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 article was originally published with the title Underground Railroad.

6 Comments

1. 1. Butchfoote 08:07 AM 7/13/11

   The NYC subway system pumps >10 millions of gallons of water out everyday to keep the system operating. Meanwhile, the oceans are rising due to Arctic and glacial icemelt.
   
   So the right thing to do is to build another underground subway in NYC? I would think that transitioning them to overheads over the next 30 years might be a bit wiser. Maybe start building the sea walls?

   Reply | Report Abuse | Link to this

2. 2. icy 09:09 AM 7/13/11

   hahaha. I second butchfoote. we should be building overheads in between the skyscrapers. or better yet, where is my anti-gravity cars?

   Reply | Report Abuse | Link to this

3. 3. skiphuffman in reply to Butchfoote 12:42 PM 7/13/11

   Or run submarines through the tunnels instead of trains.

   Reply | Report Abuse | Link to this

4. 4. lamorpa in reply to Butchfoote 12:47 PM 7/13/11

   Yeah. Maybe the oceans are filling up from all that water being pumped into them...

   Reply | Report Abuse | Link to this

5. 5. XQZME in reply to Butchfoote 10:01 PM 7/15/11

   The latest data shows sea level is dropping.
   http://wattsupwiththat.com/2011/04/17/doing-it-yourself-the-latest-global-sea-level-data-from-jason-shows-a-sharp-downtick-and-downtrend/

   Reply | Report Abuse | Link to this

6. 6. Butchfoote 02:51 PM 9/24/11

   Ah, the oceans are already draining into the new Subway Tube. Someone tell Noah to can the Ark project.

   Reply | Report Abuse | Link to this