Photo by Bruce Buckley/ENR

Crews at Sparrows Point, Md., are wrapping up six tunnel tubes that will create roughly half of the new Elizabeth River Tunnel. The immersed tube tunnel will link Norfolk, Va., and Portsmouth, Va. Crews for SKW Constructors built the tubes, which each consist of five reinforced concrete sections, in dry dock and installed temporary bulkheads for buoyancy. In June, with the aid of tub boats, the tubes will float 220 miles down the Chesapeake Bay to the construction site.