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Contemporaneous Structural Steel Specifications. Federal Building and Fire Safety Investigation of the World Trade Center Disaster (NIST NCSTAR 1-3A) ***DRAFT for Public Comments***



William E. Luecke, Thomas A. Siewert, Frank W. Gayle


This report reviews the contemporaneous (1960s era) steel and welding standards used to construct the 110-story World Trade Center (WTC) towers. It describes the major structural elements in the towers and the many grades of steels relevant to the WTC investigation. Although ASTM International structural steel standards have evolved since the towers were built, the changes are generally minor and not significant for estimating mechanical properties.
National Construction Safety Team Act Reports (NIST NCSTAR) - 1-3
Report Number


World Trade Center, high rise buildings, building collapse, disasters, fire safety, fire investigations, terrorists, terrorism, steel structures, specifications, steels, standards, structural damage, structural elements, construction
Created September 1, 2005, Updated February 19, 2017