Second Avenue Subway

The Second Avenue Subway (SAS) is a planned rapid transit subway line, part of the New York City Subway system. , Phase I, consisting of 2 mi of tunnel and three stations, is under construction underneath Second Avenue in the borough of Manhattan, and is slated for completion in December 2016.

The Second Avenue Subway has been a plan and occasional construction project since 1929. After several starts and interruptions, mostly because of lack of funds, the most recent and financially secure construction plan was launched when a tunnelling contract was awarded to the consortium of Schiavone/Shea/Skanska (S3) by the Metropolitan Transportation Authority (MTA) on March 20, 2007. This followed preliminary engineering and a final tunnel design completed by a joint venture between AECOM and Arup. Parsons Brinckerhoff is the Construction Manager of the project. This contract, and the full funding grant agreement with the Federal Transit Administration, which was received in November 2007, is for Phase I of the project, a new line between the existing BMT 63rd Street Line and 96th Street and Second Avenue. The total cost of the 8.5 mi line is expected to top $17 billion.

A ceremonial ground-breaking for the Second Avenue Subway was held on April 12, 2007; the contractor prepared the initial construction site at 96th Street on April 23, 2007. A tunnel boring machine (TBM) was originally expected to arrive six to eight months after construction began, but the utility relocation and excavation required to create its "launch box" delayed its deployment until May 2010. By May 2010, the TBM launch box was complete, and on May 14, 2010, MTA's contractors completed the TBM installation and turned it on. On March 28, 2011, S3, having completed the west tunnel to 65th Street, began drilling for the east tunnel. The TBM completed its run to the 63rd Street Station bellmouth on September 22, 2011.

The reasons for the line's many "false starts" and delays are numerous and complex. The line is sometimes referred to as "The Line That Time Forgot".