Penobscot Narrows Bridge and Observatory
|Penobscot Narrows Bridge|
The Penobscot Narrows Bridge with the Waldo–Hancock Bridge in the background
|Official name||Penobscot Narrows Bridge and Observatory|
|Carries||US 1 and Maine 3|
|Locale||Prospect – Verona Island, Maine|
|Maintained by||Maine Department of Transportation|
|Total length||2,120 feet (646 m)|
|Height||447 feet (136 m)|
|Longest span||1,161 feet (354 m)|
|Clearance below||135 feet (41 m)|
|Opened||December 30, 2006|
The Penobscot Narrows Bridge is a 2,120 feet (646 m) long cable-stayed bridge over the Penobscot River connecting Verona Island, Maine to Prospect. 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 to utilize 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.
The bridge was designed as an emergency replacement for the Waldo–Hancock Bridge. From conception to completion, just 42 months elapsed. A unique project delivery method, referred to as "owner facilitated design/build" partnered Maine DOT with FIGG as the designer and Cianbro/Reed & Reed LLC as the contractor. The elevator system in the tower, which is claimed to be the fastest and tallest elevator in Maine,  was installed by Stanley Elevator Company, Inc.
The Penobscot Bridge site also is home to the Penobscot Narrows Observatory, the first bridge observation tower in the United States and the tallest public bridge observatory in the world.  The tower reaches 420 feet (128 m) into the air and allows visitors to view the bridge, the nearby Fort Knox State Historic Site, the Penobscot River, and Bay.
The Penobscot Narrows Observatory opened to the general public on Saturday, May 19, 2007. It is open at the same times of the year as Fort Knox (May 1 to October 31). 
The bridge has been the site of at least four suicides since its opening.  This included the Rev. Robert Carlson, a well known figure in the Bangor area, who was found in the Penobscot River beneath the bridge on November 13, 2011.  Before the bridge opened, MaineDOT was aware of many suicide attempts from the Waldo-Hancock Bridge and discussed possible pedestrian safety measures for the new bridge, but no special fencing or other action was taken. 
- "Penobscot Narrows Bridge, Maine". Dywidag-systems.com. Retrieved 2012-06-12.
- "PopSci's Best of What's New 2006". Popsci.com. Retrieved 2012-06-12.
- "Police stop distressed dad from jumping off Penobscot Narrows Bridge on Father’s Day". Bangor Daily News. 2013-16-17. Retrieved 2013-06-17.
- "Rev. Robert Carlson, Greater Bangor leader, found dead in Penobscot River". Bangor Daily News. 2011-11-13. Retrieved 2013-06-11.
- "25-year-old man dead after jumping off Penobscot Narrows Bridge". Bangor Daily News. 2013-04-01. Retrieved 2013-06-11.