United Steelworkers Building
| United Steelworkers Building | |
|---|---|
| The building in 2019 | |
| Former names | IBM Building | 
| Alternative names | I.W. Abel Building, Five Gateway Center | 
| General information | |
| Type | Office | 
| Location | 60 Boulevard of the Allies | 
| Town or city | Pittsburgh, Pennsylvania | 
| Country | United States of America | 
| Coordinates | 40°26′22″N 80°00′20″W / 40.4394°N 80.0055°W | 
| Groundbreaking | December 5, 1961 | 
| Topped-out | November 8, 1962 | 
| Opening | March 19, 1964 | 
| Cost | $5 million | 
| Owner | United Steelworkers | 
| Height | 172 feet (52 m) (estimated) | 
| Technical details | |
| Floor count | 13 | 
| Design and construction | |
| Architect(s) | Curtis and Davis | 
| Developer | Equitable Life Assurance Society | 
| Structural engineer | Worthington, Skilling, Helle & Jackson | 
| Main contractor | George A. Fuller Co. | 
| IBM Building | |
| Part of | Pittsburgh Renaissance Historic District (ID13000252) | 
| Significant dates | |
| Designated CP | May 2, 2013 | 
| Designated PHLF | 2014 | 
The United Steelworkers Building, originally named the IBM Building and also known as the I.W. Abel Building or Five Gateway Center, is a highrise office building in Downtown Pittsburgh, Pennsylvania. It was built by the Equitable Life Assurance Society in 1961–64 as part of the Gateway Center project which redeveloped a large portion of the area known as the Point. The building is listed on the National Register of Historic Places as a contributing property in the Pittsburgh Renaissance Historic District and has been designated as a Pittsburgh landmark by the Pittsburgh History and Landmarks Foundation.
The building was designed by Curtis and Davis, a New Orleans–based architecture firm, with structural engineers Worthington, Skilling, Helle & Jackson. The design of the building, featuring a load-bearing steel diagrid exoskeleton, was highly unusual at the time and helped pioneer the use of diagrids and framed tube construction.