Page "Catenary" Paragraph 19

The Gateway Arch in St. Louis, Missouri, United States is sometimes said to be an ( inverted ) catenary, but this is incorrect.

It is close to a more general curve called a flattened catenary, with equation, which is a catenary if.

While a catenary is the ideal shape for a freestanding arch of constant thickness, the Gateway Arch is narrower near the top.

According to the U. S. National Historic Landmark nomination for the arch, it is a " weighted catenary " instead.

Its shape corresponds to the shape that a weighted chain, having lighter links in the middle, would form.