One aspect of Scott Allen and Sean Murphy’s Big Dig story in today’s Globe strikes me as a significant advance in our understanding of what went wrong. They write:
In the end, the connector tunnel got a ceiling like few others in the United States, counting on bolts that essentially have been super-glued into the roof to each suspend 2,600 pounds of concrete. [University of Texas professor David] Fowler and other outside experts could name only one other tunnel, in Virginia, that used a similar bolt system for such a heavy ceiling, and they say few are likely to be built in the future because of the Big Dig’s problems.
Haven’t we been told from the beginning that the epoxy-and-bolt system of connecting those concrete panels was actually a tried-and-true technique used in many projects around the country? Indeed, at one point the Big Dig accident raised the specter of massive, nationwide inspections.
The Globe story casts serious doubt on that assertion, and raises the distinct possibility that the fatal accident of July 10 wasn’t just the result of incompetent workmanship but also of a deeply flawed design.