Eiffel Tower

Eiffel Tower
Paris 06 Eiffelturm 4828.jpg

The Eiffel Tower as seen from the Champ de Mars

Information
Location Paris, France
Status Complete
Constructed 1887 – 1889
Use Observation tower
Radio broadcasting tower
Height
Antenna/Spire 324 metres (1,063 ft)
Roof 300.65 metres (986 ft)
Companies
Architect Gustave Eiffel
Structural
Engineer
Gustave Eiffel

The Eiffel Tower (French: Tour Eiffel, /tuʀ ɛfɛl/) is an iron tower built on the Champ de Mars beside the Seine River in Paris. The tower has become a global icon of France and is one of the most recognizable structures in the world.

Contents

Introduction

Named after its designer, engineer Gustave Eiffel, the Eiffel Tower is the tallest building in Paris.[1] More than 200,000,000 people have visited the tower since its construction in 1889,[2] including 6,719,200 in 2006,[3] making it the most visited paid monument in the world.[4][5] Including the 24 m (79 ft) antenna, the structure is 325 m (1,063 ft) high (since 2000), which is equivalent to about 81 levels in a conventional building.

Eiffel Tower October 2007

When the tower was completed in 1889 it was the world's tallest tower — a title it retained until 1930 when New York City's Chrysler Building (319 m — 1,047 ft tall) was completed.[6] The tower is now the fifth-tallest structure in France and the tallest structure in Paris, with the second-tallest being the Tour Montparnasse (210 m — 689 ft), although that will soon be surpassed by Tour AXA (225.11 m — 738.36 ft).

Eiffel Tower from the neighborhood.

The metal structure of the Eiffel Tower weighs 7,300 tonnes while the entire structure including non-metal components is approximately 10,000 tonnes. Depending on the ambient temperature, the top of the tower may shift away from the sun by up to 18 cm (7 in) because of thermal expansion of the metal on the side facing the sun. The tower also sways 6–7 cm (2–3 in) in the wind.[3] As demonstration of the economy of design, if the 7300 tonnes of the metal structure were melted down it would fill the 125 meter square base to a depth of only 6 cm (2.36 in), assuming a density of the metal to be 7.8 tonnes per cubic meter. The tower has a mass less than the mass of the air contained in a cylinder of the same dimensions,[7] that is 324 meters high and 88.3 meters in radius. The weight of the tower is 10,100 tonnes compared to 10,265 tonnes of air.

The first and second levels are accessible by stairways and lifts. A ticket booth at the south tower base sells tickets to access the stairs which begin at that location. At the first platform the stairs continue up from the east tower and the third level summit is only accessible by lift. From the first or second platform the stairs are open for anyone to ascend or descend regardless of whether they have purchased a lift ticket or stair ticket. The actual count of stairs includes 9 steps to the ticket booth at the base, 328 steps to the first level, 340 steps to the second level and 18 steps to the lift platform on the second level. When exiting the lift at the third level there are 15 more steps to ascend to the upper observation platform. The step count is printed periodically on the side of the stairs to give an indication of progress of ascent. The majority of the ascent allows for an unhindered view of the area directly beneath and around the tower although some short stretches of the stairway are enclosed.

Maintenance of the tower includes applying 50 to 60 tonnes of paint every seven years to protect it from rust. In order to maintain a uniform appearance to an observer on the ground, three separate colors of paint are used on the tower, with the darkest on the bottom and the lightest at the top. On occasion the colour of the paint is changed; the tower is currently painted a shade of brownish-grey.[8] On the first floor there are interactive consoles hosting a poll for the colour to use for a future session of painting. The co-architects of the Eiffel Tower are Emile Nouguier, Maurice Koechlin and Stephen Sauvestre.[9]

History

Eiffel Tower under construction in July 1888.

The structure was built between 1887 and 1889 as the entrance arch for the Exposition Universelle, a World's Fair marking the centennial celebration of the French Revolution. Eiffel originally planned to build the tower in Barcelona, for the Universal Exposition of 1888, but those responsible at the Barcelona city hall thought it was a strange and expensive construction, which did not fit into the design of the city. After the refusal of the Consistory of Barcelona, Eiffel submitted his draft to those responsible for the Universal Exhibition in Paris, where he would build his tower a year later, in 1889. The tower was inaugurated on 31 March 1889, and opened on 6 May. Three hundred workers joined together 18,038 pieces of puddled iron (a very pure form of structural iron), using two and a half million rivets, in a structural design by Maurice Koechlin. The risk of accident was great, for unlike modern skyscrapers the tower is an open frame without any intermediate floors except the two platforms. However, because Eiffel took safety precautions, including the use of movable stagings, guard-rails and screens, only one man died.

Eiffel Tower Construction view: girders at the first story

The tower was met with much criticism from the public when it was built, with many calling it an eyesore. Newspapers of the day were filled with angry letters from the arts community of Paris. One is quoted extensively in William Watson's US Government Printing Office publication of 1892 Paris Universal Exposition: Civil Engineering, Public Works, and Architecture. “And during twenty years we shall see, stretching over the entire city, still thrilling with the genius of so many centuries, we shall see stretching out like a black blot the odious shadow of the odious column built up of riveted iron plates.”[10] Signers of this letter included Messonier, Gounod, Garnier, Gerome, Bougeureau, and Dumas.

Novelist Guy de Maupassant — who claimed to hate the tower — supposedly ate lunch in the Tower's restaurant every day. When asked why, he answered that it was the one place in Paris where one could not see the structure. Today, the Tower is widely considered to be a striking piece of structural art.

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 7 stories, only a very few of the taller buildings have a clear view of the tower.

Eiffel had a permit for the tower to stand for 20 years, meaning it would have had 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 could be easily demolished) but as the tower proved valuable for communication purposes, it was allowed to remain after the expiration of the permit. The military used it to dispatch Parisian taxis to the front line during the First Battle of the Marne, and it therefore became a victory statue of that battle.

Shape of the tower

Looking up at the Eiffel Tower.

At the time the tower was built many people were shocked by its daring shape. Eiffel was criticised for the design and accused of trying to create something artistic, or inartistic according to the viewer, without regard to engineering. Eiffel and his engineers, as renowned bridge builders however, 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 certain it would withstand the wind. In an interview reported in the newspaper Le Temps, Eiffel said:

Now to what phenomenon did I 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.

—translated from the French newspaper Le Temps of 14 February 1887[11]

The shape of the tower was therefore determined by mathematical calculation involving wind resistance. Several theories of this mathematical calculation have been proposed over the years, the most recent is a nonlinear integral differential equation based on counterbalancing the wind pressure on any point on the tower with the tension between the construction elements at that point. That shape is exponential. A careful plot of the tower curvature however, reveals two different exponentials, the lower section having a stronger resistance to wind forces.[12][13]

Installations

Communications

The Eiffel tower and the Seine at night
The Eiffel tower illuminated in blue to celebrate the French presidency of the EU (July 2008.)

Since the beginning of the 20th century, the tower has been used for radio transmission. Until the 1950s, an occasionally modified set of antenna wires ran from the summit to anchors on the Avenue de Suffren and Champ de Mars. They were connected to long-wave transmitters in small bunkers; in 1909, a permanent underground radio centre was built near the south pillar and still exists today. On 20 November 1913, the Paris Observatory, using the Eiffel Tower as an antenna, exchanged sustained wireless signals with the United States Naval Observatory which used an antenna in Arlington, Virginia. The object of the transmissions was to measure the difference in longitude between Paris and Washington, D.C.[14]

Restaurants

The tower has two restaurants: Altitude 95, on the first floor (95 m, 311 ft, above sea level); and the Jules Verne, an expensive gastronomical restaurant on the second floor, with a private lift. This restaurant has one star in the Michelin Red Guide. In January 2007, a new multi-Michelin star chef Alain Ducasse was brought in to run Jules Verne.[15]

Passenger Lifts

Ground to Second level

[16] [17] The original lifts to the first and second floors were provided by two companies. Both companies had to overcome many technical obstacles as neither company (or indeed any company) had experience with installing lifts climbing to such heights with large loads. The slanting tracks with changing angles further complicated the problems. The East and West lifts were supplied by the French company Roux Combaluzier Lepape, using hydraulically powered chains and rollers. Contemporary engravings of the lift cars show that the passengers were seated at this time but it is not clear whether this was conceptual. It would be unnecessary to seat passengers for a journey time of around a couple of minutes. The North and South lifts were provided by the American Otis company using car designs similar to the original installation but using an improved hydraulic and cable scheme. The French lifts had a very poor performance and were replaced with the current installations in 1897 (West Pillar) and 1899 (East Pillar) by Fives-Lille using an improved hydraulic and rope scheme. Both of the original installations operated broadly on the principle of the Fives-Lille lifts.

The Fives-Lille lifts from ground level to the first and second levels are operated by cables and pulleys driven by massive water-powered pistons. The hydraulic scheme was somewhat unusual for the time in that it included three large counterweights of 200 tonnes each sitting on top of hydraulic rams which doubled up as accumulators for the water. As the lifts ascend the inclined arc of the pillars, the angle of ascent changes. The two lift cabs are kept more or less level and indeed are level at the landings. The cab floors do take on a slight angle at times between landings.

The principle behind the lifts is similar to the operation of a block and tackle but in reverse. Two large hydraulic rams (over 1 metre diameter) with a 16 metre travel are mounted horizontally in the base of the pillar which pushes a carriage (the French word for it translates as chariot and this term will be used henceforth to distinguish it from the lift carriage) with 16 large triple sheaves mounted on it. There are 14 similar sheaves mounted staticly. Six wire ropes are rove back and forth between the sheaves such that each rope passes between the 2 sets of sheaves 7 times. The ropes then leave the final sheaves on the chariot and passes up through a series of guiding sheaves to above the second floor and then via a pair of triple sheaves back down to the lift carriage again passing guiding sheaves.

This arrangement means that the lift carriage complete with its cars and passengers travels 8 times the distance that the rams move the chariot which is the 128 metres from the ground to the second floor. The force exerted by the rams also has to be 8 times the total weight of the lift carriage, cars and passengers plus extra to cater for various losses such as friction. The hydraulic fluid was water, normally stored in the 3 accumulators complete with counterbalance weights. To make the lift ascend, water was pumped using an electrically driven pump from the accumulators to the two rams. Since the counterbalance weights provided much of the pressure required, the pump only had to provide the extra effort. For the descent, it was only necessary to allow the water to flow back to the accumulators using a control valve. The lifts were operated by an operator perched precariously underneath the lift cars. His position (with a dummy operator) can still be seen on the lifts today.

The Fives-Lille lifts were completely upgraded in 1986 to meet modern safety requirments and to make the lifts easier to operate. A new computer controlled system was installed which completely automated the operation. One of the three counterbalances was taken out of use, and the cars were replaced with a more modern and lighter structure. Most importantly, the main driving force was removed from the original water pump such that the water hydraulic system provided only a counerbalancing function. The main driving force was transferred to a 320 kW electrically driven oil hydraulic pump which drives a pair of hydraulic motors on the chariot itself thus providing the motive power. The new lift cars complete with their carriage and a full 92 passenger load weigh 22 tonnes.

Due to elasticity in the ropes and the time taken to get the cars level 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 floor. The average journey time between floors is just 1 minute.

The original Otis lifts in the North and South pillars in their turn proved inferior to the new (in 1899) French lifts and were scrapped from the south pillar in 1900 and from the north pillar in 1913 after failed attempts to re-power them with an electric motor. The north and south pillars were to remain without lifts until 1965 when increasing visitor numbers persuaded the operators to install a relatively standard and modern rope hoisted system in the north pillar using a rope hauled counterbalance weight, but hoisted by a block and tackle system to reduce its travel to one third of the lift travel. The counterbalance is clearly visible within the structure of the North pillar. This latter lift was upgraded in 1995 with new cars and computer controls.

The South tower acquired a completely new fairly standard electrically driven lift in 1983 to serve the Jules Verne restaurant. This was also supplied by Otis.

A further 4 tonne service lift was added to the south pillar in 1989 by Otis to relieve the main lifts when moving relatively small loads or even just maintenance personnel.

The east and west hydraulic (water) lift works are on display and, at least in theory, are open to the public in a small museum located in base of the East and West tower, which is somewhat hidden from public view. Because the massive mechanism requires frequent lubrication and attention, public access is often restricted. However, when open, the wait times are much less than the other, more popular, attractions. The rope mechanism of the North tower is visible to visitors as they exit from the lift.

Second to Third level

The original Hydraulic pump for the Edoux lifts.

The original lift from the second to the third floor were also of a water powered hydraulic design supplied by Léon Edoux. Instead of using a separate counterbalance, the two lift cars counterbalanced each other. A pair of 81 metre long hydraulic rams were mounted on the second level reaching nearly half way up to the third level. A lift car was mounted on top of the rams. Ropes ran from the top of this car up to a sheave on the third level and back down to a second car. The result of this arrangement was that each car only travelled half the distance between the second and third levels and passengers were required to change lifts halfway walking between the cars along a narrow gangway with a very impressive and relatively unobstructed downward view. The 10 tonne cars held 65 passengers each or up to 4 tonnes.

One interesting feature of the original installation was that the hoisting rope ran through guides to retain it on windy days to prevent it flapping and becoming damaged. The guides were mechanically moved out of the way of the ascending car by the movement of the car itself. In spite of some antifreeze being added to the water that operated this system, it nevertheless had to close to the public from November to March each year.

The original spiral stairs to the third floor which were only 80 centimetres wide. Note also the small service lift in the background.

The original lifts complete with their hydraulic mechanism were completely scrapped in 1982 after 97 years of service. They were replaced with two pairs of relatively standard rope hoisted cars which were able to operate all the year round. The cars operate in pairs with one providing the counterbalance for the other. Neither car can move unless both sets of doors are closed and both operators have given a start command. The commands from the cars to the hoising mechanism are by radio obviating the necessity of a control cable. The replacement installation also has the advantage that the ascent can be made without changing cars and has reduced the ascent time from 8 minutes (including change) to 1 minute and 40 seconds. This instalation also has guides for the hoisting ropes but they are electrically operated. The guide once it has moved out of the way as the car ascends automatically reverses when the car has passed to prevent the mechanism becoming snagged on the car on the downward journey in the event it has failed to completely clear the car. Unfortunately these lifts do not have the capacity to move as many people as the 3 public lower lifts and long queues to ascend to the third level are common. Most of the intermediate level structure present on the tower today was installed when the lifts were replaced and allows maintenance workers to take the lift half way.

The replacement of these lifts allowed the restructuring of the criss-cross beams in upper part of the tower and further allowed the installation of two emergency staircases. These replaced the dangerous winding stairs that were installed when the tower was constructed.

Events

Lightning strikes the Eiffel Tower on June 3, 1902, at 9:20 P.M
The Eiffel Tower served as an advertising space for Citroën from 1925 to 1934.
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.

Engraved names

Main article: The 72 names on the Eiffel Tower

Gustave Eiffel engraved on the tower seventy-two names of French scientists, engineers and other notable people. This engraving was painted over at the beginning of the twentieth century but restored in 1986–1987 by the Société Nouvelle d'exploitation de la Tour Eiffel, a company contracted to operate business related to the Tower.

Image copyright claims

Images of the tower have long been in the public domain; however, in 2003 SNTE (Société nouvelle d'exploitation de la tour Eiffel) installed a new lighting display on the tower. The effect was to put any night-time image of the tower and its lighting display under copyright. As a result, it was no longer legal to publish contemporary photographs of the tower at night without permission in some countries.[23][24]

The imposition of copyright has been controversial. The Director of Documentation for SNTE, Stéphane Dieu, commented in January 2005, "It is really just a way to manage commercial use of the image, so that it isn't used in ways we don't approve." However, it also potentially has the effect of prohibiting tourist photographs of the tower at night from being published[25] as well as hindering non profit and semi-commercial publication of images of the tower.

In a recent decision, the Court of Cassation ruled that copyright could not be claimed over images including a copyrighted building if the photograph encompassed a larger area. This seems to indicate that SNTE cannot claim copyright on photographs of Paris incorporating the lit tower.

In some jurisdictions, this claim of copyright is explicitly disallowed. In Irish copyright law, works "permanently situated in a public place or in premises open to the public" may be freely included in visual reproductions.[26]

In popular culture

Main article: Eiffel Tower in popular culture
Panoramic view from underneath the Eiffel Tower.

As a global landmark, the Eiffel Tower is featured in media including films, video games, and television shows.

Lattice towers taller than the Eiffel Tower

Name Pinnacle height Year Country Town Remarks
Kiev TV Tower 1263 ft 385 m 1973 Ukraine Kiev Tallest lattice tower of the world
Tashkent Tower 1230 ft 374.9 m 1985 Uzbekistan Tashkent
Pylons of Yangtze River Crossing 1137 ft 346.5m 2003 People’s Republic of China Jiangyin 2 towers, tallest pylons in the world
Dragon Tower 1102 ft 336 m 2000 People’s Republic of China Harbin
Tokyo Tower 1091 ft 332.6 m 1958 Japan Tokyo
WITI TV Tower 1078 ft 329 m 1962 U.S. Shorewood, Wisconsin
WSB TV Tower 1075 ft 327.6 m 1957 U.S. Atlanta, Georgia

Architectural structures in France taller than the Eiffel Tower

Name Pinnacle height Year Structure type Town Remarks
Longwave transmitter Allouis 350 m 1974 Guyed Mast Allouis
HWU transmitter 350 m  ? Guyed Mast Rosnay Multiple masts
Viaduc de Millau 343 m 2004 Bridge Pillar Millau
TV Mast Niort-Maisonnay 330 m  ? Guyed Mast Niort
Transmitter Le Mans-Mayet 342 m 1993 Guyed Mast Mayet
Transmitter Roumoules 330 m 1974 Guyed Mast Roumoules spare transmission mast for long wave, insulated against ground

Reproductions

Replica at Kings Island near Cincinnati, Ohio
Replica of Eiffel Tower on factory building at Satteldorf near Crailsheim, Germany

In order of decreasing height:

Broadcasting stations

FM-radio

Programme Frequency ERP
France Inter
Regional 90,35 MHz 3 kW
France Culture 93,35 MHz 3 kW
France Musique 97,6 MHz 3 kW

TV

Programme Channel-Number Frequency ERP
Canal+ 6 182,25 MHz 100 kW
France 2 22 479,25 MHz 500 kW
TF1 25 503,25 MHz 500 kW
France 3 28 527,25 MHz 500 kW
France 5 30 543,25 MHz 100 kW
M6 33 567,25 MHz 100 kW

Other structures carrying this name

See also

References

  1. The Eiffel Tower as a World monument
  2. Number of visitors since 1889
  3. 3.0 3.1 A few statistics
  4. The Guardian: New look for Eiffel Tower
  5. LeMonde.fr : Tour Eiffel et souvenirs de Paris
  6. "ThinkQuest article on the Eiffel Tower".
  7. The Eiffel Tower Official Website
  8. Painting the Eiffel Tower
  9. Conception and design of the Eiffel Tower
  10. William Watson, Paris Universal Exposition: Civil Engineering, Public Works, and Architecture (Washington: Government Printing office, 1892), 833.
  11. Extrait de la réponse d'Eiffel
  12. Elegant Shape Of Eiffel Tower Solved Mathematically By University Of Colorado Professor
  13. The Virginia Engineer: Correct Theory Explaining The Eiffel Tower’s Design Revealed
  14. "Paris Time By Wireless," New York Times, 22 November 1913, pg 1.
  15. Paris France Guide: Paris Hotels, Food, Wine and Discounts - The Eiffel Tower Breaking News
  16. http://www.tour-eiffel.fr/teiffel/uk/documentation/dossiers/page/construction.html
  17. Société nouvelle d'exploitation de la tour Eiffel
  18. Wulf, Theodor. Physikalische Zeitschrift, contains results of the four-day long observation done by Theodor Wulf while at the top of the Eiffel Tower in 1910.
  19. "A Bonanza in Paris". Retrieved on 2008-04-04.
  20. http://www.smh.com.au/news/world/extreme-bid-to-stretch-bungy-record/2007/02/27/1172338606150.html
  21. "The Eiffel Tower: Paris' Grande Dame". france.com. Retrieved on 2007-07-24.
  22. "Soirée réussie le 28 novembre pour fêter l'année du 200 millionième visiteur" (in French). Official Site (2002). Retrieved on 2007-07-24.
  23. Statement that publishing pictures of the lighting requires a fee
  24. In the United States, for example, 17 USC 120(a) explicitly permits the publication of photographs of copyrighted architecture in public spaces. In Germany this is known as Panoramafreiheit.
  25. Eiffel Tower: Repossessed
  26. Irish Statute Books — Representation of certain artistic works on public display
  27. Reuters.com
  28. Le Figaro – Actualité en direct et informations en continu
  29. Disney's official French Pavilion page — lists the Eiffel Tower as approximately 1/10th the height of the original.
  30. Eiffel Tower
  31. :: Falconcity of Wonders (L.L.C) ::
  32. First World Plaza. Retrieved on 2008-09-13
  33. Tower model at Filiatra
  34. Photograph of Filiatra tower
  35. LUGNET Set Guide
  36. Eiffel Tower Co-op — SkyscraperPage.com

Further reading

Gallery

External links

Preceded by
Washington Monument
World's tallest structure
1889—1931
300.24m
Succeeded by
Chrysler Building