Any tall construction has to be engineered to with stand the forces of the wind. You can accomplish this in two ways – making something so heavy the wind could never push it over, or make your construction so sparse as to not give the wind hardly anything to push against. For the tower Gustave Eiffel – a master of iron bridges and probably the first serious student of aerodynamics – used an iron filigree such that the wind has almost no grip on it even though it is constructed of over 15,000 pieces. If melted down to the size of it’s base (about four acres) the molten iron would rise to a height of only about 2.3 inches.
Before the four buttresses met at the first platform 180 feet off the ground they had to be supported by large wooden trusses. If any of them was off by even a tenth of a degree it would mean inches of difference at the top. To solve this problem Eiffel put the temporary trusses on hydraulic jacks so the permanent sides could be adjusted slightly for the pieces that connected them.
To get the pieces up the tower a set of “creeping cranes” was employed using the future elevator rails as they were constructed. The cranes could construct about 30 feet above their position and then ascend to begin the process again.
Probably the first important work of Modernism, the tower had to give into a few Victorian aesthetics of the time. On the first platform gingerbread arches that were purely decorative were eventually removed. Also, below the first platform are arches meant to remind Persians of their bridges. These arches have no structural purpose thus some find they are a discredit to the structural simplicity – while others find them a pleasant compliment to the exterior curves. Either way the remain to this day.
Finished in 1889 (where it served at the entrance arch for Exposition Universelle) at a final height of 1,063 ft (at the antenna) it was not surpassed in height until New York City’s Chrysler Building was finished in 1930.
Wikipedia – Eiffel Tower
Thanks to Mario Salvadori’s Why Buildings Stand Up
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