Federal Office Building
Inves t i gat i on of Gl as s Breakage
In response to glass breakage during construction and initial occupancy, the U.S. General Services Administration engagedWJE to inspect the exterior
spandrel glass on a twenty-three story high-rise structure, now known as theWilliam S. Moorhead Federal Building, in Pittsburgh. With support from
industry experts, WJE successfully diagnosed the cause of the glass failures: inclusions originating during production of the glass rather than flexural or
thermal stresses, as originally suspected.
This study, led by Dick Elstner, was the first glass investigation conducted by WJE and added yet another specialty to the firm’s growing portfolio
of problem-solving capabilities. The project also opened the door to numerous subsequent glass investigations, including the John Hancock
Building in Boston, the College Life Buildings in Indianapolis, and the CNA Building in Chicago.
Notes of Interest
• Large glass panels were not extensively used as a
building component until the 1960s and there was
very little published information on the properties and
performance of glass panels. As a number of glass failures
began to occur, glass manufacturers were also reluctant
to disclose or share technical information. As a result,
Dick Elstner turned to a paper by E.R. Ballantyne of the
Division of Building Research in Melbourne, Australia,
entitled “Cracking of Flat Glass,”which indicated that
certain failures could be caused by small inclusions that
originated during glass production.
• “Cracking of Flat Glass”had been presented by
E.R. Ballantyne at the Australian Building Research
Congress on August 17, 1961.
• Nickel sulfide inclusions were the most common
cause of failures in tempered glass panels like those first
investigated at the Federal Office Building in Pittsburgh.
WJE 50 Years