The 300 metre Tower

The Eiffel Tower is often termed “iconic” and its curved profile is an instantly recognizable silhouette. Prior to the Tower’s construction, Eiffel suggested that the profile was directly generated by the wind pressure expected on the 300 m wrought iron Tower. Eiffel’s proposals have been investigated by several researchers who have used Eiffel’s explanations to establish different models to fit the profile of the Tower. This paper presents the results of translating part one, and the first three chapters and appendix of part two of Eiffel’s retrospective compendium of drawings, calculations, and technical descriptions in ‘La Tour de Trois Cents Mètres’, which was published after the Tower’s construction. This paper thereby uncovers the actual set of calculations, based on static graphics, and discusses the real relationship between the wind pressures assumed and the constructed profile. It is shown that in fact the proposed design strategy linking the profile to the wind pressure was not rigorously adhered to. This paper compares the proposed design strategy, the design methods assumed in the derivations of the published models and the methods actually used. The paper raises the question of whether the profile of the Eiffel Tower was purely defined by engineering principles or if more subjective decisions were made.