September 22, 2011

N.Y. Second Ave. subway tunneling complete

Image of Second Avenue Subway construction update on April 7, 2011, at the Launch Box. With the west tunnel excavation completed, workers operating the tunnel boring machine have begun mining the east tunnel. Photo by Metropolitan Transportation Authority/Patrick Cashin.

Image of Second Avenue Subway construction update on April 7, 2011, at the Launch Box. With the west tunnel excavation completed, workers operating the tunnel boring machine have begun mining the east tunnel. Photo by Metropolitan Transportation Authority/Patrick Cashin.
New York's Metropolitan Transportation Authority completed tunneling for the first phase of the Second Avenue Subway when a tunnel boring machine (TBM) reached the Lexington Avenue-63rd Street station, breaking into the existing tunnel. 

The completion of tunneling marks a major milestone in the $4.45 billion project that will provide service from 96th Street to 63rd Street as an extension of the Q train.

The TBM began its journey in March and completed the east (northbound) tunnel after making a tight, westerly curve into the existing 63rd Street Station. The tunnel will now receive the concrete lining, which provides the permanent tunnel structure. The work is part of the initial $392 million tunnels and shafts contract that was awarded in March 2007 to Skanska, Schiavone and Shea Tunnel Constructors, JV.

The 485-ton, 450-foot-long TBM used a 22-foot diameter cutterhead to mine 7,789 linear feet averaging approximately 60 linear feet a day. The average depth of the tunnel is 70 feet. During the first 200 feet, the TBM mined through ground which has been frozen, a technique which engineers employ to harden soil, or decomposed rock, enabling the excavation process.

The TBM began mining the 7,209 linear-foot west (southbound) tunnel in May 2010 from the launch box at 92nd Street and was then disassembled and pulled back to 92nd Street where it started its second run this spring to mine the east tunnel.

Work is currently underway to rehabilitate the Lexington Avenue-63rd Street station to accommodate the future Q extension. It will now take approximately three weeks to partially disassemble and pull back the TBM through the tunnel by locomotive. The TBM will be completely dismantled once it returns to the launch box and will be sent back to the contractor’s facilities.

Phase I of the Second Avenue Subway will serve more than 200,000 people per day, reducing overcrowding on the Lexington Avenue Line and restoring a transit link to a neighborhood that lost the Second Avenue Elevated in the 1940’s.

When Phase I is complete in December 2016, it will decrease crowding on the adjacent Lexington Avenue Line by as much as 13 percent, or 23,500 fewer riders on an average weekday. It will also reduce travel times by up to 10 minutes or more (up to 27 percent) for those on the far east side or those traveling from the east side to west midtown.

The line is being built in phases, with the Phase I of the Second Avenue Subway providing service from 96th Street to 63rd Street as an extension of the Q train, including three new ADA-accessible stations along Second Avenue at 96th, 86th and 72nd Streets, and new entrances to the existing Lexington Avenue-63rd Street Station at 63rd Street and Third Avenue.

Further phases of the project will extend the line from 125th Street in Harlem to Hanover Square in the Financial District. The configuration of the tracks will allow for possible future extensions into Brooklyn, Queens, and the Bronx.

Funding for this critical improvement to the MTA’s transportation network is being provided by MTA local sources and federal ($1.37 billion) sources.

Photos will be posted later today at:
http://www.flickr.com/photos/mtaphotos/

deli.cio.us digg it stumble upon newsvine
[ Request More Info about this product / service / company ]


E-NEWSLETTER

Receive the latest Metro E-Newsletters in your inbox!

Join the Metro E-Newsletters and receive the latest news in your e-mail inbox once a week. SIGN UP NOW!

View the latest eNews
Express Tuesday | Express Thursday | University Transit

White Papers

Mass Transit Capital Planning An overview of the world-class best practices for assessing, prioritizing, and funding capital projects to optimize resources and align with the organization’s most critical immediate and long-term goals.

The Benefits of Door-to-Door Service in ADA Complementary Paratransit Many U.S. transit agencies continue to struggle with the quality of ADA service, the costs, and the difficulties encountered in contracting the service, which is the method of choice for a significant majority of agencies. One of the most basic policy decisions an agency must make involves whether to provide door-to-door, or only curb-to-curb service.

Mass transit mobile Wi-Fi & the public sector case study How Santa Clara Valley Transportation Authority successfully implemented Wi-Fi on its light rail and bus lines

More white papers


STORE
METRO Magazine - April 2013

METRO Magazine
Here are the Highlight:
  • BRT Survey: Coordination Construction Top Challenges
  • Hydrogen Fuel Cells Gather Steam as Viable Fleet Option
  • Alternative Project Delivery Opens Doors to Innovation
    And much more…
  •  
    DIGITAL EDITION

    The full contents of Metro Magazine on your computer! The digital edition is an exact replica of the print magazine with enhanced search, multimedia and hyperlink features. View the current issue