This category does not require the structure to be "officially" open, but does require it to be "topped out".
ThePetronius Platform stands 610 m (2,000 ft) off the sea floor, leading some, includingGuinness World Records 2007, to claim it as the tallest freestanding structure in the world, until surpassed by the Burj Khalifa in 2010. However, it is debated whether underwater height should be counted, in the same manner as height below ground is ignored on buildings. TheTroll A platform is 472 m (1,549 ft), without any part of that height being supported by wires. Thetension-leg type of oil platform has even greater below-water heights with several examples more than 1,000 m (3,300 ft) deep. However, these platforms are not considered constant structures as the vast majority of their height is made up of the length of the tendons attaching the floating platforms to the sea floor. Despite this,Guinness World Records 2009 listed theUrsa tension leg platform as the tallest structure in the world with a total height of 1,306 m (4,285 ft).Shell'sfloating production, storage, and offloading oil platformTurritella in the Gulf of Mexico is a moored platform approximately 2,900 m (9,500 ft) tall.[1]
Completed in 1982, the tower's guy-wires were not protected against corrosion and failed due to rust and storm winds causing the tower to collapse in 1989. Small-scale experimental model of a solar draft tower, newer proposals if built could become the tallest structure on earth.
* "Mixed-use" is defined as having three or more real estate uses (such as retail, office, hotel, etc.) that are physically and functionally integrated in a single property and are mutually supporting.[16]
The central spire was destroyed in a storm in 1549. While the reputed height of 525 ft (160 m) is accepted by most sources,[19][20][21][22][23][24] others consider it doubtful[25]
See also 1549–1569. The church tower's spire burnt down after a lightning strike in 1647. Today the tower has a dome and stands at a height of 104 m (341 ft).
First building with 100+ stories. The addition of a pinnacle and antennas later increased its overall height to 448.7 m (1,472 ft). This was subsequently lowered to 443.1 m (1,454 ft).
(See also resumption 1991–2000). 75-foot analog antenna was removed from the top of the structure in 2018 in digital repack construction[citation needed]
The overall recordholders (above) are all on dry land, except for the Petronius oil platform, which was the overall recordholder from 2000-2007. During that period theKVLY-TV mast held the record for tallest structure on dry land (after previously being the overall record holder from 1963-1974 and 1991-2000).
As many large guyed masts were destroyed at the end of World War II, the dates for the years between 1945 and 1950 may be incorrect. IfWusung Radio Tower survived World War II, it was the tallest guyed structure shortly after World War II.
(See also resumption 1991–2018). 75-foot analog antenna was removed from the top of the structure in 2018 in digital repack construction[citation needed]
Freestanding structures must not be supported by guy wires (like guyed masts or partially guyed towers), or built underground or on theseabed and supported by the sea (such as thePetronius Platform). They include towers, chimneys, and skyscrapers (listed based on their pinnacle height). Until 1954, freestanding structures held the record for tallest structures overall, as seen in the Overall table above. Here are the records for freestanding structures after that point:
First building with 100+ stories. The addition of a pinnacle and antennas later increased its overall height to 448.7 m (1,472 ft). This was subsequently lowered to 443.1 m (1,454 ft).
Holder of world's tallest freestanding structure. Topped out at 829.8 m (2,722 ft) in 2009.
Diagram of the principal high buildings of the Old World, 1884
Notable mentions include thePharos (lighthouse) of Alexandria, built in the third century BC and estimated between 115–135 m (377–443 ft). It was the world's tallest non-pyramidal structure for many centuries. Another notable mention includes theJetavanaramayastupa inAnuradhapura, Sri Lanka, which was built in the third century, and was similarly tall at 122 m (400 ft). These were both the world's tallest or second-tallest non-pyramidal structure for over a thousand years.
The tallestsecular building between the collapse of the Pharos and the erection of theWashington Monument may have been theTorre del Mangia inSiena, Italy, which is 102 m (335 ft) tall, and was constructed in the first half of the fourteenth century; and the 97-metre-tall (318 ft)Torre degli Asinelli inBologna, Italy, built between 1109 and 1119.
Tokyo Tower held the record of being the tallest tower in the world from 1958 to 1967. In addition, it held the record of being the tallest structure in Japan from 1958 to 2011, when theTokyo Skytree (the current tallest tower in the world) surpassed it.
Towers include observation towers, monuments and other structures not generally considered to be "habitable buildings", they are meant for "regular access by humans, but not for living in or office work", meaning it excludes from this list of continuously habitable buildings and skyscrapers.Radio and TV masts with guy-wires for support are also excluded, since they aren't freestanding.
Bridge towers or pylons,chimneys,transmission towers, and most largestatues allow human access for maintenance, but not as part of their normal operation, and are therefore not considered to be towers.
TheCN Tower in Toronto was the world's tallest freestanding structure from 1975 to 2007.
The following is a list of structures that have historically held the title as the tallest towers in the world.
TheCouncil on Tall Buildings and Urban Habitat, an organization that certifies buildings as the "World's Tallest", recognizes a building only if at least 50% of its height is made up of floor plates containing habitable floor area.[2] Structures that do not meet this criterion, such as theCN Tower, are defined as "towers".
Up until the late 1990s, the definition of "tallest building" was not altogether clear. It was generally understood to be the height of the building to the top of its architectural elements including spires, but not including "temporary" structures (such as antennas or flagpoles), which could be added or changed relatively easily without requiring major changes to the building's design. Varying standards have been used by different organizations, so the accepted height of these structures or buildings depends on which standards are accepted. The Council on Tall Buildings and Urban Habitat has changed its definitions over time. Some of the controversy regarding the definitions and assessment of tall structures and buildings has included the following:
the definition of a structure, a building and a tower
whether a structure, building or tower under construction should be included in any assessment
whether a structure, building or tower has to be officially opened before it is assessed
whether structures built in and rising above water should have their below-water height included in any assessment.
whether a structure, building or tower that is guyed is assessed in the same category as self-supporting structures.
Within an accepted definition of a building further controversy has included the following factors:
whether only habitable height of the building is considered
whether communication towers withobservation galleries should be considered "habitable" in this sense
whether rooftopantennas, viewing platforms or any other architecture that does not form a habitable floor should be included in the assessment
whether a floor built at a high level of a telecommunications or viewing tower should change the tower's definition to that of a "building"
One historic case involved the building now famous for theTimes Square Ball. Known asOne Times Square (at 1475Broadway inMidtown Manhattan), it was the headquarters forThe New York Times,which gaveTimes Square its name. Completed in 1905, it reached a height of 364 feet (111 meters) to its roof, or 420 feet (130 meters) including its rooftop flagpole, which theTimes hoped would give it a record high status but because a flagpole is not an integral architectural part of a building, One Times Square was not generally considered to be taller than the 390-foot-high (120 m)Park Row Building inLower Manhattan, which was therefore stillNew York's tallest.[26]
A bigger controversy was the rivalry between two New York Cityskyscrapers built in theRoaring Twenties—theChrysler Building and40 Wall Street. The latter was 927 feet (283 meters) tall, had a shorter pinnacle, and had a much higher top occupied floor (the second category in the 1996 criteria for tallest building).[26] In contrast, the Chrysler Building employed a very long 125-foot (38 m) spire secretly assembled inside the building to claim the title of world's tallest building with a total height of 1,048 feet (319 m), despite having a lower top occupied floor and a shorter height when both buildings' spires are not counted in their heights.[27] Although thearchitects of record for 40 Wall wereH. Craig Severance andYasuo Matsui, the firm ofShreve & Lamb (who also designed theEmpire State Building) served as consulting architects. They wrote a newspaper article claiming that 40 Wall was actually the tallest, since it contained the world's highest usable floor. They pointed out that the observation deck of 40 Wall was nearly 100 feet (30 m) higher than the top floor of the Chrysler, whose surpassing spire was strictly ornamental and essentially inaccessible.[28] Despite the protest, the Chrysler Building was generally accepted as the tallest building in the world for almost a year, until it was surpassed by theEmpire State Building's 1,250 feet (380 meters) in 1931.
That was in turn surpassed by the 1,368-foot-high (417 m) Twin Towers of New York's originalWorld Trade Center in 1972, which were in turn surpassed by the Sears Tower in Chicago in 1974. Now called theWillis Tower since 2009, it was 1,451 feet (442 meters) to its flat rooftop, or 1,518 feet (463 meters) including its original antennas.[29] But in 1978 One World Trade Center (commonly known as the North Tower) attained a taller absolute height when it added its 360-foot (110 m) new broadcasting antenna, for a total height of 1,728 feet (526.7 meters). The WTC North Tower maintained this height record (including its antenna) from 1978 until 2000, when the owners of the Willis Tower extended its broadcasting antennae for a total height of 1,729 feet (527.0 meters).[29] Thus the status of the Willis Tower as the "totally" tallest was restored in the face of a new threat looming in the Far East—the "Siamese Twins".
The Petronas Towers remain the tallest twin towers in the world.
A major controversy erupted upon completion of thePetronas Towers inKuala Lumpur, Malaysia in 1998. These Twin Towers, at 1,483 feet (452 meters), had a higher architectural height (spires, not antennas), but a lower absolute pinnacle height and a lower top occupied floor than theWillis Tower in Chicago. Counting buildings as structures with floors throughout, and with antenna masts excluded, the Willis was still considered the tallest at that time. Excluding their spires, which are 9 meters (30 feet) higher than the flat roof of Willis, the Petronas Towers are not taller than Willis. At their convention in Chicago, theCouncil on Tall Buildings and Urban Habitat (CTBUH) found the Willis Tower (without its antennas) to be the third-tallest building, and the Petronas Towers (with their spires) to be the world's two tallest buildings.[26]
Responding to the ensuing controversy, the CTBUH then revised their criteria and defined four categories in which the world's tallest building can be measured, retaining the old criterion of height to architectural top, and adding three new categories:[26]
Highest occupied floor
Height to top of roof (omitted from criteria from November 2009 onwards)[30]
Height to architectural top (includingspires and pinnacles, but not antennas, masts or flagpoles). This measurement is the most widely used and is used to define the rankings of the 100 Tallest Buildings in the World.
Height to tip
The height-to-roof criterion was discontinued because relatively few modern tall buildings possess flat rooftops, making this criterion difficult to determine and measure.[30] The CTBUH has further clarified their definitions of building height, including specific criteria concerning subbasements and ground level entrances (height measured from lowest, significant, open-air, pedestrian entrance rather than from a previously undefined "main entrance"), building completion (must be topped out both structurally and architecturally, fully clad,and able to be occupied), condition of the highest occupied floor (must be continuously used by people living or working and be conditioned, thus includingobservation decks, but notmechanical floors) and other aspects of tall buildings.[30][31] The height is measured from the level of the lowest, significant, open-air, pedestrian entrance.
A different superlative for skyscrapers is theirnumber of floors. The original World Trade Center set that record at 110 in the early 1970s, and this was not surpassed until the Burj Khalifa opened in 2010.
The rooftop outdoor observation deck opened in December 2011. There are also several other indoor observation decks in the tower, the highest at 433.2 m (1,421 ft).
Opened on October 15, 2014, on the 148th floor. There is another observation deck at 452.1 m (1,483 ft) on the 124th floor, which has been open since the building was opened to the public.
Higher observation decks have existed onmountain tops or cliffs, rather than on tall structures. TheGrand Canyon Skywalk, constructed in 2007, protrudes 21 m (70 ft) over the west rim of the Grand Canyon and is approximately 1,100 m (3,600 ft) above theColorado River, making it the highest of these types of structures.[citation needed]
