Frequently Asked Questions - PNO

What year did the bridge open?

The bridge opened to traffic on December 30th 2006, the Observatory opened on May 19th 2007.

How long did it take to build?

It was designed and built in 42 Months or 3 years 1 month.  Most bridge projects of this size take a decade to plan and construct because normally a bridge is fully designed before any ground is broken. On this bridge the construction of the foundation was started before the bridge was fully designed.  

How much did the bridge cost?

$85 million, 5 million of that was for the Observatory.  65% of the money was a Federal Grant, the rest was paid for by the State of Maine.


Why is there an Observatory in the Bridge?

When the plans were made for the bridge the locals and the state wanted to do something with it that would bring more people to this area of Maine, to help the economy.  This design was chosen because it was modeled after the Washington Monument and 1/3 of the granite in that monument is from the same quarry that Fort Knox granite is from, Waldo mountain. 

How deep is the river?

At its deepest point it's around 100 feet deep.  Under the bridge and by the Fort its around 75 ft to 90 ft deep.

Why is the Bridge so high?             

It is how high it needs to be for ships to fit underneath.  Its also that high because that's how high the existing road was on either side of the bridge. The road deck is 140 feet above the river at high tide.

What kind of Bridge is this?

It is a Cable-Stayed Bridge.  The old bridge was a suspension bridge.  The difference is in how the cables are connected to the bridge towers, and how the cables support the roadway.  Suspension bridge cables are anchored to the earth on either side of the bridge then they run over the top of the towers while the road deck hangs, or is suspended, from the upper cable by vertical secondary cables running down to the road surface sides.  Cable Stayed on the other hand have cables that normally tie directly to the support tower on either side supporting the road surface through the center

How many cables are in the bridge?

There a different number of cables in each of the stays depending on what position they are in the bridge.  In the bottom cable stay there is 41 cables and the top cable stay has 73.  The cable stays in between have a varying number of cables depending on their location.  There are 331 miles of Epoxy coated steel cables in the bridge.  Which is about the distance from Portland to Fort Kent. 

What kind of Rock is the cliff and parking lot made of?

The rock in this area is known as the Penobscot formation.  It is made of a sulfide rich schist derived from black shale.  When the approach to the new bridge was made 340,000 tons of rock were blasted from the Prospect side.  Much of that rock was then used to make the parking area for the Observatory. 

Where is the Granite from?

All of the granite used in the construction of the bridge is Maine granite.  The Granite in the patio, facade, and lobby floor is all from Mosquito Mountain in Prospect.  The granite in the elevator floor and the floors up in the         Observatory is all Deer Isle granite.  You can tell the difference when looking at them because the Deer Isle granite           has a pinkish hue to it.

How many segments make up the bridge?

There are 181 segments that make up The Penobscot Narrows Bridge and Observatory.  Each segment weighs 300,000 pounds. They are made up of 70 cubic yards of concrete, and 20,000 lbs of steel re-bar.  Each individual     segment is 12 ft, 10 inches tall, they are 31 feet wide at the base, and 57 ft, 6 inches wide on the top (the road surface). 

What is the white stuff in the water?

It is sea foam.  It is created by the agitation of seawater.  Turbulent conditions trap air, forming persistent bubbles     that stick to each other through surface tension.  Where this area of the river is very deep, there are some very strong currents that agitate the water.  This causes the lines of sea foam that you can see when looking at the river. 

What does the word Penobscot mean?

The word Penobscot is a Native American word.  The local Native Americans from this area are known as the Penobscot Nation.  The word itself means 'rocky part” or “descending ledges”, which referred to a part of their               territory on a portion of the Penobscot River.

How far does the river go north?

The Penobscot river is 109 miles long. Though when you include the rivers West and South Branches it increases the length to 264 miles, making it the 2nd longest river system in Maine and the longest entirely in the state.  The west branch goes all the way to the Canadian border.

What kind of fish are in the Penobscot River?

One of the most well known types of fish are the Striped Bass, known as Stripers that start 'running' around the beginning of July and can be caught into September.  Other types of fish that live in the river are Alewife, Atlantic Salmon, Rainbow Smelt, Blueback Herring, American Shad, Atlantic Sturgeon, Shortnose Sturgeon, Sea Lamprey, and Mackerel.   Around the Bridge it is very common to see seals and sometimes harbor porpoises, every great once in a while even a whale will make an appearance.