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200-Ton Cutter Head for Second Avenue Subway's Tunnel Boring Machine Arrives

Majority of Tunnel Boring Machine Parts on Site for the Final Stage of Assembly

The main components of the Second Avenue Subway Tunnel Boring Machine, including the 200-ton cutter head, have arrived and were lowered into the Launch Box for the final stage of assembly. Once assembled, the Tunnel Boring Machine (TBM) will begin mining the western tunnel for the new two-track line. Mining is scheduled to commence in May.

Click here for a complete photo gallery of the TBM being assembled in the Launch Box.

 

The Second Ave Subway TBM was originally manufactured by The Robbins Company about 30 years ago. It was first used to dig the MTA's 63rd Street Tunnel in the late 1970's and has been used on at least four other projects. The machine has been reconditioned and was rebuilt in Newark, NJ at contractor Schiavone's yard where it was assembled, tested and then disassembled for shipment to the site. The TBM was most recently used on the Fall River CSO Project in Fall River, MA.

The total length of the TBM plus the trailing gear which contains the mechanical and electrical equipment that powers the cutter head is 450 feet long. The cutter head has 44 rotating discs and is the vital piece of the TBM that will drill and excavate the approximately 7,700 foot-long tunnels.

"The arrival this week of the TBM at Second Avenue is a clear indicator that the MTA 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 Dr. Michael Horodniceanu.

The Launch Box, which extends from just south of 92nd Street to 96th Street along Second Avenue and is approximately 815 feet long by an average of 63 feet wide and 56 feet deep, forms the shell of the new 96th Street Station. This is also where the machine will be assembled and launched from one of two starter tunnels in May. Excavation of the Launch Box began in June 2009 using a combination of controlled blasting and mechanical methods. In total, 117,000 cubic yards of rock and soil were removed.

The Second Avenue Subway will reduce overcrowding and delays on the Lexington Avenue line and provide better access to mass transit for residents of the far east side of Manhattan. 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, three new ADA-accessible stations along Second Avenue at 96th, 86th and 72nd Streets, and new entrances to the existing Lexington Av/63 Street Station at 63rd Street and Third Avenue.

Construction of Phase I of the Second Avenue Subway began in April 2007. When complete in December 2016, Phase I will serve 213,000 daily riders currently using other subways, buses, taxis or cars and decrease crowding on the adjacent Lexington Avenue Line by as much as 13%, 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%) for those on the far east side or those traveling from the east side to west midtown.

Please visit www.mta.info/video to view a video of the cutter head arriving.