A close look at the epoxy failure in Boston’s Big Dig shows how even the best engineering intentions can go wildly awry because of poor communications through an extended supply chain. It was widely know that fast-setting epoxy was not capable of holding sustained loads over time. That issue is now summed up by the National Transportation Safety Board as the “creep” problem. A Massachusetts highway engineer, Clement Fung, made it clear from the git-go that the fast-setting epoxy would not be approved for use in the I-90 connector tunnel ceiling because it lacked the requisite approvals. To make a long story short, the material, however, later was approved for use in non-demanding applications, such as putting tiles on walls of the tunnel. The quick-setting epoxy arrived on the work site first. Workers—apparently completely unaware of the difference—used the quick-setting materials for the ceiling.
Here’s a wild kicker: All of this, starting with request for approval to install, took place within less than a month.
Here’s another wild kicker: The total value of the epoxy materials involved was less than $1,300.
The complete communications breakdown is due at least in part to the supply chain involved. The epoxy was sold at the work site by a salesman for a local distributor of products packaged and developed by Powers Fasteners of New York. Powers Fasteners had hired a prestigious engineering firm (Simpson, Gumpertz & Heger) to solicit the necessary approvals from Massachusetts highway engineers.
According to a published report, the epoxy salesman involved plead the Fifth amendment 27 times when questioned by NTSB investigators last spring.
So who was responsible to make sure the right information got to the work site? The NTSB said it was Powers Fasteners’ responsibility. Any of you who buy from distributors, however, know that the OEM may or may not be available to supply on-the-job training, particularly for such a small order. With hindsight, of course, things would have been different.
There are still puzzling issues remaining: 1) Where else was the fast-setting epoxy used? 2) To what extent should epoxy of any type be used for long-term loads, such as holding ceiling bolts in tunnels? 3) What communications protocols should be implemented in the future to make sure such stunning problems do not occur again?
We are in a national frenzy right now about potential attacks by terrorists. But as the great man Pogo once said, “We have met the enemy… and he is us"