Robbins machines mine under NYC?s Grand Central Station

The machine was launched in October 2007, about three months ahead of the second 6.7 m (22.0 ft) diameter Robbins Main Beam TBM boring a parallel tunnel.   The two machines for the Dragados/Judlau JV have performed satisfactorily considering the tough conditions, averaging 9.8 m (32.4 ft) per day (Double Shield machine) and 11.1 m (36.6 ft) per day (Main Beam machine).

The Robbins Main Beam TBM boring the westbound tunnel has maintained good production rates despite difficult ground conditions. The drives are separated by a slim 1.5 m (5 ft) pillar of rock, providing minimal tunnel support. "Crews have reduced the gripper and thrust pressure by 45 to 50% in order to ensure that the force reacted against the tunnel walls is within safe limits," said King Daniels, Field Service Manager for Robbins.  The machine as of early July has mined about 1,400 m (4,560 ft) of its initial 2,600 m (8,530 ft) drive.

Both machines will be used to excavate multiple headings underneath Grand Central Station, requiring that they be retracted out of the freshly bored tunnels. The split tunnels will connect to various underground caverns beneath Grand Central Station.

The entire project for East Side Access consists of twin 13.7 km (8.5 mi) long tunnels traveling in eastbound and westbound directions beneath the East River.  Once operational in 2013, the new line will serve 160,000 commuters daily traveling between Manhattan and Queens.


Contact:
The Robbins Company
Brianna Home, Marketing Director
29100 Hall Street
Solon, OH 44139
USA
Email: homeb@robbinstbm.com
Internet: www.robbinstbm.com