Research restores credit for an engineering feat

Carved in stone on a Civil War-era bridge – a world-class feat of engineering that stands a couple miles northwest of Washington - are the names of builders and officials of the day. A key name, however, is missing.

New research shows that Virginian Alfred R. Rives led the design and construction of the Cabin John Bridge. Also called the Union Arch Bridge, the aqueduct and roadway reaches 220 feet across Cabin John Creek in a single span - the world's longest single-span masonry bridge for nearly 40 years and the nation's longest still today.

Rives had the training and knowledge to design and build such a span, and records, drawings and structural analyses show he did the work, say Dario Gasparini, a professor of civil engineering at Case Western Reserve University, and David A. Simmons, a bridge expert at the Ohio Historical Society. Their research is published in the new issue of the American Society of Civil Engineers' Journal of Performance of Constructed Facilities.

"This is a unique bridge in the United States that no one before 1850 and no one afterward had the audacity to try," said Gasparini, who studies structures and the history of structural engineering. "Rives had a unique set of theoretical skills and construction skills that no other engineer in the U.S. had at that time."

After digging through records in Washington, Virginia, North Carolina, and France, "We don't have any smoking gun but all the documents point to Rives," Simmons said. "The reason the bridge is there is Rives suggested it… and had the knowledge to actually do it."

The essential structure was complete when Rives, a government civil engineer, resigned to join the confederacy. While the name of then-Secretary of War Jefferson Davis, who left the government to become president of the confederacy, was removed and later restored to the bridge, Rives has not received the same recognition.

His absence among the names reflects a deeply personal rift created by the war, the researchers say.

Rives was a graduate of Virginia Military Academy. With the help of his father, William Cabell Rives, the U.S. minister to France, he was the first American admitted to the Ecole des Pont et Chausees, the world's leading structural engineering school in the 19th Century. He graduated at the top of the class of 1854.

Lieutenant Montgomery C. Meigs, a West Point graduate and member of the Corps of Engineers, hired Rives in 1855. Meigs was the chief engineer of the Washington Aqueduct project to supply Washington, D.C., with drinking water from the Potomac River at Great Falls, Md..

He had planned a six-arch bridge over Cabin John Creek, and Rives quickly showed it could be done with five arches. Rives, according to records of a colleague in the engineering department, then suggested a design based on the Grosvenor Bridge, a 200-foot single span bridge in Chester, England.