Thursday, July 26, 2012

MTA completes tunnel boring on megaprojects

MTA completes tunnel boring on megaprojects MTA

The New York Metropolitan Transportation Authority said that on Monday, Molina, the tunnel boring machine digging the last of the four East Side Access tunnels in Queens, came to a halt six feet underneath the Long Island Rail Road mainline in Long Island City, completing its run. The milestone marks the end of tunnel boring for the East Side Access project and all MTA megaprojects.

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.

The machines are each operated by crews of operating engineers working 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 Midtown and 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 Lhota. "For about 60 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."

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