Leon Thevenin (ship)
 The Léon Thévenin in front of Buitenratel in Belgium, 2009
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The Léon Thévenin is a French cable layer specializing in the detection and repair of cable damage. She has been sailing under the flag of Mauritius since February 2017 . The ship is operated by the French company Orange Marine, a subsidiary of the telecommunications company Orange SA (formerly France Télécom SA). It is stationed in Cape Town in South Africa and is used from there under the international Atlantic Cable Maintenance Agreement (ACMA). The ship is named after the French telegraph engineer Léon Charles Thévenin (1857–1926). Sister ship is the Raymond Croze .
Construction and technical data
The Léon Thévenin was commissioned on February 6, 1981 by the Compagnie Française des Câbles Sous-Marins et de Radio from the Société Nouvelle des Ateliers et Chantiers du Havre et de la Rochelle-La Pallice Réunis to replace the one on 6. -8th. January 1981 by fire destroyed Marcel Bayard . She ran on 20 September 1982 in Le Havre from the stack and was in 1983 La Seyne-sur-Mer in service. The ship is 107.82 m long (Loa) and 17.8 m wide and has a maximum draft of 6.25 m. It is measured at 5887 GT and has a load capacity of 4840 tdw .
The drive is diesel-electric . The two fixed propellers are driven by two electric motors, each with an output of 1420 kW . They allow a speed of 15 knots . For maneuvering, the ship has 550 kW transverse thrusters in the bow and stern. Electricity is generated by three of four stroke - eight-cylinder - diesel engine driven generators.
The tank volume of 1400 cubic meters gives a range of 12,000 nautical miles . The ship can accommodate a total payload of 770 m³ or 1100 tonnes of submarine cable in two large and one small hold and has space for 94 people, seafaring and technical personnel in 52 single and 21 double cabins.
In addition to the usual equipment of modern cable ships, the Léon Thévenin is equipped with a variety of special equipment to find submarine cables, detect damage and repair them. This includes a so-called ROV ( Remotely Operated Vehicle ), an eight-ton underwater vehicle called the Hector 5 that is remotely controlled via cable . It can operate at a speed of up to 2.5 knots at depths of up to 2000 m and is used to locate the fiber optic cables and their damaged areas, to cut them at the damaged area and to bring both ends to the surface of the water. After the damage has been repaired, the ROV takes care of burying it (to a depth of up to 1.5 m) and covering the recessed cable by flushing it. In addition, the ROV capable of HD - video cameras to inspect the seabed and locate cables.
Tasks and commitment
The ship is designed so that it can also be used in bad weather. Its high freeboard and the 8 m high bow also enable cruises in very rough seas ( swell scale 6 ). It can carry out cable repairs both in shallow water and in water up to 10,000 m deep. As part of the international Atlantic Cable Maintenance Agreement (ACMA), the ship works primarily in the Atlantic along the entire west coast of Africa to maintain submarine cable systems such as SAT-3 / WASC (Southern Africa - Western Africa Submarine Cable) and ACE (Africa Coast to Europe) and since 2000, when the submarine cable system SAFE (South Africa - Far East) was put into operation, also in the Indian Ocean between South Africa, Réunion and Mauritius. The EASSy (Eastern Africa Submarine Cable System) system, which went into operation in 2010 , is also supplied by Léon Thévenin . She spends around 40% of her time at sea, the rest (if not for overhaul in a shipyard ) on standby in port.
In July 1985 the ship gained a certain international fame. On June 23, 1985, the Boeing 747 of Air India Flight 182 with 329 people on board fell into the Atlantic as a result of a bomb explosion off the coast of Ireland . After using sonar -equipped British ship Gardline Locater the signals of July 9, 1985 Cockpit Voice Recorder (CVR) and flight data recorder had captured (FDR), the two devices were on 9 and 10 July by the Léon Thévenin exposed and a 3000 m long cable controlled diving robot Scarab 1 was lifted from a water depth of 2040 meters and then sent to India for analysis.
Footnotes
- ^ Renamed in 1982 to Radio France Cables & Radio (FCR); in January 1988 in France Telecom Marine; in July 2013 in Orange Marine ( http://numerifone.net/orange-marine.html )
- ↑ 1971 formed through the merger of the Ateliers et chantiers du Havre (ACH) with the Ateliers et Chantiers de La Rochelle-Pallice; the ACH was created in 1965 through the merger of three shipyards, Duchêne, Bossière and Augustin Normand, in Le Havre.
- ↑ SAT-3 / WASC / SAFE. ( Memento of February 3, 2013 on the Internet Archive ) Official website
- ↑ https://ace-submarinecable.com/
- ↑ SAT-3 / WASC / SAFE. ( Memento of February 3, 2013 on the Internet Archive ) Official website
- ↑ https://www.itnewsafrica.com/2014/04/in-pictures-this-is-what-makes-africas-internet-possible/
- ↑ = Submerged Craft Assisting Repair and Burial.
- ↑ "6000 Feet Down, Robot Grabs Air-India Jet Recorder" ( Los Angeles Times , July 11, 1985)
- ^ "First salvage raised from Air India crash", New Scientist , July 11, 1985, pp. 26-27
Web links
- Cable ship Léon Thévenin, at www.orange.com/OrangeMarine
- Preview clip: 20,000 Cables under the Sea: The Internet and the Physics of Fiber Optics , © 2010, Video, 3 minutes, engl.
- arte: 20,000 Câbles sous les mers , © 2010, video, 46 minutes, French.