Where is the best place to build a new train maintenance facility and car washer?
For the Metropolitan Transportation Authority/New York City Transit (MTA/NYCTransit) it was within the bus depot in Corona, Queens, where an existing train maintenance facility and car washer actually existed.
Work began on the new $165-million facility on Dec. 30, 2002, and not only will a new facility replace an existing one, but it is a design-build project led by Slattery Skanska of Whitestone, NY.
According to Slattery Skanska Project Manager Mike Viggiano, MTA/NYCTransit bid the project as a design-build contract to streamline the construction process.
“We were able to perform work in the front yard, while building designs were being completed. This saved a year off the project schedule,” he said.
The existing yard consists of a front yard and a backyard. The front yard has approximately 20 tracks and the backyard has 12 tracks, Viggiano explained.
“We demolished the entire backyard where the new facility is being built,” he added.
Scope of Work
The project is divided into three phases. The first phase includes four buildings: 110,000-sq.-ft. (10,219 sq m) maintenance shop with five tracks to service trains and a three-story space consisting of administrative office space; a 3,000-sq.-ft. (278 sq m) car washer building with an accompanying service building and two washer sheds; a 2,106-sq.-ft. (195.6 sq m), two-story signal building to house the signal equipment; and a 1,200-sq.-ft. (111.5 sq m) circuit breaker house that contains the direct current switchgear equipment for the tracks.
“This is a complicated project because we are interfacing with two operating departments of MTA/NYCTransit: its bus division and its subway division,” Viggiano said.
To build the new facility after demolishing the front yard, “We re-powered the front yard and ran duct backs throughout the entire track,” added Slattery Skanska Project Engineer Paul Olson.
To accomplish this, Viggiano said, a Komatsu PC45 that could be driven on the tracks was used to do the trenching for the ducts. Trenching was approximately 5 ft. (1.5 m) deep. More than 4,000 cu. yds. (3,058 cu m) of earth was removed, trucked off the site and disposed of as residential fill in New Jersey, he added.
The first phase of the project also required pouring 4,000 psi concrete. To accomplish this, a Geismer track crane was used to fill buckets driven down the tracks as much as 300 to 400 ft. (91.4 to 121.9 m), to pour the concrete.
Temporary Car Washer
Viggiano said the first phase also consisted of building a temporary car washer on a 25-ft. (7.6 m) high elevated track that leads into the yard.
“This part of the design won the project for Slattery Skanska because the original bid had multiple phases that would have required the original car washer to be kept in service during construction,” he explained.
Continuing, Viggiano said, “By building a temporary car washer, we were able to move MTA/NYCTransit operations outside the yard, permitting work to advance more smoothly.”
The first phase, which was completed by February 2004, also included construction of the circuit breaker house.
The second phase of the project, which began by February 2004 and is expected to be completed by February 2006, includes taking the backyard out of service, demolition of the 12 tracks, demolition of the existing car washer and clearing of the site.
“We designed the job to allow for the existing ballast to be left in place,” Olson said with regard to the second phase of the project.” He added that the project is “located in a wetlands area with a 100-year flood plane. As a result, the support or foundation required the driving of 18-inch Tapertube piles.”
In all, 1,400 piles were driven. They range in depth from 105 to 135 ft. (32 to 41.1 m). These piles were driven using a Junttan PM20 pile driver. The Junttan was used because of its easy maneuverability within tight spaces, Olson said.
The second phase also includes construction of the maintenance shop as an elevated slab structure 6 ft. (1.8 m) above the ground. Olson said the slab structure had to rise over the 100-year flood plane. It contains more than 10,000 cu. yds. (7,645.5 cu m) of 4,000 psi concrete, Viggiano added.
Next, Viggiano said, the project team built the steel structure above the maintenance facility. This structure consists of 1,800 tons (1,633 t) of steel.
Prior to erection of this steel, the 20,200-sq.-ft. (1,877 sq m) office portion of the building was erected using a 45-ton (40.8 t) Tadano cherry picker.
Next, the 120-ft.-wide (36.6 m) shop portion of the building was constructed. This consisted of 120-ft.-long steel trusses that were set using a Liebherr 300-ton (272.2 t) capacity hydraulic crane, he pointed out.
This phase also included construction of the signal building and car washer.
The third phase of the project, which is scheduled to take place from February 2006 through July 2006, will consist of moving MTA/NYCTransit into the new facility and then construct an on-grade, 1,000-linear-ft. (305 m) loop track, Viggiano explained.
Key project challenges included pouring the 20-in. (50.8 cm) thick elevated slab 6 ft. (1.8 m) off the ground.
According to Olson, “The elevation of the slab changes twice. One elevation is eight feet off the ground and the second elevation is from five to 6 feet off the ground. To pour the concrete with these elevations required formwork,” he added.
“We went to several formwork suppliers and after a long process, decided on Conseco Doka’s Euraex Prop System. This system consists of steel props and timber beams to form a deck to create a bottom form for the slab,” he explained.
Constructing the temporary car washer was another key project challenge because it had to be built on an elevated structure, which has never been done before for MTA/NYCT Transit, Viggiano said.
The solution to this challenge was ”executing the impossible by implementing a Slattery Skanska design,” he added.
Other project challenges included keeping an existing track operational while work progressed. This, Olson said, required extensive planning and coordination among all project team members.
Another challenge was logistics. Olson said the footprint of the building was the same as the footprint of the backyard. This meant access to the work area could only take place through the bus depot. As a result, the daily delivery of materials, including the 120-ft. long steel trusses, had to be carefully scheduled and coordinated.
Viggiano and Olson agreed that the project, as complicated as it is, is on budget and will be completed on schedule. CEG