Rare design wins a new life for old Howard County bridge

November 11, 2003|By Sandy Alexander | Sandy Alexander,SUN STAFF

Motorists cruising on Route 32 in northern Howard County likely have never noticed anything exciting about the highway bridge just south of Sykesville.

But according to the State Highway Administration, the bridge is one of seven in the United States with an aluminum girder system. It is also the longest of only three bridges made with a specific triangle-shaped internal support system designed by aeronautical engineers at a company in Hagerstown, officials said.

Because of those elements, the bridge over River Road, the Patapsco River and the CSX Railroad will be left standing when a replacement bridge - under construction - opens in the spring.

"It is highly significant if for no other reason than it is exceedingly rare," said Rita Suffness, cultural resources manger for the State Highway Administration. Aluminum bridges "were built in such small numbers in this country relative to the vast universe of steel and concrete beam bridges."

Also, she said, "It's an important milestone in terms of experimenting with new materials and fabrication techniques."

During a statewide inventory of bridges in the 1990s, Suffness determined its unusual structure made the Route 32 bridge eligible for inclusion in the National Register of Historic Places. She added it to a state Historic Bridge Inventory.

Then SHA concluded that the bridge had deteriorated in several areas where the aluminum is in contact with steel, such as where steel bearings connect to the aluminum girders.

Repairing the Route 32 bridge would be extremely difficult, Suffness said, requiring the entire structure to be lifted in place, which could cause it to buckle. She championed a plan to "keep it in good condition until we find a way to fix it."

With approval from the Maryland Historical Trust - which must provide input on any projects affecting a historical structure or area under the National Historic Preservation Act - SHA accepted Suffness' plan to keep the bridge as a historic landmark.

Highway officials will also create an educational display with descriptions and photographs to be placed below the bridge along River Road.

"It's a very unique thing they are doing to recognize the significance of the bridge," said Gil Kaufman, a metallurgical engineer and consultant for the Aluminum Association Inc. "I don't know of any other site in the U.S. where you will be able to see an aluminum bridge, especially of this design, and to learn something about it."

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