Completion of Second Avenue a Marquee Milestone in Skanska’s Century-Long Journey of Building New York
NEW YORK – Skanska USA and its partners have completed work on the first phase of the Second Avenue Subway, marking a major milestone for transportation infrastructure in the City and State of New York. On December 31, 2016, Skanska joined New York Governor Andrew Cuomo and the MTA on the subway’s inaugural trip from East 72nd Street to East 96th Street on the Upper East Side of Manhattan. The line officially opened to the public on January 1st, 2017, at 12:00 p.m.
This first completed segment of the new Second Avenue Subway—operating as an extension of the MTA’s “Q” line—runs from an existing station at East 63rd Street to three new stations at East 72nd Street, East 86th Street and East 96th Street along Second Avenue in Manhattan. The project represents the most significant single expansion of New York City’s subway infrastructure in nearly 100 years.
Since 2007, more than 500 Skanska employees undertook three major aspects of the Second Avenue Subway’s construction as part of three separate joint venture teams – S3 Tunnel Connectors (Skanska Schiavone Shea), STJV (Skanska Traylor Brothers) and CSJV (Comstock Skanska):
- Boring 2.65 miles (14,000 feet) of tunnels through rock, including the creation of an 800-foot-long subterranean "launch box" for assembly and operation of the tunnel-boring machine—which would later become the 96th Street station;
- Excavating and creating the concrete shell for the four-block-long 86th Street station; and
- Installing the track and the systems for signaling, power and communications throughout the new line.
“We’re honored to have played such a significant role in what is a remarkable moment for the City and State of New York,” said Michael Viggiano, Executive Vice President, Skanska USA. “The Second Avenue Subway was planned to improve congestion and mobility on the east side of Manhattan, making life easier for the millions of New Yorkers who will ride it every year. It’s a proud milestone for Skanska in our century-long journey of building New York.”
The addition of Second Avenue is expected to mitigate the effects of overcrowding on the Lexington Avenue line by decreasing congestion and offering more rapid commute times. The extension is expected to accommodate an anticipated 200,000 daily riders.
Second Avenue Innovations
Throughout the process of completing Second Avenue, Skanska was challenged to innovate and adapt. New methods to provide structural support to existing infrastructure, as well as noise and debris limiting technologies, allowed Skanska to continue its subterranean work without displacing aboveground traffic, commerce and residents. Examples of these innovative methods and solutions included:
- A special support system for a 30-story residential tower in order to safely excavate the foundation of the 86th Street Station to create space for the entrance of the station;
- Development of a “muck-handling system” that moved between 50 and 60 containers of rock daily (or the weight equivalent of the Statue of Liberty, each week), while minimizing dust and noise; and
- Freezing areas of soft ground to provide a safe, solid structure for the tunneling operation.
- Skanska developed the technique of “ground freezing” while tunneling New York City’s 7 Line extension, which was subsequently utilized on Second Avenue and for Sweden’s Hallandsås Tunnel.
- Ground freezing involves drilling small pipes into the ground from above, then circulating chilled brine through them—freezing the soil until it behaved more like rock, and enabling the tunnel-boring machine to safely pass through critical areas.
Overcoming such technical challenges is a regular part of subway construction. Several technologies first developed by Skanska during this project have since been standardized for use in other work.
Over a Century Spent Building Metro New York
When Skanska entered the New York City construction market beginning in 1971 through the acquisition of several well-known civil and building contractors, the company inherited a legacy that dates back more than 100 years. Skanska’s local teams have completed some of the region’s most iconic public landmarks and transportation milestones, including MetLife Stadium, the World Trade Center Transportation Hub and Oculus, the United Nations’ campus-wide Capital Master Plan, Brooklyn Bridge Park and the Second Avenue and 7 Line subway extensions.
Skanska currently employs more than 1,000 in the New York Metro Region and is consistently recognized as an overall industry leader in size, safety and performance. Current projects include: the Moynihan Train Hall at the new Empire Station Complex; the new Kosciuszko Bridge; the Bayonne Bridge’s “Raise the Roadway” project; rebuilding of the Rockaway Beach Boardwalk; and, as part of a Skanska-led partnership, the rebuilding of Central Terminal B at LaGuardia Airport.