Monday, July 30, 2007

Bridge Is a Marvel


One thing that happens when you take Route 1 up the coast to Acadia (again, not that we necessarily recommend doing so) is that you take the brand-new Penobscot Narrows Bridge. And I mean brand-new. Last July when we passed through Bucksport, we still crossed on the old suspension bridge. It's an impressive sight: The NY Times wrote about the new bridge recently:
July 10, 2007
Sure, the Bridge Is a Marvel, but How About the View?
KATIE ZEZIMA

The most breathtaking view in Maine, some say, cannot be seen from the summit of one of the state’s majestic peaks or a bluff overlooking the ocean.

Instead, they say, the best way to see the state’s natural beauty is atop something manufactured — the 420-foot public observation tower of the Penobscot Narrows Bridge and Observatory.

The observation tower, which opened in May and is the only one in the United States, provides an awe-inducing panorama of Maine’s mountains and coastline and a bird’s-eye view of the nearby village of Bucksport. The bridge opened to traffic in December.

The bridge, a 2,120-foot-long span that seems to pop up out of nowhere in this rural area about 20 miles south of Bangor, is being heralded by two very different stakeholders.

Civil engineers see it as a major innovation and a test case for cable-stayed bridges, while local tourism officials hope it will attract visitors to an area that many speed past on the way to Acadia National Park, Bar Harbor or the Canadian Maritime provinces.

...

The 13-foot-by-25-foot observation room, accessible by an elevator, offers a 360-degree view that includes the Penobscot River, islands in Penobscot Bay, mountains, hills and lots and lots of trees.

On a clear day, visibility extends 100 miles, allowing visitors to follow the curving, wide river north toward the peak of Mount Katahdin. Cadillac Mountain in Acadia National Park and the rolling Camden Hills can also be spotted.

The local view from the top of tower, an obelisk modeled after the Washington Monument, is just as impressive. The town of Bucksport beckons below, with boats bobbing in the harbor and gray-shingled buildings lining the streets. Fort Knox, a military installation built in 1844 to protect the Penobscot Valley, lies just below the bridge.

“It’s phenomenal,” said Sharon Dunbar, 43, who grew up in Bucksport and lives in Middlebury, Vt. “It’s amazing to see my hometown so clearly from up there and look down and see the waterfront and all the views. It’s breathtaking, just amazing.”

The $89 million bridge is one of a kind, civil engineers say. A typical cable-stayed bridge, in which cables stretch from one or more towers to support it, uses steel cables. This one is the first in the nation to test carbon composite cables, which are believed to be stronger than steel cables and more resistant to corrosion, said Tom Doe, the bridge’s project manager.

Six carbon cables, along with hundreds made of steel, are encased in stays, or the long, white tubes that make up the bridge. The cables are normally bundled together and placed in the stay, making it difficult to replace a single cable. But the Penobscot Narrows Bridge uses a cradle system where cables have an inch or so between them. This allows engineers to pull up to two strands out of each pylon to check them for structural integrity or switch from steel to carbon.

...

The Penobscot Narrows Bridge was a rush replacement for the neighboring Waldo-Hancock Bridge, a suspension bridge that deteriorated and corroded. Building a cable-stayed bridge took the least time and money, Mr. Doe said. The bridge’s concrete structure will also ensure that it lasts longer than a steel bridge, said Cheryl Maze of the Figg Engineering Group, which designed the bridge.

...

Ms. Kimball said many people had fond memories of the old bridge, which still stands. But, she said, people are excited that the new bridge has helped bring communities together.

“This has given us a chance to start working as a region,” she said. “Now everybody wants people to know their town is near the bridge.”