After graduation, Eiffel had hoped to find work in his uncle's workshop in Dijon, but a family dispute made this impossible.
After a few months working as an unpaid assistant to his brother-in-law, who managed a foundry, Eiffel approached the railway engineer Charles Nepveu, who gave Eiffel his first paid job as his private secretary.
 However, shortly afterwards Nepveu's company went bankrupt, but Nepveu found Eiffel a job designing a 22 m (72 ft) sheet iron bridge for the Saint Germaine railway.
Some of Nepveu's businesses were then acquired by the Compagnie Belge de Matériels de Chemin de Fer: Nepveu was appointed the managing director of the two factories in Paris, and offered Eiffel a job as head of the research department.
In 1857 Nepveu negotiated a contract to build a railway bridge over the river Garonne at Bordeaux, connecting the Paris-Bordeaux line to the lines running to Sète and Bayonne, which involved the construction of a 500 m (1,600 ft) iron girder bridge supported by six pairs of masonry piers on the river bed.
These were constructed with the aid of compressed air caissons and hydraulic rams, both innovative techniques at the time.
Eiffel was initially given the responsibility of assembling the metalwork and eventually took over the management of the entire project from Nepveu, who resigned in March 1860.

Following the completion of the project on schedule Eiffel was appointed as the principal engineer of the Compagnie Belge.
His work had also gained the attention of several people who were later to give him work, including Stanislas de la Roche Toulay, who had prepared the design for the metalwork of the Bordeaux bridge, Jean Baptiste Krantz and Wilhelm Nordling.
Further promotion within the company followed, but the business began to decline, and in 1865 Eiffel, seeing no future there, resigned and set up as an independent consulting engineer.
He was already working independently on the construction of two railway stations, at Toulouse and Agen, and in 1866 he was given a contract to oversee the construction of 33 locomotives for the Egyptian government, a profitable but undemanding job in the course of which he visited Egypt, where he visited the Suez Canal which was being constructed by Ferdinand de Lesseps.
At the same time he was employed by Jean-Baptiste Kranz to assist him in the design of the exhibition hall for the Exposition Universelle which was to be held in 1867.
Eiffel's principal job was to draw up the arch girders of the Galerie des Machines.
In order to carry out this work, Eiffel and Henri Treca, the director of the Conservatoire des Arts et Metiers, conducted valuable research on the structural properties of cast iron, definitively establishing the modulus of elasticity applicable to compound castings.
After graduation, Eiffel had hoped to find work in his uncle's workshop in Dijon, but a family dispute made this impossible. After a few months working as an unpaid assistant to his brother-in-law, who managed a foundry, Eiffel approached the railway engineer Charles Nepveu, who gave Eiffel his first paid job as his private secretary.  However, shortly afterwards Nepveu's company went bankrupt, but Nepveu found Eiffel a job designing a 22 m (72 ft) sheet iron bridge for the Saint Germaine railway. Some of Nepveu's businesses were then acquired by the Compagnie Belge de Matériels de Chemin de Fer: Nepveu was appointed the managing director of the two factories in Paris, and offered Eiffel a job as head of the research department. In 1857 Nepveu negotiated a contract to build a railway bridge over the river Garonne at Bordeaux, connecting the Paris-Bordeaux line to the lines running to Sète and Bayonne, which involved the construction of a 500 m (1,600 ft) iron girder bridge supported by six pairs of masonry piers on the river bed. These were constructed with the aid of compressed air caissons and hydraulic rams, both innovative techniques at the time. Eiffel was initially given the responsibility of assembling the metalwork and eventually took over the management of the entire project from Nepveu, who resigned in March 1860.
Following the completion of the project on schedule Eiffel was appointed as the principal engineer of the Compagnie Belge. His work had also gained the attention of several people who were later to give him work, including Stanislas de la Roche Toulay, who had prepared the design for the metalwork of the Bordeaux bridge, Jean Baptiste Krantz and Wilhelm Nordling. Further promotion within the company followed, but the business began to decline, and in 1865 Eiffel, seeing no future there, resigned and set up as an independent consulting engineer. He was already working independently on the construction of two railway stations, at Toulouse and Agen, and in 1866 he was given a contract to oversee the construction of 33 locomotives for the Egyptian government, a profitable but undemanding job in the course of which he visited Egypt, where he visited the Suez Canal which was being constructed by Ferdinand de Lesseps. At the same time he was employed by Jean-Baptiste Kranz to assist him in the design of the exhibition hall for the Exposition Universelle which was to be held in 1867. Eiffel's principal job was to draw up the arch girders of the Galerie des Machines. In order to carry out this work, Eiffel and Henri Treca, the director of the Conservatoire des Arts et Metiers, conducted valuable research on the structural properties of cast iron, definitively establishing the modulus of elasticity applicable to compound castings.
Gustave Eiffel