EIFFEL TOWER
EIFFEL TOWER
The Eiffel Tower (French: La
Tour Eiffel, [tuʁ ɛfɛl]) 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 antenna atop the Eiffel Tower in 1957, it
is now taller than the Chrysler Building by 5.2 metres (17 ft). Not
including broadcast antennae, 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 bystairs 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.
First
drawing of the Eiffel Tower by Maurice Koechlin
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". 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 symbolize "not only the art of the
modern engineer, but also the century of Industry and Science in which we are
living, and for which the way was prepared by the great scientific movement of
the eighteenth century and by the Revolution of 1789, to which this monument
will be built as an expression of France's gratitude".
Little happened until the beginning of 1886,
when Jules Grévy was re-elected as President and Édouard Lockroy was appointed as Minister for Trade. A
budget for the Exposition was passed and on 1 May Lockroy announced an
alteration to the terms of the open competition which was being held for a
centerpiece for the exposition, which effectively made the choice of Eiffel's
design a foregone conclusion: all entries had to include a study for a
300 m (980 ft) four-sided metal tower on the Champ
de Mars.
On 12 May a commission was set up to examine
Eiffel's scheme and its rivals and on 12 June it presented its decision, which
was that all the proposals except Eiffel's were either impractical or
insufficiently worked out. After some debate about the exact site for the
tower, a contract was finally signed on 8 January 1887.
This was signed by Eiffel acting in his own
capacity rather than as the representative of his company, and granted him 1.5
million francs toward the construction costs: less than a quarter of the
estimated 6.5 million francs. Eiffel was to receive all income from the
commercial exploitation of the tower during the exhibition and for the
following twenty years. Eiffel later established a separate company to manage
the tower, putting up half the necessary capital himself.
The
"Artists Protest"
Caricature of Gustave Eiffel comparing the
Eiffel tower to the Pyramids. The projected tower had been a subject of some
controversy, attracting criticism from both those who did not believe that it
was feasible and those who objected on artistic grounds, whose objections were
an expression of a longstanding debate about the relationship between
architecture and engineering.
This came to a head as work began at the
Champ de Mars: A "Committee of Three Hundred" (one member for each
metre of the tower's height) was formed, led by the prominent architect Charles Garnier and including some of the most
important figures of the French arts establishment, includingAdolphe Bouguereau, Guy
de Maupassant, Charles
Gounod and Jules
Massenet: a petition was
sent to Charles Alphand, the Minister of Works and Commissioner for
the Exposition, and was published by Le
Temps.
"We, writers, painters, sculptors,
architects and passionate devotees of the hither to untouched beauty of Paris,
protest with all our strength, with all our indignation in the name of slighted
French taste, against the erection of this useless and monstrous Eiffel Tower To
bring our arguments home, imagine for a moment a giddy, ridiculous tower
dominating Paris like a gigantic black smokestack, crushing under its barbaric
bulk Notre Dame, the Tour Saint-Jacques, theLouvre, the Dome of les
Invalides, the Arc
de Triomphe, all
of our humiliated monuments will disappear in this ghastly dream. And for
twenty years we shall see stretching like a blot of ink the hateful shadow of
the hateful column of bolted sheet metal."
Gustave Eiffel responded to these criticisms
by comparing his tower to the Egyptian Pyramids: "My tower will be the
tallest edifice ever erected by man. Will it not also be grandiose in its way?
And why would something admirable in Egypt become hideous and ridiculous in
Paris?" These criticisms were also masterfully dealt with by Édouard Lockroy in a letter of support written to
Alphand, ironically saying "Judging by the stately swell of the rhythms,
the beauty of the metaphors, the elegance of its delicate and precise style,
one can tell that this protest is the result of collaboration of the most
famous writers and poets of our time", and going on to point out that the
protest was irrelevant since the project had been decided upon months before
and was already under construction.
Indeed, Garnier had been a member of the
Tower Commission that had assessed the various proposals, and had raised no
objection. Eiffel was similarly unworried, pointing out to a journalist that it
was premature to judge the effect of the tower solely on the basis of the
drawings, that the Champ
de Mars was distant
enough from the monuments mentioned in the protest for there to be little risk
of the tower overwhelming them, and putting the aesthetic argument for the
Tower: "Do not the laws of natural forces always conform to the secret
laws of harmony?"
Some of the protestors were to change their
minds when the tower was built: others remained unconvinced. Guy
de Maupassantsupposedly
ate lunch in the tower's restaurant every day because it was the one place in
Paris where the tower was not visible. Today, the Tower is widely considered to
be a striking piece of structural
art.
Construction
Foundations of
the Eiffel Tower
Work on the foundations started on 28 January
1887. 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) to support the concrete slabs, which were 6 m
(20 ft) thick. Each of these slabs supported a block built oflimestone 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.
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 bysandboxes on the scaffold. Although construction
involved 300 on-site employees, only one person died thanks to Eiffel's stringent
safety precautions and use of movable stagings, guard-rails, and screens.
- 7 December 1887: Construction of the legs with scaffolding.
- 20 March 1888: Completion of 1st level
- 15 May 1888: Start of construction of second stage
- 21 August 1888: Completion to 2nd level
- 26 December 1888: Construction of upper stage
- 15 March 1889: Construction of cupola
Lifts
The Roux, Combaluzier et Lepape lifts during
construction: note the drive sprockets and chain in foreground 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 or even the second stage, the main means of ascent clearly
had to be lifts.
Constructing lifts to reach the first
platform was relatively straightforward: the legs of the lower section were
wide enough and so nearly straight that they could contain a straight track,
and a contract was given to the French company Roux, Combaluzier and Lepape for
two lifts to be fitted in the east and west legs.
Roux, Combaluzier and Lepape used a pair of
endless chains with rigid, articulated links to which the car was attached.
Lead weights on some links of the chains’ upper or return sections
counterbalanced most of the car’s weight. The car was pushed up by the links
below, not drawn by those above: to prevent the chain buckling it was enclosed
in a conduit. At the bottom of the run the chains passed around 3.9 m (12 ft
10 in) diameter sprockets. Smaller sprockets at the top guided the
chains.
The
Otis lifts originally fitted in the north and south legs
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. 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.
Inauguration
and the 1889 Exposition
General view of the Exposition Universelle
The main structural work was completed at the
end of March 1889 and on the 31st Eiffel celebrated this by leading a group of
government officials, accompanied by representatives of the press, to the top
of the tower. Since the lifts were not yet in operation, the ascent was
made by foot, and took over an hour, Eiffel frequently stopping to make
explanations of various features.
Most of the party chose to stop at the lower
levels, but a few, including Nouguier, Compagnon, the President of the City
Council and reporters from Le
Figaro and Le Monde Illustré completed the climb. At 2:35 Eiffel
hoisted a large French
flag, to the accompaniment of a 25-gun salute
fired from the lower level.
There was still work to be done, particularly
on the lifts and the fitting out of the facilities for visitors, and the tower
was not opened to the public until nine days after the opening of the
Exposition on 6 May: even then the lifts had not been completed. The tower was
an immediate success with the public, and nearly 30,000 visitors made the
1,710-step climb to the top using the stairs before the lifts entered service
on 26 May.
Tickets cost 2 francs for the first level, 3
for the second, and 5 for the top, with half-price admission on Sundays, and by
the end of the exhibition there had been 1,896,987 visitors. After dark the
tower was lit by hundreds of gas lamps and a beacon sending out three beams of
red, white and blue light. Two searchlights were mounted on a circular rail,
and were used to illuminate various features of the Exposition. The opening and
closing of the Exposition were announced every day by a cannon fired from the
top.
Illumination of the tower at night during the Exposition.
On the second level, the French
newspaper Le Figaro had an office and a printing press, where a special souvenir
edition, Le Figaro de la Tour, was produced. There was also a pâtisserie.
On the third level there was a post office,
where visitors could send letters or postcards as a memento of their visit.
Graffitists were also catered for: sheets of paper were mounted on the walls
for visitors to record their impressions: these were replaced daily. Gustave
Eiffel describes some of the responses as "vraiment curieuse".
Famous visitors to the tower included The
Prince of Wales, Sarah
Bernhardt, "Buffalo
Bill Cody (his Wild
West show was an attraction at the Exposition) and Thomas
Edison. Edison was
invited by Eiffel to his private apartment at the top of the tower, where
Edison presented him with one of hisphonographs: this invention was one of the sensations of
the Exposition. Edison signed theguestbook 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.
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 should be easy to demolish) but as the tower proved valuable
for communication purposes it was allowed to remain after the expiry of the
permit.
Eiffel made use of his apartment at the top
level of the tower to carry out meteorological
observations, and
also made use of the tower to perform experiments on the action of air
resistance on falling bodies. For the 1900 Exposition Universelle the lifts in the east and west legs
were replaced by lifts running as far as the second level constructed by the
French firm Fives-Lille.
These had a compensating mechanism to keep
the floor level as the angle of ascent changed at the first level, and were
driven by a similar hydraulic mechanism to the Otis lifts, although this was
situated at the base of the tower. At the same time the lift in the north
pillar was removed, and replaced by a staircase to the first level.
The layout of both first and second levels
was modified, with the space available for visitors on the second level
increased by removing the hydraulic reservoirs that had powered the lifts, hydraulic
power being provided by pressurised accumulators at the base of the tower.
·
19
October 1901
Alberto Santos-Dumont flying his No.6 airshipwon a 100,000-franc prize offered by Henri Deutsch de la Meurthe for the first person to make a flight
from St. Cloud to the Eiffel tower and back in less than half an hour.
1910
Father Theodor
Wulf measured radiant
energy at the top
and bottom of the tower. He found more at the top than expected, incidentally
discovering what are today known as cosmic
rays.
·
4
February 1912
Austrian tailor Franz
Reichelt died after
jumping metres from the first level of the tower to demonstrate his parachute design.
·
1913
The original lift in the south pillar was
removed, and replaced by a smaller electric lift.
·
1914
In the opening weeks of World
War I a radio
transmitter located in the tower jammed German radio communications. This
seriously hindered their advance on Paris, and contributed to the Allied
victory at the First Battle of the Marne.
·
1925
The con artist Victor
Lustig "sold"
the tower for scrap metal on two separate, but related occasions.
·
February
1926
Pilot Leon Collet was killed after flying
beneath the arch of the tower. His aircraft was entangled in an aerial
belonging to the wireless station.
·
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.
American soldiers watch the French flag flying on the Eiffel Tower, ca.
25 August 1944.
·
2 May
1929
A bust of Gustave Eiffel by Antoine
Bourdelle, situated at the
base of the north leg, is unveiled.
· 1935
In April the tower was used to make
experimental low-resolution television transmissions, using a short wave
transmitter of only 200 watts power. On 17 November an improved 180-line
transmitter was installed.
·
1938
The decorative arcade around the first level
was removed.
·
1940 to
1944
Upon the German
occupation of Paris in
1940 the lift cables were cut by the French. The Tower was closed to
the public during the Occupation and the lifts were not repaired until
1946. 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. 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. On 25 June,
before the Germans had been driven out of Paris, the Nazi flag was replaced
with aFrench Tricolore by two men from the French Naval
Museum, who narrowly beat three men led by Lucien Sarniguet, who had lowered
the Tricolore on 13 June 1940 when Paris fell to the Germans.
·
3
January 1956
A fire which started in the television
transmitter damaged the top of the tower: repairs took a year.
·
1957
The present radio antenna was added to the
top.
·
1965
Due to increasing visitor numbers an
additional lift system was installed in the north pillar.
·
1964
The Tower was officially declared to be an
historical monument by Minister of Cultural Affairs André
Malraux.
·
1967
According to interviews, Montreal Mayor Jean
Drapeau negotiated a
secret agreement with 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.
·
1982
The original lifts between the second and
third levels were replaced after 97 years service. These had been closed to the
public between November and March because the water in the hydraulic drive
tended to freeze. The new cars operate in pairs, with one counterbalancing the
other, and perform the journey in one stage, reducing the time taken from eight
minutes to less than two minutes. At the same time two new emergency staircases
were installed, replacing the original spiral staircases.
·
1983
The south pillar was fitted with an
electrically driven lift in 1983 to serve the Jules
Verne restaurant.
This was supplied by Otis.
·
31
March 1984
Robert
Moriarty flew a Beechcraft Bonanza through the arches of the tower.
·
1986
The Fives-Lille lifts in the east and west
legs in 1899 were extensively refurbished: the cars were replaced, a
computer-controlled system which completely automated the operation was
installed. The motive power was moved from the water hydraulic system to a new
electrically driven oil-filled hydraulic system. The original water hydraulics
were retained but only as a counterbalance system.
·
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.
·
1989
A service lift was added to the south pillar
for moving small loads or maintenance personnel.
·
27
October 1991
Thierry
Devaux, along with
mountain guide Hervé Calvayrac, performed a series of acrobatic figures
of bungee jumping (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 jump.
·
31
December 1999
For the tower's "Countdown to the Year
2000" celebration, flashing lights and high-power searchlights were installed on the tower. Fireworks
were set off all over it. An exhibition above a cafeteria on the first floor
now commemorates this event. The searchlights on top of the tower made it a
beacon in Paris's night sky, and the 20,000 flashing bulbs gave the tower a
sparkly appearance for five minutes every hour on the hour. On 31 December 2000
the lights glittered blue for several nights to welcome the new millennium. The
glittery lighting continued for 18 months until July 2001.
·
28
November 2002
The tower received its 200,000,000th guest.
·
21 June
2003
The glittering lights are turned on again and
the display is planned to continue for ten years.
·
2004
The Eiffel Tower began hosting an ice skating
rink on the first floor each winter.
Design
of the tower
Material
The Eiffel Tower from below
The puddled iron (wrought
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 6.25 cm (2.5 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
Looking upwards from the base of the tower at
night
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: 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.
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.
Accommodation
When built, the first level contained three
restaurants (one French, one Russian and one Flemish) and an
"Anglo-American Bar". After the exposition closed the Flemish
restaurant was converted to a 250 seat theatre. A 2.6 m (8 ft
6 in) promenade ran around the outside.
On the third level there were laboratories for
various experiments and a small apartment reserved for Gustave Eiffel to entertain guests. This is now visible
to the public, complete with period decorations and lifelike models of Gustave
and some guests.
Passenger lifts
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.
Comments
Post a Comment