The Times diagrams a subway tunnel suspended in midair. Click to enlarge.
About two weeks ago, The Times checked in on the Ground Zero construction and the rebuilding of the IRT subway tunnel that skirts the former World Trade Center site. While at the time, I didn’t have a chance to write about it, the article, still timely, warrants a look. It’s a fun little piece of engineering reporting about a unique stretch of the subway tunnel.
David Dunlap’s piece focuses around the engineering challenges facing work crews as they work in, around and even under the IRT tunnel. Dunlap tells us about the work:
The people don’t always ride in a hole in the ground. Those aboard the No. 1 train in Lower Manhattan are now riding part of the way through the air.
There is no view to admire. The trains are still well below street level, on tracks running within a box-shaped concrete tunnel that bisects the World Trade Center site. But instead of soil, the south half of that 975-foot stretch of subway rests on a newly built network of brawny steel beams atop a forest of minipiles reaching down to bedrock.
And in recent weeks, workers have dug out so much soil from around those minipiles that they have created an underpass beneath the subway large enough for construction machinery to pass through. In the reconstruction of the trade center, it is a significant milestone of east meeting west.
Eventually, as Dunlap tells us, the entire subway box for the 1 train will be resting on minipiles and will last as such while the construction crews fill in the gaps around it with various parts of a subterranean structure.
Now, I’m no engineer, but I love reading stories like this. There are so many unique aspects to the subways and the veritable city that exists under ground. Millions of riders on the 1 won’t ever know or notice that their trains are traveling over the ground while under the ground, but for those that do, it’s just another quirk in the New York City subways. And that, despite all of their problems, is what makes the subway so great.
A few years ago the Times had something similar (with brilliant illustration) on the reconstruction of the Atlantic Avenue station in Brooklyn. Can’t find it now, but it’s there somewhere. That was an amazing feat, that job.