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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 20th century, all cables installed use optical fiber as well as optical amplifiers, because distances range thousands of kilometers.
History
[edit]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.[1] 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.[2]
Although a telephone cable was discussed starting in the 1920s,[3] 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.[4]
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.[5] 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.
Current technology
[edit]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.[6][7]
Some new cables are being announced on the South Atlantic: SACS (South Atlantic Cable System)[8] and SAex (South Atlantic Express).[9]
TAT cable routes
[edit]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.
| Name | In service | Type | Initial channels | Final channels | Western end | Eastern end |
|---|---|---|---|---|---|---|
| TAT-1 | 1956–1978 | Galvanic | 36 | 51 | 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 | 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 | England |
| TAT-8 | 1988–2002 | Fiber-optic | 40,000 | – | New Jersey | England, France |
| TAT-9 | 1992–2004 | Fiber-optic | 80,000 | – | New Jersey, Nova Scotia | Spain, France, England |
| TAT-10 | 1992–2003 | Fiber-optic | 2 × 565 Mbit/s | – | US | Germany, Netherlands |
| TAT-11 | 1993–2003 | Fiber-optic | 2 × 565 Mbit/s | – | New Jersey | France |
| TAT-12/13 | 1996–2008 | Fiber-optic | 12 × 2.5 Gbit/s | – | US × 2 | England, France |
| TAT-14 | 2001–2020 | Fiber-optic | 3.2 Tbit/s | – | New Jersey × 2 | England, France, Netherlands, Germany, Denmark |
| CANTAT-1 | 1961–1986 | Galvanic | 80 | – | Newfoundland | Scotland |
| CANTAT-2 | 1974–1992 | Galvanic | 1,840 | – | Nova Scotia | England |
| CANTAT-3 | 1994–2010 | 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 & England |
Private cable routes
[edit]There are a number of private non-TAT cables.
| Cable name | Ready for service | Cable length (km) | Nominal capacity | Latency (ms) | Landing points | Owner |
|---|---|---|---|---|---|---|
| Gemini (decommissioned) | May 1998 | under 100 ms | north: Charlestown, US-RI; Oxwich Bay, GB-WLS; south: Manasquan, US-NJ; Porthcurno, GB-ENG | Vodafone (originally Cable & Wireless) | ||
| AC-1 | May 1998 | 14,301 km | 120 Gbit/s | 65 ms[7] | Brookhaven, US-NY; Whitesands Bay, GB-ENG; Beverwijk, NL-NH; Sylt, DE-SH | Lumen Technologies (originally Global Crossing) |
| Columbus III | December 1999 | 9,833 km | Hollywood, US-FL; Ponta Delgada (Azores), PT; Carcavelos, PT; Conil de la Frontera, ES-AN; Mazara del Vallo (Sicily), IT | various telecom operators | ||
| Yellow/AC-2 | September 2000 | 7,001 km | 640 Gbit/s | under 100 ms | Bellport, US-NY; Bude, GB-ENG | Lumen Technologies |
| Hibernia Atlantic | April 2001 | 12,200 km | 320 Gbit/s, upgraded to 10.16 Tbit/s[10] | 59 ms[7] | Lynn, US-MA; Herring Cove, CA-NS; Dublin, IE-L; Southport, GB-ENG; Coleraine, GB-NIR | GTT Communications, Inc. (originally Hibernia Networks) |
| FLAG Atlantic | June 2001 | 14,500 km | under 100 ms | Island Park, US-NY; Plerin, FR-BRE; Skewjack, GB-ENG; Northport, US-NY | Global Cloud Xchange (Reliance Communications) | |
| Tata TGN-Atlantic | June 2001 | 13,000 km | 5.1 Tbit/s | under 100 ms | Wall Township, US-NJ; Highbridge, GB-ENG | Sold by Tyco to Tata Communications in 2005 |
| Apollo | February 2003 | 13,000 km | 3.2 Tbit/s | under 100 ms | Manasquan, New Jersey, US-NJ; Lannion, FR-BRE; Bude, GB-ENG; Shirley, US-NY | Vodafone (originally Cable & Wireless)[11] |
| Greenland Connect | March 2009 | 4,780 km | Milton, CA-NL; Aasiaat, GL-QA; Sisimiut, GL-QE; Maniitsoq, GL-QE; Nuuk, GL-SM; Qaqortoq, GL-KU; Landeyjar, IS | TELE Greenland | ||
| Hibernia Express | September 2015 | 4,600 km | Halifax, CA-NS; Cork, IE-M; Brean, GB-ENG | GTT Communications, Inc. (originally Hibernia Networks) | ||
| AEConnect (AEC-1) | January 2016 | 5,522 km | 4 × 10 Tbit/s (four strand 100 × 100 Gbit/s) | 54 ms | Shirley, US-NY; Killala, IE-C | Aqua Comms |
| MAREA | February 2018 | 6,600 km | 160 Tbit/s | Virginia Beach, US-VA; Bilbao, ES-PV | Facebook (25 %), Microsoft (25 %), Telefónica (50 %) | |
| Midgardsormen | Q2 2019 (planned) | 7,848 km | Virginia Beach, US-VA; Blaabjerg, DK; Mo i Rana, NO | Midgardsormen | ||
| Dunant | September 2020 (live) | 6,400km | 250 Tbit/s | Virginia Beach, US-VA; Saint-Hilaire-de-Riez, FR | Google[12][13] | |
| Havfrue, including America Europe Connect-2 (AEC-2) branch | December 2020 | 7,851km | 108 Tbit/s | New Jersey, US; Dublin, RoI; London, UK; Amsterdam, NL; Blaabjerg, DK; Kristiansand, NO | AquaCommms, Bulk Infrastructure, Facebook and Google[14] | |
| Grace Hopper | September 2022 | 6,000km | 352 Tbit/s | New York, US; Bude, UK; Bilbao, Spain | Google[15][16] | |
| Amitié | July 2023 | 6,600km | 320 Tbit/s | Lynn, Massachusetts, US; Bude, UK; Le Porge, France | A consortium comprising Facebook, Microsoft, Aqua Comms, Vodafone (through Cable & Wireless Americas Systems), Orange[17] |
South Atlantic cable routes
[edit]| Cable name | Ready for service | Length | Landing points | Owner |
|---|---|---|---|---|
| Atlantis-2 | February 2000 | 8,500 km | Carcavelos, PT; El Médano, ES-CN; Praia, CV; Dakar, SN; Fortaleza, BR-CE; Las Toninas, AR-B | various telecom operators |
| EllaLink | Q2 2021 | 5,900 km | Sines, PT; Fortaleza, BR-CE; Santos, BR-SP | Telebras, IslaLink |
| SACS | Q3 2018 | 6,165 km | Fortaleza, BR-CE; Luanda, AO | Angola Cables |
| SAIL | Q4 2018 | 5,900 km | Fortaleza, BR-CE; Kribi, CM | Camtel, China Unicom |
See also
[edit]References
[edit]- ^ Cookson, Gillian (2006). The cable. Stroud: Tempus. ISBN 978-0-7524-3903-7.
- ^ Guarnieri, M. (March 2014). "The Conquest of the Atlantic". IEEE Industrial Electronics Magazine. 8 (1): 53–55/67. Bibcode:2014IIEM....8a..53G. doi:10.1109/MIE.2014.2299492.
- ^ Elmore, Bart (December 17, 2016). "January 2017: From the Transatlantic Telephone to the iPhone". Origins. Ohio State University. Retrieved May 28, 2021.
- ^ Short-Wave System for Transatlantic Telephony, by Polkinghorn and Schlaack BSTJ, 1935
- ^ "Being First Telephone Cable to Connect Hemispheres". Popular Mechanics, March 1954, p. 114.
- ^ "Building Networks for High-Speed Stock Trading - WSJ.com". Online.wsj.com. October 9, 2011. Retrieved September 18, 2013.
- ^ a b c "The $300m cable that will save traders milliseconds". The Daily Telegraph. London. September 11, 2011. Archived from the original on September 11, 2011. Retrieved September 18, 2013.
- ^ "Angola Cables to build the world's first submarine cable across the South Atlantic: Press Releases - NEC".
- ^ "16Tbit/s SAEx cable deal signed". October 25, 2012.
- ^ "Hibernia Offers Cross-Atlantic 40G". Light Reading. August 13, 2009.
- ^ "Submarine Cable Actions Taken PN". FCC. October 4, 2012.
- ^ Sawers, Paul (April 24, 2019). "How Google is building its huge subsea cable infrastructure". VentureBeat. Archived from the original on April 25, 2019. Retrieved April 26, 2019.
- ^ Li, Abner (April 5, 2019). "Google's Dunant trans-Atlantic cable will deliver record-breaking capacity w/ first use of SDM tech". 9to5Google. Archived from the original on April 25, 2019. Retrieved April 25, 2019.
- ^ Tanwen Dawn-Hiscox (January 16, 2018). "Aqua Comms plans Havfrue, transatlantic cable network funded by Facebook, Google". Data Center Dynamics.
- ^ Koley, Vikash (July 28, 2020). "Announcing the Grace Hopper subsea cable, linking the U.S., U.K. and Spain". Google Cloud.
- ^ Lardinois, Frederick (July 28, 2020). "Google is building a new private subsea cable between Europe and the US". TechCrunch.
- ^ "Orange landing the transatlantic Amitié cable". TotalTele. February 8, 2021.
External links
[edit]- Hayes, Jeremiah (September 2008). "A history of transatlantic cables". IEEE Communications. 46 (9): 42–48. Bibcode:2008IComM..46i..42H. doi:10.1109/MCOM.2008.4623705.
- Aronsson's Telecom History Timeline
- Timeline of Submarine Communications Cables, 1850–2024
- Submarine Cable Landings Worldwide
Transatlantic communications cable
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Definition and Scope
A transatlantic communications cable is a specialized type of submarine cable that spans the Atlantic Ocean, linking telecommunications infrastructure between land-based stations on opposite shores, primarily in North America and Europe. These cables are engineered to lie on the seabed, often buried in shallow coastal waters for protection, and transmit high volumes of digital signals including internet data, telephony, and video streaming. The International Telecommunication Union defines a submarine communications cable as "a cable laid on the sea bed, or buried in shallow water, intended to carry communications" between such stations.[5] Unlike satellite systems, which handle only about 1% of global data traffic, these fiber-optic cables provide the primary medium for reliable, low-latency transoceanic connectivity.[6] The scope of transatlantic cables extends geographically across the North and South Atlantic, encompassing routes from the eastern coasts of the United States and Canada to western Europe (such as the United Kingdom, France, and Spain), with some systems branching to Africa or the Caribbean. As part of the broader global undersea network of approximately 570 active cables and 1,712 landing stations connecting all continents except Antarctica, transatlantic cables carry nearly all intercontinental data flows between these regions. The global submarine cable network, including transatlantic systems, accounts for 99% of transoceanic digital communications worldwide. This infrastructure supports critical sectors like international finance—facilitating trillions of dollars in daily transactions—and cloud services, enabling seamless data exchange for multinational corporations and governments.[7][8] In terms of capacity and evolution, modern transatlantic cables utilize dense wavelength-division multiplexing over fiber optics to achieve terabit-per-second speeds, far surpassing earlier coaxial and telegraph systems; for instance, the MAREA cable between Virginia Beach, USA, and Bilbao, Spain, provides 200 terabits per second, equivalent to millions of simultaneous high-definition video streams. Their deployment involves international coordination under frameworks like the United Nations Convention on the Law of the Sea, which governs cable laying in international waters while requiring permissions in territorial seas up to 12 nautical miles offshore.[9] Disruptions to these cables, which occur on average more than three times per week globally due to natural hazards or human activities, underscore their vulnerability and the need for resilient design within this defined scope.[6]Significance in Global Communications
Transatlantic communications cables form the backbone of intercontinental data exchange between North America and Europe, two of the world's largest economic and technological hubs, enabling the seamless flow of information that underpins modern global connectivity. These submarine systems carry the vast majority of transatlantic internet traffic, which constitutes a critical segment of the over 95% of all international data and voice transfers routed through undersea fiber-optic cables worldwide. By providing high-capacity, low-latency links—with typical round-trip ping latencies of approximately 70 ms from Western Europe (e.g., London) to the US East Coast (e.g., New York) as of early 2026, remaining stable in the 68–70 ms range in recent years—they support essential services such as real-time financial trading, cloud computing, and video streaming, far surpassing the capabilities of satellite alternatives in terms of volume, speed, and cost-efficiency.[1][10][11] Economically, these cables drive substantial value by facilitating daily international financial transactions estimated at $10 trillion, primarily between U.S. and European markets, while also enabling the digital economy's growth through enhanced broadband access and data center interconnectivity. Deployments of new transatlantic cables have been shown to significantly improve international bandwidth capacity, leading to broader economic benefits like increased trade, productivity gains, and GDP contributions in connected regions—for instance, individual systems like MAREA have been linked to annual economic impacts of €16.7 billion in Europe alone. Major technology firms, including Google, Meta, Microsoft, and Amazon, now control about 66% of global submarine cable capacity as of 2022, reflecting their pivotal role in scaling infrastructure for AI, 5G networks, and big data applications that fuel global commerce.[10][12][13][12] From a security and geopolitical perspective, transatlantic cables are indispensable for military, governmental, and diplomatic communications within alliances like NATO, where disruptions could severely hamper operations—as evidenced by past incidents like the 2008 cable cuts that affected Mediterranean connectivity. With modern cables boasting capacities up to 352 terabits per second, such as the Grace Hopper system, they ensure resilient pathways for sensitive data amid rising threats from state actors and environmental hazards, underscoring their status as strategic assets in maintaining transatlantic stability and global information superiority. Bandwidth demands on these routes are projected to double every two years, driven by emerging technologies, highlighting their enduring significance in an increasingly interconnected world.[10][14][10]Historical Development
Telegraph Era (1850s–1920s)
The development of transatlantic telegraph cables marked a pivotal advancement in global communication during the mid-19th to early 20th centuries, transforming the weeks-long delay of transoceanic mail into near-instantaneous message exchange. Efforts began in the early 1850s, driven by the rapid expansion of land-based telegraph networks in Europe and North America, which underscored the need for a submarine link across the Atlantic. The first serious proposal came in 1854 from American entrepreneur Cyrus West Field, who founded the New York, Newfoundland and London Telegraph Company to extend existing lines from Newfoundland to Ireland. Initial attempts faced formidable engineering challenges, including cable breakage during laying and signal degradation over the 2,000-plus nautical miles, but perseverance led to the first successful transmission in 1858.[15][16] The inaugural transatlantic cable was laid in August 1858 by the Atlantic Telegraph Company, a joint British-American venture backed by Field, using the ships HMS Agamemnon and USS Niagara. Stretching approximately 2,200 nautical miles from Valentia Island, Ireland, to Trinity Bay, Newfoundland, the cable consisted of a single copper conductor insulated with gutta-percha and armored for protection against seabed hazards. On August 16, Queen Victoria sent a congratulatory message to U.S. President James Buchanan, taking 16 hours and 1 minute for 98 words, heralding the cable's operational debut. However, high-voltage testing by chief electrician Wildman Whitehouse damaged the insulation, causing failure after just three weeks and 732 messages, rendering it inoperable by September. A subsequent attempt in 1865 using the massive steamship Great Eastern—designed by Isambard Kingdom Brunel—ended in cable loss 1,200 miles out due to snags on the ocean floor. Success came in July 1866 when the Great Eastern completed a 1,852-nautical-mile cable from Valentia to Heart's Content, Newfoundland, under the Anglo-American Telegraph Company; the crew then recovered and spliced the 1865 cable, effectively doubling capacity by August. British physicist William Thomson (later Lord Kelvin) played a crucial role, inventing the mirror galvanometer to detect faint signals weakened by cable capacitance and resistance.[17][18][16] Subsequent decades saw iterative improvements and multiple cables to meet growing demand for commercial, diplomatic, and news traffic. The 1866 cable operated reliably until 1872, transmitting at speeds up to 17 words per minute by the 1870s, but faults from natural wear and fishing trawlers necessitated replacements. In 1873, the Anglo-American Telegraph Company laid a new 1,877-nautical-mile cable using the Great Eastern, followed by the Direct United States Cable Company's 3,200-nautical-mile route in 1875 from Rye Beach, New Hampshire, to Ballinskelligs, Ireland, via Nova Scotia. Competition intensified with the Commercial Cable Company, founded by John P. Mackay and James Gordon Bennett, laying two cables in 1884-1887 totaling over 6,500 nautical miles from Nova Scotia to Ireland and France, bypassing monopolistic rates of the Anglo-American firm. By the 1890s, advancements like duplex (two-way) and quadruplex (four-message simultaneous) systems, pioneered by Thomas Edison and others, boosted throughput; for instance, the 1894 Anglo-American cable (Britannia 2) incorporated stronger steel armoring. German interests entered with the 1900 German Atlantic Telegraph Company cable from the Azores to New York, spanning 2,290 nautical miles.[18][15][19] Through the early 20th century, up to eight parallel telegraph cables crisscrossed the Atlantic by the 1920s, handling thousands of messages daily and costing about $5 per word—equivalent to a skilled worker's daily wage. Key later additions included the 1906 Western Union cable from Nova Scotia to the Azores and the 1924 CS Faraday-laid cable by the Commercial Pacific Cable Company, enhancing redundancy against faults from icebergs, earthquakes, and sabotage during World War I. Technical refinements focused on better insulation with compounds like Chatterton's, repeaters for signal boosting (though limited in telegraph era), and specialized cable ships like CS Mackay-Bennett for repairs. These networks not only facilitated stock market synchronization and wartime coordination but also symbolized technological triumph, with the 1866 cable alone transmitting over 3 million messages by 1900. The era waned as telephone demands grew, but telegraph cables remained vital until the coaxial transition in the 1950s.[18][17][16]Coaxial Cable and Telephone Era (1950s–1980s)
The coaxial cable and telephone era represented a transformative phase in transatlantic communications, shifting from low-bandwidth telegraphy to high-capacity voice telephony through the deployment of submarine coaxial systems. This period, spanning the 1950s to 1980s, was dominated by the TAT (Transatlantic Telephone) series of cables, which utilized a central copper conductor insulated with polyethylene, armored for deep-sea protection, and equipped with powered repeaters to amplify signals over thousands of nautical miles. These innovations enabled reliable, real-time conversations, dramatically increasing circuit capacity from dozens to thousands of simultaneous telephone channels and reducing dependence on short-wave radio, which suffered from atmospheric interference.[20] The era commenced with TAT-1, the world's first transatlantic telephone cable, laid in 1956 between Oban, Scotland, and Clarenville, Newfoundland—a distance of approximately 1,950 nautical miles—using two parallel cables with 51 vacuum-tube repeaters spaced about 30 nautical miles apart for unidirectional amplification.[21] This joint project by AT&T (United States), the British General Post Office, and the Canadian Overseas Telecommunication Corporation provided 36 voice circuits (each supporting 3-4 kHz bandwidth), tripling the Atlantic's telephony capacity at the time and facilitating clearer, more secure calls for business, diplomacy, and personal use.[21] TAT-1 operated until 1978, proving the viability of repeatered submarine systems despite challenges like high-voltage power feeding from shore stations.[20] Subsequent cables rapidly advanced repeater technology from bulky vacuum tubes to compact transistors, enabling bidirectional transmission, shorter repeater spacing (down to 5-10 nautical miles), and higher operating frequencies up to 30 MHz for greater bandwidth. TAT-2 (1959) extended connectivity to Penmarc'h, France, with 48 circuits, while TAT-3 (1963) and TAT-4 (1965) routed directly from New Jersey to England and France, respectively, each carrying 138 circuits using rigid repeaters for improved reliability.[22][23] By the 1970s, TAT-5 (1970) connected Rhode Island to Spain with 845 circuits via germanium transistors, and TAT-6 (1976) achieved 4,000 circuits on a Rhode Island-to-France route using silicon transistors and 694 repeaters.[24][25] The era culminated with TAT-7 (1983), the last coaxial system, linking New Jersey to Porthcurno, England, with 4,200 circuits, 677 repeaters, and shore-controlled equalizers to mitigate signal distortion—handling over 10,000 calls per day before fiber optics supplanted the technology.[22] These systems, often built by consortia including AT&T, European telecoms, and international partners, were laid using specialized cable ships like the CS Long Lines, with shore ends buried via plows for protection.[24] Capacities escalated over the decades due to refined modulation techniques and materials, such as oil-filled repeaters evolving to solid-state designs, allowing coaxial cables to carry not only voice but also early data and telegraph services.[22] By the 1980s, the TAT network dominated transatlantic traffic, complementing satellites with lower latency and higher security, and laying the groundwork for digital transmission.[20]| Cable | Year | Primary Route | Capacity (Voice Circuits) | Number of Repeaters | Key Technological Note |
|---|---|---|---|---|---|
| TAT-1 | 1956 | Scotland to Newfoundland | 36 | 51 | Vacuum-tube, unidirectional |
| TAT-2 | 1959 | France to Newfoundland | 48 | 57 | Similar to TAT-1, twin cables |
| TAT-3 | 1963 | New Jersey to England | 138 | 182 | Transistor-based, bidirectional |
| TAT-4 | 1965 | New Jersey to France | 138 | 186 | Enhanced repeater gain |
| TAT-5 | 1970 | Rhode Island to Spain | 845 | 361 | Germanium transistors, 10 nm spacing |
| TAT-6 | 1976 | Rhode Island to France | 4,000 | 694 | Silicon transistors, 5.1 nm spacing |
| TAT-7 | 1983 | New Jersey to England | 4,200 | 677 | Shore equalizers, 30 MHz operation |
Fiber Optic Transition (1990s–Present)
The transition to fiber optic technology in transatlantic communications cables marked a pivotal shift from copper-based coaxial systems, enabling vastly higher data capacities through light-based signal transmission. This era began with the deployment of TAT-8 in 1988, which carried an initial capacity of 40,000 telephone circuits at 280 Mbps across two fiber pairs, but the 1990s saw rapid expansion as optical amplifiers and wavelength-division multiplexing (WDM) emerged, allowing multiple light wavelengths to travel simultaneously on a single fiber. By the mid-1990s, systems like TAT-12/13, operational in 1996, incorporated early WDM to achieve capacities exceeding 5 Gbps per fiber pair, tripling effective throughput through upgrades in 1999 that added three wavelengths. These advancements, driven by consortia including AT&T, British Telecom, and France Télécom, reduced latency and error rates compared to prior coaxial cables, supporting the burgeoning internet traffic.[27] In the late 1990s and early 2000s, dense wavelength division multiplexing (DWDM) revolutionized capacity, packing up to 80 or more channels per fiber at 10 Gbps each, pushing total system throughputs into the tens of Gbps. TAT-14, activated in 2001, exemplified this with 4 fiber pairs and an initial capacity of 640 Gbps (160 Gbps per pair using 16 × 10 Gbps DWDM channels), later upgraded via DWDM to over 3 Tbps, connecting the U.S. to the UK and France over 15,000 km. Concurrently, private initiatives like PTAT-1 (1989, upgraded in the 1990s to 2.5 Gbps) and the AC-1 cable (1998, 5 Gbps initial) diversified routes, while the FLAG Atlantic-1 (FA-1) system, launched in 2001 by Global Crossing, spanned 13,000 km with DWDM-enabled capacities reaching 10 Tbps through subsequent upgrades. These developments accommodated the dot-com boom's data demands, with fiber optics handling over 90% of transatlantic bandwidth by 2000.[28][14] The 2010s introduced coherent optical technology and space-division multiplexing (SDM), further amplifying capacities to terabits per second amid surging cloud computing and streaming needs. Marea, a 6,600 km cable operational since 2018 between Virginia Beach, U.S., and Bilbao, Spain—built by Microsoft and Meta—delivered 200 Tbps across 16 fiber pairs using advanced DWDM and coherent detection, equivalent to 22 million simultaneous HD video streams. Google's Dunant cable, activated in 2021 linking Virginia to Saint-Hilaire-de-Riez, France, achieved 250 Tbps via SDM on 12 fiber pairs, incorporating open optical line systems for flexible upgrades. Other notable systems include Havfrue/AEC-2 (2020, 200+ Tbps to Denmark with branches to Ireland and Norway) and Amitié (2023, 368 Tbps over 6,800 km from Massachusetts to Le Porge, France), both leveraging 16-pair designs and probabilistic constellation shaping for efficiency.[14] Today, transatlantic fiber optic cables form the backbone of global internet, carrying over 99% of intercontinental data traffic with aggregate capacities exceeding 1 Pbps across multiple routes. Recent innovations focus on sustainability, such as low-loss fibers and AI-optimized routing, as seen in the Grace Hopper cable (2021, 350 Tbps connecting New York to Bude, UK, and Bilbao, Spain). In 2025, AWS's Fastnet cable became operational, providing over 320 Tbps capacity between the US and Ireland.[29] Future projects like 2Africa (operational 2025, 180 Tbps with transatlantic extensions; segments activated as of November 2025) and Project Waterworth (2030, multi-terawatt potential over 50,000 km) emphasize route diversity to Europe’s southern and Nordic shores, enhancing resilience against outages. These evolutions, led by tech giants like Google, Microsoft, and Meta alongside traditional carriers, underscore fiber optics' role in enabling 5G, AI, and edge computing across the Atlantic.[14][27]Technical Components
Cable Design and Materials
Transatlantic communications cables, primarily fiber-optic systems, are engineered with a multi-layered structure to protect delicate optical fibers while enabling high-speed data transmission across oceanic distances. The core consists of multiple pairs of glass optical fibers, typically made from high-purity silica with a core doped with germanium or other materials to optimize light propagation, surrounded by a fluorine-doped cladding to minimize signal loss. These fibers, often 4 to 8 pairs for classic transatlantic routes but up to dozens in modern systems, transmit data using laser pulses via wavelength-division multiplexing, achieving capacities exceeding 20 terabits per second per fiber pair, enabling total system capacities over 200 Tbps in modern cables.[30][31][32] The fibers are embedded in a protective gel, such as petroleum jelly or silicone, to prevent water ingress and mechanical stress, then encased in a hermetic metal tube—usually copper or aluminum—for electrical conductivity to power submerged repeaters that amplify signals every 50-100 kilometers. This tube is surrounded by an aramid, fiberglass, or steel strength member to provide tensile support during laying and retrieval, capable of withstanding tensions up to several tons.[33][34][35] Subsequent layers focus on environmental resilience. An aluminum or copper water barrier seals the assembly against hydrostatic pressure, followed by layers of stranded steel wires for armoring, which shield against abrasion, anchors, fishing trawls, and seismic activity—critical for transatlantic cables traversing depths up to 8 kilometers. The outer jacket, typically high-density polyethylene, offers corrosion resistance and buoyancy control, with variations like additional galvanized steel tapes for shallow-water segments near landing stations. Overall cable diameter rarely exceeds 50-70 millimeters, balancing flexibility for deployment with durability for a 25-year design life.[33][30]| Layer (Innermost to Outermost) | Primary Material | Function |
|---|---|---|
| Optical Fibers | Silica glass (germanium-doped core, fluorine-doped cladding) | Data transmission via light pulses; low attenuation (~0.15 dB/km at 1550 nm).[31] |
| Cushioning Gel | Petroleum jelly or silicone | Cushions against vibration and moisture. |
| Central Tube | Copper or aluminum | Hermetic seal; conducts power for repeaters.[33] |
| Strength Member | Aramid (e.g., Kevlar), fiberglass, or steel wire | Tensile support during installation. |
| Water Barrier | Aluminum or copper foil | Prevents water penetration under pressure.[33] |
| Armoring | Galvanized steel wires (single or double layer) | Protection from mechanical damage; denser in high-risk areas.[30] |
| Insulation Tape | Mylar or nylon | Electrical insulation and bedding.[33] |
| Outer Jacket | Polyethylene | Waterproofing, UV resistance, and burial facilitation.[34] |
Signal Transmission and Capacity
In modern transatlantic communications cables, signals are transmitted as pulses of light through optical fibers made of silica glass, generated by lasers at the sending end and detected by photodetectors at the receiving end. This fiber-optic technology replaced earlier electrical transmission methods, enabling high-speed digital data transfer for internet, voice, and video communications across distances exceeding 6,000 kilometers. The light signals operate in the near-infrared spectrum, typically around 1550 nm wavelength, where fiber attenuation is minimal, allowing propagation with reduced loss compared to visible light.[33][1] The propagation of light over these transatlantic distances imposes a fundamental round-trip latency. In early 2026, typical round-trip ping latency from Western Europe (e.g., London) to the US East Coast (e.g., New York) over optimized routes was approximately 70 ms, with values consistently in the 68-70 ms range based on real-time measurements and provider statistics. This latency is primarily the propagation delay arising from the cable length (typically 6,000–7,000 km) and the speed of light in silica fiber (approximately 200,000 km/s), with minor additional contributions from repeaters and terminal equipment.[36] To counteract signal degradation over long distances due to absorption and scattering in the fiber, optical repeaters—essentially inline amplifiers—are integrated into the cable at intervals of approximately 50 to 100 kilometers. These repeaters employ erbium-doped fiber amplifiers (EDFAs), which use erbium ions in a silica fiber core to amplify the optical signal directly without converting it to electrical form. The amplification process involves forward pumping with high-power 980 nm laser diodes, achieving output powers greater than +15 dBm and noise figures below 4.7 dB, while gain-flattening filters ensure uniform amplification across a bandwidth of up to 40 nm. Power for the repeaters is supplied via a high-voltage direct current (typically 3,000 to 15,000 volts) fed through a central copper conductor within the cable, with the ocean providing the return path.[37][33][38] Capacity in these systems has evolved through advanced multiplexing techniques, primarily dense wavelength division multiplexing (DWDM), which superimposes multiple independent light signals on different wavelengths within the same fiber pair, often supporting 80 to 100 channels per pair. Coherent optical detection, utilizing phase and polarization information, further boosts spectral efficiency, enabling data rates up to 800 Gbps per wavelength. More recent innovations incorporate space division multiplexing (SDM) via multi-core or multi-mode fibers, increasing the number of parallel transmission paths and approaching the theoretical Shannon limit for capacity. More recent trials have demonstrated up to 1.3 Tbps per wavelength on transatlantic routes, as achieved by Telxius and Ciena in 2025.[39] A typical transatlantic cable features 8 to 16 fiber pairs, with repeaters tailored to each pair for bidirectional amplification.[40][41][37] Representative examples illustrate the scale: the MAREA cable, operational since 2018, provides a design capacity of 200 terabits per second (Tbps) using SDM and DWDM across its 6,600 km route. Similarly, the Amitié system achieved 800 Gbps per wavelength over 6,234 km in 2024, supporting cloud and AI traffic growth. Overall, the transatlantic route saw over 90 Tbps of new capacity added in 2021 alone, underscoring its role in handling more than twice the data volume of other major oceanic links.[33][41][40]Deployment, Landing, and Maintenance
The deployment of transatlantic communications cables begins with extensive route planning and marine surveys to select paths that minimize risks from seabed topography, currents, and human activities such as fishing. These surveys, often conducted using multibeam sonar and geophysical tools, ensure the cable follows an efficient great circle route across the Atlantic, typically spanning 5,000 to 7,000 kilometers while avoiding hazards like seamounts and trenches.[42][43] Once the route is finalized, the cable is manufactured in segments and loaded onto specialized cable-laying vessels, such as the SubCom Reliance-class ships, which have capacities exceeding 5,500 metric tons and are equipped with linear cable engines for controlled payout. The laying process starts at one landing station, where the shore end is deployed and buried in shallow coastal waters (up to 1,500 meters deep) using plows or remotely operated vehicles (ROVs) to protect against abrasion and external damage; in deeper waters, the cable is surface-laid at speeds of about 6 knots, allowing it to settle naturally on the seabed with calculated slack to account for ocean floor contours. The vessel traverses the entire route in a single run if possible, end-to-end testing the system before completing the far shore end, a process that can take weeks for transatlantic spans.[42][33] Landing transatlantic cables occurs at fortified coastal facilities known as cable landing stations (CLS), which serve as the interface between the submarine cable and terrestrial fiber optic networks, housing repeaters, power feed equipment, and encryption systems. In the United States, prominent CLS include Virginia Beach, Virginia, and Lynn, Massachusetts, while European endpoints feature sites like Bude, Cornwall (UK), Le Porge (France), and Bilbao (Spain). For instance, the MAREA cable lands at Virginia Beach and connects to Bilbao, facilitating high-capacity data transfer, whereas the Amitié system terminates at Lynn, Bude, and Le Porge to link North American and European networks. Nearshore burial, typically to depths of 1-2 meters, is standard to mitigate risks from anchors and trawlers, with permits required for environmental compliance.[44][45][33] Maintenance of transatlantic cables emphasizes continuous monitoring through network operations centers (NOCs) that detect faults via signal degradation, with global submarine systems experiencing around 200 faults annually, 86% attributable to external aggressions like fishing gear and ship anchors in shallow waters. Repairs are coordinated via consortium agreements such as the Atlantic Cable Maintenance Agreement (ACMA), established in 1965, which provides non-profit, shared access to a dedicated fleet for the Atlantic region, including vessels like the CS Sovereign (based in Portland, UK) and CS Pierre de Fermat (Brest, France), ensuring response times within 24 hours and transit of 7-8 days to fault sites.[46][47][48] The repair process involves locating the fault using precise coordinates from NOCs, grappling and cutting the cable to recover both ends, testing for damage, and splicing in a replacement section from onboard spares (often 100-200 kilometers of stocked cable) via fusion splicing machines, which can take 1-2 days per splice; the repaired cable is then redeployed, potentially buried with ROVs in vulnerable areas, completing the operation in about one week post-arrival. Transatlantic repairs face challenges from aging vessel fleets—64% expected to reach end-of-life by 2040—and geopolitical delays in permitting, prompting investments in multi-purpose ships and public-private partnerships for resilience. Other key vessels include the IT Infinity and IT Intrepid, operated from Halifax, Canada, with ROV and plow capabilities for Atlantic operations.[42][49][48]| Example Transatlantic Cable Systems and Landing Stations |
|---|
| System |
| MAREA (2018) |
| Amitié (2023) |
| AC-1 (1998) |
Key Cable Systems
TAT Series Routes
The TAT series, formally known as the Transatlantic Telephone cables, comprises a foundational sequence of submarine cable systems deployed across the North Atlantic from 1956 to 2001, linking North American landing points primarily in the northeastern United States and Canada to European stations in the United Kingdom, France, Spain, and later other nations. These cables evolved from analog coaxial designs for voice telephony to digital fiber-optic systems supporting high-capacity data transmission, forming the backbone of transatlantic communications until their phased retirement in the 2000s and 2010s. Owned and operated by consortia including AT&T, British Telecom, and France Télécom, the series emphasized reliable, direct routes to minimize latency and signal degradation over distances exceeding 3,000 nautical miles.[51][52] The inaugural TAT-1, laid in 1956, established the northernmost route in the series, spanning from Clarenville, Newfoundland, Canada, across the Atlantic to Oban, Scotland, with a total length of approximately 2,200 nautical miles including a coastal extension via the Cabot Strait to Sydney Mines, Nova Scotia. This coaxial cable supported 36 simultaneous voice circuits and 51 repeaters spaced at 37.5 nautical miles, revolutionizing real-time transatlantic telephony by enabling direct calls between North America and Europe for the first time. Subsequent early systems diversified southern routes: TAT-3 (1963) connected Tuckerton, New Jersey, to Widemouth Bay, England (3,518 nautical miles, 128 circuits), while TAT-4 (1965) linked Tuckerton to Saint-Hilaire-de-Riez, France (3,600 nautical miles, 128 circuits). These paths avoided deep oceanic trenches by following shallower continental shelf contours, enhancing deployment feasibility.[51][53][52] Mid-series cables further expanded capacity and geographic reach. TAT-6 (1976) followed a 3,600-nautical-mile route from Green Hill, Rhode Island, to Saint-Hilaire-de-Riez, France, accommodating 4,000 voice circuits with 745 repeaters spaced at 5 nautical miles using silicon transistor technology. TAT-7 (1983) routed 3,286 nautical miles from Tuckerton to Porthcurno, England, supporting 4,000 circuits. The transition to fiber optics began with TAT-8 (1988), the first transatlantic optical cable, which branched from Tuckerton to both Widemouth Bay, England, and Penmarch, France (total 6,705 km, 280 Mbps per fiber, equivalent to 4,000 circuits), utilizing regenerative repeaters every 67 km to boost signal integrity over the dual endpoints. These routes prioritized redundancy, with southern paths hugging the U.S. East Coast and Iberian Peninsula to connect growing European markets.[51][53] Later iterations incorporated multi-nation branching for broader connectivity. TAT-9 (1991) spanned 8,910 km from Manahawkin, New Jersey, via Pennant Point, Nova Scotia, to Goonhilly, England; Saint-Hilaire-de-Riez and Penmarch, France; and Conil, Spain (2 x 560 Mbps). TAT-10 (1992) connected Green Hill, Rhode Island, to northern European points including Norden, Germany; Terschelling and Alkmaar, Netherlands (7,354 km, 560 Mbps). TAT-12/13 (1996), a paired system, linked Rhode Island and Shirley, New York, to Porthcurno, England, and Penmarch, France (6,321 km, 3 x 5 Gbps per pair). The final TAT-14 (2001) extended 15,428 km from U.S. landings at Tuckerton, Manahawkin, and West Orange, New Jersey, to European sites including Bude and Goonhilly, United Kingdom; Saint-Hilaire-de-Riez, Concarneau, and Lannion, France (4 fibers, 16 x 10 Gbps wavelengths, up to 3.2 Tbps total capacity). This expansive route integrated dense wavelength-division multiplexing to handle surging internet traffic, landing in Denmark, Germany, the Netherlands, and Portugal via branches. All TAT systems were retired by 2020, supplanted by higher-capacity private cables.[51][54][52]| Cable | Year | Primary Route (Nautical Miles/km) | Key Landing Points | Capacity |
|---|---|---|---|---|
| TAT-1 | 1956 | Clarenville, NL to Oban, Scotland (~2,200 nm) | Clarenville (CA), Oban (UK) | 36 voice circuits[51] |
| TAT-3 | 1963 | Tuckerton, NJ to Widemouth Bay, UK (3,518 nm) | Tuckerton (US), Widemouth Bay (UK) | 128 voice circuits[51] |
| TAT-6 | 1976 | Green Hill, RI to Saint-Hilaire-de-Riez, FR (3,600 nm) | Green Hill (US), Saint-Hilaire-de-Riez (FR) | 4,000 voice circuits[51] |
| TAT-8 | 1988 | Tuckerton, NJ to Widemouth Bay, UK & Penmarch, FR (6,705 km) | Tuckerton (US), Widemouth Bay (UK), Penmarch (FR) | 280 Mbps (4,000 circuits)[51] |
| TAT-12/13 | 1996 | RI/NY to Porthcurno, UK & Penmarch, FR (6,321 km) | Rhode Island/Shirley (US), Porthcurno (UK), Penmarch (FR) | 15 Gbps total[51] |
| TAT-14 | 2001 | NJ to multiple EU sites (15,428 km) | Tuckerton/Manahawkin (US), Bude/Goonhilly (UK), Saint-Hilaire-de-Riez (FR) | 3.2 Tbps[54][52] |
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