|OPEN SPACES Larger, lighter mezzanines allow for greater circulation. (Photo courtesy of Slattery/GOTTLIEB)|
As they renovate their 100-year-old subway system, New York Citys transit officials are taking a fresh look at how to improve functionality, aesthetics and connectivity. Working beneath the surface, within utilities and around trains that never stop operating, contractors and engineers are improving 468 subway stations within four boroughs, performing technical feats while keeping the trains running.
The system celebrates its centennial this year, which is also the final year of a $10-billion, five-year capital improvement program. It includes $1.9 billion for rehabilitating 64 stations, $607 million for replacing 40 miles of track, $2 billion for new cars, $650 million for mechanical and ventilation equipment, $654 million for track structures and $1 billion for signaling upgrades.
The project builds on efforts begun in earnest 22 years ago. Work has evolved from cleansing graffiti from neglected stations to making aesthetic and maintenance improvements with a balance of engineering and architecture. A reorganized New York City Transit Authority now emphasizes a variety of contracting methods and engineering techniques. In many cases, they must accommodate what are now regarded as landmark structures.
"Stations in the past 20 years have been landmarked, and design guidelines were created for maintaining mosaics, artwork, et cetera," says Peter Samton, partner with Gruzen Samton LLP, New York City. Using guidelines developed by Rolf Ohlhausen of Ohlhausen DuBois Architects, New York City, "the idea was not to demolish everything, but to preserve and add on," he says. Now, 1% of each station projects budget is dedicated to artistic elements, including exhibits from the Arts for Transit program run by the citys Cultural Affairs Dept.
|LEADING Former chief engineer Nagaraja emphasized clearing red tape. (Photo by Aileen Cho for ENR)|
Mysore Nagaraja, president of the Metropolitan Transportation Authoritys Capital Construction Co. and subway chief engineer from 1996-2003, says hazardous material removal is a big issue. "The contractor would find asbestos and other hazardous materials, and that would delay the job," he says. "Now, all hazmat is taken out before the contractor gets there."
Such improvements helped keep 75% of the transit authoritys 1995-1999 capital program, including 42 station jobs, on time and within budget, officials say. Nagaraja says total claims during his seven-year tenure amounted to $100 million on $7 billion of capital program work.
"The transit authority developed a structure with principal engineers" for every speciality, such as project controls, estimating and scheduling, says Jerome Gold, vice president in the New York City office of Carter & Burgess, the authoritys project management oversight consultant.
Value engineering and a variety of bid letting, including a two-step technical+low price negotiation for more complex stations, encourages innovation, say contractors. "Its a cooperative effort with the TA," says Norman Hirsch, project manager with contractor Slattery Skanska, New York City. "They pick your brains for the best ideas."
"We could say, Were the owner, well do whatever we want, but you have to listen and respect your contractors," says Nagaraja. He also eschewed micromanaging. "I say that if I dont know much about a project, it was a success."
By 2020, 100 stations will comply with the American Disabilities Act as new elevators, wider ramps and other measures are installed. "Our goal is that by 2019, all 468 stations will be in good repair," says Nagaraja. "Thats about 80 stations every five years."
Station work is hampered by 24-hour operations and congested conditions. In some cases, several stations in a row are closed completely for fast-track work, increasing the need for community outreach and communication.
Aesthetics has played an increasing role in the program. At Manhattans 72nd Street station, designers could not easily widen platforms because extensive utility relocation would swell the budget to $100 million instead of the allotted $40 million, says Samton, whose firm partnered with architect Richard Dattner LLP on the design. A new brick headhouse, a 20-ft platform extension, elevators and a skylight were built "within strict dimensions above the tracks while keeping trains and people moving," Samton says.
|FITTING IN 72nd Street station redesign emphasized circulation and community context. (Photo courtesy of Gruzen Samton LLP)|
Further north, four subway stations in the Columbia University area were renovated simultaneously in 14 months. Columbia, eager to have the stations done for its 200th anniversary, donated $1.5 million to the $85-million construction cost. Brooklyn Museums station also was included in the nine-month fast-track design because of its anniversary. Features such as glass wall blocks exemplify a transit trend "toward architecture for a common humanity," says Lonnie Coplen, Carter & Burgess project manager.
But in other stations, circulation and connection improvements take precedence, says Coplen. At 53rd Street on the Lexington line, traversing Manhattans east side, a $60-million project involved constructing a new mezzanine with a connecting elevator and escalator to two platforms. The first is about 25 ft below street level and the second 30 ft below that.
There, Slattery Skanska crews installed overlapping augered concrete secant piles to form a watertight box. Steel sheeting was not used because of concerns of vibrations to nearby office buildings and a hospital, says Hirsch. Crews used two rigs, one working from the surface and the other some 11 ft below at the mezzanine level, to place the piles. When the box was complete, they dropped a shaft another 65 ft to the deepest subway line for an escalator.
|DEEP Times Square cross section shows utility layers, similar to those in Brooklyn (shown below). (Photo courtesy of NYCTA)|
At the authoritys request, the escalator was installed 11 months ahead of schedule, earning the contractor a $25,000 bonus. Though that was the only item to be officially accelerated, "we hope to be out of here by the end of this year" instead of February 2005, says Hirsch.
The systems most recognizable station is probably Times Square, now in the midst of a $262-million, eight-year renovation. Twelve subway lines service the sprawling 50,000-sq-ft, five-level station. Reaching 60-ft-depths, it is used by 500,000 people daily in the heart of Manhattan. To ease and increase access to the trains, contractors are widening and creating pedestrian passages, breaking through multiple levels for new elevator/escalator shafts and broadening token booth lobbies.
The projects $91-million second phase, being performed by a local joint venture of Schiavone/Granite Halmar, is scheduled for a 2006 completion. Some 7,000 sq ft of old storage rooms have been converted to offices, and a new entrance to the shuttle to Grand Central Station constructed, says Liam Dalton, assistant project director for CTE Engineers. CTE is in joint venture with Bovis Lend Lease as construction manager for phases 1 and 2.
The $85-million construction of Phase 1 included extending the main entrance by 10 ft, widening passages by up to 6 ft, and building new entrances in conjunction with new office buildings, notes Mike Sweeney, project executive for CTE.
The design by local architects William Nicholas Bodouva & Associates and Kohn Pedersen Fox included natural lighting, new ventilation and speaker systems and new "transparent" stairwells that allow for better surveillance of platform activity. The elements are continued in Phase 2.
|(Photo top courtesy of NYCTA; bottom courtesy of Turner Construction)|
One mezzanine was widened from 12 ft to 60 ft. A 48-in. water main over the station roof had to be supported while the roofand the streetwas raised 3 ft for a temporary decking system. Forty-four cast-iron duct banks were opened and relocated.
Crews demolished a 120-ft passageway and are reconfiguring a "mixing bowl" of walkway ramps with new staircases, three elevators and two escalators. The station is so maze-like that early in the job Dalton told one station worker, "Dont leave me, or Ill get lost," he says.
One 700-ft-long busy passageway needs retiling and relighting. "We filmed a video and showed it to user groups to convince them to let us close it at night and get it done quickly," says Sweeney. The job will take eight nights.
Phase 3 will entail a 24-month schedule to shift tracks 250 ft and create a center platform for the arriving and departing shuttle trains to Grand Central Terminal. That phase, estimated at $85 million, is scheduled for completion in 2006.
Times Square station is not the only one with multiple transfer lines. Atlantic Avenue in Brooklyn has 10, plus a connection to the Long Island Rail Road. Designed by a joint venture of architect di Domenico + Partners and Parsons Brinckerhoff, New York City, the renovation features a mix of enhanced circulation and artistic elements, such as wave designs along an improved walkway to Pacific Station. The $160-million rehabilitation also features a unique method of suspending the subway lines box tunnel, supporting the weight of the street with 90-ft-long temporary supports. Passages also were widened from some 20 ft to 60 ft, while trains kept running.
|MAMMOTH EFFORTS Major station rehabilitation work such as at Atlantic Avenue in Brooklyn ranges from elevated tracks to underground platforms. (Photo courtesy of Slattery/GOTTLIEB)|
Extensive pile tests were conducted before the project kicked off in 2002 because the method had never been done on a NYCTA subway station before, says Vijay Verma, NYCTA construction manager. "The method saved [a year]," Verma says, "and it was safer" than excavating in sections.
Local consultant Irwin Toporoff says he conceived the scheme on a previous highway job. "We came up with the idea of putting piles through the street," he says. "Here, they put them through the platform of the structure."
Workers brought 10-in.-dia, hollow steel pile tubes in 5-ft segments by work trains. From there, they drilled the piles 70 ft through the subway platforms and a lower concourse level into sandy soil. They erected the piles segment by segment, filling them with concrete.
|PARTNERS Diffley, Verma and Abdullaziz did Atlantic Ave. (Photo by Aileen Cho for ENR)|
Thirty-ft-long steel crossbeams weighing 300 lb per ft were delivered by work trains and forklifts equipped with rubber belts to minimize noise and chance of electrification from contact with the third rail, says Riadh Abdulaziz, project director for Turner Construction Co., New York City, the construction oversight manager.
The forklifts threaded between platform columns spaced at 15 ft. To set the beams crosswise across the roof, crews with contractor Schiavone Construction, Secaucus, N.J., used cable winches and forklifts with special clamps on both sides of the track. "Headroom is so sensitivenot even a foot," says Abdulaziz. "Excess vibrations could not be allowed."
The 28 beams sat on the temporary piles to accept the transfer of the roof weight with special "pancake" shallow jacks inserted between the roof and girders. On a good weekend night, up to 12 beams could be placed.
|CONGESTED Workers deck a busy Manhattan street. Photo courtesy of Slattery Skanska|
The structural steel of the track beds, also supported on temporary piles, was replaced from the level below, where workers also built new steel columns to support widened passageways. "Wed come in, demolish a part of track, install the temporary steel, put in the piles, build the track, and repeat," says Bryan Diffley, Schiavone general superintendent. "We poured up to 100 ft worth of track invert in one weekend."
To support the street, two 40-ft-deep holes were excavated from the surface so that structural steel beams could be lowered through the 4-ft-thick subway roof. With the aid of sixteen 8-ft-dia caissons the beams supported street decking while one passageway was widened from 12 ft to 60 ft.
The job entailed widening 15 stairways, installing eight elevators, relocating utilities and renovating a small old station house that the community deemed a historical landmarkso much so that "I went to Minnesota to find special bricks," says Abdulaziz. "They cost $4 each." The headhouse, renovated for about $500,000, now sits floorless on the station roof, acting as a skylight. The four-year rehabilitation is almost complete.
While artistic and historical elements are becoming de rigueur for New York City stations, energy efficiency is following close behind. In Queens, the $87-million Roosevelt/74th St. station rehabilitation features photovoltaic panels generating solar energy on the canopy roof structures of the new mezzanine.
|DEEP SHAFTS Adding subway escalators and elevators is tricky in tight spaces. (Photo courtesy of Slattery Skanska)|
"We will use what we did at Roosevelt as a model," says Dan Kaplan, senior principal with Fox & Fowle, the New York City architect. "It could serve as a prototype for the rest of the system." The panels are about 8 x 8 ft and allow for improved ventilation, says Ben Malamed, senior structural engineer for locally based Vollmer Associates LLP, the structural engineer. Kaplan adds that through computer models for the platforms, "we opened up the windows to act as a chimney pulling air out of the ground" to reduce summer temperatures for waiting passengers and create more air movement. The emphasis on "sustainable design" was first used on the rehabilitated Stillwell Avenue station in Brooklyn, says Malamed.
Matching the curved clamshell shape of the roofs steel pieces with poured concrete was challenging, says Victor Paterno, project manager for Slattery Skanska. The contractor must also relocate a 42-in.-dia, 30-ft-deep sewer so that the passageway over it can be widened. Four elevators are being added, stairways widened and an elevated mezzanine over the street will be widened 30 ft, requiring nighttime street closures, says Talib Lokhandwala, NYCTA construction administrator.
|TEAM Paterno, Lokhandwala, Portes discuss 74th St. (Photo by Aileen Cho for ENR)|
An adjacent intermodal bus depot is also being rebuilt, with six roof trusses 45 ft to 108 ft long and 8 ft deep replacing piers. They will allow for four 12-ft lanes, says Stuart Lerner, Vollmer project executive. The entire job is scheduled to be completed in late 2005, but "were pushing for completion by the end of this year," says Seymour Portes, NYCTA station rehabilitation program manager.
Other significant jobs in the 2000-2004 program include a $198-million, 10-station rehabilitation in the Bronx, to be done in 24 months; the $33.8-million DeKalb Avenue station in Brooklyn; and five stations along Brooklyns Canarsie line, an estimated $40-million job with bids to be let this summer, says Portes.
The next budget cycle will include work such as new 25-ft-long passages between two Brooklyn stations and a major Columbus Circle complex renovation. MTA Capital Construction Co. will administer the new Fulton Street Transit Center and the South Street Ferry terminal construction as part of the downtown Manhattan redevelopment, plus the Second Avenue Subway and 7 Line extension to Pennsylvania Stationpending sufficient funding.