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Yangtze River Power Line Crossings
The Yangtze River power line crossings are overhead power lines that cross the Yangtze River in China. There are at least three power line crossings on the Yangtze River at Jiangyin, Nanjing, and Wuhu. The towers of the crossing in Jiangyin are among the highest in the world. Jiangyin One exists at Jiangyin, Jiangsu Province, China. Each pylon is situated at and at . It is a section of the 500 kV power line from the Yancheng power station to the Dou Shan substation in the province of Jiangsu. The power line section running over the river has a span width of . It is carried by two tall suspension towers, each weighing 4,192 tonnes. (for comparison, the towers even surpass the height of the Eiffel Tower, which is , including antenna). They are identical lattice towers of square cross section with an area of × 68 m at the base and × 8 m at the top. The pylons carry four conductors on the lower crossarm, above ground, with a length of and two conductors on the upper crossarm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overhead Line Crossing
An overhead line crossing is the crossing of an obstacle—such as a traffic route, a river, a valley or a strait—by an overhead power line. The style of crossing depends on the local conditions and regulations at the time the power line is constructed. Overhead line crossings can sometimes require extensive construction and can also have operational issues. In such cases, those in charge of construction should consider whether a crossing of the obstacle would be better accomplished by an underground or submarine cable. Crossings of roads and railway lines Overhead line crossings of roads, railway lines, and small- and medium-sized watercourses do not normally require special construction. However, in the first years of overhead line building a scaffold under the line was required, when a railway line or a road was crossed. Later in Germany and some other countries on each end of a powerline crossing of a state-operated railway a dead-end tower was required, which can s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insulator String
An electrical insulator is a material in which electric current does not flow freely. The atoms of the insulator have tightly bound electrons which cannot readily move. Other materials—semiconductors and conductors—conduct electric current more easily. The property that distinguishes an insulator is its resistivity; insulators have higher resistivity than semiconductors or conductors. The most common examples are non-metals. A perfect insulator does not exist because even insulators contain small numbers of mobile charges (charge carriers) which can carry current. In addition, all insulators become electrically conductive when a sufficiently large voltage is applied that the electric field tears electrons away from the atoms. This is known as the breakdown voltage of an insulator. Some materials such as glass, paper and PTFE, which have high resistivity, are very good electrical insulators. A much larger class of materials, even though they may have lower bulk resistivity, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SkyscraperPage
SkyscraperPage is a website for skyscraper hobbyists and enthusiasts that tracks existing and proposed skyscrapers around the world. The site is owned by Skyscraper Source Media, a supplier of skyscraper diagrams for the publication, marketing, and display industries, and is a publisher of illustrated skyscraper diagram poster products. They are based in Victoria, British Columbia. The site has over 60,000 drawings of skyscrapers, other major macro-engineering projects, and tall structures around the world. The scale of the drawings are one pixel per meter. The images are created using pixel art. Using these diagrams, skyscrapers and other tall structures can be compared. General information is also given about each structure if available, such as the location, the year built, the height and the number of floors. The site also hosts a discussion forum for skyscraper enthusiasts. See also * SkyscraperCity * Emporis * List of Internet forums * List of tallest buildings in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Tallest Freestanding Steel Structures
This is a list of tallest freestanding steel structures in the world past and present. To be a freestanding steel structure it must not be supported by guy wires, the list therefore does not include guyed masts and the main vertical and lateral structural elements and floor systems in the case of buildings, are constructed from steel. This type of construction is a rarity today as most tall buildings are built with a composite structure featuring a reinforced concrete core. Oil platforms built using rigid steel jackets, such as the Bullwinkle (oil platform), are included and ranked as the local medium(water) does not provide any horizontal support. In fact they are over engineered specifically to resist water forces them rather than modulate them as compliant towers are designed to do. Demolished structures and structures under construction are also included but not ranked. Steel Structures (above 275 m / 900 ft in height) indicates a structures no longer standing. indicates a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Tallest Freestanding Structures In The World
This is a list of tallest freestanding structures in the world past and present. To be freestanding a structure must not be supported by guy wires, the sea or other types of support. It therefore does not include guyed masts, partially guyed towers and drilling platforms but does include towers, skyscrapers (pinnacle height) and chimneys.''See Tallest freestanding structures by skyscraperpage.com/ref> Freestanding structures (past or present) over * indicates a structure that is no longer standing. * For all structures the pinnacle height is given, so the height of skyscrapers may be different from the values at List of tallest buildings in the world. * Structures under construction are included in main list if its current height is over . Other freestanding structures (past or present): between and Timeline of world's tallest freestanding structures See also * List of tallest structures by country * List of tallest demolished freestanding structures * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Tallest Buildings And Structures In The World
The world's tallest human-made structure is the Burj Khalifa in Dubai (of the United Arab Emirates). The building gained the official title of "tallest building in the world" and the tallest self-supported structure at its opening on January 9, 2010. Burj Khalifa was developed by Emaar properties, designed by Skidmore, Owings and Merrill and built by BESIX, Samsung Construction and Arabtec. The second-tallest self-supporting structure and the tallest tower in the world is the Tokyo Skytree. The tallest guyed structure is the KVLY-TV mast at 1987 feet. The Council on Tall Buildings and Urban Habitat, an organization that certifies buildings as the "World's Tallest", recognizes a building only if at least 49% of its height is made up of floor plates containing habitable floor area. Structures that do not meet this criterion, such as the CN Tower, are defined as "towers". There are dozens of radio and television broadcasting towers which measure over 600 metres (about ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yangtze River Bridges And Tunnels
The bridges and tunnels across the Yangtze River carry rail and road traffic across China's longest and largest river and form a vital part of the country's transportation infrastructure. The river bisects China proper from west to east, and every major north–south bound highway and railway must cross the Yangtze. Large urban centers along the river such as Chongqing, Wuhan, and Nanjing also have urban mass transit rail lines crossing the Yangtze. Pontoon bridges have been used by militaries for two thousand years on the Yangtze, but until the completion of the Wuhan Yangtze River Bridge in 1957, there were no permanent bridges along the main stretch of the river known as ''Chang Jiang'' (the " Long River"), from Yibin to the river mouth in Shanghai, a distance of . Since then, over 75 bridges and six tunnels have been built over this stretch, the overwhelming majority since 1990. They reflect a broad array of bridge designs and, in many cases, represent significant achieve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anhui
Anhui , (; formerly romanized as Anhwei) is a landlocked province of the People's Republic of China, part of the East China region. Its provincial capital and largest city is Hefei. The province is located across the basins of the Yangtze River and the Huai River, bordering Jiangsu to the east, Zhejiang to the southeast, Jiangxi to the south, Hubei to the southwest, Henan to the northwest, and Shandong for a short section in the north. With a population of 63.65 million, Anhui is the 8th most populous province in China. It is the 22nd largest Chinese province based on area, and the 12th most densely-populated region of all 34 Chinese provincial regions. Anhui's population is mostly composed of Han Chinese. Languages spoken within the province include Jianghuai Mandarin, Wu, Hui, Gan and small portion of Zhongyuan Mandarin Chinese. The name "Anhui" derives from the names of two cities: Anqing and Huizhou (now Huangshan City). The abbreviation for Anhui is "" after the histori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wuhu City
Wuhu () is a prefecture-level city in southeastern Anhui province, China. Sitting on the southeast bank of the Yangtze River, Wuhu borders Xuancheng to the southeast, Chizhou and Tongling to the southwest, Hefei city to the northwest, Ma'anshan city to the northeast, Jiangsu Province to the east, and is approximately southwest of Nanjing. With the urbanization trend in the southern part of Nanjing, a conurbation between Nanjing, Maanshan and Wuhu is in building with more than 10,660,000 inhabitants. Administration The prefecture-level city of Wuhu administers 8 county-level divisions, including 5 districts, 1 county, and 1 county-level city. *Defunct - Sanshan District Climate Demographics Population As of the 2020 Chinese census, Wuhu had a total population of 3,644,420 inhabitants whom 1,622,799 lived its built-up (or metro) area made of Jiujiang District, Jinghu District and Yijiang District. The city has over 47 ethnic minorities present — the largest being the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HVDC Three Gorges-Changzhou
A high-voltage direct current (HVDC) electric power transmission system (also called a power superhighway or an electrical superhighway) uses direct current (DC) for electric power transmission, in contrast with the more common alternating current (AC) transmission systems. Most HVDC links use voltages between 100 kV and 800 kV. However, a 1,100 kV link in China was completed in 2019 over a distance of with a power capacity of 12 GW. With this dimension, intercontinental connections become possible which could help to deal with the fluctuations of wind power and photovoltaics. HVDC allows power transmission between AC transmission systems that are not synchronized. Since the power flow through an HVDC link can be controlled independently of the phase angle between source and load, it can stabilize a network against disturbances due to rapid changes in power. HVDC also allows the transfer of power between grid systems running at different frequencies, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dead-end Tower
A dead-end tower (also anchor tower, anchor pylon) is a fully self-supporting structure used in construction of overhead power lines. A dead-end transmission tower uses horizontal strain insulators at the end of conductors. Dead-end towers may be used at a substation as a transition to a "slack span" entering the equipment, when the circuit changes to a buried cable, when a transmission line changes direction by more than a few degrees, or at intervals along a straight run to limit the extent of a catastrophic collapse. Since dead-end towers require more material and are heavier and costlier than suspension towers, it is uneconomic to build a line with only self-supporting structures.D.G. Fink, H.W. Beaty, ''Standard Handbook for Electrical Engineers Eleventh Edition'', McGraw-Hill, 1978 , pp. 14-80, 14-81 Dead-end towers are used at regular intervals in a long transmission line to limit the cascading tower failures that might occur after a conductor failure. An in-line dead- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
