2001 - 2001 Narragansett Bay Commission CSO Tunnel Providence, RI

A 30-foot diameter, 690-ton hard-rock tunnel boring machine was used for the excavation through rock formations for the tunnel’s main spine along with various other excavation support techniques. The project also included constructing a 50-million-gallon-per-day pump station within a gymnasium-sized cavern carved out in rock 30-stories below ground; a state-of-the-art computer control system; and seven near-surface facilities that include structures for diverting overflows into 250-foot deep drop shafts.