The Boyz St. Louis Arch Home Page

History of the Saint Louis Arch

         The construction on the Saint Louis Arch started on February 12, 1963 and was completed on October 28 1965.  On the 24th of July 1967 it was opened to the public.  It cost about $13 million to build.  The federal government funded 75% and the city funded the remaining 25%.
          The arch was designed by Eero Saarinen, a Finnish imigrant.  He entered and won a nationwide competition organized by the Jefferson Expansion Memorial Association for the design of the Arch.  Fred Severud was the structural engineer for the project.
          The Arch is 630ft. between the outer surface on it's triangular base and 630ft. in height.  Each base is an equilateral triangle with sides 54 ft. long.  It has a reinforced concrete base 60 ft. deep into the ground, and also there are 252 alloy steel tensioning bars in each leg of the arch which securely supports it.  It was designed to withstand earthquakes and can sway as much as 18 inches under extreme conditions without structural damage.  The Arch is made of stainless-steel and is in the form of an inverted catenary curve.
          Why use a catenary curve?  The benefit lies in the physics behind the catenary.  All the force needed to hold something curved in this fashion is concentrated at both ends of the catenary.  The best example of a catenary is if you were to hold a heavy chain at both ends.  The curve it forms in hanging is catenary.  All the force and support needed to maintain it's shape and to remain perfectly at rest exists in the balance between the force of gravity and the force being used to hold it up, your hands.  The Arch was built in this way because all this force would be pointed downward into the earth, with no extra force on the structure itself.  This makes the Arch extraordinarily durable in extreme conditions the structure of the visible part of the Arch does not support itself.  This structural support is burried 60ft underground in very strong foundations, which can be read about in the first link on the links page.

Check out the rest of our page, including the scale model we built based on the same principles mentioned above!

Want to see the model we built?  Click here

Check out some cool links

Have any comments?  Send us email