7 Lines Contract C
Award of Merit-Transportation
To extend Manhattan's No. 7 subway line westward, a massive $1.1-billion construction effort was undertaken to dig new tunnels. After four years, the project has produced an L-shaped excavation stretching from Times Square, the No. 7 subway line's current terminus, to West 25th Street, and it includes a soaring new subway station at West 34th Street and 11th Avenue to serve the emerging Hudson Yards neighborhood.
The project has added two nearly mile-long tunnels as well as a 960-ft-long station with a mezzanine level. The subterranean lattice also includes several passageways for accessing and traversing the station as well as shafts for air and utilities.
Two enormous boring machines dug most of the tunnels, and controlled blasting played a part, too. Much of the excavation work took place beneath apartment buildings and close to their foundations without issue, says project submitter MTA Capital Construction (MTACC). The tunnels also crossed the path of the existing Eighth Avenue subway line without disrupting service, MTACC adds.
The project also finished ahead of schedule, which caused more than one ENR New York judge to take note, saying that most major U.S. subway projects are completed late. The team "used every trick in the book and applied them in the right places," says one judge.
Contract C-26503: Construction of Running Tunnels and Station Structures for the Number 7 Subway Line Extension, New York
Owner/Developer: MTA Capital Construction
Funding Partner: Hudson Yards Development Corp.
Construction Manager: HLH7 (JV of Hill International; LiRo Group; HDR)
General Contractor: S3II Tunnel Constructors (JV of J.F. Shea Construction; Skanska USA Civil Northeast; Schiavone Construction Co.)
Structural, Civil, MEP Engineer & Lead Designer: Parsons Brinckerhoff
Submitted by: MTA Capital Construction