Tunnel Boring Completed on All MTA Megaprojects

At 7:30 a.m. on Monday, July 23, 2012, Molina, the tunnel boring machine digging the fourth of four East Side Access tunnels in Queens, came to a halt six feet underneath the LIRR Main Line in Long Island City, completing its run. The milestone marks the end of tunnel boring for the East Side Access project, and in fact, all MTA megaprojects.

Image of Second Avenue Subway Tunnel Boring Machine

A fleet of seven monstrous 200-ton tunnel boring machines have inched their way forward underneath the city since the first one launched in the fall of 2007. For the first time in five years, the machines' grinding, shrieking roar is no longer reverberating through the earth under the city.

The machines are each operated by crews of operating engineers working a score strong around the clock; they have tungsten carbide rotating-disc cutters embedded on a 22-foot-diameter shield, and trailing gear that could stretch the length of several Manhattan blocks. The machines have built 13 miles of new tunnels through the mica-inflected granite schist that anchors the skyscrapers of Midtown, and through challenging boulder-strewn soft ground in Long Island City, Queens.

Among its many destinations, the muddy crushed rock that is created by the digging, known as muck, has been put to use in the foundations for new college dormitories in Jersey City, stable soil under a golf course, and fill that created Brooklyn Bridge Park along the Brooklyn waterfront. But what is most important to future generations of New Yorkers will be the tunnels in place where the rocks and dirt once stood.

"Sixteen brand new, concrete-lined tunnels now exist under New York City where none did five years ago," said MTA Chairman Joseph J. Lhota. "For about sixty years, two generations, the New York transit system was essentially functioning in a status quo, with little action on expansion to meet the needs of a growing region. Today, we are lengthening a subway line, building the first quarter of what will be a new north-south trunk line running the length of Manhattan, and realizing a long-held dream of connecting the Long Island Rail Road to Grand Central Terminal. The conclusion of tunnel boring reminds us that New Yorkers remain capable of great achievements."

"Although we've completed tunneling, many components of these megaprojects remain to be completed before service can begin," said Dr. Michael Horodniceanu, President of MTA Capital Construction. "In the months and years ahead, workers on all three projects will continue to excavate station caverns. They will build the platforms, stairways, mezzanines, elevators and escalators that will make up the new stations. They will lay tracks and third rail and install electrical and signal systems and communications equipment. They will build facilities that will allow for ventilation, air temperature moderation, and emergency access to these new tunnels. Much work remains to be done."

In order to accommodate the boring of East Side Access' final tunnel, the Long Island Rail Road had temporarily canceled three evening rush hour trains and modified the schedules of an additional eight. Now, crews will begin to secure the machine in place, and trains service is expected to return to normal sometime next week. Details of service restoration will be forthcoming in a subsequent press release.

Videos of selected tunnel boring milestones can be seen at these links:

Here are details of the MTA's seven tunnel boring machines and the work they performed on the MTA's system expansion megaprojects.

TBM Project Started Ended Feet Mined Runs Starting Point Fate

"Adi"

Second Avenue Subway

May 14, 2010

Sept. 22, 2011

14,951

2

92nd Street and Second Avenue

Finished at 63rd Street and Third Avenue. Refurbished and shipped to Indianapolis for work on another project.

"Georgina"

7 Extension

July 21, 2009

July 15, 2010

4,655

1

Eleventh Ave & 26th St.

Finished under Port Authority Bus Terminal & dismantled

"Emma"

7 Extension

June 12, 2009

June 11, 2010

4,630

1

Eleventh Ave & 26th St.

Finished under Port Authority Bus Terminal & dismantled

SELI

East Side Access

September 25, 2007

June 10, 2011

16,163

4

63rd Street & Second Avenue

Buried under Park Avenue at 37th Street

Robbins

East Side Access

December 21, 2007

May 27 2010

16,306

4

63rd Street & Second Avenue

Dismantled and removed by contractors.

"T.E.S.S."

East Side Access

July 9, 2011

May 30, 2012

4,118

2

Sunnyside Yard Launch Box

Being scrapped.

"Molina"

East Side Access

May 17, 2011

July 23, 2012

6,503

2

Sunnyside Yard Launch Box

Being scrapped.