Eiffel Tower

The French structural designer, Gustave Eiffel, was given the task of designing a structure for the World Trade Fair in 1889 that was to be held in Paris.  His ideas that led him to this marvellous structure, the Eiffel tower, came from biomimetics.

Hermann Von Meyer, who was an anatomist, in the 1850’s, had been conducting research on the femur (thigh bone).  The femur was of interest to Hermann due to its horizontal extension into the hip socket so the load carried by the joint is off-centre.  It was found that the load could be supported due to a tiny lattice arrangement of bones on the head of the femur called trabeculae. 

A Swiss engineer Karl Cullman after having looked at Von Meyer’s work, noticed that the structure of these trabeculae were identical to the lines of stress and compression produced by the supported load.  Meaning that the trabeculae were formed exactly where the support was required.  Eiffel then used this developed work to design the Eiffel tower.  Eiffel used a lattice of studs and braces to support the curved structure of the tower, similar to the way that the trabeculae support the curves in the head of the femur. So biomimetics inspired a structure to be designed that was capable of efficiently supporting a structure with an off-centre load distribution.

 

Figure 1 This image shows the crane principal stress lines and compares them to the trabeculae lines on the femur. It is observed that there is a correlation between these two sets of lines.

This image shows the base of the Eiffel tower.  The lattice structure of the studs and braces can be seen.