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Unbuilt supertall skyscraper, The Illinois

Supertall is a term that refers to an extremely tall skyscraper. Image File history File links Acap. ... Image File history File links Download high resolution version (225x891, 60 KB) This image is of a drawing, painting, print, or other two-dimensional work of art, and the copyright for it is most likely owned by either the artist who produced the image, the person who commissioned the work... Image File history File links Download high resolution version (225x891, 60 KB) This image is of a drawing, painting, print, or other two-dimensional work of art, and the copyright for it is most likely owned by either the artist who produced the image, the person who commissioned the work... In 1956, Frank Lloyd Wright proposed a mile-high (1,609 metres/5,280 feet) structure known as either Mile High Illinois, Illinois Sky-City, or simply The Illinois. ... This article does not cite any references or sources. ...

Although no official definition exists, a height of approximately 300 meters or 1,000 feet is a generally agreed minimum of architecture enthusiasts for a skyscraper to qualify as supertall. The term also applies to proposed structures over 1 kilometer (1,000 m / 3,281 ft) or 1 mile (5,280 ft / 1,609 m) in height — designs which have never advanced beyond the concept or planning stages. Additionally, the term may be used for an architectural structure of any type taller than 300 meters, such as free-standing towers, guyed masts, chimneys, bridge pillars or other non-building structures. Most supertall structures rank among the top 10 in a particular category of (local) height records. Section of the dome of Florence Cathedral. ... To help compare different orders of magnitude this page lists lengths between 1 km and 10 km (103 and 104 m). ... An architectural structure is a free-standing or guy anchored manmade outdoor construction for permanent use. ... This article does not cite any references or sources. ... Masts of the Rugby VLF transmitter in England Radio masts and towers are, typically, tall structures designed to support antennas (also known as aerials in the UK) for telecommunications and broadcasting, including television. ... Look up Chimney in Wiktionary, the free dictionary. ... A log bridge in the French Alps near Vallorcine. ...

Of the approximately 1,150 existing supertall structures, most are guyed masts for FM radio and television broadcasting in the United States. This stems from the country having expansive flat areas where individual TV stations can build towers to service a wide area or population center, and of the circumstance that in the USA most broadcasting companies built their own tower; therefore it is not rare for multiple supertall radio towers to be located in close proximity. Other supertall structures are guyed masts for TV-broadcasting outside the USA, for scientific experiments and for transmission in the VLF, longwave and mediumwave range, free-standing and partially guyed TV-towers, chimneys and last but not least some skyscrapers. There are also two supertall electricity pylons belonging to Yangtze River Crossing, a supertall bridge (Millau Viaduct) and a supertall dam (Nurek Dam). KVLY-TV mast, which is guy-wire supported. ... Frequency modulation (FM) is a form of modulation that represents information as variations in the instantaneous frequency of a carrier wave. ... The Yangtze River Crossing may refer to one of three overhead power lines crossing the Yangtze River, China. ... The Millau Viaduct (French: ) is a large cable-stayed road-bridge that spans the valley of the River Tarn near Millau in southern France. ... The Nurek (Norak) Dam is a large earthfill dam located at 38. ...

Structures

Challenges

Conceptual supertall designs, such as The Illinois by Frank Lloyd Wright (image, right), X-Seed 4000, and Sky City 1000 are probably technologically and architecturally feasible, but are considered by some to be simply too tall to be of any particular use. These designs tend to be bold and visionary, portending a shift in the nature of urban living towards multi-layered cities, and reflective of the human impulse to always build bigger and taller structures.^{[citation needed]} Although building supertall structures is often a way of showing prestige and technical abilities, their construction brings sometimes great benefits for the planned use. In 1956, Frank Lloyd Wright proposed a mile-high (1,609 metres/5,280 feet) structure known as either Mile High Illinois, Illinois Sky-City, or simply The Illinois. ... Frank Lloyd Wright (June 8, 1867 – April 9, 1959) was one of the worlds most prominent and influential architects. ... The X-Seed 4000 is the tallest building ever fully designed for a building proposal at 4,000 meters high (13,123. ... Tokyos proposed Sky City 1000 Sky City 1000 is a possible future urban project aimed at helping put an end to major congestion and lack of green space in the Tokyo, Japan ward area. ... Crowded Shibuya, Tokyo shopping district An urban area is an area with an increased density of human-created structures in comparison to the areas surrounding it. ...

Building supertall structures of any kind is expensive, because the erection costs do not grow in direct proportion to height of structure, but grow faster. So a 1,000 ft (305 m) radio mast in the USA costs between $0.7 and $1.1 million to build, while a 2,000 ft (610 m) radio mast in the USA costs $2.4 to $4 million to build. Compared to guyed masts, the erection costs for free-standing structures escalate almost exponentially with their height, which set their height in most cases at an economical limit. Another consequence of this circumstance is that for supertall transmission towers the erection of guyed masts is in most cases preferred.

Supertall structures of all kinds have to withstand greater wind forces than smaller structures of the same type, requiring various structural engineering measures to handle them. Further, the construction site must be approved by flight safety authorities.

Buildings

The Sears Tower in Chicago is a current example of a supertall structure.

The Burj Dubai, when completed, will be the tallest structure in the world.

Supertall skyscrapers save land by housing a large number of residents and/or workers on a relatively small footprint. However, fire safety and rapid evacuation problems increase with building height and the number of people the building is designed to serve. In addition, water and sewage networks become more expansive as buildings get taller, especially when they must handle the needs of many people. Many skyscrapers have observation decks open to tourists. Image File history File links Download high resolution version (500x643, 80 KB) Summary Photo taken 1998 by uploader. ... Image File history File links Download high resolution version (500x643, 80 KB) Summary Photo taken 1998 by uploader. ... This article does not cite any references or sources. ... Image File history File links Burj_dubai. ... Image File history File links Burj_dubai. ... The Burj Dubai (Arabic: Dubai Tower) is a supertall skyscraper currently under construction in the New Downtown of Dubai, United Arab Emirates. ... Fire safety is a component of Building Safety. ... Look up evacuation in Wiktionary, the free dictionary. ...

Radio towers

Supertall radio masts and towers for UHF-/VHF-transmission allow a wide area of reception. Because of reflections, which disturb radio wave propagation, their erection is only sensible in flatter areas, without higher mountains.

Therefore nearly all very high radio towers (taller than 300 meters (1,000 feet)) for UHF-/VHF-transmission are situated in flat areas. As guyed masts of same height are cheaper than free-standing towers, building guyed masts is preferred in most cases. Free-standing towers, however, show less oscillation by external forces like wind than guyed masts, and require no sites for guy anchors. So they are built either if no place for guy anchors is available or for towers which may not show too large oscillations by external forces, as towers with observation decks and/or towers with larger cabinets and/or directional antennas.

In some cases building a partially guyed tower, consisting of a free-standing basement tower with a mast guyed to the ground on the top, may be a good choice under technical and financial points of view, as it is cheaper to build than a completely free-standing tower of same height and offers a basement section more stable than a free-standing tower.

Supertall mast radiators, e.g. half-wave radiators for longwave radio, allow larger areas of fading-free reception, because in comparison to shorter mast radiators, the ratio of skywave and groundwave radiation is much smaller, so fading occurs in areas much further away from the transmission tower than using a shorter mast radiator. However, because nowadays the range of longwave transmitters is more determined by jamming from other stations working in the same channel, using halfwave mast-radiators does not greatly improve longwave reception at a greater distance from the transmission antenna. The only realized half-wave mast radiator for longwave was the Warsaw Radio Mast. The usage of supertall mast radiators and antenna structures with heights between 300 and 450 meters (1,000 and 1,480 feet) is however very sensitive for high power longwave radio stations with greater bandwidth requirement like longwave broadcasting or LORAN-C, because these antenna structures require for the realization of a quarter-wave length radiator no or only little electrical lengthening, which reduces bandwidth and antenna efficiency and increases also antenna voltage. This article does not cite any references or sources. ... The Warsaw radio mast in Konstantynów The Warsaw radio mast a few months after collapse Warsaw Radio Mast from far away The Warsaw radio mast was the tallest structure ever built; however, it existed only from 1973 to 1991. ... LORAN (LOng RAnge Navigation) is a terrestrial navigation system using low frequency radio transmitters. ... This article, image, template or category should belong in one or more categories. ...

The WITN Tower in Grifton, North Carolina. It stands 605 meters (1,984.9 feet) tall.

For VLF transmission the use of supertall masts either as mast radiators (electrically lengthed as an umbrella antenna) or as carriers of wire antennas is perhaps the best choice. However the erection costs grow faster than the height of the masts, as do the costs of maintenance. So one tries to find out whether it is possible (by using electrical lengthing) not to build the masts unnecessarily tall. Because the bandwidth of most VLF-transmitters is very low, the use of excessive electrical lengthing is possible without bigger problems. At VLF there is also very little skywave propagation, so there is no requirement for skywave suppression characteristics of the antenna. In contrast to its skywave propagation, the groundwave propagation of VLF is very good and one can easily increase the range of the transmitter by increasing the power. In this frequency range it may be cheaper to run a high power transmitter with a less effective antenna using lower masts than to build and maintain an antenna using extreme tall masts. So VLF transmitters often use very tall masts (height between 200 and 400 meters (660 to 1,320 feet)) for their transmitting antennas, but their masts are not among the tallest ever built. In the Western hemisphere the masts of VLF transmitter Lualualei on Hawaii are the tallest structures used for transmission in this frequency range. Image File history File linksMetadata Download high resolution version (768x1024, 55 KB) Source: http://flickr. ... Image File history File linksMetadata Download high resolution version (768x1024, 55 KB) Source: http://flickr. ... Grifton is a town located in Pitt County, North Carolina. ... A typical mast radiator Base feed: mast is fed from Aerial Tuning Unit on right via conductor to top of brown ceramic insulator. ... This article, image, template or category should belong in one or more categories. ... This article, image, template or category should belong in one or more categories. ... This article, image, template or category should belong in one or more categories. ... The VLF transmitter Lualualei is a facility for VLF-transmission of the US Navy at Lualualei, Hawaii. ...

Nevertheless satisfactorily working VLF and LF transmitters can be built according to the works of the radio engineer Ernst Alexanderson without using supertall towers. Such antennas include the Kalundborg longwave broadcasting transmitter and the SAQ-VLF transmitter in Grimeton, Sweden. Their towers are approximately 120 meters (400 feet) tall. Ernst Frederick Werner Alexanderson (January 25, 1878–May 14, 1975) was a Swedish-American electrical engineer. ... The Transmitter Kalundborg is a transmission facility for long- and mediumwave near Kalundborg in Denmark. ... SAQ is the callsign of the VLF transmitter Grimeton Saq saq? Example: 1. ...

For mediumwave-transmission, supertall mast radiators are a bad choice because they show high skywave emission, which results in excessive fading at night. However there are some special highly effective fading-reducing antenna types for mediumwave broadcasting which do require supertall towers. Because of the high erection costs for the required towers, their use is only sensible for high power stations working on nearly interference free channels at the lower end of the mediumwave band. So only a few broadcasting stations like RKS Liblice 2 use or have used such antennas. Mediumwave radio transmissions serves as the most common band for broadcasting. ... RKS Liblice 2 is a high-power broadcasting facility for mediumwave near Liblice, Czech at 14°5313 E and 50°0402N. It uses as antenna two 355 metre high guyed masts of lattice steel. ...

Chimneys

Trbovlje Chimney in Slovenia. It stands 360 meters (1,200 feet) tall.

Historically, supertall chimneys were used to improve the dispersion of waste gases and heat from a factory or power generation station. However, tall chimneys did not eliminate toxic substances in the smoke — it simply distributed a lower concentration of pollutants over an increased area, often over a population center. A well known exemplar is the Inco Superstack in Sudbury, Ontario. In many countries, recent enactment of stricter pollution laws has reduced simply dispersing exhaust with huge chimneys and requires emissions cleaning equipment to be installed. The regulations reduced the need for extremely tall chimneys, as the resulting polluting emissions are of a low concentration so that distribution over a wide area is no longer necessary. However, a supertall chimney may be appropriate for a factory or conventional thermal power station situated in a valley, exampled by the Trbovlje Chimney at Trbvolje Power Station in Slovenia, located in a deep valley. Chimney of the Trbovlje coal power plant, so called Trbovlje chimney, 364 m, located near Trbovlje, Slovenia. ... Chimney of the Trbovlje coal power plant, so called Trbovlje chimney, 364 m, located near Trbovlje, Slovenia. ... Trbovlje Chimney The Trbovlje Chimney (Slovene: Trboveljski dimnik) is the largest chimney in Europe. ... Look up Chimney in Wiktionary, the free dictionary. ... This article or section does not cite any references or sources. ... The Inco Superstack from a distance of about 10 km, seen from the far side of Lake Ramsey. ... Greater Sudbury (2001 census population 155,219) is a city in Northern Ontario. ... Trbovlje Chimney The Trbovlje Chimney (Slovene: Trboveljski dimnik) is the largest chimney in Europe. ...

Pylons

For power line crossings of sea narrows and wide rivers overhead powerlines carried by tall pylons on each side of the sea narrow or river can be used. While such crossings with pylons lower than 230 m (755 ft) at each shore of the sea narrow or river were reallized in many countries, only one such crossing with supertall pylons, the Yangtze River Crossing in China, was built. This results in the fact, that if such tall pylons would be required, laying an underground cable through the sea narrow or the river may be more practical. At long spans, the use of bundled conductors, which are standard for powerlines with voltages greater than 200,000 volts (200 kV) for physical reasons, can result in wind-induced oscillations, that may even lead to short circuits, if they approach too closely. Single conductors thick enough to transport the same amount of electricity as bundled conductors show more corona losses and are therefore not the best choice, but sometimes used for overhead powerline crossings with not extremely high power loads.^{[citation needed]} A more serious problem at such crossings, is that conductive materials of high tensile strength are required, if crossing pylons should get not too high ( the minimum clearance of conductors of upper mentioned Yangtze River Crossing using standard conductors with a span width of 2,380 m (7,808 ft) is 55 m (180 ft), while the pylons used are 346 m (1,135 ft) tall!). Unfortunately these materials demonstrate a higher specific electrical resistance than standard conductors, resulting in higher losses. Therefore their use is only sensible, when power transmission requirements are not too high. It is hereby to mention, that the overhead powerline crossing of Messina Strait with steel conductors, two 232 m (761 ft) tall pylons on each side of Messina Strait and a span width of 3,280 m (10,761 ft) was replaced by a submarine cable. Power line redirects here. ... For the Second World War frigate class, see River class frigate The Murray River in Australia A waterfall on the Ova da Fedoz, Switzerland A river is a large natural waterway. ... The metre (American English:meter) is a measure of length. ... A foot (plural: feet or foot;[1] symbol or abbreviation: ft or, sometimes, ′ – a prime) is a unit of length, in a number of different systems, including English units, Imperial units, and United States customary units. ... The Yangtze River Crossing may refer to one of three overhead power lines crossing the Yangtze River, China. ... 6 or 15cm outside diameter, oil-cooled cables, traversing the Grand Coulee Dam throughout. ... In science and engineering, conductors, such as a electrical connector, are materials that readily conduct electric current through electrical conduction. ... Oscillation is the variation, typically in time, of some measure as seen, for example, in a swinging pendulum. ... For alternate meanings see Short circuit (disambiguation) A short circuit (sometimes known as simply a short) is a fault whereby electricity moves through a circuit in an unintended path, usually due to a connection forming where none was expected. ... The metre (American English:meter) is a measure of length. ... A foot (plural: feet or foot;[1] symbol or abbreviation: ft or, sometimes, ′ – a prime) is a unit of length, in a number of different systems, including English units, Imperial units, and United States customary units. ... The metre (American English:meter) is a measure of length. ... A foot (plural: feet or foot;[1] symbol or abbreviation: ft or, sometimes, ′ – a prime) is a unit of length, in a number of different systems, including English units, Imperial units, and United States customary units. ... The metre (American English:meter) is a measure of length. ... A foot (plural: feet or foot;[1] symbol or abbreviation: ft or, sometimes, ′ – a prime) is a unit of length, in a number of different systems, including English units, Imperial units, and United States customary units. ... Electrical resistance is a measure of the degree to which an electrical component opposes the passage of current. ... The former electricity pylon on the Sicilian site of Messina Strait (Torre Faro) The Pylons of Messina are the pylons of the former above-ground 220 kV high-voltage line crossing the Strait of Messina between Italy and Sicily, part of a longer power line from Sorgente to Rizziconi. ... Satellite photo of the Strait of Messina, taken June 2002. ... The metre (American English:meter) is a measure of length. ... A foot (plural: feet or foot;[1] symbol or abbreviation: ft or, sometimes, ′ – a prime) is a unit of length, in a number of different systems, including English units, Imperial units, and United States customary units. ... The metre (American English:meter) is a measure of length. ... A foot (plural: feet or foot;[1] symbol or abbreviation: ft or, sometimes, ′ – a prime) is a unit of length, in a number of different systems, including English units, Imperial units, and United States customary units. ...

Bridges

The Millau Viaduct in France.

Supertall bridge towers must withstand enormous forces and are designed to support the weight of the bridge and vehicles crossing the bridge in addition to the dynamic structural loads caused by vehicle movement, which are especially considerable for railroad bridges. Bridges with supertall pillars may be built as suspension bridges or other types of bridges carried by cable. The only realized supertall bridge is Millau Viaduct, a cable-stayed bridge for a motorway across a valley in France. The proposed Strait of Messina Bridge would have qualified as supertall, had it not been canceled due to the depth of the strait making a bridge with pillars economically questionable. However, if a bridge over Messina Strait will be ever built, it may use supertall bridge pillars as these may be still easier to build as a bridge pillar in the deep Messina Strait. Image File history File links Millau_viaduc. ... Image File history File links Millau_viaduc. ... The Millau Viaduct (French: ) is a large cable-stayed road-bridge that spans the valley of the River Tarn near Millau in southern France. ... This article or section does not adequately cite its references or sources. ... This is the top-level page of WikiProject trains Rail tracks Rail transport refers to the land transport of passengers and goods along railways or railroads. ... A suspension bridge is a type of bridge that has been created since ancient times as early as 100 AD. Simple suspension bridges, for use by pedestrians and livestock, are still constructed, based upon the ancient Inca rope bridge. ... The Millau Viaduct (French: ) is a large cable-stayed road-bridge that spans the valley of the River Tarn near Millau in southern France. ... Motorway symbol in UK, France and Ireland. ... Satellite photo of the Strait of Messina, taken June 2002. ...

Rope-type Spans (powerlines, aerial tramways, etc.) and bridges without supertall support structures that cross a valley higher than the height level defined as criteria for supertall structures at the point where the valley is deepest, should not be classified as supertall structures , because in these constructions the maximum height above the ground has minimal influence on the design.^{[citation needed]} Fljótsdalur in East Iceland, a rather flat valley A valley or a low area between two hills dale (in Scotland, a glen) is a landform, which can range from a few square kilometres to hundreds or even thousands of square kilometres in area. ...

Other structures

Supertall dams require a deep canyon-like valley as a construction site. So far only one such dam (Nurek Dam in Tajikistan) has been built and two further are under construction. The Nurek (Norak) Dam is a large earthfill dam located at 38. ...

Solar updraft towers in contrast have to be built as supertall structures, because this improves the efficiency of the facility. Schematic of a Solar updraft tower This article is about a type of power plant. ...

A future use for supertall structures may be special towers with maglev tracks for launching spacecraft and space elevators. This article needs additional references or sources for verification. ... The Space Shuttle Discovery as seen from the International Space Station. ... A space elevator would consist of a cable anchored to the Earths surface, reaching into space. ...

See also

• Megastructure
• World's tallest structures
• List of world's tallest structures
• List of masts
• List of towers
• List of chimneys
• List of skyscrapers
• Skyscraper