Eero Saarinen's Elegant Gateway Arch Hides Mathematical Rigor in its Simplistic, Futuristic Design

The Gateway Arch. St. Louis MO.

Sitting on the banks of the Mississippi River, The Gateway Arch is a monument to the role St. Louis played in the westward expansion of the United States. The arch also commemorates the opening of the West to settlers following the Louisiana Purchase in 1803 and the Lewis and Clark Expedition in 1804-06. Following the Great Depression, civic leader, Luther Eli Smith, felt the public needed "spiritual things" and opened a design competition for a monument which would be publicly funded. Of the 172 submissions, one received a unanimous selection. The winning submission in 1948 was by Finnish-American architect, Eero Saarinen. His design was described as "relevant, beautiful, perhaps inspired". Eero Saarinen was the son of architect, Eliel Saarinen, and was well known for his modern, futuristic designs, including the Dulles Airport Terminal, the TWA Flight Center at JFK Airport, and the MIT Chapel. Saarinen's Gateway Arch design showed both "mathematical rigor and form simplicity in a contemporary material". The basis of the arch's design is the catenary curve- and idealized representation of a free-hanging chain, bending under its own weight. The curve is created by tension from each end. The design of the arch is the inverse presentation. The arch is supported entirely by compression from its own weight. Additionally, the arch measures 630' tall and 630' wide. The legs are stacked equilateral pressed concrete triangles- starting at 54' at the base and 17' where they join at the top. It was critical that placement of the base triangular blocks be precise to enable them to join together at the top. Each triangular section is steel-clad and tightly fit to create high structural stability. Each leg is set 60' into the ground- with 1/3 directly in the bedrock. The arch is designed to be earthquake resistant due to St. Louis being near the New Madrid Fault Line and can sway 9'' in either direction and withstand winds up to 150 mph. The interior of the arch is hollow to house 2 trams- each with 8 cars that carry 5 people, seated. The observation deck has 16 windows on each side- the east facing Illinois and the Mississippi River and to the west of the city of St. Louis. The arch is the centerpiece of the 62 acre Gateway Arch Park and was completed in 1965, four years after Eero Saarinen's death. The project cost $13 million at the time it was built, and due to budget constraints Saarinen's full design for the grounds weren't realized. In 2018 renovations were completed to connect the park with downtown St. Louis via a new walkway- bridging the Old Courthouse with the National Park's new glass walled visitor's center. (Previously they weren't connected with Interstate 44 separating them.) Eric Moraczewski, Gateway Arch Foundation executive director has said, "we've really completed his (Saarinen's) vision by connecting the city to the Arch". Renovations and additions were completed by architect, Scott Newman FAIA, and the project is seeking LEED Gold Certification. Eero Saarinen's design has become a symbol of St. Louis with its iconic framing of the historic Old Courthouse. Saarinen is now considered a champion of neo-futuristic design and a master of the 20th century architecture. Aline Louchheim, New York Times architecture critic is quoted saying his 1948 sketches show his "boundless American optimism" and praised the "profoundly evocative and truly monumental expression". The Gateway Arch remains the tallest monument in the United States and the tallest arch in the world. In 1990 it won the AIA Twenty-Five Year Award and the site was listed as a National Historic Landmark in 1987.