Inside The Construction Of The New Subway Line NYC Has Wanted Since The 1920s [PHOTOS]

New York City's Second Avenue Subway project, which will extend the route of the Q train into the Upper East Side, has been so delayed, Mayor Michael Bloomberg has said he's got "a 50-50 chance of living to see" it open for service, "but not much more than that."

"Delayed" is something of an understatement - serious plans to build the line were proposed in the 1920s and 1940s, and were scrapped both times, according to the New York Times.

Now, the Metropolitan Transportation Authority (MTA) is steadily making progress, and announced last month that it has completed all blasting operations for Phase 1 of the project. It has published photos of the underground work, and things do look like they're coming along nicely.

Here's what the area below the Upper East Side looks like now.

The Second Ave Subway, the MTA says, is "the largest expansion of the subway system in generations."

As is stands, the project should cost $4.45 billion, and open for service in December 2016.

This space is going to be the 72nd Street station.

It's clear there's some work left to do.

Here's a look at the future 86th Street station.

Now contractors will come in and finish the mezzanine and platforms, entrances, and ancillary buildings.

They also have to install all of the mechanical, electrical, and plumbing systems the new subway line will need.