 It replaced the Waldo–Hancock Bridge, built in 1931.The Penobscot Narrows Bridge is one of three bridges in the US (the others being Zakim Bridge in Boston, Massachusetts, and Veterans' Glass City Skyway in Toledo, Ohio) constructed recently using a cradle system that carries the strands within the stays from bridge deck to bridge deck, as a continuous element, eliminating anchorages in the pylons.Each epoxy-coated steel strand is carried inside the cradle in a one-inch steel tube.