Paris, 1889 – As the world gathered to celebrate the 100-year anniversary of the French Revolution, Paris played host to the Exposition Universelle, a grand World’s Fair that showcased the marvels of the era. Among the many ambitious plans submitted for a monumental entrance to the exposition on the Champ-de-Mars, one design would go on to become an enduring symbol of Paris and an engineering marvel – the Eiffel Tower.

The commission to build the monumental entrance was awarded to Eiffel et Compagnie, a renowned consulting and construction firm led by Alexandre-Gustave Eiffel, a celebrated bridge builder, architect, and metals expert. While Eiffel himself is often credited with the tower’s creation, the concept was the brainchild of one of his talented employees, Maurice Koechlin, a brilliant structural engineer who fine-tuned the design.

The construction of the Eiffel Tower began on July 1, 1887, and remarkably, just twenty-two months later, the assembly of its towering supports was completed. Every element of the tower, all 18,000 pieces, was meticulously designed, calculated, and manufactured with extraordinary precision at Eiffel’s factory in Levallois-Perret, just outside Paris.

A skilled team of constructors, experienced from their work on other metal viaduct projects, managed a workforce of 150 to 300 workers on-site, turning this ambitious vision into reality, akin to a colossal erector set.

Rivets were the key to holding all the metal pieces together, employing a refined method of construction for the time. Each piece was initially assembled using bolts, later replaced one by one with thermally assembled rivets, which contracted during cooling, ensuring an incredibly tight fit.

The laborious process of riveting required a team of four men for each joint: one to heat the rivet, another to hold it in place, a third to shape the head, and a fourth to deliver the decisive blow with a sledgehammer. Interestingly, only a third of the 2,500,000 rivets used in the tower’s construction were inserted on-site; the rest were installed at the factory.

The foundation of the tower rested on concrete foundations, secured several meters below ground-level on a bed of compacted gravel. Each corner edge was supported by its own block, applying a pressure of 3 to 4 kilograms per square centimeter, and these blocks were interconnected by walls.

Facing the Seine, the builders utilized watertight metal caissons and compressed air to work below the water level. The tower took shape with the aid of wooden scaffolding and small steam cranes mounted onto the structure itself. The first level was assembled using twelve temporary wooden scaffolds, each 30 meters high, and four larger scaffolds, each 40 meters high.

“Sandboxes” and hydraulic jacks helped position the metal girders with astonishing accuracy, down to a single millimeter. The foundation took just five months to complete, and in a mere twenty-one months, the metal pieces of the Eiffel Tower were assembled.

On March 31, 1889, Eiffel marked the completion of the principal structural work by leading a group of press and officials on a tour of the tower – climbing it via the stairs. At the pinnacle, Eiffel raised the French flag to the thundering booms of a 25-gun salute, a triumphant moment for this monumental achievement.

Nine days after the opening of the exposition on May 6, the Eiffel Tower was finally opened to the public. While not all Parisians were initially enthusiastic about the towering structure, its popularity grew exponentially. Millions of visitors marveled at the architectural wonder during and after the World’s Fair.

Interestingly, not everyone in Paris was enamored with the Eiffel Tower. The renowned novelist Guy de Maupassant was said to despise the structure so much that he would dine at the restaurant located at its base to avoid even catching a glimpse of its looming silhouette.

Originally granted a permit to stand for 20 years, the Eiffel Tower was destined to be dismantled in 1909, with ownership reverting to the City of Paris. However, due to its value for communication purposes, the tower was allowed to remain, ultimately becoming an iconic symbol of Paris and a testament to the brilliance of engineering and human ingenuity.