Several proposals have favored a bridge, dismissing the tunnel concept as too costly to build and maintain. Others have backed a tunnel-only or hybrid design, including a 2017 feasibility study launched by then-New York Gov. Andrew Cuomo. Despite the time and effort spent researching the plans, none of them have advanced to the point of construction, hampered by concerns over cost (about $50 billion, according to the 2017 study), environmental harm and a lack of political support. It remains to be seen whether Steven Shapiro, the Easton developer and project’s latest steward, can bring it to fruition. For a Sound crossing, Perez said he envisions crews working from barges to drive pre-assembled concrete piles into the seafloor at shallower depths, since deeper foundations are typically more complex and costly. Another option is to build an underwater tunnel using a tunnel boring machine. Sometimes called a “worm” or a “mole,” these massive cylindrical machines would eat through soil and rock beneath the Sound’s floor and spit it out through a pipe on the other side, where it would be transported to the surface on a conveyor belt. As it excavates, the machine would install pre-cast concrete sections to form the tunnel’s lining.
Bridge, tunnel or both? The 90-year struggle to connect Long Island and Connecticut
