World's tallest structures
For many millennia the record holder for World's tallest structure was clear cut. In order, they were:
Period of record
|
|---|
Unfortunately there has been much debate as to the ranking of the World's tallest structures since the middle of the 20th century, chiefly depending on the criteria used for selecting the structures admissible to the list.
In particular, there is debate about whether:
- guy-wire-supported structures can be counted
- only habitable height counts
- roof-top antennass can be counted towards height of inhabitable buildings
- observation galleries on communication towers make them into inhabitable buildings
- structures under construction can be included in the list
- structures rising out of water should have their below-water height included
KVLY-TV mast
The tallest currently-standing structure is the KVLY-TV mast in North Dakota, at 629m (2,063 feet). It is a transmission antenna, consisting of a bare metal structure supported by guy-wires.
There was once a taller such mast, the Warszawa radio mast near Warsaw, Poland at 645 m (2,115 ft), but it collapsed in 1991.
The Petronius Platform stands 610 m (2,001 ft) tall, making it the tallest freestanding structure in the world. However, as this oil and natural gas platform is partially supported by buoyancy, some critics feel the below-water height should not be accounted for.
The CN Tower in Toronto stands 553.33m (1,815 feet) tall, making it the tallest freestanding structure on land.
Up until 1998 the tallest building status was pretty much uncontested. Counting buildings as structures with floors throughout, New York City's World Trade Center was the tallest including the antennas, Sears Tower in Chicago excluding the antennas. As antennas were usually excluded, Sears Tower was counted as the tallest. When Petronas Twin Towers in Kuala Lumpur, Malaysia was built, some felt that the "spire" extending to 9 meters higher than the roof of Sears Towers was just added to "cheat" its way into the spot as tallest building. Excluding the spire, the Petronas Towers were not taller than the Sears Tower. Therefore, the Council on Tall Buildings and Urban Habitat defined four categories in which the "world's tallest building" can be measured:
As of April 20, 2004, Taipei 101 in Taipei, Taiwan leads in the first category with 508 m (1,667 ft); in the second category with an occupied floor at 438 m (1,437 ft); and in the third category with 448 m (1,470 ft). The first category was formerly held by the Petronas Twin Towers with 452 m (1,483 ft), and before that by Sears Towers with 443 m (1,448 ft). The second category was held by the Sears Tower, with 435 m (1,431 ft). The third category was formerly held by the Sears Tower with 442 m (1,445 ft).
The Sears Tower still leads in the fourth category with 529 m (1736 ft), previously held by the World Trade Center until its destruction in 2001; its antenna included, it measured 536 m (1,758 ft). The World Trade Center became the world's tallest buildings to be demolished - indeed, its site entered the record books twice on September 11, 2001, in that category, replacing the Singer Building, which once stood a block from the WTC site.
The CN Tower is excluded from these categories because it is not a "habitable building", which is defined as a frame structure made with floors and walls throughout.The World's tallest structures (of any sort)
The World's tallest structures (not supported by guy-ropes)
The World's tallest habitable buildings
The height is measured from the sidewalk level of the main entrance. In all of these categories, Sears Towers had held the number one spot. After Petronas was built, it became second in the first category only.
Name
|
|---|
A Solar tower that has been proposed in Australia would be 1 km (0.62 miles) tall. Engineering feasibility has been demonstrated to the satisfaction of consulting engineers, and construction is a matter of financial viability.
The 492m (1614 ft; roof height) Shanghai World Financial Center in Shanghai, China has proposed completion in 2007, but has been delayed by evaluation of soil stability. A competing on-going project for the world's tallest is the 474 m (1555 ft) Union Square Phase 7 in Hong Kong, also scheduled for completion in 2007. This would make either building the tallest under categories 2 and 3 by the CTBUH.
The Freedom Tower of the new World Trade Center in New York City will reach 1,776 feet (541.3 metres) to its spire and about 1100 feet (335 m) to its roof once completed in 2008. This would make it the tallest building under categories 1 and 4 by the CTBUH. The cornerstone was laid on July 4, 2004.
The height of the proposed Burj Dubai tower (to be completed in 2008) has not been revealed, but at the moment it is thought it will be over 650-700m (2130-2300 ft) tall, which would put it at the number one spot in all four of CTBUH's categories, as well as become the tallest freestanding structure.
Comparison of top skyscrapers
Proposed record-breaking structures
Related articles
External references