Deep Level Underground
Deep level underground is construction that is 20 metres or more below ground and not using the cut-and-cover method, especially train stations, air raid shelters and bunkers, and some tunnels and mines. Cut-and-cover is a simple method of construction for shallow tunnels where a trench is excavated and roofed over with an overhead support structure that is strong enough to carry the load of what is to be built above the tunnel. History Mining Although some deep mining took place as early as the late Tudor period (in North-East England, and along the Firth of Forth coast in Scotland) deep shaft mining in Britain began to develop extensively in the late 18th century, with rapid expansion throughout the 19th century and early 20th century when the industry peaked. Before 1800, a great deal of coal was left in places as extraction was still primitive. As a result, in the deep Tyneside pits (300 to 1,000 ft deep) only about 40 percent of the coal could be extracted. The use of wo ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Tunnel
A tunnel is an underground passageway, dug through surrounding soil, earth or rock, and enclosed except for the entrance and exit, commonly at each end. A pipeline is not a tunnel, though some recent tunnels have used immersed tube construction techniques rather than traditional tunnel boring methods. A tunnel may be for foot or vehicular road traffic, for rail traffic, or for a canal. The central portions of a rapid transit network are usually in the tunnel. Some tunnels are used as sewers or aqueducts to supply water for consumption or for hydroelectric stations. Utility tunnels are used for routing steam, chilled water, electrical power or telecommunication cables, as well as connecting buildings for convenient passage of people and equipment. Secret tunnels are built for military purposes, or by civilians for smuggling of weapons, contraband, or people. Special tunnels, such as wildlife crossings, are built to allow wildlife to cross human-made barriers safely. ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Bakerloo Line
The Bakerloo line () is a London Underground line that goes from in suburban north-west London to in south London, via the West End. Printed in brown on the Tube map, it serves 25 stations, 15 of which are underground, over . It runs partly on the surface and partly in deep-level tube tunnels. The line's name is a portmanteau of its original name, the Baker Street & Waterloo Railway. From to Harrow & Wealdstone (the section above ground), the line shares tracks with the London Overground Watford DC line and runs parallel to the West Coast Main Line. There is, however, a short tunnel at the western end of . Opened between 1906 and 1915, many of its stations retain elements of their design to a common standard: the stations below ground using Art Nouveau decorative tiling by Leslie Green, and the above-ground stations built in red brick with stone detailing in an Arts & Crafts style. It is the ninth-busiest line on the network, carrying more than 111 million passengers annu ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countries of Namibia, Botswana, and Zimbabwe; and to the east and northeast by Mozambique and Eswatini. It also completely enclaves the country Lesotho. It is the southernmost country on the mainland of the Old World, and the second-most populous country located entirely south of the equator, after Tanzania. South Africa is a biodiversity hotspot, with unique biomes, plant and animal life. With over 60 million people, the country is the world's 24th-most populous nation and covers an area of . South Africa has three capital cities, with the executive, judicial and legislative branches of government based in Pretoria, Bloemfontein, and Cape Town respectively. The largest city is Johannesburg. About 80% of the population are Black South Afri ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Witwatersrand
The Witwatersrand () (locally the Rand or, less commonly, the Reef) is a , north-facing scarp in South Africa. It consists of a hard, erosion-resistant quartzite metamorphic rock, over which several north-flowing rivers form waterfalls, which account for the name Witwatersrand, meaning "white water ridge" in Afrikaans.Truswell, J.F. (1977). ''The Geological Evolution of South Africa''. pp. 21, 27–28, 33–36. Cape Town: Purnell. This east-west-running scarp can be traced with only one short gap, from Bedfordview (about west of O.R. Tambo International Airport) in the east, through Johannesburg and Roodepoort, to Krugersdorp in the west (see the diagram at left below).Norman, N.; Whitfield, G. (2006) ''Geological Journeys''. pp. 38–49, 60–61. Cape Town: Struik Publishers. The scarp forms the northern edge of a plateau (or ridge) which rises about above the surrounding plains of the Highveld. A number of picturesque Johannesburg suburbs, including Observatory, Linksfi ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Gold Mining
Gold mining is the extraction of gold resources by mining. Historically, mining gold from alluvial deposits used manual separation processes, such as gold panning. However, with the expansion of gold mining to ores that are not on the surface, has led to more complex extraction processes such as pit mining and gold cyanidation. In the 20th and 21st centuries, most volume of mining was done by large corporations, however the value of gold has led to millions of small, artisanal miners in many parts of the Global South. Like all mining, human rights and environmental issues are common issues in the gold mining industry. In smaller mines with less regulation, health and safety risks are much higher. History The exact date that humans first began to mine gold is unknown, but some of the oldest known gold artifacts were found in the Varna Necropolis in Bulgaria. The graves of the necropolis were built between 4700 and 4200 BC, indicating that gold mining could be at least 700 ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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TauTona
The TauTona Mine or Western Deep No.3 Shaft, was a gold mine in South Africa. At approximately deep, it was home to the world's second deepest mining operation, rivalled only by the Mponeng Gold Mine, but was closed in 2018. The mine was one of the three Western Deep Levels mines of the West Wits gold field west of Johannesburg. The mine is near the town of Carletonville. TauTona neighbours the Mponeng and Savuka mines and they share processing abilities. All three were owned by AngloGold Ashanti until Savuka was closed in 2017, TauTona in 2018 and Mponeng was purchased by Harmony Gold in 2020. The mine was built by the Anglo American Corporation and its deep main shaft was sunk in 1957. The name TauTona means "great lion" in the Setswana language. The mine began operation in 1962. It was one of the most efficient mines in South Africa and remained in continuous operation even during periods when the price of gold was low. Two secondary shafts were added to bring the mine to ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Jerusalem–Yitzhak Navon Railway Station
Jerusalem–Yitzhak Navon Railway Station ( he, תחנת הרכבת ירושלים – יצחק נבון, ''Tahanat HaRakevet Yerushalaim–Yitzhak Navon''; ar, محطة أورشليم – يتسحاق ناڤون), originally named Jerusalem–HaUma railway station is an Israel Railways passenger terminal in Jerusalem, located at 6 Shazar Avenue. The station is the eastern terminus of the Tel Aviv–Jerusalem railway. It is the world's deepest heavy-rail passenger station, the fourth deepest underground station in the world, and the deepest underground station outside the former Soviet Union, with its platforms extending down to below street level. It is located across from Binyanei HaUma and constitutes part of a major public transportation hub, being situated adjacent to the Jerusalem Central Bus Station as well as next to a station serving current and future lines of the Jerusalem Light Rail. The station is named after Jerusalem native Yitzhak Navon, the fifth President of ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Commonwealth Of Independent States
The Commonwealth of Independent States (CIS) is a regional intergovernmental organization in Eurasia. It was formed following the dissolution of the Soviet Union in 1991. It covers an area of and has an estimated population of 239,796,010. The CIS encourages cooperation in economic, political and military affairs and has certain powers relating to the coordination of trade, finance, lawmaking, and security. It has also promoted cooperation on cross-border crime prevention. As the Soviet Union disintegrated, Belarus, Russia and Ukraine signed the Belovezh Accords on 8 December 1991, declaring that the Union had effectively ceased to exist and proclaimed the CIS in its place. On 21 December, the Alma-Ata Protocol was signed. The Baltic states (Estonia, Latvia and Lithuania), which regard their membership in the Soviet Union as an illegal occupation, chose not to participate. Georgia withdrew its membership in 2008 following the Russo-Georgian War. Ukraine formally ended its ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Tunnelling Shield
A tunnelling shield is a protective structure used during the excavation of large, man-made tunnels. When excavating through ground that is soft, liquid, or otherwise unstable, there is a potential health and safety hazard to workers and the project itself from falling materials or a cave-in. A tunnelling shield can be used as a temporary support structure. It is usually in place for the short-term from when the tunnel section is excavated until it can be lined with a permanent support structure. The permanent structure may be made up of, depending on the period, bricks, concrete, cast iron, or steel. Although modern shields are commonly cylindrical, the first "shield", designed by Marc Isambard Brunel, was actually a large, rectangular, scaffold-like iron structure with three levels and twelve sections per level, with a solid load-bearing top surface. The structure protected the men from cave-ins as they laboured within it, digging the tunnel out in front of the shield. History ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Waterloo & City Line
The Waterloo & City line, colloquially known as The Drain, is a London Underground shuttle line that runs between Waterloo and Bank with no intermediate stops. Its primary traffic consists of commuters from south-west London, Surrey and Hampshire arriving at Waterloo main line station and travelling forward to the City of London financial district. For this reason, the line has historically not operated on Sundays or public holidays, except in very limited circumstances. However, following the COVID-19 pandemic, the line is currently only open on weekdays. It is one of only two lines on the Underground network to run completely underground, the other being the Victoria line. Printed in turquoise on the Tube map, it is by far the shortest line on the Underground network, being long, with an end-to-end journey lasting just four minutes. In absolute terms, it is the least-used Tube line, carrying just over 15 million passengers annually. However, in terms of the average nu ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Victoria Line
The Victoria line is a London Underground line that runs between in south London and in the north-east, via the West End. It is printed in light blue on the Tube map and is one of the only two lines on the network to run completely underground, the other being the Waterloo & City line. The line was constructed in the 1960s and was the first entirely new Underground line in London for 50 years. It was designed to reduce congestion on other lines, particularly the Piccadilly line and the branch of the Northern line. The first section, from Walthamstow Central to , opened in September 1968 and an extension to followed in December. The line was completed to Victoria station in March 1969 and was opened by Queen Elizabeth II who rode a train from Green Park to Victoria. The southern extension to Brixton opened in 1971, and Pimlico station was added in 1972. The Victoria line is operated using automatic train operation, but all trains have drivers. The 2009 Tube Stock rep ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Piccadilly Line
The Piccadilly line is a deep-level London Underground line running from the north to the west of London. It has two branches, which split at Acton Town, and serves 53 stations. The line serves Heathrow Airport, and some of its stations are near tourist attractions such as Piccadilly Circus and Buckingham Palace. The District and Metropolitan lines share some sections of track with the Piccadilly line. Printed in dark blue (officially "Corporate Blue", Pantone 072) on the Tube map, it is the fourth busiest line on the Underground network, with over 210 million passenger journeys in 2011/12. The first section, between Finsbury Park and Hammersmith, was opened in 1906 as the Great Northern, Piccadilly and Brompton Railway (GNP&BR). The station tunnels and buildings were designed by Leslie Green, featuring ox-blood terracotta facades with semi-circular windows on the first floor. When Underground Electric Railways of London (UERL) took over the line, it was renamed the Piccadil ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |