When an agency has completed a mile-long pair of 22-ft-dia tunnels deep under a river and 140 ft beneath New York City, one might think that would be enough for one project. But that’s just the beginning for the $7.2-billion East Side Access project.
While 800,000 cu yd of excavation for station caverns continues just feet from one of the world’s busiest rail terminals, contractors are gearing up for another tough tunneling task on the other side of the East River in Queens—in one of the world’s busiest rail interlocking yards. The first segments, as heavy as 270,000 lb, of a slurry-shield TBM are being placed in preparation for excavation of 10,500 ft worth of tunnel. The two TBMs, with 22.5-ft-diameters, will be the first of their kind to be used in New York in conjunction with precast concrete lining.