The Penobscot Narrows Bridge is a 2120ft long cable-stayed bridge that carries US 1/SR 3 over the Penobscot River. It connects Verona Island to Prospect, in the U.S. state of Maine. It replaced the Waldo–Hancock Bridge, built in 1931.Technical informationThe Penobscot Narrows Bridge is one of three bridges in the US 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. Each strand acts independently, allowing for removal, inspection and replacement of individual strands. The cable-stay system was designed with a system that uses pressurized nitrogen gas to defend against corrosion.In June 2007, six reference strands within three stays were replaced with carbon fiber strands – a first in the US. Monitoring on the strands will evaluate this material for future use in bridge designs. These engineering innovations helped the bridge appear in the December 2006 edition of Popular Science as one of the 100 best innovations of the year. The total project cost was $85 million.