History of the Eiffel Tower

A competition with 107 entries, a sketch by two engineers nobody remembers, two years and two months of iron, and a permit to demolish it that ran out in 1909. How 10,100 tons of it got there, and stayed. The small-group Eiffel Tower tours tell it on the way up.

A competition, and 107 answers to it

France was preparing to mark the centenary of its Revolution with the 1889 Exposition Universelle, and a competition was announced in the Journal Officiel. The brief was unambiguous and slightly mad: study the possibility of erecting an iron tower on the Champ-de-Mars with a square base 125 metres across and 300 metres tall.

A hundred and seven projects came back. The one chosen belonged to Gustave Eiffel, a contractor; Maurice Koechlin and Émile Nouguier, the two chief engineers in his company; and Stephen Sauvestre, an architect.

June 1884: two engineers and a sketch

The idea was not Eiffel’s. Koechlin and Nouguier had it in June 1884: a very tall pylon of four lattice-girder columns, splayed at the base, drawing together at the top and tied to each other at intervals. Extended to 300 metres it reached the symbolic figure of a thousand feet.

Eiffel registered the patent on 18 September 1884 — a configuration for metal supports and pylons capable of exceeding 300 metres — and the tower has carried his name ever since.

The men who built it

Sauvestre was brought in for a specific reason: to make the thing acceptable to look at. Public opinion was against a bare iron pylon in the middle of Paris, and the arches under the first platform, the decorative treatment of the piers and the pavilions on the first floor are all his. They are also, a century and a half on, exactly what makes the silhouette unmistakable.

Behind them were 50 engineers and designers producing 5,300 workshop drawings, 150 workers at the Levallois-Perret factory and between 150 and 300 on the Champ-de-Mars itself.

26 January 1887 to 31 March 1889

Two years, two months and five days. Five of those months went on the foundations and twenty-one on the metal. On the narrow platform at the top, on the day it was finished, Eiffel received his Legion of Honour.

How you rivet 18,038 pieces of iron

Every piece was bolted together in the factory first, then the bolts were replaced one at a time with rivets driven hot. A rivet contracts as it cools, which pulls the joint tighter than any bolt can. It took a team of four to place each one: one to heat it, one to hold it, one to shape the head and one to strike it with a sledgehammer.

There are 2,500,000 of them, and only about a third were driven on site. The rest were done in the workshop at Levallois-Perret, which is why the tower went up as fast as it did.

The assembly used wooden scaffolding and small steam cranes that climbed the tower as it grew, riding the runners later used by the lifts. Sand boxes and hydraulic jacks placed the girders to one millimetre.

Working under the Seine

The piers rest on concrete blocks a few metres down, on compacted gravel, each corner edge pressing on its own block at three to four kilograms per square centimetre. On the side nearest the river that was not straightforward.

The builders sank watertight metal caissons and pumped compressed air into them, so that men could dig below the water line inside a bubble. It is a technique borrowed from bridge work, and Eiffel’s company had built a good many bridges.

The twenty-year clause, and the radio that saved it

The tower was only ever meant to stand for twenty years. The permit required it to come down, and in 1909 it was due.

What saved it was that Eiffel had spent those twenty years making it useful. He encouraged scientific work on and from the structure, and then wireless telegraphy arrived and 300 metres of iron in the middle of Paris turned out to be the best aerial in France. It carried radio signals, became a military listening post, broadcast the first public radio programme and eventually carried television.

It has been repainted twenty times since, takes almost seven million visitors a year and has had close to 300 million through it since 1889. The demolition never happened.

Twenty coats of paint

Eiffel wrote in 1900 that paint was the essential element in the conservation of metal work, and that the more meticulous the job the longer the tower would endure. He was right, and the seven-year cycle adopted after the 1899 campaign has been kept to ever since — 60 tonnes at a time.

The colours have moved with the century: Venetian red in the workshop, reddish-brown in 1889, ochre in 1892, then five shaded tones in 1899 running from yellow-orange at the base to light yellow at the top. Yellow-brown held from 1907 to 1947, brownish-red in the 1950s, and “Eiffel Tower Brown” from 1968. The twentieth campaign began in 2019 and put the yellow-brown back for the 2024 Games. The full sequence is on the facts page.

Where to check these figures

Every figure above comes from the monument’s own published pages, listed below. Hours and rates move, so check yours before you travel.

• The birth of the Eiffel Tower
• The Eiffel Tower facts, height and weight
• Painting the Eiffel Tower
• Gustave Eiffel