Boasting 17 million acres of forestland and 3,500 miles of coastline, Maine is known for its abundance of beautiful scenery. The completion of the new Penobscot Narrows Bridge and Observatory — the first bridge observatory in the United States and the tallest public structure of its kind in the world — is making it even easier for natives and tourists to partake of the Pine Tree State's picturesque countryside.
The Penobscot Narrows Bridge extends 2,120 feet over the Penobscot River and is the state's first cable stay bridge, connecting the town of Prospect with Verona Island. Two 447-foot pylons flank either end of the edifice, with the westerly Prospect pylon housing the observatory and its four-level glass observation deck. The 42-story observatory, accessed via a speedy 50-second elevator ride, offers 360-degree views of the Midcoast and Down East, Maine.
Overseen by Maine's Department of Transportation, the project's general contractor was the design/build joint venture of Cianbro Corp., Pittsfield, Maine, and Reed and Reed of Woolwich, Maine. E.S. Boulos, headquartered in Westbrook, Maine, was contracted to perform approximately $1.4 million worth of power, lighting, fire alarm, lightning protection, and other specialty electrical installations for both the bridge and observatory.
“What made this project unique was planning for the staging of materials and tools to support the work because of the limited work area and the number of trades working at the same time,” says Wade Stedt, E.S. Boulos' project manager at the time of the bridge and observatory's construction. “Another issue was the activity taking place above and below where we happened to be working and the safety aspects involved. For instance, cranes would be operating to build the tower, and our men would be working on the deck or on the ground level. You also had work taking place on the bridge level and up in the pylon towers. People had to be aware of that.”
A 12.4kV feeder located on the Verona side of the bridge supplies the primary electrical power for the bridge and observatory. In addition to cabling that runs through the bridge deck and down the pylon on the Prospect side, the bridge features an emergency standby power generator in case of a power outage.
Other lighting includes FAA luminaires situated at the top of the bridge pylons for aircraft as well as navigation beacons within the underside of the bridge deck for ship guidance.
“Aesthetic lighting fixtures on the bridge deck illuminate the cable stays and pylons,” says Stedt. “At night, you can see them from many miles away.”
The utility tunnel, located inside the deck structure, also contains lighting and receptacles. To provide fire protection, smoke detectors, horn strobes, and other alarm-signaling equipment are connected into the structure's sprinkler system. In addition, the bridge and observatory are equipped with a lightning protection system, which was designed by Figg Engineering.
According to Stedt, a crew of 12 electricians from IBEW Local 1253 worked throughout the 18-month project.
“One of the most notable aspects of the project is the 4-level observation deck,” he adds. “The views from up there are just incredible.”