S3 Tunnel Constructors, a Skanska USA Civil/JF Shea Constructors/Schiavone Construction joint venture (JV), will start tunnelling as part of the $3.8bn (£2.5bn) Phase 1 of Second Avenue Subway in Manhattan this month.
The JV will begin tunnelling its £224.5M worth of 2.4km long twin tube section from 92nd to 63rd streets once the Robbins tunnel boring machine (TBM) has been assembled in the 240m long by 25m wide cut and cover launch shaft between 96th and 92nd streets.
The TBM is 137.2m long with a diameter of 7.2m and has a 200t cutter head with 44 rotating discs. Once assembled, it will begin mining the western-most tunnel in a southerly direction.
“The arrival [last month] of the TBM at Second Avenue is a clear indicator that the MTA [Metropolitan Transit Authority] is delivering on a major expansion project that will have a dramatic impact on Manhattan’s East Side easing overcrowding within our transit system and serving as an economic driver for the region as a whole,” said MTA Capital Construction president Michael Horodniceanu.
This phase is part of a larger scheme that will eventually provide a two-track 13.7km long line linking the Metro-North suburbs and Harlem at 125th Street to the financial district at the southern tip of lower Manhattan.
Phase 1 construction began in April 2007 and is scheduled for completion in December 2016.