Sabtu, 29 Oktober 2011

Eiffel Tower

History

Vue Lumière No 992 - Panorama pendant l'ascension de la Tour Eiffel (1898).ogv
Panoramic view during ascension of the Eiffel Tower by the Lumière brothers, 1898

25 August 1944: American soldiers watch as the Tricolor flies from the Eiffel Tower again.
A video of the jump
Franz Reichelt's preparations and fall from the Eiffel Tower.

Lightning strikes the Eiffel Tower on 3 June 1902, at 9:20 pm

Adolf Hitler with the Eiffel Tower in the background
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. 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. Eiffel was assisted in the design by engineers Émile Nouguier and Maurice Koechlin and architect Stephen Sauvestre.[11] The risk of accident was great as, 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. The tower was inaugurated on 31 March 1889, and opened on 6 May.
The tower was much criticised by 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."[12] Signers of this letter included Jean-Louis-Ernest Meissonier, Charles Gounod, Charles Garnier, Jean-Léon Gérôme, William-Adolphe Bouguereau, and Alexandre Dumas.
Novelist Guy de Maupassant—who claimed to hate the tower[13]—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; 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 could be easily demolished) but as the tower proved valuable for communication purposes, it was allowed to remain after the expiry of the permit. The military used it to dispatch Parisian taxis to the front line during the First Battle of the Marne.

Timeline of events

10 September 1889
Thomas Edison visited the tower. He signed the guestbook with the following 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.
1910
Father Theodor Wulf measured radiant energy at the top and bottom of the tower, discovering at the top more than was expected, and thereby detecting what are today known as cosmic rays.[14]
4 February 1912
Austrian tailor Franz Reichelt died after jumping 60 metres from the first deck of Eiffel tower with his home-made parachute.
1914
A radio transmitter located in the tower jammed German radio communications during the lead-up to the First Battle of the Marne.
1925
The con artist Victor Lustig "sold" the tower for scrap metal on two separate, but related occasions.[15]
1930
The tower lost the title of the world's tallest structure when the Chrysler Building was completed in New York City.
1925 to 1934
Illuminated signs for Citroën adorned three of the tower's four sides, making it the tallest advertising space in the world at the time.
1940–1944
[citation needed] Upon the German occupation of Paris in 1940, the lift cables were cut by the French so that Adolf Hitler would have to climb the steps to the summit. The parts to repair them were allegedly impossible to obtain because of the war. In 1940 German soldiers had to climb to the top to hoist the swastika, 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. It was said that Hitler conquered France, but did not conquer the Eiffel Tower. A Frenchman scaled the tower during the German occupation to hang the French flag. In August 1944, when the Allies were nearing Paris, 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. Some say Hitler was later persuaded to keep the tower intact so it could later be used for communications. The lifts of the Tower were working normally within hours of the Liberation of Paris.
3 January 1956
A fire damaged the top of the tower.
1957
The present radio antenna was added to the top.
1980s
A restaurant and its supporting iron scaffolding midway up the tower was dismantled; it was purchased and reconstructed on St. Charles Avenue and Joesphine Street in the Garden District of New Orleans, Louisiana, by entrepreneurs John Onorio and Daniel Bonnot, originally as the Tour Eiffel Restaurant, later as the Red Room and now as the Cricket Club (owned by the New Orleans Culinary Institute). The restaurant was re-assembled from 11,000 pieces that crossed the Atlantic in a 40-foot (12 m) cargo container.
31 March 1984
Robert Moriarty flew a Beechcraft Bonanza through the arches of the tower.[16]
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 Paris police upon reaching the ground.[17]
27 October 1991
Thierry Devaux, along with mountain guide Hervé Calvayrac, performed a series of acrobatic figures of bungee jump (not allowed) from the second floor of the Tower. Facing the Champ de Mars, Thierry Devaux was using an electric winch between each figure to go back up. When firemen arrived, he stopped after the sixth bungee jump.[18]
New Year's Eve 1999
The Eiffel Tower played host to Paris' Millennium Celebration. On this occasion, flashing lights and four high-power searchlights were installed on the tower, and fireworks were set off all over it. An exhibition above a cafeteria on the first floor commemorates this event. Since then, the light show has become a nightly event. The searchlights on top of the tower make it a beacon in Paris' night sky, and the 20,000 flash bulbs give the tower a sparkly appearance every hour on the hour.[19]
28 November 2002
The tower received its 200,000,000th guest.[20][21]
2004
The Eiffel Tower began hosting an ice skating rink on the first floor each winter.[22]

Engraved names

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.

Design of the tower

Material

The pig iron structure of the Eiffel Tower weighs 7,300 tonnes while the entire structure, including non-metal components, is approximately 10,000 tonnes. As a demonstration of the economy of design, if the 7,300 tonnes of the metal structure were melted down it would fill the 125 metre square base to a depth of only 6 cm (2.36 in), assuming the density of the metal to be 7.8 tonnes per cubic metre. Depending on the ambient temperature, the top of the tower may shift away from the sun by up to 18 cm (7.1 in) because of thermal expansion of the metal on the side facing the sun.

Wind considerations

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, however, as 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 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.[23]
Researchers have found that Eiffel used empirical and graphical methods accounting for the effects of wind rather than a specific mathematical formula. Careful examination of the tower shows a basically exponential shape; actually two different exponentials, the lower section overdesigned to ensure resistance to wind forces. Several mathematical explanations have been proposed over the years for the success of the design; the most recent is described as a nonlinear integral equation based on counterbalancing the wind pressure on any point on the tower with the tension between the construction elements at that point.[24][25] As a demonstration of the tower's effectiveness in wind resistance, it sways only 6–7 cm (2–3 in) in the wind.[24][25][26]

Maintenance

Maintenance of the tower includes applying 50 to 60 tonnes of paint every seven years to protect it from rust. The height of the Eiffel Tower varies by 15 cm due to temperature.

Aesthetic considerations

In order to maintain a uniform appearance to an observer on the ground, three separate colours 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 bronze.[27] On the first floor there are interactive consoles hosting a poll for the colour to use for a future session of painting.
The only non-structural elements are the four decorative grillwork arches, added in Stephen Sauvestre's sketches, which served to reassure visitors that the structure was safe, and to frame views of other nearby architecture.[28][29][30]

Tourism

Popularity

More than 200,000,000 people have visited the tower since its construction in 1889,[31] including 6,719,200 in 2006.[26] The tower is the most-visited paid monument in the world.[32]

Passenger elevators


View of Eiffel Tower from the Montparnasse Tower.

Ground to the second level

The original elevators 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 elevators climbing to such heights with large loads. The slanting tracks with changing angles further complicated the problems. The East and West elevators were supplied by the French company Roux Combaluzier Lepape, using hydraulically powered chains and rollers. The North and South elevators were provided by the American company Otis using car designs similar to the original installation but using an improved hydraulic and cable scheme. The French elevators 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.[33][34]
The Fives-Lille elevators 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 elevators ascend the inclined arc of the pillars, the angle of ascent changes. The two elevator 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 Eiffel Tower illuminated in blue to celebrate the French presidency of the EU (July 2008)
The principle behind the elevators 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 elevator carriage) with 16 large triple sheaves mounted on it. There are 14 similar sheaves mounted statically. 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 elevator carriage, complete with its cars and passengers, travels 8 times the distance that the rams move the chariot, 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 account for various losses such as friction. The hydraulic fluid was water, normally stored in three accumulators, complete with counterbalance weights. To make the elevator 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 elevators were completely upgraded in 1986 to meet modern safety requirements and to make the elevators 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 counterbalancing 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 elevator 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 elevators in the North and South pillars in their turn proved to be inferior to the new (in 1899) French elevators 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 elevators until 1965 when increasing visitor numbers persuaded the operators to install a relatively standard and modern cable hoisted system in the north pillar using a cable-hauled counterbalance weight, but hoisted by a block and tackle system to reduce its travel to one third of the elevator travel. The counterbalance is clearly visible within the structure of the North pillar. This latter elevator was upgraded in 1995 with new cars and computer controls.
The South pillar acquired a completely new fairly standard electrically driven elevator in 1983 to serve the Jules Verne restaurant. This was also supplied by Otis. A further four-ton service elevator was added to the South pillar in 1989 by Otis to relieve the main elevators when moving relatively small loads or even just maintenance personnel.
The East and West hydraulic (water) elevator 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 elevator .

Second to the third level


The original spiral stairs to the third floor which were only 80 centimetres wide. Note also the small service elevator in the background.
The original elevators 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 elevator 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. An elevator 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 elevators halfway walking between the cars along a narrow gangway with a very impressive and relatively unobstructed downward view. The ten-ton cars held 65 passengers each or up to four tons.
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 Hydraulic pump for the Edoux lifts
The original elevators 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 hoisting 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 installation 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 elevators do not have the capacity to move as many people as the three public lower elevators and long lines to ascend to the third level are common. Most of the intermediate level structure present on the tower today was installed when the elevators were replaced and allows maintenance workers to take the elevator half way.
The replacement of these elevators 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.

Restaurants

The tower has two restaurants: Le 58 tour Eiffel, on the first floor 311 ft (95 m) above sea level; and the Le Jules Verne, a gastronomical restaurant on the second floor, with a private lift. This restaurant has one star in the Michelin Red Guide. In January 2007, the multi-Michelin star chef Alain Ducasse was brought in to run Jules Verne.[35]

Attempted relocation

According to interviews given in the early 1980s, Montreal Mayor Jean Drapeau negotiated a secret agreement with French President 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 which operated the tower out of fear that the French government could refuse permission for the tower to be restored to its original location.[36]

Reproductions


Replica at the Paris Las Vegas Hotel, Nevada, United States
As one of the most iconic images in the world, the Eiffel Tower has been the inspiration for the creation of over 30 duplicates and similar towers around the world.

Communications

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.[37] Today, both radio and television stations broadcast their signals from the top of the Eiffel.

FM-radio

Frequency kW Service
87.8 MHz 10 France Inter
89.0 MHz 10 RFI Paris
89.9 MHz 6 TSF Jazz
90.4 MHz 10 Nostalgie
90.9 MHz 4 Chante France

Television

Analogue

Analogue television signals ceased from the Eiffel Tower on 8 March 2011.
Frequency VHF UHF kW Service
182.25 MHz 6 100 Canal+
479.25 MHz 22 500 France 2
503.25 MHz 25 500 TF1
527.25 MHz 28 500 France 3
543.25 MHz 30 100 France 5
567.25 MHz 33 100 M6

Image copyright claims

The tower and its representations have long been in the public domain. However, a French court ruled, in June 1990, that a special lighting display on the tower in 1989, for 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.[38] The Société d'exploitation de la tour Eiffel (SETE) now considers any illumination of the tower to be under copyright.[39] As a result, it is no longer legal to publish contemporary photographs of the tower at night without permission in France and some other countries.
The imposition of copyright has been controversial. The Director of Documentation for what was then the Société nouvelle d'exploitation de la tour Eiffel (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,[40] as well as hindering non-profit and semi-commercial publication of images of the tower. Besides, French doctrine and jurisprudence traditionally allow pictures incorporating a copyrighted work as long as their presence is incidental or accessory to the main represented subject,[41] a reasoning akin to the De minimis rule. Thus, SETE could not claim copyright on photographs of panoramas of Paris incorporating the lit tower.

In popular culture

As a global landmark, the Eiffel Tower is featured in media including films, video games, and television shows.
In a commitment ceremony in 2007, Erika Eiffel, an American woman famously "married" the Eiffel Tower. Her relationship with the tower has been the subject of extensive global publicity.[42]

Taller structures

Although it was the world's tallest structure when completed in 1889, the Eiffel Tower has since lost its standing both as the tallest lattice tower and as the tallest structure in France.

Lattice towers taller than the Eiffel Tower

Name Pinnacle height Year Country Town Remarks
Kiev TV Tower 1,263 ft (385 m) 1973 Ukraine Kiev Tallest lattice tower of the world
Tashkent Tower 1,230 ft (375 m) 1985 Uzbekistan Tashkent
Pylons of Yangtze River Crossing 1,137 ft (347 m) 2003 People's Republic of China Jiangyin 2 towers, tallest pylons in the world
Dragon Tower 1,102 ft (336 m) 2000 People's Republic of China Harbin
Tokyo Tower 1,091 ft (333 m) 1958 Japan Tokyo
WITI TV Tower 1,078 ft (329 m) 1962 U.S. Shorewood, Wisconsin
WSB TV Tower 1,075 ft (328 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 Military VLF-Transmitter, 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
La Regine transmitter 330 m 1973 Guyed Mast Saissac Military VLF transmitter
Transmitter Roumoules 330 m 1974 Guyed Mast Roumoules spare transmission mast for long wave, insulated against ground

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