Subway Construction Cuts, Covers, Mines its Way Down 2nd Avenue

Event: The Second Avenue Subway: A Twenty-First Century Subway for the City of New York
Location: Center for Architecture, 03.12.10
Speaker: Judith Kunoff, AIA — Chief Architect, NYC Transit Authority
Organizer: AIANY Transportation & Infrastructure Committee

sas-platform

Second Avenue Subway platform.

Courtesy http://www.mta.info/capconstr/sas/

It is 90 years after a commission was formed to determine the feasibility of the Second Avenue Subway (SAS). Now, after a cycle of jump-starts and stalls, the TBM (tunnel boring machine) is slated to connect to the F and Q lines next year, thus paving the way for the completion of Phase 1. While it is understandable that there is a level of skepticism, Judith Kunoff, AIA, chief architect at the NYC Transit Authority, is optimistic that the 2016 deadline will be met and the new T line will soon run from 96th Street to 63rd Street.

The reasons for the delays are as cyclical as the economy. The SAS’s funding has suffered the burden of the Great Depression, WWII, the Korean War, the 1970s oil crisis, and now the latest economic downturn. Not only that, but construction itself has faced its own pitfalls due to unexpected challenges. Two 100-year-old water main feeds at 91st and 95th Streets needed to be replaced; and a Memorandum of Understanding with the NYC Department of Buildings was created to ensure that building owners are taking responsibility for their buildings’ stabilization during tunnel construction.

Nevertheless, construction has begun. Residents and business owners along Second Avenue can attest that rock excavation is well underway at 96th St. Although the “cut and cover” method that is being used is very disruptive to the Upper East Side neighborhood, it is necessary as it will allow for larger maintenance spaces, Kunoff explained. Luckily, this portion of Phase 1 is almost complete. Blasting has just begun at 72nd St. using “mined cavern” construction, which is much less disturbing as most of the work occurs under ground.

The stations themselves incorporate a combination of new sustainability goals (using green specifications) and existing standards for ease of maintenance. For example, there is an attempt to buy locally or within the U.S., the concrete mixture incorporates fly ash, and regenerative breaking is typical. Technologies are used to reduce energy consumption as well, such as heat extraction over the vehicles and air will be tempered with fans at both ends of the platforms. Also, a continuous soffit integrates mechanical, electrical, security, fire alarms, audio, and signage in one.

The design of the stations references the SAS construction. Developed by the NYC Transit Authority with AECOM, the shape of the arched canopies, escalator shafts, and egress passages represent the TBM coming to the surface. The finishes are comprised of porcelain panels and granite tiles, and flat screen panels display advertisements and Arts for Transit.

Ultimately, as has been the case throughout the SAS’s history, major funding is needed to complete the project, stated Kunoff. And while state funding and federal funding have contributed, she hoped aloud that New York State will be in the position to give more funds to help establish a capital program, or at least make a dent in the $1 billion deficit.