Rebuilding Underground

Top-to-Bottom Rehab Brings Upgrades to Wall Street Station

by Kyla K. Wilson

New York City Transit's Wall Street station serving the 4 and 5 subway lines is getting a much-needed $48 million makeover to replace its roof and rehabilitate the interiors.

The project entails a major reworking of a station at the heart of Manhattan's Financial District, which required the project team to ensure that its work did not interfere with enhanced security measures and operations for nearby institutions such as the New York Stock Exchange.

The project, which began early last year, was originally slated to finish in October 2009, but various breaks and breakthroughs along the way have shaved an entire year off of the schedule.

The transit agency split the main areas of focus into two contracts, one for replacing the roof structure and the other for station interiors. The overall goal is to modernize the station but also recapture its historic feel through extensive rehabilitation and restoration of details such as the original wall and floor tile, says Blanko Kleva, program manager for the transit agency's Capital Program Management division.

"We replicated and restored details so the station will look more or less like it originally did when it was put in service," Kleva adds.

The transit unit and its parent agency, the Metropolitan Transportation Authority, timed the project to take advantage of train service diversions already planned for other subway improvement projects, most notably the massive reconstruction and reconfiguration a few blocks north to create the $880 million Fulton Street Transit Center. Complete service diversions, with no trains running through the station, were available on weekends and weeknights on dozens of occasions.

"Having several projects work on the same service diversion saves support costs and reduces impact on our riders," Kleva says. "Our project required service diversions to replace the structural roof beams and rebuild the platform edge."

The service diversions also gave the project team a chance to run at an accelerated pace.

The team already has a leg up with the unexpectedly fast completion of the roof work, which was supposed to be split into one phase last year and another this year. Instead, the project team was able to finish all of the programmed work last year.

The roof work began in April 2006, with Prude Construction of Whitestone, N.Y., as general contractor. The effort entailed replacing 14 steel structural beams, each 20 ft long, which had been damaged by water intrusion over the years.

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"We had to excavate all the way from street level down to the structural roof of the station," Kleva says. "There were many utilities in the way and there was a lot of coordination."

The roof replacement team also had to manage traffic in the area because it had to keep one lane of Broadway, the road above, moving at all times under an agreement reached with the city's department of transportation.

"There was a combined effort from all the different agencies," says John Duggan, project engineer for Prude.

Along the way from street to station roof, the team relocated and replaced utilities and water mains, while also rebuilding electrical and water service manholes. It also had to support and maintain some of the utilities that it was not replacing, such as water mains and gas lines.

One of the biggest obstacles was an 80-ft-long section of a 16-in-diameter steam main, Kleva says. The main, which services most of the buildings in the area, runs almost directly above the roof, creating a tight project area with little room to maneuver the delivery and installation of the new steel beams and concrete roof slab.

The team had to remove and then reinstall the steam main, a job that it could only take on between May and October to not interrupt the heating seasons.

"We had to coordinate and temporarily support all the other utilities to get to the steam main," Kleva says. "Once the steam main was accessible, we had to coordinate with a specialty contractor working for Con Ed to abate the steam main before it could be cut out."

The roof project's original schedule envisioned the team closing the western side of Broadway and working on one part of the roof during a first phase in summer 2006, and then returning for a second phase in summer 2007 to work on the eastern side. But a key decision came in midsummer when the project team was ahead of schedule on the first phase and the city transportation department gave the green light to proceed right away with the second phase.

Various breaks contributed to the speeded-up schedule, such as receiving better cooperation than anticipated from local utilities and having a smoother time than planned with the street work.

Once the team replaced the subway roof, it again had to coordinate with another specialty contractor approved by Con Ed to install a new steam main.

Now, a separate contractor team led by Citnalta Construction of Bohemia, N.Y., is focused on the station improvements, a soup-to-nuts effort that started last year and will upgrade all current systems. The work entails the installation of new lighting, conduits, communication tools, and electrical distribution rooms, as well as installation of new floor and wall tiles.

The team is also elevating the 600-ft-long platform ledges and widening them at the track edges to meet federal Americans with Disability Act rules. Another major task is pouring a concrete base under the new porcelain tile floors.

"We are working closely with New York City Transit's landmarks consultant about approving materials and installing mock-ups prior to starting work," says Gary Yerganian, project executive for Citnalta.

Another big hurdle remains finding ways to accommodate the people who work in the crowded district.

"We have to be considerate with noise issues during the day and closures of street stairs during our daily construction operations," Yerganian says. "Delivery of materials and removal of debris are mostly limited to nights as is the use of work trains in the station. And DOT permits for the street are limited, not allowing us many choices for vertical movement of materials."

Key Players

Owner: New York City Transit

Roof Contractor: Prude Construction, Whitestone, N.Y.

Interior Station Rehabilitation Contractor: Citnalta Construction, Bohemia, N.Y.

Steel Contractor: Imperial Ironworks, Bronx

Electrical and Communications Contractor: Five Star Electric, New York

Tile-Marble-Mosaics-Terra Cotta: NY Stone & Ceramic Tile, New York