Working in the Dry: Cofferdams, In-River Construction, and the United States Army Corps of Engineers

This study documents and analyzes the history of advances in inland river construction techniques involving cofferdam and in-the-wet construction methods used by the U.S. Army Corps of Engineers. Cofferdams are the traditional solution for constructing a bridge pier, dam foundation, or other structure where the work site is underwater. The study includes a review of early American inland waterway improvements completed without federal participation, examines the origins of the Corps of Engineers engineering traditions, and documents the Corps earliest in-river projects, including the 1830s Potomac River Aqueduct, which represented one of the Corps earliest uses of cofferdams for in-river construction. Particular attention is devoted to the development of cofferdam designs used to create slackwater improvements on the Ohio River and other inland rivers during the late-nineteenth and early-twentieth century. The development of steel sheet pile cofferdams, which permitted larger cofferdams in deeper water, is explored in relationship to the construction of Mississippi River locks and dams in the 1930s.