Wednesday, July 12, 2006

"The Least Safe Tunnel In America"

That was the verdict of the editor of Toll Road News on my radio show yesterday. Peter Samuel covers toll projects fulltime around the world. He couldn't name one bridge where someone had been killed due to a design or construction flaw after just three years. He couldn't name off the top of his head the last time a tunnel failure had killed somone, period. And he couldn't name a similar sized public works project that had gone from $2.5 billion to $15 billion in cost overruns.

And then, after re-counting the flooding, the falling debris, the slurry wall failures, etc. he came to his conclusion: "There isn't another major tunnel in America as unsafe as the Big Dig."

Today, Samuel says he's got the "smoking gun" on what happened Monday night:

From a photograph in the Boston Globe the anchors look to have been quite modest in size for something that supports multi-ton slabs - they look to be approx 6 inch x 3/4inch (150mm x 20mm) threaded rods. These were placed in a hole drilled vertically about 6 inches (150mm) up into the concrete. The hole may have been about 3/8 inch (10mm) larger that the threaded rod. The anchors depended for their strength on grip of the epoxy to the concrete and the grip of the epoxy to the threads of the steel rod.

And worst of all the anchors look to be very short for the kind of job they have to do. 6 inches is very little length to get a real grip into the concretework.

There's only one word for this - the good British word shonky. A handyman who used it you'd shun.

Over at Toll Road News, the "official" label for the project is "The Big Botch." If you have a better name, please send it to