Tunnel-Boring Machines Ready NY Subways

February 3, 2011

Two giant tunnel-boring machines, crawling along like worms underneath the Big Apple, made transit history. Below neighborhoods on Manhattan’s West Side, they both achieved a difficult 90° turn, helped by a ground-freezing technique—the first time TBMs have successfully excavated through frozen ground. A third machine is crawling through steel-braced earth underneath the dense urban development on the upper East Side. In Queens, another TBM is taking shape for more tunnel duty.


--Engineering News-Record