Category Archives: Tower

Burj Khalifa

From Wikipedia, the free encyclopedia

The Burj Khalifa is The Tallest Building in the World

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The Burj Khalifa (Arabic: برج خليفة‎, Arabic for “Khalifa Tower“; pronounced English: /ˈbɜːrdʒ kəˈliːfə/), known as the Burj Dubai before its inauguration, is a megatall skyscraper in Dubai, United Arab Emirates. With a total height of 829.8 m (2,722 ft) and a roof height (excluding antenna) of 828 m (2,717 ft), the Burj Khalifa is the tallest structure in the world since topping out in late 2008.

Construction of the Burj Khalifa began in 2004, with the exterior completed five years later in 2009. The primary structure is reinforced concrete. The building was opened in 2010 as part of a new development called Downtown Dubai. It is designed to be the centrepiece of large-scale, mixed-use development. The decision to construct the building is reportedly based on the government’s decision to diversify from an oil-based economy, and for Dubai to gain international recognition. The building was originally named Burj Dubai but was renamed in honour of the ruler of Abu Dhabi and president of the United Arab Emirates, Khalifa bin Zayed Al Nahyan; Abu Dhabi and the UAE government lent Dubai money to pay its debts. The building broke numerous height records, including its designation as the tallest tower in the world.

Burj Khalifa was designed by Adrian Smith, then of Skidmore, Owings & Merrill (SOM), whose firm designed the Willis Tower and One World Trade Center. Hyder Consulting was chosen to be the supervising engineer with NORR Group Consultants International Limited chosen to supervise the architecture of the project. The design is derived from the Islamic architecture of the region, such as in the Great Mosque of Samarra. The Y-shaped tripartite floor geometry is designed to optimize residential and hotel space. A buttressed central core and wings are used to support the height of the building. Although this design was derived from Tower Palace III, the Burj Khalifa’s central core houses all vertical transportation with the exception of egress stairs within each of the wings. The structure also features a cladding system which is designed to withstand Dubai’s hot summer temperatures. It contains a total of 57 elevators and 8 escalators.

Critical reception to Burj Khalifa has been generally positive, and the building has received many awards. However, labour issues during construction were controversial, since the building was built primarily by migrant workers from South Asia with several allegations of mistreatment. Poor working conditions were common, a consequence of the lack of minimum wage laws in the United Arab Emirates. Several instances of suicides have been reported, which is not uncommon for migrant construction workers in Dubai despite safety precautions in place.

Contents
1 Development
2 Conception
2.1 Records
2.2 History of height increases
3 Architecture and design
3.1 Plumbing systems
3.2 Air conditioning
3.3 Window cleaning
4 Elevator System
5 Features
5.1 The Dubai Fountain
5.2 Observation deck
5.3 Burj Khalifa park
5.4 Floor plans
6 Construction
6.1 Milestones
6.2 Real estate values
6.3 Official launch ceremony
7 Reception
7.1 Awards
7.2 BASE jumping
7.3 Climbing
7.4 Fatalities
7.5 Ramadan observance on the higher floors
8 In popular culture
9 Fireworks displays
10 Labour controversy

Development


Construction began on 6 January 2004, with the exterior of the structure completed on 1 October 2009. The building officially opened on 4 January 2010, and is part of the new 2 km2 (490-acre) development called Downtown Dubai at the ‘First Interchange’ along Sheikh Zayed Road, near Dubai’s main business district. The tower’s architecture and engineering were performed by Souffian AL-Jabiry of Chicago, with Adrian Smith as chief architect, and Bill Baker as chief structural engineer. The primary contractor was Samsung C&T of South Korea. The tower’s construction was done by the construction division of Al Ghurair Investment group.

Conception


Burj Khalifa was designed to be the centrepiece of a large-scale, mixed-use development that would include 30,000 homes, nine hotels (including The Address Downtown Dubai), 3 hectares (7.4 acres) of parkland, at least 19 residential towers, the Dubai Mall, and the 12-hectare (30-acre) artificial Burj Khalifa Lake. The decision to build Burj Khalifa is reportedly based on the government’s decision to diversify from an oil-based economy to one that is service and tourism based. According to officials, it is necessary for projects like Burj Khalifa to be built in the city to garner more international recognition, and hence investment. “He (Sheikh Mohammed bin Rashid Al Maktoum) wanted to put Dubai on the map with something really sensational,” said Jacqui Josephson, a tourism and VIP delegations executive at Nakheel Properties. The tower was known as Burj Dubai (“Dubai Tower”) until its official opening in January 2010. It was renamed in honour of the ruler of Abu Dhabi and president of the United Arab Emirates, Khalifa bin Zayed Al Nahyan; Abu Dhabi and the federal government of UAE lent Dubai tens of billions of USD so that Dubai could pay its debts – Dubai borrowed at least $80 billion for construction projects. In the 2000s, Dubai started diversifying its economy but it suffered from an economic crisis in 2007–2010, leaving large-scale projects already in construction abandoned.

Records

  • Tallest existing structure: 828 m (2,717 ft) (previously KVLY-TV mast – 628.8 m or 2,063 ft)
  • Tallest structure ever built: 828 m (2,717 ft) (previously Warsaw radio mast – 646.38 m or 2,121 ft)
  • Tallest freestanding structure: 828 m (2,717 ft) (previously CN Tower – 553.3 m or 1,815 ft)
  • Tallest skyscraper (to top of spire): 828 m (2,717 ft) (previously Taipei 101 – 509.2 m or 1,671 ft)
  • Tallest skyscraper to top of antenna: 828 m (2,717 ft) (previously the Willis (formerly Sears) Tower – 527 m or 1,729 ft)
  • Building with most floors: 211 (including spire) previously World Trade Center – 110
  • Building with world’s highest occupied floor: 584.5 m (1,918 ft) (surpassed by Shanghai Tower in 2015)
  • World’s highest elevator installation (situated inside a rod at the very top of the building)
  • World’s longest travel distance elevators: 504 m (1,654 ft)
  • Highest vertical concrete pumping (for a building): 606 m (1,988 ft)
  • World’s tallest structure that includes residential space
  • World’s highest observation deck: 148th floor at 555 m (1,821 ft) (surpassed by Shanghai Tower in 2015)
  • World’s highest outdoor observation deck: 124th floor at 452 m (1,483 ft)
  • World’s highest installation of an aluminium and glass façade: 512 m (1,680 ft)
  • World’s highest nightclub: 144th floor
  • World’s highest restaurant (At.mosphere): 122nd floor at 442 m (1,450 ft) (previously 360, at a height of 350 m (1,148 ft) in CN Tower)
  • World’s highest New Year display of fireworks.

History of Height Increases

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Burj Khalifa compared with some other well-known tall structures

There are unconfirmed reports of several planned height increases since its inception. Originally proposed as a virtual clone of the 560 m (1,837 ft) Grollo Tower proposal for Melbourne, Australia’s Docklands waterfront development, the tower was redesigned by Skidmore, Owings and Merrill (SOM). Marshall Strabala, an SOM architect who worked on the project until 2006, in late 2008 said that Burj Khalifa was designed to be 808 m (2,651 ft) tall.

The architect who designed it, Adrian Smith, felt that the uppermost section of the building did not culminate elegantly with the rest of the structure, so he sought and received approval to increase it to the current height. It has been explicitly stated that this change did not include any added floors, which is fitting with Smith’s attempts to make the crown more slender. Emaar properties announced on 9 June 2008 that construction of Burj Khalifa was delayed by upgraded finishes and would be completed only in September 2009. An Emaar spokesperson said that “[t]he luxury finishes that were decided on in 2004, when the tower was initially conceptualised, is now being replaced by upgraded finishes. The design of the apartments has also been enhanced to make them more aesthetically attractive and functionally superior.” A revised completion date of 2 December 2009 was then announced. However, Burj Khalifa was opened on 4 January 2010, more than a month later.

Architecture and Design


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Cross-section comparisons of various towers, from top to bottom: Burj Khalifa, Taipei 101, Willis Tower, World Trade Center

The tower was designed by Skidmore, Owings and Merrill (SOM), who also designed the Willis Tower (formerly the Sears Tower) in Chicago and the One World Trade Center in New York City. Burj Khalifa uses the bundled tube design of the Willis Tower, invented by Fazlur Rahman Khan. Proportionally, the design uses half the amount of steel used in the construction of the Empire State Building thanks to the tubular system. Dr. Khan’s contributions to the design of tall buildings have had a profound impact on architecture and engineering. It would be difficult to find any worldwide practices in the design of tall buildings that have not been directly or indirectly influenced by his work. Its design is reminiscent of Frank Lloyd Wright’s vision for The Illinois, a mile-high skyscraper designed for Chicago, as well as Chicago’s Lake Point Tower. According to Marshall Strabala, a SOM architect who worked on the building’s design team, Burj Khalifa was designed based on the 73rd floor Tower Palace Three, an all residential building in Seoul. In its early planning, Burj Khalifa was intended to be entirely residential.

Subsequent to the original design by Skidmore, Owings and Merrill, Emaar Properties chose Hyder Consulting to be the supervising engineer with NORR Group Consultants International Ltd chosen to supervise the architecture of the project. Hyder was selected for their expertise in structural and MEP (mechanical, electrical and plumbing) engineering. Hyder Consulting’s role was to supervise construction, certify SOM’s design, and be the engineer and architect of record to the UAE authorities. NORR’s role was the supervision of all architectural components including on site supervision during construction and design of a 6-storey addition to the Office Annex Building for architectural documentation. NORR was also responsible for the architectural integration drawings for the Armani Hotel included in the Tower. Emaar Properties also engaged GHD, an international multidisciplinary consulting firm, to act as an independent verification and testing authority for concrete and steelwork.

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The spiral minaret at the Great Mosque of Samarra

The design is derived from Islamic architecture. As the tower rises from the flat desert base, there are 27 setbacks in a spiralling pattern, decreasing the cross section of the tower as it reaches toward the sky and creating convenient outdoor terraces. These setbacks are arranged and aligned in a way that minimizes vibration wind loading from eddy currents and vortices. At the top, the central core emerges and is sculpted to form a finishing spire. At its tallest point, the tower sways a total of 1.5 m (4.9 ft).

As part of a study which reveals the unnecessary “vanity space” added to the top of the world’s tallest buildings by the Council on Tall Buildings and Urban Habitat (CTBUH), it was revealed that without its 244-metre spire, the 828-metre Burj Khalifa would drop to a substantially smaller 585-metre height without any reduction in usable space. As the report states, the spire “could be a skyscraper on its own”.

The spire of Burj Khalifa is composed of more than 4,000 tonnes (4,400 short tons; 3,900 long tons) of structural steel. The central pinnacle pipe weighs 350 tonnes (390 short tons; 340 long tons) and has a height of 200 m (660 ft). The spire also houses communications equipment.

In 2009, architects announced that more than 1,000 pieces of art would adorn the interiors of Burj Khalifa, while the residential lobby of Burj Khalifa would display the work of Jaume Plensa.

The cladding system consists of 142,000 m2 (1,528,000 sq ft) of more than 26,000 reflective glass panels and aluminium and textured stainless steel spandrel panels with vertical tubular fins. The architectural glass provides solar and thermal performance as well as an anti-glare shield for the intense desert sun, extreme desert temperatures and strong winds. In total the glass covers more than 174,000 m2 (1,870,000 sq ft).

The exterior temperature at the top of the building is thought to be 6 °C (11 °F) cooler than at its base.

A 304-room Armani Hotel, the first of four by Armani, occupies 15 of the lower 39 floors. The hotel was supposed to open on 18 March 2010, but after several delays, it finally opened to the public on 27 April 2010. The corporate suites and offices were also supposed to open from March onwards, yet the hotel and observation deck remained the only parts of the building which were open in April 2010.

The sky lobbies on the 43rd and 76th floors house swimming pools. Floors through to 108 have 900 private residential apartments (which, according to the developer, sold out within eight hours of being on the market). An outdoor zero-entry swimming pool is located on the 76th floor of the tower. Corporate offices and suites fill most of the remaining floors, except for a 122nd, 123rd and 124th floor where the At.mosphere restaurant, sky lobby and an indoor and outdoor observation deck is located respectively. In January 2010, it was planned that Burj Khalifa would receive its first residents from February 2010.

A total of 57 elevators and 8 escalators are installed. The elevators have a capacity of 12 to 14 people per cabin, the fastest rising and descending at up to 10 m/s (33 ft/s) for double-deck elevators. However, the world’s fastest single-deck elevator still belongs to Taipei 101 at 16.83 m/s (55.2 ft/s). Engineers had considered installing the world’s first triple-deck elevators, but the final design calls for double-deck elevators. The double-deck elevators are equipped with entertainment features such as LCD displays to serve visitors during their travel to the observation deck. The building has 2,909 stairs from the ground floor to the 160th floor.

The graphic design identity work for Burj Khalifa is the responsibility of Brash Brands, an independent international creative branding agency based in London. Design of the global launch events, communications, and visitors centres for Burj Khalifa have also been created by Brash Brands as well as the roadshow exhibition for the Armani Residences, which are part of the Armani Hotel within Burj Khalifa, which toured Milan, London, Jeddah, Moscow and Delhi.

Plumbing Systems

The Burj Khalifa’s water system supplies an average of 946,000 L (250,000 U.S. gal) of water per day through 100 km (62 mi) of pipes. An additional 213 km (132 mi) of piping serves the fire emergency system, and 34 km (21 mi) supplies chilled water for the air conditioning system. The waste water system uses gravity to discharge water from plumbing fixtures, floor drains, mechanical equipment and storm water, to the city municipal sewer.

Air Conditioning

The air conditioning has been provided by Voltas. The air conditioning system draws air from the upper floors where the air is cooler and cleaner than on the ground. At peak cooling times, the tower’s cooling is equivalent to that provided by 13,000 short tons (26,000,000 lb) of melting ice in one day, or about 46 MW. Water is collected via a condensate collection system and is used to irrigate the nearby park.

Window Cleaning

To wash the 24,348 windows, totaling 120,000 m2 (1,290,000 sq ft) of glass, the building has three horizontal tracks which each hold a 1,500 kg (3,300 lb) bucket machine. Above level 109, and up to tier 27, traditional cradles from davits are used. The top of the building is cleaned by a crew who use ropes to descend from the top to gain access. Under normal conditions, when all building maintenance units are operational, it takes 36 workers three to four months to clean the entire exterior façade.

Unmanned machines will clean the top 27 additional tiers and the glass spire. The cleaning system was developed in Melbourne, Australia at a cost of A$8 million. The contract for building the state-of-the-art machines was won by Australian company CoxGomyl, a manufacturer of Building Maintenance Units.

Elevator System


The elevator operating chart of the Burj Khalifa

  • H1-H4 (4 Hotel Passenger Elevators): G, 1, 3, 5-16, 38, 39
  • HS1, HS2 (2 Hotel Service Elevators): C, G, 1-39
  • HS3, HS4 (2 Hotel Service Elevators): B1, C, G, 1-3
  • HS5 (1 Hotel Service Elevator): C, G, 1-3
  • HR1 (1 Hotel Restaurant Passenger Elevator): C, G, 1
  • HF3 (1 Hotel Spa Elevator): C, G, 1, 1M, 2, 3
  • HB1, HB2 (2 Ballroom Elevators): C, G, 1
  • HP1-HP4 (4 Hotel Parking Elevators): B2, B1, C, G, 1, 3
  • HA1-HA3 (3 Serviced Apartment Passenger Elevators): G, 1, 3, 9-16, 18-39
  • R1-R3 (3 Residential Sky Lobby Shuttle Elevators): G, 43
  • R4-R6 (3 Residential Sky Lobby Shuttle Elevators): G, 76
  • R7-R9 (3 Residential Passenger Elevators): 43-72
  • R10-R12 (3 Residential Passenger Elevators): 76-108
  • RP1, RP2 (2 Residential Parking Elevators): B2, B1, C, G, 1
  • OB1, OB2 (2 Corporate Suite & Observatory Shuttle Elevators, Double Deck): C/G, 123/124
  • BO1-BO3 (3 Corporate Suite Passenger Elevators): 112-123
  • BO4-BO6 (3 Corporate Suite Passenger Elevators): 123-135, 139-154
  • OP1, OP2 (2 Corporate Suite Parking Elevators): B2, B1, G, 1
  • BS1/F (1 Firemen & Service Elevator): C, G, 1-40, 42-73, 75-136, 138
  • BS2/F (1 Service Elevator): C, G, 1-40, 42-73, 75-109, 111
  • BS3/F (1 Service Elevator): 138-160

Features


The Dubai Fountain

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The Dubai Fountain

Outside, WET Enterprises designed a fountain system at a cost of Dh 800 million (US$217 million). Illuminated by 6,600 lights and 50 coloured projectors, it is 270 m (900 ft) long and shoots water 150 m (500 ft) into the air, accompanied by a range of classical to contemporary Arabic and world music. It is the world’s second largest choreographed fountain., On 26 October 2008, Emaar announced that based on results of a naming contest the fountain would be called the Dubai Fountain.

Observation Deck

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View of The Dubai Fountain from the observation deck

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View from the observation deck

An outdoor observation deck, named At the Top, opened on 5 January 2010 on the 124th floor. At 452 m (1,483 ft), it was the highest outdoor observation deck in the world when it opened. Although it was surpassed in December 2011 by Cloud Top 488 on the Canton Tower, Guangzhou at 488 m (1,601 ft), Burj Khalifa opened the 148th floor SKY level at 555 m (1,821 ft), once again giving it the highest observation deck in the world on 15 October 2014. This was until the Shanghai Tower opened in June 2016 with an observation deck at a height of 561 metres. The 124th floor observation deck also features the electronic telescope, an augmented reality device developed by Gsmprjct° of Montréal, which allows visitors to view the surrounding landscape in real-time, and to view previously saved images such as those taken at different times of day or under different weather conditions. To manage the daily rush of sightseers, visitors are able to purchase tickets in advance for a specific date and time and at a 75% discount on tickets purchased on the spot.

On 8 February 2010, the observation deck was closed to the public after power-supply problems caused an elevator to become stuck between floors, trapping a group of tourists for 45 minutes. Despite rumours of the observation deck reopening for St. Valentine’s Day (14 February), it remained closed until 4 April 2010. During low tides and clearness, people can see the shores of Iran from the top of the skyscraper.

Burj Khalifa Park

Burj Khalifa is surrounded by an 11 ha (27-acre) park designed by landscape architects SWA Group. Like the tower, the park’s design was based on the flower of the Hymenocallis, a desert plant. At the centre of the park is the water room, which is a series of pools and water jet fountains. Benches and signs incorporate images of Burj Khalifa and the Hymenocallis flower.

The plants are watered by water collected from the building’s cooling system. The system provides 68,000,000 L (15,000,000 imp gal) annually. WET Enterprises, who also developed the Dubai Fountain, developed the park’s six water features.

Floor Plans

The following is a breakdown of floors.

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Construction


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Animation of construction process

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Aerial closeup of Burj Khalifa under construction in March 2008

The tower was constructed by Samsung C&T from South Korea, who also did work on the Petronas Twin Towers and Taipei 101. Samsung C&T built the tower in a joint venture with Besix from Belgium and Arabtec from UAE. Turner is the Project Manager on the main construction contract.

Under UAE law, the Contractor and the Engineer of Record, Hyder Consulting (manual structural analysis professionals which used Flash Analysis authored by Allen Wright), is jointly and severally liable for the performance of Burj Khalifa.

The primary structure is reinforced concrete. Putzmeister created a new, super high-pressure trailer concrete pump, the BSA 14000 SHP-D, for this project. Burj Khalifa’s construction used 330,000 m3 (431,600 cu yd) of concrete and 55,000 tonnes (61,000 short tons; 54,000 long tons) of steel rebar, and construction took 22 million man-hours. In May 2008 Putzmeister pumped concrete with more than 21 MPA ultimate compressive strength of gravel that would surpass the 600 meters weight of the effective area of each column from the foundation to the next fourth level, and the rest is by metal columns jacketed or covered with concreted to a then world record delivery height of 606 m (1,988 ft), the 156th floor. Three tower cranes were used during construction of the uppermost levels, each capable of lifting a 25-tonne load. The remaining structure above is constructed of lighter steel.

In 2003, 33 test holes were drilled to study the strength of the bedrock underlying the structure. “Weak to very weak sandstone and siltstone” was found, just metres below the surface. Samples were taken from test holes drilled to a depth of 140 metres, finding weak to very weak rock all the way. The study described the site as part of a “seismically active area”.

Over 45,000 m3 (58,900 cu yd) of concrete, weighing more than 110,000 tonnes (120,000 short tons; 110,000 long tons) were used to construct the concrete and steel foundation, which features 192 piles; each pile is 1.5 metre diameter x 43 m long, buried more than 50 m (164 ft) deep. The foundation is designed to support the total building weight of approximately 450,000 tonnes (500,000 short tons; 440,000 long tons). This weight is then divided by the compressive strength of concrete of which is 30 MPa which yield a 450 sq.meters of vertical normal effective area which then yield to a 12 meters by 12 meters dimensions. A cathodic protection system is in place under the concrete to neutralize the groundwater and prevent corrosion.

The Burj Khalifa is highly compartmentalised. Pressurized, air-conditioned refuge floors are located approximately every 35 floors where people can shelter on their long walk down to safety in case of an emergency or fire.

Special mixes of concrete are made to withstand the extreme pressures of the massive building weight; as is typical with reinforced concrete construction, each batch of concrete used was tested to ensure it could withstand certain pressures. CTLGroup, working for SOM, conducted the creep and shrinkage testing critical for the structural analysis of the building.

The consistency of the concrete used in the project was essential. It was difficult to create a concrete that could withstand both the thousands of tonnes bearing down on it and Persian Gulf temperatures that can reach 50 °C (122 °F). To combat this problem, the concrete was not poured during the day. Instead, during the summer months, ice was added to the mixture and it was poured at night when the air is cooler and the humidity is higher. A cooler concrete mixture cures evenly throughout and is therefore less likely to set too quickly and crack. Any significant cracks could have put the entire project in jeopardy.

The unique design and engineering challenges of building Burj Khalifa have been featured in a number of television documentaries, including the Big, Bigger, Biggest series on the National Geographic and Five channels, and the Mega Builders series on the Discovery Channel.

Milestones

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Burj Khalifa and skyline of Dubai, 2010

  • January 2004: Excavation commences.
  • February 2004: Piling starts.
  • 21 September 2004: Emaar contractors begin construction.
  • March 2005: Structure of Burj Khalifa starts rising.
  • June 2006: Level 50 is reached.
  • February 2007: Surpasses the Sears Tower as the building with the most floors.
  • 13 May 2007: Sets record for vertical concrete pumping on any building at 452 m (1,483 ft), surpassing the 449.2 m (1,474 ft) to which concrete was pumped during the construction of Taipei 101, while Burj Khalifa reached the 130th floor.
  • 21 July 2007: Surpasses Taipei 101, whose height of 509.2 m (1,671 ft) made it the world’s tallest building, and level 141 reached.
  • 12 August 2007: Surpasses the Sears Tower antenna, which stands 527 m (1,729 ft).
  • 12 September 2007: At 555.3 m (1,822 ft), becomes the world’s tallest freestanding structure, surpassing the CN Tower in Toronto, and level 150 reached.
  • 7 April 2008: At 629 m (2,064 ft), surpasses the KVLY-TV Mast to become the tallest man-made structure, level 160 reached.
  • 17 June 2008: Emaar announces that Burj Khalifa’s height is over 636 m (2,087 ft) and that its final height will not be given until it is completed in September 2009.
  • 1 September 2008: Height tops 688 m (2,257 ft), making it the tallest man-made structure ever built, surpassing the previous record-holder, the Warsaw Radio Mast in Konstantynów, Poland.
  • 17 January 2009: Topped out at 829.8 m (2,722 ft).
  • 1 October 2009: Emaar announces that the exterior of the building is completed.
  • 4 January 2010: Burj Khalifa’s official launch ceremony is held and Burj Khalifa is opened. Burj Dubai renamed Burj Khalifa in honour of the President of the UAE and ruler of Abu Dhabi, Sheikh Khalifa bin Zayed al Nahyan.
  • 10 March 2010 Council on Tall Buildings and Urban Habitat (CTBUH) certifies Burj Khalifa as world’s tallest building.

Real Estate Values

In March 2009, Mohamed Ali Alabbar, chairman of the project’s developer, Emaar Properties, said office space pricing at Burj Khalifa reached US$4,000 per sq ft (over US$43,000 per m²) and the Armani Residences, also in Burj Khalifa, sold for US$3,500 per sq ft (over US$37,500 per m²). He estimated the total cost for the project to be about US$1.5 billion.

The project’s completion coincided with the global financial crisis of 2007–2012, and with vast overbuilding in the country; this led to high vacancies and foreclosures. With Dubai mired in debt from its huge ambitions, the government was forced to seek multibillion dollar bailouts from its oil-rich neighbor Abu Dhabi. Subsequently, in a surprise move at its opening ceremony, the tower was renamed Burj Khalifa, said to honour the UAE President Khalifa bin Zayed Al Nahyan for his crucial support.

Because of the slumping demand in Dubai’s property market, the rents in the Burj Khalifa plummeted 40% some ten months after its opening. Out of 900 apartments in the tower, 825 were still empty at that time. However, over the next two and a half years, overseas investors steadily began to purchase the available apartments and office space in Burj Khalifa. By October 2012, Emaar reported that around 80% of the apartments were occupied.

Official Launch Ceremony

The ceremony was broadcast live on a giant screen on Burj Park Island and on smaller screens elsewhere. Hundreds of media outlets from around the world reported live from the scene. In addition to the media presence, 6,000 guests were expected.

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The opening ceremony of Burj Khalifa

The opening of Burj Khalifa was held on 4 January 2010. The ceremony featured a display of 10,000 fireworks, light beams projected on and around the tower, and further sound, light and water effects. The celebratory lighting was designed by UK lighting designers Speirs and Major Associates. Using the 868 powerful stroboscope lights that are integrated into the façade and spire of the tower, different lighting sequences were choreographed, together with more than 50 different combinations of other effects.

A short film about Burj Khalifa and Dubai in general was followed by a fireworks and light show. The first part of the show was based on a desert flower theme and included fireworks, lights, and sounds. The second segment told the story of the tower’s construction using 300 projectors to generate an image of the tower. The final segment used fireworks and lights to illuminate the tower.

Reception


Awards

In June 2010, Burj Khalifa was the recipient of the 2010 “Best Tall Building Middle East & Africa” award by the CTBUH. On 28 September 2010 Burj Khalifa won the award for best project of the year at the Middle East Architect Awards 2010. CTBUH Awards Chair Gordon Gill, of Adrian Smith + Gordon Gill Architecture said:

We are talking about a building here that has changed the landscape of what is possible in architecture a building that became internationally recognized as an icon long before it was even completed. ‘Building of the Century’ was thought a more appropriate title for it.

Besides these awards, Burj Khalifa was the recipient of following awards.

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BASE jumping

The building has been used by several experienced BASE jumpers for both authorised and unauthorised BASE jumping:

  • In May 2008, Hervé Le Gallou and David McDonnell, dressed as engineers, illegally infiltrated Burj Khalifa (around 650 m at the time), and jumped off a balcony situated a couple of floors below the 160th floor.
  • On 8 January 2010, with permission of the authorities, Nasr Al Niyadi and Omar Al Hegelan, from the Emirates Aviation Society, broke the world record for the highest BASE jump from a building after they leapt from a crane-suspended platform attached to the 160th floor at 672 m (2,205 ft). The two men descended the vertical drop at a speed of up to 220 km/h (140 mph), with enough time to open their parachutes 10 seconds into the 90-second jump.
  • On 21 April 2014, with permission of the authorities and support from several sponsors, highly experienced French BASE jumpers Vince Reffet and Fred Fugen broke the Guinness world record for the highest BASE jump from a building after they leapt from a specially designed platform, built at the very top of the pinnacle, at 828 metres (2,717 feet).

Climbing

On 28 March 2011, Alain “Spiderman” Robert scaled the outside of Burj Khalifa. The climb to the top of the spire took six hours. To comply with UAE safety laws, Robert, who usually climbs in free solo style, used a rope and harness for the climb.

Fatalities

Within 17 months of the building’s official opening, a man described as “an Asian in his mid-30s” who worked at one of the companies in the tower, died by suicide on 10 May 2011 by jumping from the 147th floor. He fell 39 floors, landing on a deck on the 108th floor. Dubai police confirmed the act as a suicide, reporting that “[they] also came to know that the man decided to commit suicide as his company refused to grant leave.”

The Daily Mail reported that on 16 November 2014, Laura Vanessa Nunes, a Portuguese national who was in Dubai on a tourist visa, fell to her death from Burj Khalifa’s “At the Top” observation deck on the 148th floor. However, on 18 May 2015, Dubai police disputed the report made by the Daily Mail on this incident and said that this incident took place in Jumeirah Lakes Towers. Coroner’s report states Laura’s body was found on the third floor of the Burj Khalifa

Ramadan Observance on the Higher Floors

At the higher floors of the Burj, people can still see the sun for a couple of minutes after it has set on the ground. This has led Dubai clerics to rule that those living above the 80th floor should wait 2 additional minutes to break their Ramadan fast, and those living above the 150th floor, 3 minutes.

In Popular Culture


  • Some scenes of the 2011 American action film Mission: Impossible – Ghost Protocol were shot on and in the Burj Khalifa, where Tom Cruise, portraying the character of Ethan Hunt, performed many of the stunts himself.
  • An alternate version of the Burj Khalifa appears in the 2012 video game Spec Ops: The Line.
  • A building that resembles the Burj Khalifa was featured in an episode of the American animated comedy series The Simpsons entitled “YOLO”, which aired on 10 November 2013. The building is known to be the tallest building in Springfield, a fictional American town which is the show’s setting.
  • In the 2016 American science fiction film Independence Day: Resurgence, the Burj Khalifa was seen where it – along with many other structures – is being thrown into
  • London by the aliens using their mothership’s anti-gravity pull.
  • Various other Western, Indian and Pakistani movies/ shows have been filmed, including the Amazing Race.
  • This building can also be seen in one of the Dubai tracks in the Wii version of Need for Speed: Nitro.
  • In the 2017 American disaster film Geostorm, the building is hit by a massive tsunami, which causes the antenna to fall off and the building itself to tilt at a precarious angle.

Fireworks Displays


  • 2010–2011: Fireworks accompanied by lasers and lights were displayed from the Burj Khalifa, making it the highest New Year’s Eve fireworks display in the world. The theme of the 2011 New Year fireworks was the “New Year Gala”, a tribute to the spirit of Dubai, which is home to over 200 nationalities. The display also marked the first anniversary of Burj Khalifa.
  • 2012–2013: The fireworks display on the Burj Khalifa – in a blaze of light and colour – engulfed the tower, synchronised and choreographed to a live performance by the Prague Philharmonic Orchestra. A window table for the New Year event was also arranged on the 122nd floor of the building at Atmosphere restaurant, at cost of Dh16,000 (US$4,300) per person.
  • On 27 November 2013, the Burj Khalifa was illuminated with lights and a fireworks display following announcement of Dubai as the winning city to host the World Expo 2020.
  • 2013–2014: The Burj Khalifa and surrounding areas were the site of a record-breaking fireworks display as part of the UAE’s New Year’s Eve celebrations, with a reported 400,000 fireworks being set off continuously for six minutes.
  • 2014–2015: The Burj Khalifa was illuminated by a 828 m (2,717 ft) custom build LED facade which was installed on the building where light shows were displayed followed by the fireworks.

Labour Controversy


The Burj Khalifa was built primarily by workers from South Asia and East Asia. This is generally because the current generation of UAE locals prefer governmental jobs and do not have an attitude favouring private sector employment. On 17 June 2008, there were 7,500 skilled workers employed at the construction site. Press reports indicated in 2006 that skilled carpenters at the site earned £4.34 a day, and labourers earned £2.84. According to a BBC investigation and a Human Rights Watch (HRW) report, the workers were housed in abysmal conditions, and worked long hours for low pay. During the construction of Burj Khalifa, only one construction-related death was reported. However, workplace injuries and fatalities in the UAE are “poorly documented”, according to HRW.

On 21 March 2006, about 2,500 workers, who were upset over buses that were delayed for the end of their shifts, protested and triggered a riot, damaging cars, offices, computers and construction equipment. A Dubai Interior Ministry official said the rioters caused almost £500,000 in damage. Most of the workers involved in the riot returned the following day but refused to work.

Tallest buildings in the world (350 m+)

Opera Snapshot_2017-11-21_002419_en.wikipedia.org


A Smog-eating Twisting Tower that features Luxury Apartments will soon open in Taiwan

Leanna Garfield, Business Insider US August 3, 2017

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The Tao Zhu Yin Yuan Tower by Vincent Callebaut Architectures in Taipei, Taiwan. Vincent Callebaut Architectures

A twisting, smog-eating tower is nearly finished in Taipei, Taiwan.

The skyscraper’s facade, roof, and balconies will contain 23,000 trees and shrubs – nearly the same amount found in New York’s Central Park. Inside, it will hold 40 luxury condos.

The plants are projected to absorb 130 tons of carbon dioxide per year – the equivalent of about 27 cars, lead designer Vincent Callebaut told Business Insider.

Called the Tao Zhu Yin Yuan Tower, or Agora Garden, the building topped out in July and is set to open by the fall. Take a look inside.


The 455,694-square-foot structure, a double-helix twisting 90-degrees from base to top, is modeled on a DNA strand, Callebaut said.

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Vincent Callebaut Architectures


The 20-story skyscraper sits in the XinYi District, in the heart of Taipei City.

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Vincent Callebaut Architectures


The top floor was completed in July 2017.

Opera Snapshot_2017-11-20_195316_www.businessinsider.sg


The photo on the right shows what the tower will look like once the trees and shrubs are planted.

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Vincent Callebaut Architectures


The firm claims the balconies’ plants will absorb 130 tons of carbon dioxide per year — a small fraction of the roughly 260 million tons of CO2 Taiwan in 2008, the latest year data is available.

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Vincent Callebaut Architectures
Source: International Energy Agency


Plants will also grow inside to the tower’s hallways, which will have glass flooring.

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Vincent Callebaut Architectures


Each unit will include a living room, dining room, family room, kitchen, and multiple bedrooms with walk-in closets.

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Vincent Callebaut Architectures


Two Penthouses will each stretch 5,920 square feet.

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Vincent Callebaut Architectures


Residents will have a stunning view of Taipei from their terraces …

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Vincent Callebaut Architectures


… and they’ll be able to swim in the skyscraper’s indoor pool.

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Vincent Callebaut Architectures


Other amenities will include a garage and a fitness center — both naturally ventilated and lit.

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Vincent Callebaut Architectures


Callebaut, a Belgian architect, is known for his greenery-filled buildings. He sees the new tower as a small step toward a more sustainable future.

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Vincent Callebaut Architectures

Callebaut’s other projects include a masterplan to revamp an industrial zone in Brussels, Belgium by adding luxury housing, restaurants, shops, office space, and greenhouses. His firm submitted the plan to the local government for review in February.

He is also working on a manta ray-shaped ferry terminal in Seoul, Korea. The designs for that structure, which were unveiled in June, also call for it to be covered in plants. And a solar-and-wind-powered building Callebaut designed in Cairo, Egypt is under construction and will contain rooftop community gardens and green living walls.


Construction on Agora Garden started in 2013, and is expected to wrap up in September.

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Vincent Callebaut Architectures


Opera Snapshot_2017-11-20_203401_www.livinspaces.net

Opera Snapshot_2017-11-20_203303_www.livinspaces.net

The Tao Zhu Yin Yuan Tower is a pioneering sustainable residential tower designed by Paris based Vincent Callebaut Architectures. After being awarded the project commission in a 2010 competition, the architects set out to create a building akin to an “inhabited tree” that could offer a vertical landscape with minimal energy consumption.

helix-eco-tower_23Vince-Callebaut

The 21 storey tower which is currently under construction in the Xinjin District of Taipei City, Taiwan, is directly modeled after a strand of DNA — a double helix twisting 90-degrees from base to top with each level turning by 4.5 degrees. According to the architects, this unique form provides solutions to 4 main objectives:

  • To be perfectly integrated in the North / South pyramidal profile of the Building Volume along with its East / West rhomboidal profile as well as the North-South reverse pyramid profile.
  • To generate a maximum of cascades for suspended open-air gardens, not part of the floor area ratio.
  • To offer every resident exceptional panoramic views of the Taipei skyline by multiplying the transversal views, especially towards the very close Taipei 101 tower and the Central Business District.
  • To generate from a flexible standardized level a progressive geometry which ensures the privacy of each apartment by avoiding direct visual axes.

The design of the Tao Zhu Yin Yuan tower (which means “The Retreat of Tao Zhu”), features a number of environmental as well as technological components that aid in reducing energy consumption.

The central core (which is a twisted vertical garden) has been designed to separate totally the vertical circulations into two housing units on each level. This core is fixed and features a double skin curtain wall system, that enables passive climate control for the vertical circulation and inner spaces, allowing for both natural ventilation and light. The core also features 2 staircases, 4 high speed elevators of 24 people (1800 kg), 1 car elevators (also useful to carry enormous art pieces, luxury antique vehicles, or even huge pianos, etc.), 2 sky garages in glass and also all the vertical shafts for the main flows. All these vertical flows are covered by a huge bearing exoskeleton in reinforced steel.

The apartments offer maximum spatial and technical flexibility. Spatially, each unit covers about 550 sqm, following two typical layouts on alternating floors, to best fit into the building’s virendeel beam structure. All levels are linked at both ends by two spiralling mega columns covered by green walls. This ensures each apartment remains completely free of columns.The technical flexibility is obtained by the integration of double decks and double walls that allow services and utilities remain hidden and embedded.

Other environmental features include a rainwater recycling system, low e-glass, a photovoltaic solar array on the roof and canopies. The tower will also be covered in 23,000 trees and shrubs on the various terraces and roof gardens. This extensive vegetations is intented to absorb up to 130 tons of carbon dioxide (CO2) emissions each year — the equivalent of around 27 cars.

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The tower has been described as a “Carbon-absorbing green tower” by Callebaut himself. In a report from CNN, the architect likens the building to an urban forest.

“The tower presents a pioneer concept of sustainable residential eco-construction that aims at limiting the ecological footprint of its inhabitants”

-Vincent Callebaut

The Tao Zhu Yin Yuan tower is expected to be completed by September 2017. You can see (many) more images as well as an in-depth, detailed description of the concept on the Vincent Callebaut project page.

Here are some construction images from the tower taken earlier in the year.

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PROJECT DETAILS

  • TYPE: International Competition – First Prize Winner in November 2010
  • INTERNATIONAL ARCHITECT: Vincent Callebaut Architectures, Paris
  • CLIENT: BES Engineering Corporation, Taipei
  • CONTRACTOR: Taiwan Kumagai Co, Ltd
  • CONTRACT LOCATION: XinYin District, Taipei City, Taiwan
  • PROGRAM: 42 Sustainable Apartments + Facilities
  • SURFACE AREA: 42.335.34 m²
  • DELIVERY: September 2017
  • CURRENT PHASE: Under construction
  • GREEN CERTIFICATION: U.S. Green Building Council, LEED Gold + Low Carbon Building Alliance, Diamond Level
  • LOCAL ARCHITECT: LKP Design, Taipei
  • STRUCTURAL ENGINEER: King Le Chang & Associates, Taipei
  • LOCAL MEP ENGINEERING: Sine & Associates, Taipei
  • INTERNATIONAL INTERIOR ARCHITECT: Wilson & Associates (WA), Los Angeles
  • INTERNATIONAL LANDSCAPE ARCHITECT: SWA, Sausalito, San Francisco
  • LOCAL LANDSCAPE ARCHITECT: Horizon & Atmosphere (H&A), Taipei
  • INTERNATIONAL LIGHTING DESIGNER: L’Observatoire International, New-York
  • LOCAL LIGHTING DESIGNER: Unolai Design, Taipei
  • GREEN CONSULTANT: Enertek, Taipei
  • VCA’S TEAM: Emilie Diers, Frederique Beck, Jiao Yang, Florence Mauny,
  • Volker Erlich, Philippe Steels, Marco Conti Sikic, Benoit Patterlini, Maguy Delrieu, Vincent Callebaut
  • MODEL MAKER: Patrick Laurent

Source: livinspacesnet

Leaning Tower of Pisa

From Wikipedia, the free encyclopedia

Opera Snapshot_2017-11-17_181816_en.wikipedia.org

The_Leaning_Tower_of_Pisa_SB.jpeg

The Leaning Tower of Pisa (Italian: Torre pendente di Pisa) or simply the Tower of Pisa (Torre di Pisa [ˈtorre di ˈpiːza]) is the campanile, or freestanding bell tower, of the cathedral of the Italian city of Pisa, known worldwide for its unintended tilt. The tower is situated behind the Pisa Cathedral and is the third oldest structure in the city’s Cathedral Square (Piazza del Duomo), after the cathedral and the Pisa Baptistry.

The tower’s tilt began during construction in the 12th century, caused by an inadequate foundation on ground too soft on one side to properly support the structure’s weight. The tilt increased in the decades before the structure was completed in the 14th century. It gradually increased until the structure was stabilized (and the tilt partially corrected) by efforts in the late 20th and early 21st centuries.

The height of the tower is 55.86 metres (183.27 feet) from the ground on the low side and 56.67 metres (185.93 feet) on the high side. The width of the walls at the base is 2.44 m (8 ft 0.06 in). Its weight is estimated at 14,500 metric tons (16,000 short tons). The tower has 296 or 294 steps; the seventh floor has two fewer steps on the north-facing staircase. Prior to restoration work performed between 1990 and 2001, the tower leaned at an angle of 5.5 degrees, but the tower now leans at about 3.99 degrees. This means the top of the tower is displaced horizontally 3.9 metres (12 ft 10 in) from the centre.

Contents
1 Architect
2 Construction
2.1 Timeline
2.2 Builders
3 History following construction
4 Alternative candidates
5 Technical information
6 Gallery

Architect


There has been controversy about the real identity of the architect of the Leaning Tower of Pisa. For many years, the design was attributed to Guglielmo and Bonanno Pisano, a well-known 12th-century resident artist of Pisa, famous for his bronze casting, particularly in the Pisa Duomo. Pisano left Pisa in 1185 for Monreale, Sicily, only to come back and die in his home town. A piece of cast bearing his name was discovered at the foot of the tower in 1820, but this may be related to the bronze door in the façade of the cathedral that was destroyed in 1595. A 2001 study seems to indicate Diotisalvi was the original architect, due to the time of construction and affinity with other Diotisalvi works, notably the bell tower of San Nicola and the Baptistery, both in Pisa.

Construction


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The Pisa Baptistery (in the foreground), the Pisa Cathedral (in the middleground), and the Leaning Tower of Pisa (in the background)

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Leaning Tower of Pisa in 2004

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Leaning Tower of Pisa

Construction of the tower occurred in three stages over 199 years. Work on the ground floor of the white marble campanile began on August 14, 1173 during a period of military success and prosperity. This ground floor is a blind arcade articulated by engaged columns with classical Corinthian capitals.

The tower began to sink after construction had progressed to the second floor in 1178. This was due to a mere three-metre foundation, set in weak, unstable subsoil, a design that was flawed from the beginning. Construction was subsequently halted for almost a century, because the Republic of Pisa was almost continually engaged in battles with Genoa, Lucca, and Florence. This allowed time for the underlying soil to settle. Otherwise, the tower would almost certainly have toppled. In 1198, clocks were temporarily installed on the third floor of the unfinished construction.

In 1272, construction resumed under Giovanni di Simone, architect of the Camposanto. In an effort to compensate for the tilt, the engineers built upper floors with one side taller than the other. Because of this, the tower is curved. Construction was halted again in 1284 when the Pisans were defeated by the Genoans in the Battle of Meloria.

The seventh floor was completed in 1319. The bell-chamber was finally added in 1372. It was built by Tommaso di Andrea Pisano, who succeeded in harmonizing the Gothic elements of the bell-chamber with the Romanesque style of the tower. There are seven bells, one for each note of the musical major scale. The largest one was installed in 1655.

After a phase (1990–2001) of structural strengthening, the tower is currently undergoing gradual surface restoration, in order to repair visible damage, mostly corrosion and blackening. These are particularly pronounced due to the tower’s age and its exposure to wind and rain.

Timeline

  • On January 5, 1172, Donna Berta di Bernardo, a widow and resident of the house of dell’Opera di Santa Maria, bequeathed sixty soldi to the Opera Campanilis petrarum Sancte Marie. The sum was then used toward the purchase of a few stones which still form the base of the bell tower.
    On August 9, 1173, the foundations of the tower were laid.
    Nearly four centuries later Giorgio Vasari wrote: “Guglielmo, according to what is being said, in [this] year 1174 with Bonanno as sculptor, laid the foundations of the bell tower of the cathedral in Pisa.”
  • On December 27, 1233, the worker Benenato, son of Gerardo Bottici, oversaw the continuation of the construction of the bell tower.
    On February 23, 1260, Guido Speziale, son of Giovanni, a worker on the cathedral Santa Maria Maggiore, was elected to oversee the building of the tower.
  • On April 12, 1264, the master builder Giovanni di Simone and 23 workers went to the mountains close to Pisa to cut marble. The cut stones were given to Rainaldo Speziale, worker of St. Francesco.
  • Giorgio Vasari indicated that Tommaso di Andrea Pisano was the designer of the belfry between 1360 and 1370.

Builders

  • One possible known builder of Pisa Tower was Gerardo di Gerardo. His name appears as a witness to the above legacy of Berta di Bernardo as “Master Gerardo”, and as a worker whose name was Gerardo.
  • A more probable builder was Diotisalvi, because of the construction period and the structure’s affinities with other buildings in Pisa, but he usually signed his works, and there is no signature by him in the bell tower.
  • Giovanni di Simone was known to be heavily involved in the completion of the tower, under the direction of Giovanni Pisano, who at the time was master builder of the Opera di Santa Maria Maggiore. Di Simone could be the same Giovanni Pisano who completed the belfry tower.

History following construction


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Plaque in memory of Galileo Galilei’s experiments

Galileo Galilei is said to have dropped two cannonballs of different masses from the tower to demonstrate that their speed of descent was independent of their mass. However, the only primary source for this is the biography Racconto istorico della vita di Galileo Galilei (Historical Account of the Life of Galileo Galilei), written by Galileo’s secretary Vincenzo Viviani and published in 1717, long after Viviani’s death.

During World War II, the Allies discovered that the Germans were using the tower as an observation post. A U.S. Army sergeant sent to confirm the presence of German troops in the tower was impressed by the beauty of the cathedral and its campanile, and thus refrained from ordering an artillery strike, sparing it from destruction.

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Lead counterweights, 1998

Numerous efforts have been made to restore the tower to a vertical orientation or at least keep it from falling over. Most of these efforts failed; some worsened the tilt. On February 27, 1964, the government of Italy requested aid in preventing the tower from toppling. It was, however, considered important to retain the current tilt, due to the role that this element played in promoting the tourism industry of Pisa.

A multinational task force of engineers, mathematicians, and historians gathered on the Azores islands to discuss stabilisation methods. It was found that the tilt was increasing in combination with the softer foundations on the lower side. Many methods were proposed to stabilise the tower, including the addition of 800 tonnes of lead counterweights to the raised end of the base.

The tower and the neighbouring cathedral, baptistery, and cemetery are included in the Piazza del Duomo UNESCO World Heritage Site, which was declared in 1987.

The tower was closed to the public on January 7, 1990, after more than two decades of stabilisation studies and spurred by the abrupt collapse of the Civic Tower of Pavia in 1989. The bells were removed to relieve some weight, and cables were cinched around the third level and anchored several hundred meters away. Apartments and houses in the path of the tower were vacated for safety. The solution chosen to prevent the collapse of the tower was to slightly straighten it to a safer angle by removing 38 cubic metres (1,342 cubic feet) of soil from underneath the raised end. The tower was straightened by 45 centimetres (17.7 inches), returning to its 1838 position. After a decade of corrective reconstruction and stabilization efforts, the tower was reopened to the public on December 15, 2001 and was declared stable for at least another 300 years. In total, 70 metric tons (77 short tons) of earth were removed.

In May 2008, engineers announced that the tower had been stabilized such that it had stopped moving for the first time in its history. They stated that it would be stable for at least 200 years.

Alternative candidates


Two German churches have challenged the tower’s status as the world’s most lop-sided building: the 15th-century square Leaning Tower of Suurhusen and the 14th-century bell tower in the town of Bad Frankenhausen. Guinness World Records measured the Pisa and Suurhusen towers, finding the former’s tilt to be 3.97 degrees. In June 2010, Guinness World Records certified the Capital Gate building in Abu Dhabi, UAE as the “World’s Furthest Leaning Man-made Tower”. The Capital Gate tower has an 18-degree slope, almost five times more than the Pisa Tower; however the Capital Gate tower has been deliberately engineered to slant. The Leaning Tower of Wanaka in New Zealand, also deliberately built, leans at 53 degrees to the ground.

Technical Information


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An elevation image of the Leaning Tower of Pisa cut with laser scan data from a University of Ferrara/CyArk research partnership, with source image accurate down to 5 mm (0.2 in). This elevation shows the interesting quandary facing the campanile. The circular shape and great height (currently 55.86 m (183 ft 3.21 in) on the lowest side and 56.67 m (185 ft 11.10 in) m on the highest) of the campanile were unusual for their time, and the crowning belfry is stylistically distinct from the rest of the construction. This belfry incorporates a 14 cm (5.5 in) correction for the inclined axis below. The siting of the campanile within the Piazza del Duomo diverges from the axial alignment of the cathedral and baptistery of the Piazza del Duomo

  • Elevation of Piazza del Duomo: about 2 metres (6 feet, DMS)
  • Height from the ground floor: 55.863 metres (183 ft 3 in), 8 stories
  • Height from the foundation floor: 58.36 m (191 ft 5.64 in)
  • Outer diameter of base: 15.484 metres (50 ft 9.6 in)
  • Inner diameter of base: 7.368 metres (24 ft 2.1 in)
  • Angle of slant: 3.97 degrees[27] or 3.9 metres (12 ft 10 in) from the vertical[30]
  • Weight: 14,700 metric tons (16,200 short tons)
  • Thickness of walls at the base: 2.44 metres (8 ft 0 in)
  • Total number of bells: 7, tuned to musical scale, clockwise
    1st bell: L’Assunta, cast in 1654 by Giovanni Pietro Orlandi, weight 3,620 kg (7,981 lb)
  • 2nd bell: Il Crocifisso, cast in 1572 by Vincenzo Possenti, weight 2,462 kg (5,428 lb)
  • 3rd bell: San Ranieri, cast in 1719–1721 by Giovanni Andrea Moreni, weight 1,448 kg (3,192 lb)
  • 4th bell: La Terza (1st small one), cast in 1473, weight 300 kg (661 lb)
    5th bell: La Pasquereccia or La Giustizia, cast in 1262 by Lotteringo, weight 1,014 kg (2,235 lb)
  • 6th bell: Il Vespruccio (2nd small one), cast in the 14th century and again in 1501 by Nicola di Jacopo, weight 1,000 kg (2,205 lb)
  • 7th bell: Dal Pozzo, cast in 1606 and again in 2004, weight 652 kg (1,437 lb)[31]
    Number of steps to the top: 296[32]

About the 5th bell: The name Pasquareccia comes from Easter, because it used to ring on Easter day. However, this bell is older than the bell-chamber itself, and comes from the tower Vergata in Palazzo Pretorio in Pisa, where it was called La Giustizia (The Justice). The bell was tolled to announce executions of criminals and traitors, including Count Ugolino in 1289.[33] A new bell was installed in the bell tower at the end of the 18th century to replace the broken Pasquareccia.

About the 5th bell: The name Pasquareccia comes from Easter, because it used to ring on Easter day. However, this bell is older than the bell-chamber itself, and comes from the tower Vergata in Palazzo Pretorio in Pisa, where it was called La Giustizia (The Justice). The bell was tolled to announce executions of criminals and traitors, including Count Ugolino in 1289. A new bell was installed in the bell tower at the end of the 18th century to replace the broken Pasquareccia.

Gallery


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View looking up

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Entrance door to the bell tower

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External loggia

 

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Inner staircase from sixth to seventh floor

 

 

 

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Inner staircase from seventh to eighth (the top) floor

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View from the top

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Assunta bell

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Pasquareccia bell

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View, looking down from the top

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A popular photo opportunity with tourists is to pose as if one was either holding up or pushing over the tower

Eiffel Tower

From Wikipedia, the free encyclopedia

Opera Snapshot_2017-11-17_181645_en.wikipedia.org

614px-Tour_Eiffel_Wikimedia_Commons_(cropped)

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The Eiffel Tower (/ˈaɪfəl ˈtaʊ.ər/ EYE-fəl TOW-ər; French: tour Eiffel, pronounced [tuʁ‿ɛfɛl] About this sound listen) is a wrought iron lattice tower on the Champ de Mars in Paris, France. It is named after the engineer Gustave Eiffel, whose company designed and built the tower.

Constructed from 1887–89 as the entrance to the 1889 World’s Fair, it was initially criticized by some of France’s leading artists and intellectuals for its design, but it has become a global cultural icon of France and one of the most recognisable structures in the world. The Eiffel Tower is the most-visited paid monument in the world; 6.91 million people ascended it in 2015.

The tower is 324 metres (1,063 ft) tall, about the same height as an 81-storey building, and the tallest structure in Paris. Its base is square, measuring 125 metres (410 ft) on each side. During its construction, the Eiffel Tower surpassed the Washington Monument to become the tallest man-made structure in the world, a title it held for 41 years until the Chrysler Building in New York City was finished in 1930. Due to the addition of a broadcasting aerial at the top of the tower in 1957, it is now taller than the Chrysler Building by 5.2 metres (17 ft). Excluding transmitters, the Eiffel Tower is the second-tallest structure in France after the Millau Viaduct.

The tower has three levels for visitors, with restaurants on the first and second levels. The top level’s upper platform is 276 m (906 ft) above the ground – the highest observation deck accessible to the public in the European Union. Tickets can be purchased to ascend by stairs or lift (elevator) to the first and second levels. The climb from ground level to the first level is over 300 steps, as is the climb from the first level to the second. Although there is a staircase to the top level, it is usually accessible only by lift.

Contents
1 History
1.1 Origin
1.2 Artists’ protest
1.3 Construction
1.3.1 Lifts
1.4 Inauguration and the 1889 exposition
1.5 Subsequent events
2 Design
2.1 Material
2.2 Wind considerations
2.3 Accommodation
2.4 Passenger lifts
2.5 Engraved names
2.6 Aesthetics
2.7 Maintenance
3 Tourism
3.1 Transport
3.2 Popularity
3.3 Restaurants
4 Replicas
5 Communications
5.1 FM radio
5.2 Digital television
6 Illumination copyright
7 Taller structures
7.1 Lattice towers taller than the Eiffel Tower
7.2 Structures in France taller than the Eiffel Tower
8 See also
9 References
10 Bibliography
11 External links

History


Origin

The design of the Eiffel Tower was the product of Maurice Koechlin and Émile Nouguier, two senior engineers working for the Compagnie des Établissements Eiffel, after discussion about a suitable centrepiece for the proposed 1889 Exposition Universelle, a world’s fair to celebrate the centennial of the French Revolution. Eiffel openly acknowledged that inspiration for a tower came from the Latting Observatory built in New York City in 1853. In May 1884, working at home, Koechlin made a sketch of their idea, described by him as “a great pylon, consisting of four lattice girders standing apart at the base and coming together at the top, joined together by metal trusses at regular intervals”. Eiffel initially showed little enthusiasm, but he did approve further study, and the two engineers then asked Stephen Sauvestre, the head of company’s architectural department, to contribute to the design. Sauvestre added decorative arches to the base of the tower, a glass pavilion to the first level, and other embellishments.

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First drawing of the Eiffel Tower by Maurice Koechlin including size comparison with other Parisian landmarks such as Notre Dame de Paris, the Statue of Liberty and the Vendôme Column

The new version gained Eiffel’s support: he bought the rights to the patent on the design which Koechlin, Nougier, and Sauvestre had taken out, and the design was exhibited at the Exhibition of Decorative Arts in the autumn of 1884 under the company name. On 30 March 1885, Eiffel presented his plans to the Société des Ingénieurs Civils; after discussing the technical problems and emphasising the practical uses of the tower, he finished his talk by saying the tower would symbolise,

Not only the art of the modern engineer, but also the century of Industry and Science in which we are living, and for which the way was prepared by the great scientific movement of the eighteenth century and by the Revolution of 1789, to which this monument will be built as an expression of France’s gratitude.

Little progress was made until 1886, when Jules Grévy was re-elected as president of France and Édouard Lockroy was appointed as minister for trade. A budget for the exposition was passed and, on 1 May, Lockroy announced an alteration to the terms of the open competition being held for a centrepiece to the exposition, which effectively made the selection of Eiffel’s design a foregone conclusion, as entries had to include a study for a 300 m (980 ft) four-sided metal tower on the Champ de Mars. (A 300-meter tower was then considered a herculean engineering effort). On 12 May, a commission was set up to examine Eiffel’s scheme and its rivals, which, a month later, decided that all the proposals except Eiffel’s were either impractical or lacking in details.

After some debate about the exact location of the tower, a contract was signed on 8 January 1887. This was signed by Eiffel acting in his own capacity rather than as the representative of his company, and granted him 1.5 million francs toward the construction costs: less than a quarter of the estimated 6.5 million francs. Eiffel was to receive all income from the commercial exploitation of the tower during the exhibition and for the next 20 years. He later established a separate company to manage the tower, putting up half the necessary capital himself.

Artists’ protest

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Caricature of Gustave Eiffel comparing the Eiffel tower to the Pyramids

The proposed tower had been a subject of controversy, drawing criticism from those who did not believe it was feasible and those who objected on artistic grounds. These objections were an expression of a long-standing debate in France about the relationship between architecture and engineering. It came to a head as work began at the Champ de Mars: a “Committee of Three Hundred” (one member for each metre of the tower’s height) was formed, led by the prominent architect Charles Garnier and including some of the most important figures of the arts, such as Adolphe Bouguereau, Guy de Maupassant, Charles Gounod and Jules Massenet. A petition called “Artists against the Eiffel Tower” was sent to the Minister of Works and Commissioner for the Exposition, Charles Alphand, and it was published by Le Temps on 14 February 1887:

We, writers, painters, sculptors, architects and passionate devotees of the hitherto untouched beauty of Paris, protest with all our strength, with all our indignation in the name of slighted French taste, against the erection … of this useless and monstrous Eiffel Tower … To bring our arguments home, imagine for a moment a giddy, ridiculous tower dominating Paris like a gigantic black smokestack, crushing under its barbaric bulk Notre Dame, the Tour Saint-Jacques, the Louvre, the Dome of les Invalides, the Arc de Triomphe, all of our humiliated monuments will disappear in this ghastly dream. And for twenty years … we shall see stretching like a blot of ink the hateful shadow of the hateful column of bolted sheet metal.

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A calligram by Guillaume Apollinaire

Gustave Eiffel responded to these criticisms by comparing his tower to the Egyptian pyramids: “My tower will be the tallest edifice ever erected by man. Will it not also be grandiose in its way? And why would something admirable in Egypt become hideous and ridiculous in Paris?” These criticisms were also dealt with by Édouard Lockroy in a letter of support written to Alphand, ironically saying, “Judging by the stately swell of the rhythms, the beauty of the metaphors, the elegance of its delicate and precise style, one can tell this protest is the result of collaboration of the most famous writers and poets of our time”, and he explained that the protest was irrelevant since the project had been decided upon months before, and construction on the tower was already under way.

Indeed, Garnier was a member of the Tower Commission that had examined the various proposals, and had raised no objection. Eiffel was similarly unworried, pointing out to a journalist that it was premature to judge the effect of the tower solely on the basis of the drawings, that the Champ de Mars was distant enough from the monuments mentioned in the protest for there to be little risk of the tower overwhelming them, and putting the aesthetic argument for the tower: “Do not the laws of natural forces always conform to the secret laws of harmony?”

Some of the protesters changed their minds when the tower was built; others remained unconvinced. Guy de Maupassant supposedly ate lunch in the tower’s restaurant every day because it was the one place in Paris where the tower was not visible.

By 1918, it had become a symbol of Paris and of France after Guillaume Apollinaire wrote a nationalist poem in the shape of the tower (a calligram) to express his feelings about the war against Germany. Today, it is widely considered to be a remarkable piece of structural art, and is often featured in films and literature.

Construction

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Foundations of the Eiffel Tower

Work on the foundations started on 28 January 1887. Those for the east and south legs were straightforward, with each leg resting on four 2 m (6.6 ft) concrete slabs, one for each of the principal girders of each leg. The west and north legs, being closer to the river Seine, were more complicated: each slab needed two piles installed by using compressed-air caissons 15 m (49 ft) long and 6 m (20 ft) in diameter driven to a depth of 22 m (72 ft) to support the concrete slabs, which were 6 m (20 ft) thick. Each of these slabs supported a block of limestone with an inclined top to bear a supporting shoe for the ironwork.

Each shoe was anchored to the stonework by a pair of bolts 10 cm (4 in) in diameter and 7.5 m (25 ft) long. The foundations were completed on 30 June, and the erection of the ironwork began. The visible work on-site was complemented by the enormous amount of exacting preparatory work that took place behind the scenes: the drawing office produced 1,700 general drawings and 3,629 detailed drawings of the 18,038 different parts needed. The task of drawing the components was complicated by the complex angles involved in the design and the degree of precision required: the position of rivet holes was specified to within 0.1 mm (0.0039 in) and angles worked out to one second of arc. The finished components, some already riveted together into sub-assemblies, arrived on horse-drawn carts from a factory in the nearby Parisian suburb of Levallois-Perret and were first bolted together, with the bolts being replaced with rivets as construction progressed. No drilling or shaping was done on site: if any part did not fit, it was sent back to the factory for alteration. In all, 18,038 pieces were joined together using 2.5 million rivets.

At first the legs were constructed as cantilevers, but about halfway to the first level, construction was paused in order to create a substantial timber scaffold. This renewed concerns about the structural integrity of the tower, and sensational headlines such as “Eiffel Suicide!” and “Gustave Eiffel Has Gone Mad: He Has Been Confined in an Asylum” appeared in the tabloid press. At this stage, a small “creeper” crane designed to move up the tower was installed in each leg. They made use of the guides for the lifts which were to be fitted in the four legs. The critical stage of joining the legs at the first level was completed by the end of March 1888. Although the metalwork had been prepared with the utmost attention to detail, provision had been made to carry out small adjustments in order to precisely align the legs; hydraulic jacks were fitted to the shoes at the base of each leg, capable of exerting a force of 800 tonnes, and the legs were intentionally constructed at a slightly steeper angle than necessary, being supported by sandboxes on the scaffold. Although construction involved 300 on-site employees, only one person died thanks to Eiffel’s stringent safety precautions and the use of movable gangways, guardrails and screens.

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The start of the erection of the metalwork.

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7 December 1887: Construction of the legs with scaffolding.

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20 March 1888: Completion of the first level.

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15 May 1888: Start of construction on the second stage.

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21 August 1888: Completion of the second level.

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26 December 1888: Construction of the upper stage.

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15 March 1889: Construction of the cupola.

Lifts

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The Roux, Combaluzier & Lepape lifts during construction. Note the drive sprockets and chain in the foreground

Equipping the tower with adequate and safe passenger lifts was a major concern of the government commission overseeing the Exposition. Although some visitors could be expected to climb to the first level, or even the second, lifts clearly had to be the main means of ascent.

Constructing lifts to reach the first level was relatively straightforward: the legs were wide enough at the bottom and so nearly straight that they could contain a straight track, and a contract was given to the French company Roux, Combaluzier & Lepape for two lifts to be fitted in the east and west legs. Roux, Combaluzier & Lepape used a pair of endless chains with rigid, articulated links to which the car was attached. Lead weights on some links of the upper or return sections of the chains counterbalanced most of the car’s weight. The car was pushed up from below, not pulled up from above: to prevent the chain buckling, it was enclosed in a conduit. At the bottom of the run, the chains passed around 3.9 m (12 ft 10 in) diameter sprockets. Smaller sprockets at the top guided the chains.

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The Otis lifts originally fitted in the north and south legs

Installing lifts to the second level was more of a challenge because a straight track was impossible. No French company wanted to undertake the work. The European branch of Otis Brothers & Company submitted a proposal but this was rejected: the fair’s charter ruled out the use of any foreign material in the construction of the tower. The deadline for bids was extended but still no French companies put themselves forward, and eventually the contract was given to Otis in July 1887. Otis were confident they would eventually be given the contract and had already started creating designs.

The car was divided into two superimposed compartments, each holding 25 passengers, with the lift operator occupying an exterior platform on the first level. Motive power was provided by an inclined hydraulic ram 12.67 m (41 ft 7 in) long and 96.5 cm (38.0 in) in diameter in the tower leg with a stroke of 10.83 m (35 ft 6 in): this moved a carriage carrying six sheaves. Five fixed sheaves were mounted higher up the leg, producing an arrangement similar to a block and tackle but acting in reverse, multiplying the stroke of the piston rather than the force generated. The hydraulic pressure in the driving cylinder was produced by a large open reservoir on the second level. After being exhausted from the cylinder, the water was pumped back up to the reservoir by two pumps in the machinery room at the base of the south leg. This reservoir also provided power to the lifts to the first level.

The original lifts for the journey between the second and third levels were supplied by Léon Edoux. A pair of 81 m (266 ft) hydraulic rams were mounted on the second level, reaching nearly halfway up to the third level. One lift car was mounted on top of these rams: cables ran from the top of this car up to sheaves on the third level and back down to a second car. Each car only travelled half the distance between the second and third levels and passengers were required to change lifts halfway by means of a short gangway. The 10-ton cars each held 65 passengers.

Inauguration and the 1889 exposition

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General view of the Exposition Universelle

The main structural work was completed at the end of March 1889 and, on 31 March, Eiffel celebrated by leading a group of government officials, accompanied by representatives of the press, to the top of the tower. Because the lifts were not yet in operation, the ascent was made by foot, and took over an hour, with Eiffel stopping frequently to explain various features. Most of the party chose to stop at the lower levels, but a few, including the structural engineer, Émile Nouguier, the head of construction, Jean Compagnon, the President of the City Council, and reporters from Le Figaro and Le Monde Illustré, completed the ascent. At 2:35 pm, Eiffel hoisted a large Tricolour to the accompaniment of a 25-gun salute fired at the first level.

There was still work to be done, particularly on the lifts and facilities, and the tower was not opened to the public until nine days after the opening of the exposition on 6 May; even then, the lifts had not been completed. The tower was an instant success with the public, and nearly 30,000 visitors made the 1,710-step climb to the top before the lifts entered service on 26 May. Tickets cost 2 francs for the first level, 3 for the second, and 5 for the top, with half-price admission on Sundays, and by the end of the exhibition there had been 1,896,987 visitors.

After dark, the tower was lit by hundreds of gas lamps, and a beacon sent out three beams of red, white and blue light. Two searchlights mounted on a circular rail were used to illuminate various buildings of the exposition. The daily opening and closing of the exposition were announced by a cannon at the top.

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Illumination of the tower at night during the exposition

On the second level, the French newspaper Le Figaro had an office and a printing press, where a special souvenir edition, Le Figaro de la Tour, was made. There was also a pâtisserie.

At the top, there was a post office where visitors could send letters and postcards as a memento of their visit. Graffitists were also catered for: sheets of paper were mounted on the walls each day for visitors to record their impressions of the tower. Gustave Eiffel described some of the responses as vraiment curieuse (“truly curious”).

Famous visitors to the tower included the Prince of Wales, Sarah Bernhardt, “Buffalo Bill” Cody (his Wild West show was an attraction at the exposition) and Thomas Edison. Eiffel invited Edison to his private apartment at the top of the tower, where Edison presented him with one of his phonographs, a new invention and one of the many highlights of the exposition. Edison signed the guestbook with this message:

To M Eiffel the Engineer the brave builder of so gigantic and original specimen of modern Engineering from one who has the greatest respect and admiration for all Engineers including the Great Engineer the Bon Dieu, Thomas Edison.

Eiffel had a permit for the tower to stand for 20 years. It was to be dismantled in 1909, when its ownership would revert to the City of Paris. The City had planned to tear it down (part of the original contest rules for designing a tower was that it should be easy to dismantle) but as the tower proved to be valuable for communication purposes, it was allowed to remain after the expiry of the permit.

Eiffel made use of his apartment at the top of the tower to carry out meteorological observations, and also used the tower to perform experiments on the action of air resistance on falling bodies.

Subsequent Events

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Panoramic view during ascent of the Eiffel Tower by the Lumière brothers, 1898

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Franz Reichelt’s preparations and jump from the Eiffel Tower

For the 1900 Exposition Universelle, the lifts in the east and west legs were replaced by lifts running as far as the second level constructed by the French firm Fives-Lille. These had a compensating mechanism to keep the floor level as the angle of ascent changed at the first level, and were driven by a similar hydraulic mechanism to the Otis lifts, although this was situated at the base of the tower. Hydraulic pressure was provided by pressurised accumulators located near this mechanism. At the same time the lift in the north pillar was removed and replaced by a staircase to the first level. The layout of both first and second levels was modified, with the space available for visitors on the second level. The original lift in the south pillar was removed 13 years later.

On 19 October 1901, Alberto Santos-Dumont, flying his No.6 airship, won a 100,000-franc prize offered by Henri Deutsch de la Meurthe for the first person to make a flight from St. Cloud to the Eiffel Tower and back in less than half an hour.

Many innovations took place at the Eiffel Tower in the early 20th century. In 1910, Father Theodor Wulf measured radiant energy at the top and bottom of the tower. He found more at the top than expected, incidentally discovering what are known today as cosmic rays. Just two years later, on 4 February 1912, Austrian tailor Franz Reichelt died after jumping from the first level of the tower (a height of 57 metres) to demonstrate his parachute design. In 1914, at the outbreak of World War I, a radio transmitter located in the tower jammed German radio communications, seriously hindering their advance on Paris and contributing to the Allied victory at the First Battle of the Marne. From 1925 to 1934, illuminated signs for Citroën adorned three of the tower’s sides, making it the tallest advertising space in the world at the time. In April 1935, the tower was used to make experimental low-resolution television transmissions, using a shortwave transmitter of 200 watts power. On 17 November, an improved 180-line transmitter was installed.

On two separate but related occasions in 1925, the con artist Victor Lustig “sold” the tower for scrap metal. A year later, in February 1926, pilot Leon Collet was killed trying to fly under the tower. His aircraft became entangled in an aerial belonging to a wireless station. A bust of Gustave Eiffel by Antoine Bourdelle was unveiled at the base of the north leg on 2 May 1929. In 1930, the tower lost the title of the world’s tallest structure when the Chrysler Building in New York City was completed. In 1938, the decorative arcade around the first level was removed.

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American soldiers watch the French flag flying on the Eiffel Tower, c. 25 August 1944

Upon the German occupation of Paris in 1940, the lift cables were cut by the French. The tower was closed to the public during the occupation and the lifts were not repaired until 1946. In 1940, German soldiers had to climb the tower to hoist a swastika-centered Reichskriegsflagge, but the flag was so large it blew away just a few hours later, and was replaced by a smaller one. When visiting Paris, Hitler chose to stay on the ground. When the Allies were nearing Paris in August 1944, Hitler ordered General Dietrich von Choltitz, the military governor of Paris, to demolish the tower along with the rest of the city. Von Choltitz disobeyed the order. On 25 June, before the Germans had been driven out of Paris, the German flag was replaced with a Tricolour by two men from the French Naval Museum, who narrowly beat three men led by Lucien Sarniguet, who had lowered the Tricolour on 13 June 1940 when Paris fell to the Germans.

A fire started in the television transmitter on 3 January 1956, damaging the top of the tower. Repairs took a year, and in 1957, the present radio aerial was added to the top. In 1964, the Eiffel Tower was officially declared to be a historical monument by the Minister of Cultural Affairs, André Malraux. A year later, an additional lift system was installed in the north pillar.

According to interviews, in 1967, Montreal Mayor Jean Drapeau negotiated a secret agreement with Charles de Gaulle for the tower to be dismantled and temporarily relocated to Montreal to serve as a landmark and tourist attraction during Expo 67. The plan was allegedly vetoed by the company operating the tower out of fear that the French government could refuse permission for the tower to be restored in its original location.

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Base of the Eiffel Tower

In 1982, the original lifts between the second and third levels were replaced after 97 years in service. These had been closed to the public between November and March because the water in the hydraulic drive tended to freeze. The new cars operate in pairs, with one counterbalancing the other, and perform the journey in one stage, reducing the journey time from eight minutes to less than two minutes. At the same time, two new emergency staircases were installed, replacing the original spiral staircases. In 1983, the south pillar was fitted with an electrically driven Otis lift to serve the Jules Verne restaurant. The Fives-Lille lifts in the east and west legs, fitted in 1899, were extensively refurbished in 1986. The cars were replaced, and a computer system was installed to completely automate the lifts. The motive power was moved from the water hydraulic system to a new electrically driven oil-filled hydraulic system, and the original water hydraulics were retained solely as a counterbalance system. A service lift was added to the south pillar for moving small loads and maintenance personnel three years later.

Robert Moriarty flew a Beechcraft Bonanza under the tower on 31 March 1984. In 1987, A.J. Hackett made one of his first bungee jumps from the top of the Eiffel Tower, using a special cord he had helped develop. Hackett was arrested by the police. On 27 October 1991, Thierry Devaux, along with mountain guide Hervé Calvayrac, performed a series of acrobatic figures while bungee jumping from the second floor of the tower. Facing the Champ de Mars, Devaux used an electric winch between figures to go back up to the second floor. When firemen arrived, he stopped after the sixth jump.

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The tower is the focal point of New Year’s Eve and Bastille Day (14 July) celebrations in Paris.

For its “Countdown to the Year 2000” celebration on 31 December 1999, flashing lights and high-powered searchlights were installed on the tower. Fireworks were set off all over it. An exhibition above a cafeteria on the first floor commemorates this event. The searchlights on top of the tower made it a beacon in Paris’s night sky, and 20,000 flashing bulbs gave the tower a sparkly appearance for five minutes every hour on the hour.

The lights sparkled blue for several nights to herald the new millennium On 31 December 2000. The sparkly lighting continued for 18 months until July 2001. The sparkling lights were turned on again on 21 June 2003, and the display was planned to last for 10 years before they needed replacing.

The tower received its 200,000,000th guest on 28 November 2002. The tower has operated at its maximum capacity of about 7 million visitors since 2003. In 2004, the Eiffel Tower began hosting a seasonal ice rink on the first level. A glass floor was installed on the first level during the 2014 refurbishment.

Design


Material

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The Eiffel Tower from below

The puddled iron (wrought iron) of the Eiffel Tower weighs 7,300 tons, and the addition of lifts, shops and antennae have brought the total weight to approximately 10,100 tons. As a demonstration of the economy of design, if the 7,300 tons of metal in the structure were melted down, it would fill the square base, 125 metres (410 ft) on each side, to a depth of only 6.25 cm (2.46 in) assuming the density of the metal to be 7.8 tons per cubic metre. Additionally, a cubic box surrounding the tower (324 m x 125 m x 125 m) would contain 6,200 tons of air, weighing almost as much as the iron itself. Depending on the ambient temperature, the top of the tower may shift away from the sun by up to 18 cm (7 in) due to thermal expansion of the metal on the side facing the sun.

Wind Considerations

When it was built, many were shocked by the tower’s daring form. Eiffel was accused of trying to create something artistic with no regard to the principles of engineering. However, Eiffel and his team – experienced bridge builders – understood the importance of wind forces, and knew that if they were going to build the tallest structure in the world, they had to be sure it could withstand them. In an interview with the newspaper Le Temps published on 14 February 1887, Eiffel said:

Is it not true that the very conditions which give strength also conform to the hidden rules of harmony? … Now to what phenomenon did I have to give primary concern in designing the Tower? It was wind resistance. Well then! I hold that the curvature of the monument’s four outer edges, which is as mathematical calculation dictated it should be … will give a great impression of strength and beauty, for it will reveal to the eyes of the observer the boldness of the design as a whole.

He used graphical methods to determine the strength of the tower and empirical evidence to account for the effects of wind, rather than a mathematical formula. Close examination of the tower reveals a basically exponential shape. All parts of the tower were over-designed to ensure maximum resistance to wind forces. The top half was even assumed to have no gaps in the latticework. In the years since it was completed, engineers have put forward various mathematical hypotheses in an attempt to explain the success of the design. The most recent, devised in 2004 after letters sent by Eiffel to the French Society of Civil Engineers in 1885 were translated into English, is described as a non-linear integral equation based on counteracting the wind pressure on any point of the tower with the tension between the construction elements at that point.

The Eiffel Tower sways by up to 9 centimetres (3.5 in) in the wind.

Accommodation

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Gustave Eiffel’s apartment

When originally built, the first level contained three restaurants—one French, one Russian and one Flemish—and an “Anglo-American Bar”. After the exposition closed, the Flemish restaurant was converted to a 250-seat theatre. A promenade 2.6-metre (8 ft 6 in) wide ran around the outside of the first level. At the top, there were laboratories for various experiments, and a small apartment reserved for Gustave Eiffel to entertain guests, which is now open to the public, complete with period decorations and lifelike mannequins of Eiffel and some of his notable guests.

In May 2016, an apartment was created on the first level to accommodate four competition winners during the UEFA Euro 2016 football tournament in Paris in June. The apartment has a kitchen, two bedrooms, a lounge, and views of Paris landmarks including the Seine, the Sacre Coeur, and the Arc de Triomphe.

Passenger Lifts

The arrangement of the lifts has been changed several times during the tower’s history. Given the elasticity of the cables and the time taken to align the cars with the landings, each lift, in normal service, takes an average of 8 minutes and 50 seconds to do the round trip, spending an average of 1 minute and 15 seconds at each level. The average journey time between levels is 1 minute. The original hydraulic mechanism is on public display in a small museum at the base of the east and west legs. Because the mechanism requires frequent lubrication and maintenance, public access is often restricted. The rope mechanism of the north tower can be seen as visitors exit the lift.

Engraved Names

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Names engraved on the tower

Gustave Eiffel engraved on the tower the names of 72 French scientists, engineers and mathematicians in recognition of their contributions to the building of the tower. Eiffel chose this “invocation of science” because of his concern over the artists’ protest. At the beginning of the 20th century, the engravings were painted over, but they were restored in 1986–87 by the Société Nouvelle d’exploitation de la Tour Eiffel, a company operating the tower.

Aesthetics

The tower is painted in three shades: lighter at the top, getting progressively darker towards the bottom to perfectly complement the Parisian sky. It was originally reddish brown; this changed in 1968 to a bronze colour known as “Eiffel Tower Brown”.

The only non-structural elements are the four decorative grill-work arches, added in Sauvestre’s sketches, which served to make the tower look more substantial and to make a more impressive entrance to the exposition.

One of the great Hollywood movie clichés is that the view from a Parisian window always includes the tower. In reality, since zoning restrictions limit the height of most buildings in Paris to seven storeys, only a small number of tall buildings have a clear view of the tower.

Maintenance

Maintenance of the tower includes applying 60 tons of paint every seven years to prevent it from rusting. The tower has been completely repainted at least 19 times since it was built. Lead paint was still being used as recently as 2001 when the practice was stopped out of concern for the environment.

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Panorama of Paris and its suburbs from the top of the Eiffel Tower

Tourism


Transport

The nearest Paris Métro station is Bir-Hakeim and the nearest RER station is Champ de Mars-Tour Eiffel. The tower itself is located at the intersection of the quai Branly and the Pont d’Iéna.

Popularity

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Number of visitors per year between 1889 and 2004

More than 250 million people have visited the tower since it was completed in 1889. In 2015, there were 6.91 million visitors. The tower is the most-visited paid monument in the world. An average of 25,000 people ascend the tower every day which can result in long queues. Tickets can be purchased online to avoid the long queues.

Restaurants

The tower has two restaurants: Le 58 Tour Eiffel on the first level, and Le Jules Verne, a gourmet restaurant with its own lift on the second level. This restaurant has one star in the Michelin Red Guide. It is run by the multi-Michelin star chef Alain Ducasse and owes its name to the famous science-fiction writer Jules Verne. Additionally, there is a champagne bar at the top of the Eiffel Tower.

Replicas

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Replica at the Paris Las Vegas Hotel, Nevada, United States

As one of the most iconic landmarks in the world, the Eiffel Tower has been the inspiration for the creation of many replicas and similar towers. An early example is Blackpool Tower in England. The mayor of Blackpool, Sir John Bickerstaffe, was so impressed on seeing the Eiffel Tower at the 1889 exposition that he commissioned a similar tower to be built in his town. It opened in 1894 and is 158.1 metres (518 ft) tall. Tokyo Tower in Japan, built as a communications tower in 1958, was also inspired by the Eiffel Tower.

There are various scale models of the tower in the United States, including a half-scale version at the Paris Las Vegas, Nevada, one in Paris, Texas built in 1993, and two 1:3 scale models at Kings Island, Ohio, and Kings Dominion, Virginia, amusement parks opened in 1972 and 1975 respectively. Two 1:3 scale models can be found in China, one in Durango, Mexico that was donated by the local French community, and several across Europe.

In 2011, the TV show Pricing the Priceless on the National Geographic Channel speculated that a full-size replica of the tower would cost approximately US$480 million to build.

Communications


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Top of the Eiffel Tower

The tower has been used for making radio transmissions since the beginning of the 20th century. Until the 1950s, sets of aerial wires ran from the cupola to anchors on the Avenue de Suffren and Champ de Mars. These were connected to longwave transmitters in small bunkers. In 1909, a permanent underground radio centre was built near the south pillar, which still exists today. On 20 November 1913, the Paris Observatory, using the Eiffel Tower as an aerial, exchanged wireless signals with the United States Naval Observatory, which used an aerial in Arlington, Virginia. The object of the transmissions was to measure the difference in longitude between Paris and Washington, D.C. Today, radio and digital television signals are transmitted from the Eiffel Tower.

FM Radio

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Digital Television

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A television antenna was first installed on the tower in 1957, increasing its height by 18.7 m (61.4 ft). Work carried out in 2000 added a further 5.3 m (17.4 ft), giving the current height of 324 m (1,063 ft). Analogue television signals from the Eiffel Tower ceased on 8 March 2011.

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The Eiffel Tower illuminated in 2015

The tower and its image have long been in the public domain. In June 1990 a French court ruled that a special lighting display on the tower in 1989 to mark the tower’s 100th anniversary was an “original visual creation” protected by copyright. The Court of Cassation, France’s judicial court of last resort, upheld the ruling in March 1992. The Société d’Exploitation de la Tour Eiffel (SETE) now considers any illumination of the tower to be a separate work of art that falls under copyright. As a result, the SNTE alleges that it is illegal to publish contemporary photographs of the lit tower at night without permission in France and some other countries for commercial use.

The imposition of copyright has been controversial. The Director of Documentation for what was then called the Société Nouvelle d’exploitation de la Tour Eiffel (SNTE), Stéphane Dieu, commented in 2005: “It is really just a way to manage commercial use of the image, so that it isn’t used in ways [of which] we don’t approve”. SNTE made over €1 million from copyright fees in 2002. However, it could also be used to restrict the publication of tourist photographs of the tower at night, as well as hindering non-profit and semi-commercial publication of images of the illuminated tower.

French doctrine and jurisprudence allows pictures incorporating a copyrighted work as long as their presence is incidental or accessory to the subject being represented, a reasoning akin to the de minimis rule. Therefore, SETE may be unable to claim copyright on photographs of Paris which happen to include the lit tower.

Taller Structures


The Eiffel Tower was the world’s tallest structure when completed in 1889, a distinction it retained until 1929 when the Chrysler Building in New York City was topped out. The tower has lost its standing both as the world’s tallest structure and the world’s tallest lattice tower but retains its status as the tallest freestanding (non-guyed) structure in France.

Lattice Towers taller than the Eiffel Tower

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Structures in France taller than the Eiffel Tower

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