Digging to Grand Central

TBMs Rumble Beneath Manhattan

Deep beneath Park Avenue, tunnel-boring machines are digging their way from Second Street to Grand Central Terminal as part of the $6.3 billion East Side Access project to bring more Long Island Rail Road trains into Midtown.

“Our project goal is to bring 24 trains into Grand Central in the rush hour,” says Mysore Nagaraja, president of the MTA Capital Construction Co., the New York Metropolitan Transit Authority’s construction arm. “This will increase capacity of the Long Island Rail Road by more than 50%. This is the first time in 100 years that the Long Island Rail Road capacity has been increased.”

Currently 37 Long Island Rail Road trains arrive at Penn Station daily during rush hour. It cannot add any more trains. Once people debark, most of them face a 20- to 30-minute commute to reach the East Side. Nagaraja says demand exists for more service from Long Island, both inbound and out from the city.

“A lot of people come by car,” Nagaraja adds. “By making this available, people will give up their cars and take the train.”

MTA expects service to begin in 2014 and to serve about 160,000 customers daily.

“Every day, it’s an amazing thing to see it working as well as it is,” says Steve Lee, executive program manager for the URS-led Program Management Consultant team.

Project overview

The project brings Long Island Rail Road trains into Manhattan through two new tunnels. Trains will go underground at Harold Interlocking, pass below Amtrak’s Sunnyside Yard and connect with an existing 63rd Street tunnel, built in 1969. Subway trains run on the top two segments of the tunnel. The bottom two segments have been left unused for years.

From 63rd Street, two hard-rock-tunnel boring machines will create train tunnels under Manhattan. A station will be built deep below Grand Central Terminal.

“It’s like building a ship in a bottle because everything is coming through Queens,” says Peter Cap, project director for the General Engineering Consultant, a tri-venture between PB Americas, STV and Parsons Transportation Group, all of New York. Cap works for PB Americas.

Irv Chesner of STV and Kent Haggas of Parsons serve as deputy project directors.

“We are building this project so that the public is not materially inconvenienced and building something that will last 100 years,” Cap says. “In Queens, we are building something in the midst of and without severely disturbing the busiest passenger rail interlocking in the United States: Harold Interlocking.”

With the deep station and tunnels, the project requires ventilation. MTACC will build three emergency ventilation facilities. Neighboring properties at 50th Street objected to the planned 160-ft building, Nagaraja says. That led to a redesign of a smaller facility, with a portion of the site devoted to a park. Contracts for the ventilation facilities will be let late this year or early 2009.

Tunnel boring

Dragados/Judlau, a joint venture between Dragados USA of Spain and Judlau Contracting of New York, received the $428 million tunnel-boring contract. Dragados is a 70% partner, Judlau a 30% partner.

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Crews lowered the pieces of the tunnel-boring machine into the 63rd Street tunnel through a massive excavation. Then workers hauled the pieces through the tunnel to an assembly chamber under 63rd Street and Second Avenue, created with drilling and blasting, where crews assembled the two machines and began testing. The first machine began boring in fall 2007, and the second was in testing at the end of December.

The two 200-ton, computer-guided tunnel-boring machines will create 22-ft diameter passageways. Muck and ground rock left in its wake is moved out of the tunnel using a conveyor system.

“[The machine] reaches out with its side thrusters and holds onto the wall,” Lee says. “Meanwhile, the boring head advances to the end of its stroke. Then the grippers come back in and release the main part of the machine, and it pulls up like an inchworm. It’s pulling itself through this rock.”

Additional tunnels will branch off the two coming out of the existing tunnel under the East River. Four tunnels will run under portions of Manhattan and then eight as they close in on Grand Central. The tunnels decrease to four again as they continue past the terminal to a storage area at 38th Street. Once there, crews will partially disassemble the boring machines to move them, and then they will reassemble them to start the next branch, Cap says.

The first tunnel machine has pressed more than 2,000 ft into Manhattan, with the machines expecting to average at least 50 ft per day. Nagaraja acknowledges it’s a dangerous job and that contractors are prepared to initiate immediate grouting if a facture develops in the rock.

Pablo Diez, project manager for Dragados, anticipates finishing in July 2010.

Grand Central Station

Dragados/Judlau also received the $734 million contract to build the station envelope 140 ft below Grand Central Terminal. It involves blasting rock to create two caverns.

“We will make sure with the blasting that buildings above are well protected,” Nagaraja says.

Each cavern will house a three-level station. Each station will have two tracks and a platform, a mezzanine level above and then above that another platform with two more tracks. There will be a total of four platforms with eight tracks and a mezzanine between them. From the mezzanine, high-rise escalators will travel 90 ft to the new concourse to be built in the western portion of the lower level of Grand Central.

The new space will replace the former Metro-North Madison Yard, moved to accommodate the East Side Access project.

Cap expects work on the caverns to begin in the spring and require sophisticated staging. The first tunnel-boring machine should have reached Grand Central by then.

Working in Queens

At Wood Interlocking, Long Island Rail Road workers are putting in new turnouts, switches, instrument houses and signal bridges that will allow greater flexibility at the Queens site.

“This will be especially important for the temporary phases of the work,” Lee says. “We have to move tracks aside to get the tunnels in.”

Pile Foundation Construction Co. of Hicksville, N.Y., is excavating a 60-ft-deep, open-cut, slurry wall hole that the soft-earth-boring equipment will use for entry to tunnel underneath Sunnyside. The company bid $83 million for the contract.

“He is going gangbusters,” says Lee, who estimates the contractor has about 20 cranes working on the pit.

Nagaraja expects MTACC will award the soft-earth-tunneling contract in mid-2008.

Perini Corp. of Framingham, Mass., received a $139.2 million contract for the first phase of construction to reconfigure Harold Interlocking and tracks leading to Sunnyside Yard. Perini’s project includes putting in retaining walls, widening bridges and building an entry to the tunnel and approach structures. Civil crews will work with Amtrak and Long Island Rail Road employees moving the rails and equipment.

“There are between 700 or 800 trains that pass that area everyday,” STV’s Chesner says. “To keep them all running while constructing an open-cut approach, doing tunneling work, rerouting utilities and keeping everything on schedule will be a major accomplishment.”

Useful sources:
Metropolitan Transportation Authority
http://www.mta.info/capconstr/esas/index.html

Team Box:
Owner: Metropolitan Transportation Authority, New York
Program Manager: URS Corp, New York
General Engineering Consultant: A joint venture of PB Americas, STV and Parsons Transportation Group, New York.
Tunnel and Station Contractor: Dragados/Judiau, a joint venture between Dragados USA, Spain, and Judlau Contracting, New York
Queens Excavation Contractor: Pile Foundation Construction Co., Hicksville, N.Y.