Centuries-Old Span Gets 21st Century Makeover
📅 Wed December 19, 2012 - Northeast Edition
Brenda Ruggiero - CEG CORRESPONDENT
Photo courtesy of Lisa Broadwater
The overall repair project will include installation of a series of micro-piles to stabilize the fill material that is placed inside the bridge between the wing-walls. The outer stone veneer also will be rebuilt.
Crews are currently working on repairs to structural deterioration of a bridge that has stood for nearly 200 years in western Maryland.
The Casselman River Bridge was opened for business in 1813 in what is now Grantsville, Md. At the time, the 87-ft. (26.5 m) span bridge was the longest stone arch bridge in the United States and served the old National Road linking Cumberland, Md., with the Ohio River.
Last winter, some of the large cut stones fell out of one of the wing-walls.
“On Feb. 29, it was reported to my office that a portion of the northwest wing-wall had collapsed,” said Dave Decker, southern regional engineer of the Maryland Department of Natural Resources engineering and construction. “The bridge, which is only used for pedestrian traffic, was closed to the public and we had it inspected by an engineering firm. The result was that the arch and bridge were stable, but should remain closed until repaired.”
In late June, when negotiations were proceeding with an engineering firm for design of the repair, a report was received of additional damage.
“Because of concern that a large piece of the parapet wall would collapse, we proceeded as an emergency to have a 12-foot section of the parapet wall removed. This section of the wall weighed approximately 15 tons,” Decker said.
According to Decker, the overall repair project will include installation of a series of micro-piles to stabilize the fill material that is placed inside the bridge between the wing-walls. The outer stone veneer also will be rebuilt.
The contract was awarded to Brayman Construction, Saxonburg, Pa., and the project manager is Evan Sockaci. The contract amount is $421,750, and 90 days were given to complete the work. Hopes are that the work will not actually take that long, but moving into fall and winter means that weather could become a factor.
“Between the side walls of the bridge, the wing-walls, the bridge is filled with stone and dirt,” Decker explained. “Over time, water seeps down off the deck into the fill, and eventually pushes the exterior stone out, thus collapsing the wall. It has happened at least three times that we are aware of. We are expecting this fix to hold for many decades. The micro-piles will take all the pressure from the fill off the exterior stone veneer, thereby keeping the bridge stable. Because this type of collapse seems to happen every 25 to 30 years, we were looking for a long-term solution that would keep the wall stable for a long time, and think the idea the engineer came up with will do that.”
According to reports, the bridge was restored in the 1940s, and crumbling and falling stones were corrected in 1979. Some work was also done on the arch then, and decking was changed as well. In 1996 and 2002, mortar was replaced between the stones.
Decker said there are various challenges to a project of this nature.
“The bridge is a National Landmark and the Maryland Historical Trust holds an easement on the bridge to make sure the historic value of the bridge is maintained,” he said. “We are very sensitive to that issue and expect that once the work is complete, the bridge will look exactly like it should. As work proceeds, the contractor will have to be very careful not to allow damage to occur to adjoining sections of the bridge, and be especially careful of the arch section.”
Maxmor-Hill Restoration of Baltimore, Md., restoration specialist, is in charge of the masonry.
“It’s a unique job,” Sockaci said. “Since we’re working on old structure, we have to be careful, and we have to be sensitive to the National Park issues. But the bridge is the main challenge, and on the back side we have had some access issues.”
The micro-piles are being drilled using a Casagrande M9-1 drill rig. Other equipment used on the job includes small equipment such as a Caterpillar 311 excavator.
The Casselman River Bridge crosses an area known as Little Crossings. In 1755, George Washington (a young military aide at that time), was on the staff of British General Edward Braddock. Braddock’s army fought the French at a fort near what is now Pittsburgh, Pa. They reportedly forded the river at Little Crossings, and also retreated back there after their defeat.
In the 1760s, the area became a major thoroughfare for westward travelers. In the early 19th century, widespread road construction was under way, and the National Road project was a part of those improvements. The Casselman River Bridge was one of many upgrades to Braddock’s Road. The area became a busy center of commerce and transportation, with stage coaches, wagons, horsemen, and foot travelers using the bridge. It was kept in service until 1933, when a new steel bridge was erected to accommodate automobiles.
Currently, the bridge is part of the Casselman River Bridge State Park, and is only opened to pedestrians. The park covers a 4-acre parcel and is a popular spot for fly fishermen, photographers and history enthusiasts.