Study: Fire caused WTC collapse
Following a three-year investigation, a government agency concludes that fire caused to the collapse of the 47-story Building 7 in the World Trade Center complex.
The Commerce Department’s National Institute of Standards and Technology (NIST) has concluded that the 47-story World Trade Center (WTC) Building 7 collapsed on Sept. 11, 2001, primarily due to fire--the first known instance of fire leading to the complete collapse of a tall building.
“Heating of floor beams and girders caused a critical support column to fail, initiating a fire-induced progressive collapse that brought the building down,” said NIST WTC lead investigator Shyam Sunder. “Video and photographic evidence, combined with detailed computer simulations, show that neither explosives nor fuel oil fires played a role in the collapse of WTC 7.”
The report pointed to one key factor leading to the collapse: thermal expansion of long-span floor systems at temperatures “hundreds of degrees below those typically considered in current practice for fire resistance ratings.” Also, the report recommended stronger building codes and standards that ensure even in the face of severe fire and failure of fire-fighting systems, buildings remain standing.
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Annual Salary Survey
After almost a decade of uncertainty, the confidence of plant floor managers is soaring. Even with a number of challenges and while implementing new technologies, there is a renewed sense of optimism among plant managers about their business and their future.
The respondents to the 2014 Plant Engineering Salary Survey come from throughout the U.S. and serve a variety of industries, but they are uniform in their optimism about manufacturing. This year’s survey found 79% consider manufacturing a secure career. That’s up from 75% in 2013 and significantly higher than the 63% figure when Plant Engineering first started asking that question a decade ago.