Track 5 - TALL / Presentation 3

The Exposed Structural Steel Façade of the U.S. Steel Building 

Clifton Fordham

clifton.fordham@temple.edu

Weathering steel is a steel alloy incorporating copper, chromium and nickel that was developed by a subsidiary of the United States Steel Corporation and patented in 1933. Its primary attributes are exceptional strength and resistance to corrosion, the latter which is provided by a thin layer of corrosion protective film that develops on the surface of the steel as it acclimates to the environment in which is deployed. The strength and low maintenance for the steel initially lent itself to the fabrication of railroad storage containers, barges and trolley cars, and by the mid-1960’s it was widely adopted for the construction of bridges in the United States. 

The first architecturally comprehensive application of weathering steel was for the John Deere World Headquarters complex outside of Moline, Illinois, designed by Eero Saarinen and opened in 1964. The nine-story administrative building featured exposed steel columns, girders and screen elements, all outside of the building’s environmental envelope. In the naturalistic setting designed by Sasaki Associates, the brown steel elements and glass appear to dematerialize, and help the structure blend into the encompassing wooded environment.  

A lesser known, but significant, application of weathering steel is the 64-story (841 ft. tall) Pittsburgh headquarters for U.S. Steel designed by the New York architects Harrison and Abramovitz and the structural engineering firm Skilling, Helle, Christianson and Robertson. By the time the building was completed in 1971, U.S. Steel wasn’t the leading producer of weathering steel, but instead profited from the rights to Corten Steel which are two major types of weathering steel. Like Alcoa, which clad its Pittsburgh headquarters (1953) in aluminum panels as both a demonstration of the material’s architectural potential and as a direct advertisement for the company’s products, US Steel sought similar outcomes in its new headquarters. 

The U.S. Steel building featured and exterior steel structure made Corten steel with Corten infill panels with punched openings in the spirt of the Alcoa building. Both buildings accomplished a structural “honesty” that eluded Mies van der Rohe’s signature I-beams that vertically spanned the face of his buildings. Van der Rohe’s expressive steel was non-structural and painted black to protecting them from rusting. For example, the structural steel for the Seagram building was encased in concrete to protect it from the heat of fire. Fire resistant paint, also known as intumescent paint, was developed during World War II for military applications and was first tested by Underwriters Laboratories in 1945 and acknowledged in some building codes by the mid-1950’s. Intumescent paint is costly to maintain and less reliable than other fire-proofing technologies. When figuring the height of the U.S Steel building and its location of the design objectives of U.S. Steel building warranted finding other fireproofing measures. 

The façade fireproofing solution devised in 1967 for the U.S. Steel building was a tubular steel columns form filled with a salt-water solution, a technology dating back to the eighteenth century, which did not evolve past system prototypes. (Inspired by the concept, a similar system was implemented in the four-story American Securities Insurance Company building in Atlanta which was completed in 1971 before the U.S Steel Building.) Water is circulated by heat and thus required no mechanical parts to maintain its functionality. The precision during fabrication that was required to keep the fluid sealed was offset by savings from not implementing typical fireproofing technologies.  

This investigation of the design and design context for U.S. Steel Building and relates it to comparable weathering steel structures. It explores how the convergence of building technologies, often after they are initially available, can be applied to solve newer problems within design cultures and regulatory contexts that have to be navigated and modified to allow for progress.