Great Structures FIG. 3 The Eiffel Tower: build it up

To scale: heights, floor sizes, the base and the foundations follow Eiffel's 1900 book and SETE. Simplified: far fewer lattice bars; the outline above the second floor is assumed; the pillars join at the second floor; soil layers simplified; the rivet is drawn thicker; jack tilt, sway, lean and growth are exaggerated where marked.

Height: 330 m
Date: 1 Jun 1889
Since first dig: 2y 4m 6d
Iron: 7,300 t
Site rivets: 1.05 M
Floors: 3 of 3

Date1 Jun 1889, 330.0 m

The big idea

The Eiffel Tower is an iron lattice shaped by the wind. Four curved pillars stand on deep foundations, lean in and join, so the tower is widest where the wind's leverage is greatest and slender where little is left to hold. It is made of thousands of exact, pre-drilled parts riveted hot, and most of its outline is open air, so it is very light for its size.

Memory trick: “Dig deep, lean in, rivet hot, let the wind slip through.”

A bit of history: Two engineers in Gustave Eiffel's company, Maurice Koechlin and Émile Nouguier, sketched the tower in 1884, and the architect Stephen Sauvestre gave it its arches and finish. It won the competition for the Paris Exposition Universelle of 1889. Digging began in late January 1887; the top was reached and the flag raised on 31 March 1889, and the tower opened to visitors on 15 May 1889. It was meant to stand for 20 years, but its use for science and radio helped keep it, and in 1910 its permit was extended.

Before a single rivet went in, Eiffel's team drew more than 5,000 drawings and worked out the cost. Jesus used the same picture: For which of you, intending to build a tower, sitteth not down first, and counteth the cost, whether he have sufficient to finish it? (Luke 14:28, KJV)