The Eiffel Tower is a puddle iron lattice tower located on the Champ de Mars in Paris. Built in 1889, it has become both a global icon of France and one of the most recognizable structures in the world. The tower is the tallest building in Paris and the most-visited paid monument in the world; millions of people ascend it every year. Named for its designer, engineer Gustave Eiffel, the tower was built as the entrance arch to the 1889 World's Fair.
The tower stands 324 metres (1,063 ft) tall, about the same height as an 81-storey building. Upon its completion, it surpassed the Washington Monument to assume the title of tallest man-made structure in the world, a title it held for 41 years, until the Chrysler Building in New York City was built in 1930; however, due to the addition in 1957 of the antenna, the tower is now taller than the Chrysler Building. Not including broadcast antennas, it is the second-tallest structure in France after the 2004 Millau Viaduct.
The tower has three levels for visitors. Tickets can be purchased to ascend, by stairs or lift, to the first and second levels. The walk to the first level is over 300 steps, as is the walk from the first to the second level. The third and highest level is accessible only by elevator. Both the first and second levels feature restaurants.
The tower has become the most prominent symbol of both Paris and France, often in the establishing shot of films set in the city.
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. 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." 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—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.
Design of the tower
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.
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 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. 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.
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. Contemporary engravings of the elevators 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 of a couple of minutes. 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.
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 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 .
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 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.
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. The Société d'exploitation de la tour Eiffel (SETE) now considers any illumination of the tower to be under copyright. 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, 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, a reasoning akin to the De minimis rule. Thus, SETE could not claim copyright on photographs of panoramas of Paris incorporating the lit tower.
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