For the Universal Exhibition of 1889, a date that marked the centenary of the French Revolution, the Journal Officiel launched a major competition to “study the possibility of erecting an iron tower on the Champ-de-Mars. The tower would have a square base, 125 metres on each side and 300 meters high.” The project proposal by entrepreneur Gustave Eiffel, engineers Maurice Koechlin and Emile Nouguier and architect Stephen Sauvestre was chosen out of a total of 107.
Fifty engineers and designers produced 5,300 drawings, and over 100 workers built more than 18,000 different parts of the tower in a workshop. Another 132 workers assembed them on site.
• Work on the foundations began on January 26, 1887 and took ive months, with the workers using only spades. The rubble was taken away by carts drawn by horses and steam locomotives.
• The pillars. While there was no problem building pillars 2 and 3 on the Champ-de-Mars side, on the Seine River side, pillars 1 and 4 required air-compressed foundations using corrugated steel caissons ive meters under water.
• The deepest foundations lay just 15 meters underground. The feet of the tower were set in each of these foundation ditches (four foundations in masonry, which supported the four pillars, known as truss frames).
• Assembling the irst loor. The dificulty of the assembly lay in the point of departure at the base of the truss frames. They had to be positioned at a slanting angle so that they would meet the horizontal beams on the irst loor. To achieve this, the engineers used hydraulic jacks to move each “foot” and erected
an original scaffolding system, on top of which were a number of boxes of sand that emptied to regulate the slant of the truss frames. The jacks no longer exist, but the Eiffel Tower operating company, Société d’Exploitation de la Tour Eiffel, has reproduced them, and they are on show in the Ferrié Pavilion on the irst loor of the Tower.
• The second loor was assembled with cranes that took the same route as the elevators. All of the parts were built in the Eiffel workshops in Levallois, on the edge of Paris, and riveted into position on site. The Tower was mounted rather like a giant Meccano® with remarkable precision, which was a major
innovation at the time.
• From the second to the third loor, the carpenters worked wonders and there was not one single fatal accident during the construction period.
• The monument was inaugurated on March 31, 1889. On that day, Gustave Eiffel climbed the 1,710 steps of the Tower to plant the French lag at its peak. He was followed by the members of the Council of Paris, including Emile Chautemps, President of the Paris City Council. The Eiffel Tower was the highest building
in the world until 1929, when the Chrysler Building in New York topped it at 319 metres.
Key figures for an epic
• The four pillars of the Eiffel Tower stand in a square that measures 125 meters on each side. They are oriented in line with the 4 cardinal points.
• The metal structure weighs 7,300 tons.
• Total weight: 10,100 tons.
• Number of rivets used: 2,500,000.
• Number of iron parts: 18,038.
• Cost of construction: 7,799,401.31 French gold francs of 1889.