Editing Eiffel Tower (section)

==Design==
===Material===
[[File:Sous la Tour Eiffel 1.jpg|thumb|The Eiffel Tower from below]]

The [[Puddling (metallurgy)|puddle iron]] (wrought iron) of the Eiffel Tower weighs 7,300 [[tonne]]s,<ref name="Hanser2006">{{cite book|author=David A. Hanser|title=Architecture of France|url=https://books.google.com/books?id=zojzUU976h0C&pg=PA66|year=2006|publisher=Greenwood Publishing Group|isbn=978-0-313-31902-0|page=66}}</ref> and the addition of lifts, shops and antennae have brought the total weight to approximately 10,100&nbsp;tonnes.<ref>{{cite book|title=DK Eyewitness Travel Guide: Europe|url=https://books.google.com/books?id=AiYCSa4U6UYC&pg=PA163|year=2012|publisher=Dorling Kindersley|isbn=978-1-4093-8577-6|page=163}}</ref> As a demonstration of the economy of design, if the 7,300&nbsp;tonnes of metal in the structure were melted down, it would fill the square base, {{convert|125|m|ft}} on each side, to a depth of only {{convert|6.25|cm|in|abbr=on}} assuming the density of the metal to be 7.8&nbsp;tonnes per cubic metre.<ref>Harriss, 1976 p.60.</ref> Additionally, a cubic box surrounding the tower (324&nbsp;m&nbsp;×&nbsp;125&nbsp;m&nbsp;×&nbsp;125&nbsp;m) would contain {{Formatnum:6200}}&nbsp;tonnes of air, weighing almost as much as the iron itself. Depending on the [[Room temperature|ambient temperature]], the top of the tower may shift away from the sun by up to {{convert|18|cm|in|round=0.5|abbr=on}} due to [[thermal expansion]] of the metal on the side facing the sun.<ref>Harriss, 1976 p. 231.</ref>

===Wind and weather considerations===
[[File:Lightning striking the Eiffel Tower - NOAA.jpg|thumb|upright=0.8|left|Lightning striking the Eiffel Tower in 1902]]
When it was built, Eiffel was accused of trying to create something artistic with no regard to the principles of engineering. However, Eiffel and his team were experienced bridge builders. In an interview with the newspaper ''[[Le Temps (Paris)|Le Temps]]'' published on 14 February 1887, Eiffel said:

{{blockquote|style=text-align:justify|Is it not true that the very conditions which give strength also conform to the hidden rules of harmony?{{nbsp}}... 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{{nbsp}}... 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.<ref name=debate>{{cite web|url=http://www.toureiffel.paris/en/everything-about-the-tower/themed-files/71.html |title=Debate and controversy surrounding the Eiffel Tower |author=SETE |website=Official Eiffel Tower website |access-date=2 January 2013 |url-status=dead |archive-url=https://web.archive.org/web/20150908052239/http://www.toureiffel.paris/en/everything-about-the-tower/themed-files/71.html |archive-date=8 September 2015 |df=dmy }}</ref>}}

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 function|exponential]] shape.<ref name="sciencedaily2005">{{cite web|url=https://www.sciencedaily.com/releases/2005/01/050106111209.htm |title=Elegant shape of Eiffel Tower solved mathematically by University of Colorado professor |website=Science Daily |date=7 January 2005 |access-date=24 May 2010}}</ref> All parts of the tower were overdesigned to ensure maximum resistance to wind forces. The top half was assumed to have no gaps in the latticework.<ref>Watson, 1992 p. 807.</ref> After it was completed, some have put forward various mathematical hypotheses in an attempt to explain the success of the design. A one devised in 2004 after letters sent by Eiffel to the French Society of Civil Engineers in 1885 were translated into English described it 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.<ref name="sciencedaily2005"/>

The Eiffel Tower sways by up to {{convert|9|cm|in|abbr=on}} in the wind.<ref>{{cite web|url=http://www.toureiffel.paris/en/faq/115.html |title=FAQ: History/Technical |author=SETE |website=Official Eiffel Tower website |access-date=16 April 2016 |url-status=dead |archive-url=https://web.archive.org/web/20160408210156/http://www.toureiffel.paris/en/faq/115.html |archive-date=8 April 2016 }}</ref>

{{Clear left}}

===Floors===
====Ground floor====
[[File:Paris Eiffel 092.JPG|thumb|Base of the Eiffel Tower]]
The four columns of the tower each house access stairs and lifts to the first two floors, while at the south column only the lift to the second floor restaurant is publicly accessible.

====1st floor====
The first floor is publicly accessible by lift or stairs. When originally built, the first level contained three restaurants—one French, one Russian and one [[Flemish Region|Flemish]]—and an "Anglo-American Bar". After the exposition closed, the Flemish restaurant was converted to a 250-seat theatre. Today there is the {{lang|fr|Le 58 Tour Eiffel}} restaurant and other facilities.

[[File:La Tour Eiffel - terrasse de la première plate-forme.jpg|thumb|A promenade {{convert|2.6|m|adj=on}} wide ran around the outside of the first level]]

====2nd floor====
The second floor is publicly accessible by lift or stairs and has a restaurant called {{lang|fr|[[Le Jules Verne]]}}, a [[gourmet]] restaurant with its own lift going up from the south column to the second level. This restaurant has one star in the [[Michelin Guide|Michelin Red Guide]]. It was run by the multi-[[Michelin star]] chef [[Alain Ducasse]] from 2007 to 2017.<ref>{{cite web|author=Dali Wiederhoft|url=http://www.bonjourparis.com/story/eiffel-tower-sightseeing-restaurants-links-transit/|title=Eiffel Tower: Sightseeing, restaurants, links, transit|publisher=Bonjour Paris|archive-url=https://web.archive.org/web/20140106040320/http://www.bonjourparis.com/story/eiffel-tower-sightseeing-restaurants-links-transit/|archive-date=6 January 2014}}</ref> As of May 2019, it is managed by three-star chef [[Frédéric Anton]].<ref name=ParisDigest>{{Cite web |url=https://www.parisdigest.com/monument/tour-eiffel.htm |title=Eiffel Tower in Paris | year=2018 |publisher=Paris Digest |access-date=14 September 2018}}</ref> It owes its name to the famous science-fiction writer [[Jules Verne]].

====3rd floor====
The third floor is the top floor, publicly accessible by lift.

Originally 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 [[mannequin]]s of Eiffel and some of his notable guests.<ref name=Morton>{{cite web|author=Caitlin Morton|title=There is a secret apartment at the top of the Eiffel Tower|url=http://www.architecturaldigest.com/story/eiffel-tower-paris-secret-apartment?sp&sp|website=Architectural Digest|publisher=Conde Nast|access-date=30 June 2015|date=31 May 2015}}</ref>

[[File:Gustaves Apartment - Eiffel (3384390462).jpg|thumb|Gustave Eiffel's apartment at the third floor]]

From 1937 until 1981, there was a restaurant near the top of the tower. It was removed due to structural considerations; engineers had determined it was too heavy and was causing the tower to sag.<ref>{{cite news |last= Marcus|first= Frances Frank|date= 10 December 1986|title= New Orleans's 'Eiffel Tower'|url= https://www.nytimes.com/1986/12/10/garden/new-orleans-s-eiffel-tower.html|work=[[The New York Times]] |access-date= 22 November 2018}}</ref> This restaurant was sold to an American restaurateur and transported to New York and then New Orleans. It was rebuilt on the edge of [[Garden District, New Orleans|New Orleans' Garden District]] as a restaurant and later event hall.<ref>{{cite web |url= https://wgno.com/2015/09/15/where-can-you-find-pieces-of-the-eiffel-tower-in-new-orleans/|title= Where you can find pieces of the Eiffel Tower in New Orleans|last= Thomas|first= Jabari|work= WGNO|date= 15 September 2015|publisher= [[WGNO]]|access-date= 22 November 2018}}</ref> Today there is a champagne bar.

===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.{{citation needed|date=February 2024}}

[[File:Tour Eiffel Ascenseur Roux, Combaluzier et Lepape.jpg|thumb|The Roux, Combaluzier & Lepape lifts during construction]]

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 had to be the main means of ascent.<ref name=vogel_20>Vogel, pp. 20–21.</ref>

Constructing lifts to reach the first level was done by making the legs wide enough at the bottom and so nearly straight that they could contain a straight track. A contract was given to the French company Roux, Combaluzier & Lepape for two lifts to be fitted in the east and west legs.<ref name=vogel_28>Vogel, p. 28.</ref> 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 {{convert|3.9|m|ftin|abbr=on}} diameter [[sprocket]]s. Smaller sprockets at the top guided the chains.<ref name=vogel_28/>

[[File:Eiffel-Otis lift-poyet.jpg|thumb|left|upright|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 Elevator Company|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.<ref name="vogel_23-4">Vogel, pp. 23–24.</ref> Otis were confident they would eventually be given the contract and had already started creating designs.<ref>Harriss 1976, p. 93</ref>

The car was divided into two superimposed compartments, each holding 25 passengers, with the lift operator occupying an exterior platform on the first level. [[Power (physics)|Motive power]] was provided by an inclined hydraulic ram {{convert|12.67|m|ftin|abbr=on}} long and {{convert|96.5|cm|in|abbr=on}} in diameter in the tower leg with a stroke of {{convert|10.83|m|ftin|abbr=on}}: 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.<ref>Harriss 1975, p. 93</ref>

The original lifts for the journey between the second and third levels were supplied by Léon Edoux. A pair of {{convert|81|m|ft|abbr=on}} 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 travelled only 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.<ref>{{cite book|url=http://gallica.bnf.fr/ark:/12148/bpt6k106381w/f187.image|title=La Tour de Trois Cents Mètres|author=Eiffel, Gustave|year=1900|publisher=Société des imprimeries Lemercier|location=Paris|language=fr|pages=171–3}}</ref>

===Engraved names===
{{Main|List of the 72 names on the Eiffel Tower}}
[[File:Les savants de la Tour Eiffel.jpg|thumb|right|Names engraved on the tower]]

Gustave Eiffel engraved on the building of the tower the names of 72 French scientists, engineers and mathematicians as a recognition of their contributions. 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 {{lang|fr|Société Nouvelle d'exploitation de la Tour Eiffel}}, a company operating the tower.<ref name="lab&names">{{cite web |author=SETE |title=The Eiffel Tower Laboratory |url=http://www.toureiffel.paris/en/everything-about-the-tower/themed-files/88.html |website=Official Eiffel Tower website |date=2010 |access-date=25 January 2017 |url-status=dead |archive-url=https://web.archive.org/web/20170212232554/http://www.toureiffel.paris/en/everything-about-the-tower/themed-files/88.html |archive-date=12 February 2017 }}</ref>

===Aesthetics===
[[File:Eiffel Tower plans 21.jpg|thumb|Some original architectural details]]
The tower is painted in three shades: lighter at the top, getting progressively darker towards the bottom to complement the Parisian sky.<ref name=paintingcolor>{{cite web|title=The Eiffel Tower gets beautified|url=http://www.toureiffel.paris/images/actualites/PDF/how_the_eiffel_tower_gets_beautified.pdf|author=SETE|website=Official Eiffel Tower website|access-date=8 November 2015|url-status=dead|archive-url=https://web.archive.org/web/20151121090936/http://www.toureiffel.paris/images/actualites/PDF/how_the_eiffel_tower_gets_beautified.pdf|archive-date=21 November 2015}}</ref> It was originally reddish brown; this changed in 1968 to a bronze colour known as "Eiffel Tower Brown".<ref name=painting>{{cite web |title=Painting the Eiffel Tower |url=http://www.toureiffel.paris/everything-about-the-tower/themed-files/97 |author=SETE |website=Official Eiffel Tower website |access-date=25 January 2017 |url-status=dead |archive-url=https://archive.today/20161026114502/http://www.toureiffel.paris/everything-about-the-tower/themed-files/97 |archive-date=26 October 2016 }}</ref> In what is expected to be a temporary change, the tower was painted [[Olympic gold medal|gold]] in commemoration of the [[2024 Summer Olympics]] in Paris.<ref>{{Cite web |last=Oliver |first=Huw |title=The Eiffel Tower is being painted gold for the 2024 Olympics |url=https://www.timeout.com/news/the-eiffel-tower-is-getting-a-golden-makeover-ahead-of-the-2024-olympics-020821 |access-date=2022-11-30 |website=Time Out Worldwide |date=8 February 2021 |language=en-GB}}</ref><ref>{{Cite web |date=2021-02-03 |title=Eiffel Tower receives €50m makeover to make it look more golden for the Olympics |url=https://www.independent.co.uk/news/world/europe/eiffel-tower-olympics-makeover-2024-paris-b1796893.html |access-date=2022-11-30 |website=The Independent |language=en}}</ref>

Following the 2024 Summer Olympics held in Paris, Mayor [[Anne Hidalgo]] proposed keeping the [[Olympic symbols|Olympic rings]] on the tower permanently. The rings, which measure {{Convert|95|ft|m}} wide and {{Convert|43|ft|m}} high, were initially installed for the Games and were scheduled for removal after the [[2024 Summer Paralympics|Paralympics]]. Hidalgo's decision faced criticism from the Eiffel family and some residents concerned about altering the protected monument. The original 30-ton rings would be replaced with lighter versions for long-term display.<ref>{{Cite web | last=Kennedy | first=Niamh  | last2=Edwards | last3=Vandoorne | first3=Saskya  |date=2024-09-04 |title=Paris mayor plans to keep Olympic rings on the Eiffel Tower. But not everyone is happy |url=https://edition.cnn.com/2024/09/04/travel/paris-mayor-olympic-rings-eiffel-tower-scli-intl/index.html |access-date=2024-09-06 |website=CNN |language=en}}</ref>

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.<ref>{{cite web |url=http://www.corusconstruction.com/en/reference/teaching_resources/architectural_studio_reference/history/development_of_the_clear_span_building/exhibition_buildings/ |title=History: Development of clear span buildings – Exhibition buildings |work=Architectural Teaching Resource |publisher=Tata Steel Europe, Ltd |access-date=4 January 2014 |archive-url=https://web.archive.org/web/20131005073648/http://www.tatasteelconstruction.com/en/reference/teaching_resources/architectural_studio_reference/history/development_of_the_clear_span_building/exhibition_buildings/ |archive-date=5 October 2013}}</ref>

A pop-culture movie cliché is that the view from a Parisian window always includes the tower.<ref>{{cite web|url=https://www.france.com/editorials/eiffel_tower/|title=The Eiffel Tower|publisher=France.com|access-date=27 January 2018}}</ref> 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.<ref>{{Cite web|title=Eiffel Tower (Paris ( 7 th ), 1889)|url=https://structurae.net/en/structures/eiffel-tower|access-date=27 February 2021|website=Structurae|language=en}}</ref>

[[File:Eiffel Tower Drone 4k-Qx c1X3zfEc-313-251.webm|thumb|[[Bird's-eye view]] of the Eiffel Tower]]

===Maintenance===
Maintenance of the tower includes applying 60&nbsp;tons of paint every 7 years to prevent it from [[rust]]ing. The tower has been completely repainted at least 19 times<!-- as of 2024 --> since it was built, with the most recent being in 2010. [[Lead paint]] was still being used as recently as 2001 when the practice was stopped out of concern for the environment.<ref name="allyouneed">{{cite web|url=http://www.eiffel-tower.com/images/PDF/about_the_Eiffel_Tower.pdf|title=All you need to know about the Eiffel Tower|author=SETE|website=Official Eiffel Tower website|access-date=15 April 2016}}</ref><ref>{{Cite news|last=Bavelier|first=Ariane|url=https://www.lefigaro.fr/culture/2009/03/28/03004-20090328ARTFIG00210-coup-de-pinceau-sur-la-tour-eiffel-.php|title=Coup de pinceau sur la tour Eiffel|date=3 December 2013|work=Lefigaro|access-date=28 March 2009}}</ref><ref>{{Cite news|url=https://www.france24.com/en/live-news/20240524-eiffel-tower-ticket-prices-to-rise-by-20-percent|title=Eiffel Tower ticket prices to rise by 20 percent |date=24 May 2024 |work=France 24 |access-date=25 May 2024}}</ref>