To make the project more acceptable to public opinion, Nugier and Kohlin instructed the architect Stephen Sovestra to work on the appearance of the project.
Co-investor proposed stone pedestals to ennoble the lower part, monumental arches to connect the columns and the first level, large glass halls on each level, bulbous design for the top and a variety of other decorative features allowing to decorate the entire structure. As a result, the project was simplified, but some elements, such as large arches at the base, were preserved, which in part gives it a very distinctive look.
The curvature of the rack is mathematically determined to offer the most effective resistance to wind. As Eifel himself explains: " All the cutting force of the wind passes inside the front edge rack. The lines directed tangentially to each vertical with the point of each tangent at one height will always intersect at the second point, which is exactly the point through which the stream flows, resulting from the effect of the wind on that part of the tower support located above the two indicated points. "
The assembly of the support began on July 1, 1887, and was completed twenty-two months later.
All elements were prepared at the Eifel factory, located in Levallois-Perret, on the outskirts of Paris. Each of the 18,000 elements used to build the Tower was specially designed and calculated, traced to the nearest tenth of a millimeter,- and 0then 3 assembled- together, forming new pieces of five meters each. The team of designers, who worked on large projects of metal viaducts, was responsible for 150-300 workers at the site of the assembly of this giant set of elements.
All metal parts of the tower are held together by rivets, a well-refined construction method at a time when the tower was built. At first, the pieces were assembled at the factory with bolts, which were then replaced one by one with thermally assembled rivets that contracted during cooling, thus ensuring a very tight fit. For each setting of one rivet, a team of four people was needed: one to warm it, the other to hold it in place, the third to form the head and the fourth to hammer it with a sledgehammer. Only a third of the 250,000 rivets used in the construction of the Tower were inserted directly on site.
The bet was to " study the possibility of installing an iron tower on the Champ de Mars with a square base, 125 meters high and 300 meters high." The project of Gustav Eiffel, businessman Maurice Kohlin and Emil Nugire, engineers and Stephen Souverre, architect, who was selected from 107 applications.
Emil Nugier and Maurice Kehlin, two chief engineers at Eiffel, had an idea for a very high tower in June 1884. It was to be designed as a large pylon with four columns of lattice beams separated at the base and assembled together at the top and connected to each other by more metal beams at regular intervals.
Support posts on concrete bases are set several meters below the ground level above the layer of compacted gravel. Each edge rests on its own support block, applying pressure to it from 3 to 4 kilograms per square centimeter, and each block is connected to the rest of the walls.
On the side of the Seine, construction workers used waterproof metal caissons and squeezed compressed air so that they could operate below the water level.
The tower was assembled using wooden forests and small steam cranes installed on the tower itself.
The first level was assembled by using twelve temporary wooden forests with a height of 30 meters and four large forests of 40 meters each.