The St. Louis Arch is a large commemorative sculpture located on the west bank of the Mississippi. Its form is an inverted, weighed cantenary curve (Grigonis, 2011). A centenary curve is the shape that a chain forms if it is allowed to hang from the two ends by its own weight. In order to replicate the curve of the St. Louis Arch, the links in the middle chain must be of lighter weight than the links at the end of the chain, thus the curve is described as “weighted.” The designer, Eero Saarinen, chose this type of curve to give the arch the illusion of soaring up into the heavens (Grigonis, 2011). This type of arch appears to be taller than it is wide, but this is due to an optical illusion because of the thinner line breadth at the curve of the arch. The St. Louis Arch is almost exactly as wide as it is tall, with a height and width of approximately 630 feet (The Gateway Arch, n.d.).
Beyond its shape, the arch structure has several very unique features. The cross-sections of the arch are equilateral triangles that range from 54 feet each side to as small as 17 feet each side at the top, with the point of the triangle facing inward (Grigonis, 2011). The structure is a double-walled triangle within a triangle; each made with 3/8 inch carbon steel panels and held in place with high-strength steel rods. The outer skin of the structure is made up of 1/4-inch thick stainless steel panels. The structure includes over 160,000 square feet of stainless steel and the order, to United States Steel Corporation and Eastern Stainless Steel Corporation, was the largest steel order for a single structure ever made (Grigonis, 2011). The triangular sections were prefabricated in Pittsburgh, shipped to St. Louis, and then stacked on site to build the arch. The hollow center of the arch includes an eight-car train that moves passengers from the lower right arch base up to an observatory section in the center of the arch and back down (The Gateway Arch, n.d.).
As mentioned above, the arch is located within a park on the western banks of the Mississippi River. This location is deliberate, as the arch was built to commemorate the function of St. Louis as the gateway of the European occupation of the west. Interestingly, it was in that location that the village of St. Louis occupied when visited by Lewis and Clark during their historic trip west in 1803 (Grigonis, 2011). The arch is within an urban landscape and its design was picked to harmonize with several area landmarks, including the Basilica of St. Louis, the oldest cathedral in the west, and the Old Court House Dome, located just to the west of the arch (Figure 1). Slightly controversial is the dedication of the arch to a famous case decided in that courthouse, the Dred Scott decision of 1857. The Dred Scott decision denied U.S. citizenship to free blacks or slaves and brought the slavery issue into sharp focus. Although a pro-slavery decision, this court case is cited as one of the actions that pushed the United States into civil war, and led to the eventual abolishment of that practice (Grigonis, 2011).
A key characteristic of the space created by the St. Louis arch is the weighted caternary arch shape and the resulting height optical illusion, mentioned above. By using this altered shape, rather than insisting on a pure arch, Saarinen is following a tradition of the ancient Greeks, who would often subtly alter a structure to maximize visual appeal, even when it meant that it no longer strictly followed mathematical formulas (Grigonis, 2011). The arch, the tallest man-made monument in the world, gracefully spans the space above the more standard scale urban buildings of downtown St. Louis (Figure 1). Being an arch, it divides the space it occupies into two distinct areas -- one within its boundaries and all the space outside of its boundaries. Another interesting characteristic of an arch as a shape is that it directs the eye from one base to the other. In this way, the St. Louis Arch provides a well-recognized and dynamic artistic shape expressed in a monumental scale, resulting in a visually arresting sculpture.
The arch also has several significant symbolic functions. It is a visual representation of the “big sky” aspect of the American west and in this way is a physical symbol of the hopes and dreams of those going west to seek their fortune. The arch also functions as a literal gateway, as it defines a space through which settlers would travel to make the westward move. The materials used on the arch also affect the space defined by this structure. The stainless steel skin has the ability to look very different depending on the light that is being reflected from it. Whether glistening in clear sunlight, or more matte in a cloudier day, the arch’s surface helps to contribute to the celestial quality of the sculpture. The shadow cast by the arch upon the surrounding buildings, a striking part of what is seen from the observation deck on a sunny day, is also an interesting aspect of the space defined by this sculpture.
My personal reaction to the St. Louis Arch is the desired soaring effect of the designer and an interest in learning how that effect was created. As with all large monument projects, there was obviously a huge amount of design skill, planning, and organization needed to produce such a large structure. Because of the decisions made by the designers in both shape and context, the St. Louis Arch is a highly successful and modern expression of the hope and promise of the American west.
Figure 1. The St. Louis Arch (Sykes, 2005).
References
Grigonis, R. (2011). The Gateway Arch: Its history and architecture (St. Louis, Missouri). Interesting America. Retrieved from
http://www.interestingamerica.com/2011-04 09_Gateway_Arch_Architecture_by_R_Grigonis_41.html
Sykes, B. (2005). Wikimedia Commons, 14 April. Retrieved from
http://commons.wikimedia.org/wiki/File:St_Louis_Gateway_Arch.jpg
The Gateway Arch (n.d.). National Park Service, U.S. Department of the Interior. Retrieved from
http://www.gatewayarch.com/experience/
