The contractor-owned Robbins machine was refurbished and redesigned in Cleveland, Ohio and Mt. Pleasant, Pennsylvania facilities following its most recent excavation at New York’s Second Avenue Subway.
Its latest rebuild was complex, Robbins stated. However, the machine is scheduled to be launched from a deep shaft in early 2013, proceeding towards the Belmont Wastewater Treatment Plant in what is expected to be competent limestone and dolomite rock. Robbins continuous conveyors, including a horizontal and vertical conveyor, will aid in muck removal on the long drive.
Once complete, the tunnel will be lined with un-reinforced concrete, making the finished diameter 5.5m. Cleaner water is the ultimate goal of the city’s new Deep Rock Tunnel Connector, along with four shorter tunnels that will be added on afterwards. The tunnel will convey up to 2.1 million m3 (550 million gallons) of combined sewer overflows daily to the Southport Advanced Water Treatment Plant. By 2025, the network of five tunnels will total over 40km, and will reduce wastewater overflow into the White River, Fall Creek, Pogues Run and Pleasant Run waterways by 95 per cent or more.
