Guangzhou's new TV tower, Canton Tower, named Guangzhou Tower (广州塔) in Chinese, is situated in the city center business area of Guangzhou. Canton Tower has a nickname: Xiao Man’s waist (Xiao Man, a famous geisha in the Tang Dynasty (618AD-907AD), had a very beautiful slender waist ).
Canton Tower, at 610 meters counting the 156 meter antenna that sits atop the 454 meter tower proper (which is the consensus on how to measure the total height of a tower), is currently the world's tallest tower, and given its unique construction, which facilitates "building high", Canton Tower will likely remain the tallest tower for some time, unless someone comes up with a building design that is even more clever than that of Canton Tower (note that Canton Tower is the world's tallest tower, not the world's tallest building... there is a limit to the size of the base of an edifice that can qualify as a tower rather than as a building – to satisfy your curiosity, the world's tallest building is the Burj Khalifa in Dubai, standing at 828 meters, including its spire).
Canton Tower is situated just south of the Zhu ("Pearl") River, which runs from west to east here, before turning south just east of the city and eventually widening into the Pearl River Estuary. Put slightly differently, Canton Tower lies about 1 kilometer due south of the densest part of downtown Guangzhou. The geographic position of Canton Tower can also be fixed in relation to Ersha Island, since Ersha Island – home to most of the foreign consulates in Guangzhou – lies about 1 kilometer northwest of Canton Tower. Thus Canton Tower lies about 1 kilometer due south of downtown Guangzhou and about 1 kilometer southeast of the center of Ersha Island in the city's Haizhu ("Pearl of the sea") District, not far from Chigang Pagoda.
The Pioneering Builders
Like all modern building construction of today, the task of designing Guangzhou's new TV tower was an international competition where interested architects submitted design proposals, and a team of judges decided on the best design among the proposal submitted. The architect team of Mark Hemel and Barbara Kuit (husband and wife, in fact) of the Amsterdam-based company, Information Based Architecture (IBA), had submitted what was to be the winning design proposal. The IBA design proposal envisioned building the new TV tower in collaboration with the British engineering firm, Arup (whose founder is Danish-British Ove Arup) – in particular, in close cooperation with Arup's Dutch engineer, Joop Paul – and with the additional consultancy expertise of Chinese typhoon and earthquake specialists, since the city of Guangzhou is no stranger to these two naturally-occurring phenomena.
To get an idea of how stiff the design competition was, major international players such as Cannon Design, Kohn Pedersen Fox Associates (KPF), Richard Rogers and Coop Himmelb(l)au were among the other architect firms to submit proposals for the construction of Guangzhou's new TV tower. However, the unique and sleek design proposed by IBA, plus the fact that IBA had taken Arup on board, effectively made this a one-horse race.
Integral to the construction project was an urban area plan that would encompass not only the TV tower and the 18 hectare park surrounding its base, but also a television broadcasting center, an elevated plaza, a pagoda park, administrative offices, a shopping mall and an international class hotel – comprising in all roughly 74 hectares of new construction space, including green oases.
The Pioneering Construction Method
The basic idea of the construction of the tower that would be named Canton Tower (the naming was itself a separate competition) was an outer, tube-like shell of vertical rods (but interconnected, creating a latticework) with an oval (elliptical) disc at each end of this shell, but with a twist: the top disc would be rotated on its vertical axis in relation to the rigidly fixed disc at the bottom, "twisting" the latticework and causing the otherwise straight-walled, oval-cylindrical shape of the outer, latticework shell to narrow in its mid-section, roughly in the form of an elongated, not quite completed (not so constricted in its mid-section) hourglass (the author-editor of this article believes that the concept of twisting two end discs connected to a "tube" of vertical rods is not original – in fact, this author-editor is positive that he has seen the same principle applied to an Asian-made wicker footstool!).
The twisting of the outer shell would not only produce a new, feminine tower design (think: narrow waist... admittedly, the general shape of a tower, if not of any tall building in general, is somewhat phallic, therefore masculine), it would also produce a stronger tower with an economy of material, or 'a densification of material' at the "waist", to quote the architects (surely, the same design principle in the wicker footstool is deliberately chosen precisely in order to produce a sturdier, more rigid footstool, even though the footstool in question has round end discs), it would also have an outer shell that would be see-through, suggesting a sense of lightness that contrasts sharply with the conventional, massive, concrete-steel-and-glass tower construction, and lasty, it would also, thanks to the twisting of the outer shell, result in a slender "waist" with fluted ends that would impart a sense of motion to the tower (think of a spinning, female ballet dancer).
The outer, latticework shell is of steel (a whopping 650,000 tonnes of it, in fact), with an inner core of concrete. It is stabilized along its vertical length by a further 46 "discs" (tubular rings) studded with LED lights that light up at night, profiling the slender "waist" of the tower. Moreover, each of these rings, due to the ovalness of the end discs and due to the narrow "waist", must needs be of varying degrees of ovalness as well as of varying circumference. Since there existed no prior "mould" for this design (apart from the aforementioned, round-ended, "twisted" footstool), the tower had to be built part by part and assembled onsite with the help of three-dimenional computerized vizualizations, so as to ensure that the finished product resembled the computer-generated model.
The concrete interior of the tower is in the form of five small buildings spaced along the height of the tower, interspersed with gardens, and with a skywalk in the form of a 166 meter outdoor, spiral staircase that passes through the "waist" of the tower, beginning at the height of 168 meters and ending at the height of 334 meters, which, since the outer shell is closest to the inner core along this section of the tower, provides the visitor an opportunity to appreciate the tower's construction method, close-up.
Of course, if you are in a hurry, you can skip the skywalk and zip from ground level to the top storey in one of the tower's 6 "supersonic" elevators that go from 0 to 450 meters in a little over 60 seconds (the final 4 meters is consumed by the observation deck on the top storey, and of course the elevator must have space for the pulley housing that sits above the final elevator storey).
For eardrum protection, the air pressure inside the elevators will be constantly and automatically adjusted, thus eliminating the need to frequently swallow in order to relieve pressure on one's ear drums.
The designers hope that all visitors to the tower will sooner or later take the time to explore the "scenic route" – in whole or in its parts – otherwise the interior experience of Canton Tower risks being pretty flat, so to speak.
It proved to be something of a challenge for the constructors to fulfill a last-minute request for a two-storey rotating restaurant near the top (the restaurant's lower storey sits 424 meters above ground level), since it would have to fit not within a circle, but within an ellipse. In the final analysis, a smaller, circular, rotating disc was fitted in the concrete core of the elliptically-shaped tower, which solution presents possibly an even more interesting "tivoli ride" than would have a circular disc rotating within a perfectly concentrically-shaped outer disc (with the former solution, one would tend to notice the pronounced, elliptical ends as they glide past, heightening the perception of being in rotation).
The final challenge was in making sure that the building could withstand the ravages of typhoons and earthquakes. This would require the help of unique experts. Professor Zhu Ledong of Tongji University was invited to conduct a series of exhaustive tests to determine whether the tower would stand up to – literally – the strong, gale force winds of the area's tyhoons. Professor Zhu's tests revealed that the structure would indeed withstand the worst that a typhoon could throw at it, as it were. The final hurdle was a series of earthquake tests to determine the tower's structural viability in this extreme circumstance.
For this task, earthquake expert and professor Zhou Fulin of Guangzhou University was called in. Professor Zhou's inspection team found some degree of weakness in two areas: the antenna, given its exposed position of extremity; and in the "waist" section, where the stress on the steel rods is greatest, but the inspection team determined that the revealed weaknesses were of too slight a magnitude to cause alarm. However, the inspection team did recommend the incorporation of some form of vibration-dampening mechanism to prevent the tower – under a sustained quake that might send a series of opposing shockwaves rippling up through the structure – from suffering structural damage. They therefore recommended the usual tunnel mass dampers, which stabilize both against the rippling (reverberating) shockwaves of earthquakes and the whiplash effect (a one-off reverberating effect) of the strong but intermittent winds that often accompany a typhoon.
The proposed solution was deemed both unnecessarily costly and slightly clumsy, the latter in the sense that tunnel mass dampers occupy a great deal of ground level space, which would mar both the function and the elegant appearance of the new tower design. The engineering team therefore came up with a novel, alternative solution involving large, counterweigt water tanks, to be placed on the storeys immediately above the revolving restaurant, that would serve a dual purpose: in the event of a strong sway in the tower due to wind or an earthquake, the water tanks, which are mounted on tracks, would automatically shift around to the opposite side – i.e., to the side from whence the pressure was being applied – thus counterbalancing the effect of a sway in the tower produced either by wind or by an earthquake; and in the event of a fire, the tanks' contents could be used to douse the flames.
Canton Tower is equipped with over 600 electronic sensors, most of them embedded in the tower's steel outer latticework or in its concrete core, where they constantly measure stress, vibration and temperature changes. This data will be constantly monitored, and will be recorded and stored – together with relevant data from external events that might have caused deviations from the norm, such as earthquakes and typhoons – to serve as an aid in improving, where possible, the design of future super-towers such as Canton Tower.
The Three Main Functions
Canton Tower is but a small – albeit, a very important and very beautiful – part of the large-scale infrastructural remake of the city of Guangzhou. Canton Tower combines three primary functions: an infotainment and sightseeing venue, its main future function in fact (Canton Tower will offer unparalleled views of a huge tract of land, river and sea surrounding the city of Guangzhou); a dining and entertainment venue; and of course the tower will transmit radio and TV signals. A fourth function that derives partly from the other three is that Canton Tower, given its supreme height and its striking beauty, is likely to become the Eiffel Tower of Guangzhou.
The main function of the tower's lower section is educational in nature, in the broadest sense, since on display will be exhibits featuring the history, culture, economy and tourism of the city of Guangzhou as the city has developed over time. Various other service facilities of interest to the tourist are also situated here. The main function of the tower’s upper section is dining and entertainment, as well as sightseeing from the observation deck on the tower's upper storey.
Infotainment and Sightseeing
On the infotainment side, the tower will house a museum of Chinese history and culture, an experimentarium, a 3D cinema for films and special presentations, and the tower's spacious lobby can as well double as a venue for various street-level events such as book fairs, art exhibitions and the like. In addition, there is a special exhibition hall whose purpose is to display large-scale city planning models – such as the urban area development model that the Canton Tower project itself once was.
As to sightseeing, from the 40-meter by 54-meter (corresponding to ½ of a soccer field!) observation deck atop the tower, visitors will be able to see all of Guangzhou – and a good deal beyond – laid out at their feet. The exact position of Canton Tower is not a matter of happenstance, but was carefully chosen, since the tower stands in the crosshairs, as it were, that split Zhujiang New Town's "commercial" axis – which runs from north to south, linking up railway stations, the downtown area of New Town, Zhuhai executive zone and the new passenger transportation port – from Zhujiang New Town's Pearl River "scenic" axis, which runs from west to east along the course of the Pearl River at this point. This special location of Canton Tower offers not only the usual panoramic view of the city, but also a more structured view of the layout of Zhujiang New Town immediately below.
At night, a set of three laser lights, each with a beam range of 1 kilometer, will search the night skies with their brilliantly white, crisscrossing beams above the tower, adding to Canton Tower's sublime majesty.
Dining and Entertainment
There is a coffee shop at 174 meters height and a full-fledged, rotating, double-deck restaurant at 424 meters height. A video game arcade is located in the lower half of the tower, and in-between the five suspended buildings ranged along the height of the tower are hanging, outdoor gardens, some with teahouses. The rotating, double-deck restaurant near the top of the tower can seat 400 persons.
Radio and TV Transmitting
It would be a pity to build such a tall tower without integrating within it a radio and television transmitting function, as well as a cellphone signal transmission function, but of course, Canton Tower is first and foremost a transmitting tower, hence the 156 meter antenna atop the main structure, notwithstanding that the tower's function as a tourism venue – both its dining, entertainment, sightseeing and infotainment functions – will most certainly overshadow the tower's commercial value as a transmitting tower.
As something special, the transmitting antenna has an electronically controlled set of lights which will display a different color depending on the day of the week. Thus by simply observing the color of Canton Tower's antenna on any given day, one can determine the day of the week, should one's electronic watch, cellphone, and Palm device all suddenly fail :) – joking aside, this small detail harks back to China's ancient history, where different joss stick ("incense") aromas signalled the different periods of the day: early-, mid- or late morning; early-, mid- or late afternoon; etc.
The radio, TV and cellphone transmission functions of the tower proper will of course be augmented by the Broadcast and Television Center building, located adjacent to the tower.
Note: to be centered!
Of course, acquiring the ground on which the tower complex would be built came at a price: a total of 18,342 square meters of housing had to be demolished, and given that this was an older, somewhat run-down quarter of Guangzhou, that translates to quite a large number of persons living in close quarters. That said, urban renewal is a necessary part of any city, notwithstanding the pain that it causes the individuals directly affected. But it would be unreasonable to stand in the way of progress, and in any case, Guangzhou's housing authority found alternative accomodation for the affected individuals, though it is difficult, if not impossible, to always please everyone in such circumstances.
Canton Tower has begun to commence business from October 1, 2010. The ticket price for visiting the parts of the tower located between ground level and the rotating, double-deck restaurant are currently planned to cost 100 Yuan per person, while high-speed elevator access to the double-deck restaurant and the observation deck above the restaurant is set to cost 150 Yuan per person.