History of the Atlantic Cable & Undersea Communications |
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Cable Recovery |
Cable recovery techniques were developed soon after cable laying began in the early 1850s. Accidents during laying meant that cable ends were occasionally lost to the sea bed, and existing cables needed to be retrieved and repaired when damage occurred through manmade or natural causes. To aid in the maintenance of cables, and to avoid conflicts with the routes of existing cables as new ones are laid, the route of each cable is surveyed, and the track of the cable as laid is precisely charted. Compare these two surveys from 1890 and 1973, which show how improvements in technology have aided this task. In 1973 the best satellite navigation equipment allowed an accuracy of about ± ¼ mile; now GPS satellite systems make the surveying and charting of new cables and location of existing cables even more precise, with accuracy of just a few feet. Cables have been recovered by grappling for over 150 years, an operation aided today by the use of Remote Operated Vehicles (ROVs). The first successful deep-water operation was the recovery in 1866 by Great Eastern of the lost 1865 cable. When an existing cable has to be recovered, the location of the fault is calculated by electrical measurements made from the two shore ends, and the position is found on the cable chart. The repair ship then sails to the position of the fault and retrieves the cable. Once the cable is located on the seabed it may be hauled up intact in a bight (in shallow water), or it may be necessary to cut the cable and haul up the end of the good section. This is then buoyed, and the operation repeated on the other side of the fault. A new section of cable is spliced in and the repaired cable is released back to the sea bed. This article shows how cables were spliced about a hundred years ago. Similar techniques were used on copper cables until they were superseded by fiber optic cables in the 1980s. Here's how repeaters were spliced into a coaxial copper cable in the 1970s. When cables are recoved for repair, especially if they have been in position for some years, they are often found covered with marine growths. The type of growth depends on the geographical location, the water temperature,and the depth of the cable. On this page are many examples of recovered cables, covering a span of about 150 years. |
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The first submarine cable between Britain and Europe, laid in 1850 from Dover to Calais, consisted only of unarmoured core and failed almost immediately. Sections of it were recovered in 1854 and 1875:
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The 1865 Atlantic cable, lost during laying that year, was recovered and completed the following year. This sample of the core of the 1865 cable is accompanied by a note on its provenance:
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This piece of the 1866 South Foreland (England) - La Panne (Belgium) cable was recovered by CS Telconia on 2nd January 1926:
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On May 8th, 1867 the grounding of an iceberg at the mouth of Trinity Bay, Newfoundland, resulted in crushing damage to a section of the shore end of the 1866 Atlantic cable. This sample of the damaged cable was recovered during the repair operation on June 18th, 1867, and is shown here courtesy of site visitor Simon Cheifetz:
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In 1868 the English terminus of the 1858 cable between Dunwich and Zandvoort was moved to South Lowestoft, and a new piece of cable was used to make the diversion. A fault in this new cable was picked up in 1884:
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This cable section from the 1869 French Atlantic Cable laid by Great Eastern was recovered in 1909 by CS Colonia and is now in the Science Museum, London, where it is displayed in the Making of the Modern World exhibition:
This similar display of a section of the 1873 Atlantic cable recovered in 1906 by CS Cambria may be seen in the Cable section of the Information Age gallery at the Science Museum:
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These sections of the cable laid in the Straits of Kertch in 1869 and 1884 as part of the Indo-European Telegraph Company's system were recovered in 1889:
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This sketch shows a section of the 1870 Penang-Singapore cable, recovered during the repair of a fault in 1871. The cable was damaged in 30 fathoms of water by the tooth of a swordfish, which pierced the cable.
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In 1901 CS Sherard Osborn picked up this section of the Singapore - Hong Kong cable, laid in 1871 by Telcon for the China Submarine Telegraph Company:
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This section of what is believed to be the 1871 Porth Crugmor to Howth (Ireland) No 1 cable, was recovered on the beach at Anglesey in 2009:
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This section of the 1879 French Atlantic Cable, mounted in a fitted presentation case, was recovered in 1887:
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This section of the 1881 Atlantic cable between England and Nova Scotia was recovered in 1942:
The 1881 cable section shown here was recovered in 1942. The donor of the cable included these notes:
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In 1893 CS Grappler recovered two sections of the 1870-73 West India Panama Telegraph Company cables, one between Cuba and Jamaica; the other off Demerara, British Guiana. The recovered samples are of identical construction, each being the deep sea section. A tag accompanying the cable sections gives details of the recovery.
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This section of what is believed to be the 1926 Bamfield (British Colombia) to Fanning Island cable was retrieved from the Pacific sea bed during a recovery & repair operation, date unknown:
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This section of the Singapore - Hong Kong No. 6 telegraph cable shows a penetration through the armouring and insulation to the conductor:
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This piece of the 1900 German Atlantic cable (Azores-Coney Island, New York section) was recovered off Long Island, New York, in 2009 after 109 years of submersion. The cable is in remarkably good condition, with the armoring wires rusted but mostly intact and the copper conductor clean and bright. |
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Tom Perera recovered this section of the 1921 Key West - Havana Telephone cable from the ocean off Key West in 1997. This was one of the first loaded telephone cables. |
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This section of armoured cable from the Pan-Jam (Panama-Jamaica) cable was recovered from about 1000 meters of water in the Caribbean several years ago, having been submerged for about 15 years:
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Last revised: 28 December, 2020 |
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