Technology See Inside Underground Railroad: A Peek inside New York City's Subway Line of the Future By Anna Kuchment Photograph by Floto + Warner Sixty-five feet below the streets of Manhattan, workers are digging the city’s first new subway line since the 1940s. The Second Avenue subway, to be named the T line, will eventually stretch from 125th Street in East Harlem to Hanover Square in the financial district. The first stretch of the line, from 96th Street to 63rd Street, is set to open in December 2016, carrying more than 200,000 passengers every day. Scientific American visited the base of operations for the dig this past April, as engineers completed the downtown tunnel and set to work on the uptown side. A 700-foot-long tunnel-boring machine, or TBM, does the actual digging, moving at a rate of up to 100 feet a day through the city’s bedrock, a blend of granite, mica, gneiss and garnet known as Manhattan schist. “The rock in the tunnel is twice as strong as concrete, and still the TBM cuts through it like a piece of cake,” says project manager Alaeden Jlelaty of Swedish construction firm Skanska. The TBM, nicknamed “Adi” for the granddaughter of an MTA official, delivers 2.99 million pounds of thrust, the equivalent of 12 Boeing 747s. This is only a preview. Get the rest of this article now! Select an option below: Buy Digital Issue Customer Sign In *You must have purchased this issue or have a qualifying subscription to access this content It has been identified that the institution you are trying to access this article from has institutional site license access to Scientific American on nature.com. Click here to access this article in its entirety through site license access. ADVERTISEMENT Scientific American is a trademark of Scientific American, Inc., used with permission © 2015 Scientific American, a Division of Nature America, Inc. All Rights Reserved.