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Eiffel Tower
Avenue Gustave Eiffel, Champ de Mars, Paris, France
Eiffel Tower
associated engineer
Alexandre Gustave Eiffel
Maurice Koechlin
Emile Nouguier
date  28th January 1887 - 31st March 1889
era  Victorian  |  category  Amusement Structure  |  reference  Tb149931
photo  1900 Exposition, public domain via Wikimedia Commons
The world famous Eiffel Tower, symbol of Paris, was constructed for the 1889 Exposition Universelle (World Fair), marking the 100th anniversary of the French Revolution. Originally intended to be temporary, the wrought iron tower is now the most visited paid attraction in the world, and is the tallest building in the city at 324m.
Planning for a suitable monument for the exposition began in May 1884, when Swiss structural engineer Maurice Koechlin (1856-1946) conceived the idea of building a tall pylon of iron lattices. It consisted of four columns splayed at the base, meeting before the top and linked together by horizontal girders. Koechlin developed the design with French civil engineer Emile Nouguier (1840-98) while both were working for the Compagnie des Etablissements Eiffel, run by Alexandre Gustave Eiffel (1832-1923).
Though initially ambivalent, Eiffel allowed Nouguier and Koechlin to continue with the project. They commissioned French architect Charles Léon Stephen Sauvestre (1847-1919) to improve the look of the tower. He added masonry bases to the legs and the now-characteristic iron arches that connect the columns to the first level.
On 18th September 1884, the by now enthusiastic Eiffel registered a patent for the tower’s design. He chose puddled (wrought) iron as the main material for its strength and durability, plus it was more cost effective than masonry. It is also flexible compared to cast iron, which is brittle, and so can better accommodate wind loading and temperature-driven expansion and contraction.
On 2nd May 1886, the Journal Officiel launched a competition to explore the possibility of erecting a 300m tall metal tower on the Champ de Mars. More than 100 entries were submitted but only Eiffel’s tower fulfilled the rather biased brief. Nevertheless, many people doubted his ability to complete such a project — the tallest tower in the world at the time was the 169.2m Washington Monument.
Eiffel was awarded the contract on condition that he was solely responsible for the project's finance and construction, and for the tower's maintenance during the fair, which would run from 15th May to 6th November, 1889. In return he would receive 1.5 million francs — just one quarter of the estimated 6 million francs required — plus all income derived from the tower's commercial use for 20 years after the fair closed.
Construction commenced on 28th January 1887. At first, the novel design drew criticism, and on 14th February a consortium of well-known writers, artists and architects wrote a protest (Protestation contre la Tour de M. Eiffel) published in the newspaper Le Temps. In a lengthy interview in the same edition, Eiffel replied, "Je crois, pour ma part, que la Tour aura sa beauté propre" (I believe the Tower will possess its own beauty).
The design approach taken by Eiffel was to consider the superstructure as a series of lattice-trussed upright piers, the curvature of which was calculated as offering the most efficient wind resistance. The maximum wind deflection of the completed tower is 90mm. In addition, in hot weather, expansion of the iron frame on the side facing the sun can make the top of the tower bend some 75mm in the other direction.
Eiffel’s labour force of up to 250 people, working from 5,329 engineering drawings, produced an astonishing structure. Its footprint is 124.9m square and it sits on a foundation 33.5m above sea level. The first stage gallery is 57.6m above ground and the second stage 115.7m. The third stage is 276.1m above the ground and offers a panoramic view of Paris.
Site investigation revealed that the ground nearest the River Seine, at the north and west corners of the tower, was far softer than the ground at the south and east corners. Permanent compressed-air caissons were used for the construction of the north and west column foundations, which are 4.9m deeper than the other two.
The four principal girders at the four corners of each leg sit on concrete slabs, making 16 slabs in all. On the landward side, the slabs are 2m thick, founded on a layer of compacted gravel. On the river side, each 6.1m thick slab sits on an iron caisson, 14.9m long and 6.1m wide. Two piles were driven through each caisson to a depth of 21.9m before the slabs were cast.
The finished slabs are built up with masonry to form massive buttresses, each inclined inwards at an angle of 44 degrees, capped with courses of dressed limestone from the Château Landon quarry. Each buttress has an iron shoe for support of the principal girders, fixed into the masonry with two anchor bolts 7.9m long and 102mm in diameter. The legs are 74.2m apart at ground level.
By the end of June, the foundations and buttresses were complete. Assembly of the ironwork up to the first stage began on 1st July, with the help of steam-powered cranes. The principal girders were positioned to an accuracy of 1mm, using a system of sand boxes and hydraulic jacks to adjust the iron shoes at the base of the legs.
Initially, the legs were constructed as cantilevers but were given additional support using temporary timber scaffolds, 30-40m high. On 7th December 1887, the legs were completed to the first level.
In March 1888, the first stage was completed. Beneath the balcony, the names of 72 French scientists, engineers and mathematicians are embossed in letters about 600mm high. Work began on the second stage in May. By the end of August, the timber scaffolding under the first stage had been removed, the arches between the lower legs installed and the second stage completed.
By the end of December, construction of the upper part of the tower had passed the midpoint between second and third stages. By March 1889, construction of the cupola at the top of the third stage was underway.
Eiffel had an office and private apartment on the third stage. The separate wrought iron elements of the tower were fabricated at his factory in Levallois-Perret, on the outskirts of Paris, and assembled into sections weighing no more than 3 tonnes. The sections were delivered to site daily and lifted into position by creeper cranes running on inclined rails inside the tower’s legs. All members were connected by hot riveting, both at the factory and on site.
Eiffel oversaw every aspect of the project personally, and was always looking to maximise efficiency — even installing a workers' canteen inside the tower. However, he reluctantly subcontracted the provision of hydraulic elevators to specialists. He realised that most visitors would not want to climb the 1,710 steps to the top of the tower.
Up to the first stage, the curvature of the legs was slight enough to permit lifts to run on straight inclined tracks, similar to a cliff railway. Roux, Combaluzier & Lepape double-deck elevators were installed in the east and west legs. The lift cars were hauled up the track by a pair of endless chains enclosed in conduit. They carried passengers between ground level and the first stage.
A second pair of lifts was installed in the north and south legs conveying passengers from the ground to the second stage. As the curvature of the main girders becomes progressively steeper between first and second levels, the tracks followed three straight chords connected by short segmental curves. These Otis elevators also had double-deck cars but were pulled upwards using pistons, which operated more efficiently and with less friction. Passengers were seated because of the change in inclination during ascent.
Hydraulic pressure for the Roux and Otis elevators was provided by a large open reservoir on the second stage. Water flowed down to a tank below ground and was pumped back up by two Girard pumps located in the engine room at the base of the south leg.
A direct plunger type elevator ran vertically between the second and third stages. It was invented by Félix Léon Edoux (1827-1910) and the only one of its type in the world. Its track had a platform halfway between stages, with one ram-driven lift car operating over each half of the run. Passengers transferred from one to the other as the cars reached the platform. Water for hydraulic power was supplied by Worthington tandem compound steam pumps in the engine room.
The Eiffel Tower was completed on 31st March 1889, and opened to the public on 15th May along with the opening of the fair, though the elevators were not in service until 26th. It had cost 7.8 million gold francs to construct. Its total weight is 10,260 tonnes, of which 7,420 tonnes is ironwork — 18,038 pieces of it, joined together by 2.5 million rivets.
The tower was painted in three shades of reddish brown, with the 72 names picked out in gold. After dark, it was lit by numerous gas lamps in opaline globes. An electric beacon mounted inside the cupola flashed every 90 seconds, sending tricolour signals of red, white and blue across the city and two mobile searchlights mounted on a rail around the third stage highlighted various parts of the site. A cannon fired from the top marked the fair's daily opening and closing. Almost two million people visited the tower during the exposition.
On 11th September 1889, American inventor Thomas Alva Edison (1847-1931) visited Eiffel’s eyrie on the third stage and presented him with a phonograph. Eiffel used the office as a laboratory for meteorological, astronomical and physiological observations, physics and aerodynamics experiments, and investigations in the use of scientific apparatus.
On 5th November 1898, Eugène Adrien Ducretet (1844-1915) carried out the first wireless telegraphy trials between the Eiffel Tower and the Pantheon 4km away, from a transmitter installed at the top of the tower. In 1899, radio waves from the tower crossed the English Channel (La Manche) for the first time.
The next year, in preparation for the 1900 Exposition Universelle, the Roux elevators were replaced by Fives-Lille hydraulic elevators with self-levelling cars that ran up to the second stage. The Otis elevator in the south leg was replaced by a wide staircase up to the first stage. The tower was furnished with 5,000 electric lamps. In 1912, the Otis elevator in the north leg would be replaced with an electric-powered lift.
At Eiffel’s suggestion, in 1903 Captain Gustave Auguste Ferrié (1868-1932) began using the tower for experiments in military applications of wireless transmission, enabling transmission and reception over 400km. Ferrié was authorised to install antennae on top of the tower, and he conducted his operations from a timber shelter next to the south leg.
In 1909, the 20 year lease expired and control reverted to the City of Paris. With the outbreak of World War I (1914-18), plans for demolition were abandoned and the tower became an important military radio and telegraph centre. The lease was renewed for another 70 years.
During 1925-36, André Gustave Citroën (1878-1935) was responsible for the first purely decorative lighting display on the tower. The name Citroën, adorned three sides of the structure, spelled out in 250,000 lights and visible for 30km. Also in 1925, conman Victor Lustig (1890-1947) twice tried to sell the tower to scrap metal dealers. He received money from the first buyer but the police were alerted by the second, though Lustig evaded arrest.
Up until 1930, when the 319.4m Chrysler Building was completed in New York, the Eiffel Tower was the world’s tallest building. Its height was increased to its present 324m by the addition of a mast in 1957. It remains the tallest building in Paris, by just a metre (2015).
During the German occupation of Paris in World War II (1939-45), the tower was closed to the public and its elevators disabled. In 1965, a Schneider electric elevator was installed in the north leg. It was modernised in 1994-5 and 1997, and its speed reducer was changed in 2004.
By 1980, the tower was in disrepair, and a major programme of renovation was undertaken in 1980-3. Work included removing more than 1,000 tonnes of extra weight created by concrete additions and radio and television masts added over the years. Part of the original staircase were dismantled and sold, and the entire structure was repainted.
In 1983, a Duolift-Otis electric elevator was installed in the south leg for the exclusive use of Restaurant Jules Verne customers, and updated in 1994-5. In 1989, a 4 tonne freight elevator was constructed in the same leg, and refurbished in 2003 and 2007. Also in 1983, the Edoux elevator was dismantled as it did not function well in winter. Its hydraulic pump was put on display at the first level.
The golden lighting scheme of the Eiffel Tower that we see today was unveiled on 31st December 1985. Invented by electrician and lighting engineer Pierre Bideau, it consists of 336 searchlights equipped with sodium lamps, all located at the base of the tower and directed up into the structure. The lights are activated automatically at dusk.
The Fives-Lille hydraulic elevators were modernised in 1986 and 1987, when high pressure oil hydraulic motors replaced the hydraulic accumulators. The elevators were refurbished in 1992, 1995 and 2005. In 2008-12, the west leg elevators were replaced, after which the east leg elevators were also replaced.
in 1986-7, the Société Nouvelle d'exploitation de la Tour Eiffel restored the 72 embossed names below the first stage, which had been painted over since the beginning of the 20th century.
The Eiffel Tower was last painted in 2009, and has had lead-free paint since 2002. It has been repainted 18 times altogether, once every seven years on average. Over the years its colour has changed through reddish brown, yellow ochre, chestnut brown and is now bronze.
Sanding, rust proofing and repainting is done by hand by a team of 25 painters using 50km of safety ropes and 2 hectares of safety nets. The tower stays open throughout. It takes some 15-18 months to apply 60 tonnes of paint to the 250,000 sq m of surface area, and costs around 4 million Euros.
In 2010, the tower received its 250 millionth visitor. It lies within the Paris, Banks of the Seine UNESCO World Heritage Site.
The spacious but least visited first stage was refurbished in 2014, to a design by French architect Moatti-Rivière. Two of the existing pavilions were rebuilt and the third given new façades, providing new facilities and event spaces, with disabled access. A 4,260 sq m glass floor was constructed enabling daring visitors to gain a different perspective on the structure.
In March 2015, two 5.2m tri-blade wind turbines were installed. They generate 10MWh of electricity — a tiny proportion of the Eiffel Tower’s annual power consumption of 6.7GWh.
Elevators: Roux Combaluzier & Lepape, Otis Brothers & Co, Félix Léon Edoux
Architect (2014): Moatti-Rivière
Contractor (2014): SETE
Wind turbnes (2015): Urban Green Technology
Research: ECPK
bibliography
"Elevator Systems of the Eiffel Tower, 1899" by Robert M. Vogel, United States National Museum, Bulletin 228, Smithsonian Institution, Washington D.C., 1961
http://paris-eiffel-tower-news.com
http://whc.unesco.org
www.archdaily.com
www.eiffeltower.co.in
www.eiffeltowerguide.com
www.hevac-heritage.org
www.history.com
www.nce.co.uk
www.telegraph.co.uk
www.toureiffel.paris
Location

Eiffel Tower