 to 2003, initially carrying 2 x 565 Mbit/s between United States and Norden in Germany.
TAT-12/13 is a ring cable system consisting of the 12th and 13th consortia transatlantic telephone cables, in operation from 1996, initially carrying 2 × 5 Gbit/s.
CANTAT-1 was the first Canadian transatlantic telephone cable, between Hampden, Newfoundland and eventually Grosses-Roches, Quebec and Oban, United Kingdom, which followed on from the success of TAT-1. It was conceived and approved as stage one of a proposed commonwealth round the world cable and was done at a cost of $8,500,000. The system was jointly owned by Cable & Wireless and the Canadian Overseas Telecommunication Corporation (COTC).
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 20th century, all cables installed used optical fiber as well as optical amplifiers, because distances range thousands of kilometers.
A submarine communications cable is a cable laid on the seabed between land-based stations to carry telecommunication signals across stretches of ocean and sea. The first submarine communications cables laid beginning in the 1850s carried telegraphy traffic, establishing the first instant telecommunications links between continents, such as the first transatlantic telegraph cable which became operational on 16 August 1858.
Transatlantic telegraph cables were undersea cables running under the Atlantic Ocean for telegraph communications. Telegraphy is now an obsolete form of communication, and the cables have long since been decommissioned, but telephone and data are still carried on other transatlantic telecommunications cables. The first cable was laid in the 1850s from Valentia Island off the west coast of Ireland to Bay of Bulls, Trinity Bay, Newfoundland. The first communications occurred on August 16th 1858, but the line speed was poor, and efforts to improve it caused the cable to fail after three weeks.
A cable layer or cable ship is a deep-sea vessel designed and used to lay underwater cables for telecommunications, electric power transmission, military, or other purposes. Cable ships are distinguished by large cable sheaves for guiding cable over bow or stern or both. Bow sheaves, some very large, were characteristic of all cable ships in the past, but newer ships are tending toward having stern sheaves only, as seen in the photo of CS Cable Innovator at the Port of Astoria on this page. The names of cable ships are often preceded by "C.S." as in CS Long Lines.
The history of telecommunication began with the use of smoke signals and drums in Africa, Asia, and the Americas. In the 1790s, the first fixed semaphore systems emerged in Europe. However, it was not until the 1830s that electrical telecommunication systems started to appear. This article details the history of telecommunication and the individuals who helped make telecommunication systems what they are today. The history of telecommunication is an important part of the larger history of communication.
Telecommunications engineering is a subfield of electronics engineering which seeks to design and devise systems of communication at a distance. The work ranges from basic circuit design to strategic mass developments. A telecommunication engineer is responsible for designing and overseeing the installation of telecommunications equipment and facilities, such as complex electronic switching systems, and other plain old telephone service facilities, optical fiber cabling, IP networks, and microwave transmission systems. Telecommunications engineering also overlaps with broadcast engineering.
M. Robert Aaron was an American electrical engineer specializing in telecommunications.
TRANSPAC or Trans-pacific cable (TPC) is a series of undersea cables under the Pacific Ocean.
HAW-1 was the first submarine telephone cable laid between Hawaii and the mainland United States. HAW-1 was laid in 1957, and consisted of two cables, each transmitting in one direction over 36 channels, with an individual length of 2,625 Nmi (4,862 km). The cable spans between Hanauma Bay, Oahu, Hawaii and Point Arena, California.
COMPAC, the Commonwealth Pacific Cable System, was an undersea telephone cable system connecting Canada with New Zealand and Australia. It was completed by closing the last gap in Honolulu Harbor, Hawaii, at 6:25 a.m. B.S.T. on October 10, 1963. Public service of the cable commenced early in December 1963.
