Paris’ Iconic Eiffel Tower Expands During Hot Summer Days

Kokcha News Agency: The Eiffel Tower, a symbol of Paris and a major tourist attraction, undergoes a fascinating transformation during the summer months. Built for the 1889 World’s Fair to commemorate the 100th anniversary of the French Revolution, the tower was originally named “Tour de 300 mètres” (300-Meter Tower) and was designed by engineer Gustave Eiffel based on the proposal of Maurice Koechlin and Émile Nougier.

As temperatures rise in the summer, the Eiffel Tower expands and becomes taller than its original design. According to a report by Independent, the tower is made of cast iron, a material Eiffel had used in previous projects like the Garabit Viaduct and Scotland’s Forth Bridge. Despite weighing 7,300 tons, its lightweight design makes it resistant to wind, a feature that was considered an engineering marvel at the time.

Thermal Expansion:
Metals expand when heated and contract when cooled, a phenomenon known as “thermal expansion.” The iron and steel components of the Eiffel Tower have a thermal expansion coefficient that causes the structure to elongate by approximately 12 microns per meter for every degree increase in temperature. This expansion is thinner than a strand of human hair.

In theory, a 300-meter-long metal structure could expand by up to 36 centimeters with a 100-degree temperature difference. However, the Eiffel Tower’s actual height variation between summer and winter is around 12 to 15 centimeters. Additionally, when sunlight hits one side of the tower more intensely, it can cause the structure to lean slightly away from the sun.

This responsiveness to temperature changes not only makes the Eiffel Tower an engineering marvel but also turns it into a giant “thermometer” for the city of Paris.