Eiffel Tower | Tourism Sight

The Eiffel Tower (French: La tour Eiffel is an iron lattice tower located on the Champ de Mars in Paris. It was named after the engineer Gustave Eiffel, whose company designed and built the tower. Erected in 1889 as the entrance arch to the 1889 World's Fair, it was initially criticised by some of France's leading artists and intellectuals for its design, but has become both a global cultural icon of France and one of the most recognizable structures in the world. The tower is the tallest structure in Paris and the most-visited paid monument in the world; 6.98 million people ascended it in 2011. The tower received its 250 millionth visitor in 2010.
The tower is 324 metres (1,063 ft) tall, about the same height as an 81-storey building. During its construction, the Eiffel Tower surpassed the Washington Monument to assume the title of the 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. Because of the addition of the aerial atop the Eiffel Tower in 1957, it is now taller than the Chrysler Building by 5.2 metres (17 ft). Not including broadcast aerials, it 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. The third level observatory's upper platform is 276 m (906 ft) above the ground,the highest 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 walk from the first to the second level. Although there are stairs to the third and highest level, these are usually closed to the public and it is generally only accessible by lift.
The design of the Eiffel Tower was originated by Maurice Koechlin and Émile Nouguier, two senior engineers who worked for the Compagnie des Établissements Eiffel, after discussion about a suitable centrepiece for the proposed 1889 Exposition Universelle, a World's Fair which would celebrate the centennial of the French Revolution. In May 1884 Koechlin, working at home, made an outline drawing of their scheme, 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".[3] Initially Eiffel himself showed little enthusiasm, but he did sanction further study of the project, 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, a glass pavilion to the first level, and other embellishments. This enhanced 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 a paper on the project to the Société des Ingiénieurs Civils; after discussing the technical problems and emphasising the practical uses of the tower, he finished his talk by saying that the tower would symbolise
Work on the foundations started on 28 January 1887.[13] Those for the east and south legs were straightforward, each leg resting on four 2 m (6.6 ft) concrete slabs, one for each of the principal girders of each leg but the other two, 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)[14] to support the concrete slabs, which were 6 m (20 ft) thick. Each of these slabs supported a block built of limestone each with an inclined top to bear a supporting shoe for the ironwork. Each shoe was anchored into the stonework by a pair of bolts 10 cm (4 in) in diameter and 7.5 m (25 ft) long. The foundations were complete by 30 June and the erection of the ironwork began. The very visible work on-site was complemented by the enormous amount of exacting preparatory work that was entailed: the drawing office produced 1,700 general drawings and 3,629 detailed drawings of the 18,038 different parts needed.[15] 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 (0.04 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 the factory in the nearby Parisian suburb of Levallois-Perret and were first bolted together, the bolts being replaced by 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 there were 18,038 pieces joined by two and a half million rivets.
The start of the erection of the metalwork
At first the legs were constructed as cantilevers but about halfway to the first level construction was paused in order to construct a substantial timber scaffold. This caused a renewal of the concerns about the structural soundness of the project, and sensational headlines such as "Eiffel Suicide!" and "Gustave Eiffel has gone mad: he has been confined in an Asylum" appeared in the popular press.At this stage a small "creeper" crane was installed in each leg, designed to move up the tower as construction progressed and making use of the guides for the lifts which were to be fitted in each leg. The critical stage of joining the four legs at the first level was complete by the end of March 1888. Although the metalwork had been prepared with the utmost precision, 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, each capable of exerting a force of 800 tonnes, and in addition the legs had been intentionally constructed at a slightly steeper angle than necessary, being supported by sandboxes on the scaffold. Although construction involved 300[13] on-site employees, only one person died thanks to Eiffel's stringent safety precautions and use of movable stagings, guard-rails, and screens.

The lifts to the second platform presented a more complex problem, because a straight track was not possible. No French company was willing 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.[19] Otis had been confident that they would eventually be given the contract and had already started design studies. The car was divided into two superimposed compartments, each holding 25 passengers, with the lift operator occupying an exterior platform on the lower level. Motive power was provided by an inclined hydraulic ram, 12.67 m (36 ft) long 96.5 cm (38 in) diameter 10.83 m 35 ft 6 in stroke in the tower leg: 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 platform. 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 from the second to the third floor 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 then 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 ten-ton cars held 65 passengers each
At the time the tower was built many people were shocked by its daring shape. Eiffel was accused of trying to create something artistic without regard to engineering. However, Eiffel and his engineers, 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 them. In an interview with the newspaper Le Temps (Paris) of 14 February 1887, Eiffel said
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. As proof of the tower's effectiveness in wind resistance, it sways only 6–7 cm (2–3 in) in the wind.
As described the arrangement of the lifts has been changed several times during the course of the Tower's history.
Owing to the elasticity of the cables 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 1899 east and west hydraulic mechanism works are on display to the public in a small museum in the base of the east and west towers, which is somewhat hidden from public view. Because the massive mechanism requires frequent lubrication and attention, public access is often restricted. The rope mechanism of the north tower is visible to visitors as they exit from the lift.
Engraved names
Main article: List of the 72 names on the Eiffel Tower
A few of the names on the tower
Gustave Eiffel engraved on the tower seventy-two names of French scientists, engineers, and mathematicians in recognition of their contributions. Eiffel chose this "invocation of science" because of his concern over the artists' protests against the tower. 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.
The tower and its representations have long been in the public domain. However, in June 1990 a French court ruled that a special lighting display on the tower in 1989 (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.[63] The Société d'Exploitation de la Tour Eiffel (SETE) now considers any illumination of the tower to be under copyright.[64] 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 could be used to prohibit tourist photographs of the tower at night from being published,[citation needed] as well as hindering non-profit and semi-commercial publication of images of the tower. 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,[65] a reasoning akin to the de minimis rule. Thus, SETE could not claim copyright on, for example, photographs or panoramas of Paris including the lit tower.