Davis Island Lock and Dam

At its centennial in 1985, the site of Davis Island Lock and Dam under the bluff overlooking the Ohio River at Bellevue was quiet. There being no highway access, the site had been largely forgotten. Only by scrambling through brush and weeds could one find the remnants of the lock house foundation, concrete walkways, gate recesses, and retaining wall at the river bank marking the site of one of the most memorable achievements in the annals of international waterway engineering technology. -- wrote Dr. Leland Johnson in his book The Davis Island Lock and Dam 1870-1922.

The planning, construction and operation of the Davis Island Lock and Dam, the first federally built navigation structure on the Ohio River, during the decades following the Civil War presented the Army Engineers with unparalleled engineering challenges. The innovative technology they applied to meet those challenges left indelible marks upon the history of Pittsburgh, the Ohio River and waterway engineering throughout the United States. At Davis Island in 1885, the engineers completed the largest Chanoin dam and navigation lock ever built to that date. Its design became the standard at the 50 additional locks and dams built to canalize the Ohio River, first to a six-foot depth and after 1910 to a 9-foot depth from Pittsburgh to Cairo, Illinois.

The project's planning and design taxed engineering ingenuity to the utmost, leading to a worldwide search for engineering solutions to the problems presented by inland river navigation and resulting in an international technology exchange which has continued into the 20th century. Its construction required the application of a broad array of technological innovations, and its operation required the adaptation of a variety of experimental water control structures and procedures to meet the demands of a burgeoning waterway commerce.

The origins of the Davis Island project lay in the natural conditions of the lower Allegheny, Monongahela and Ohio rivers, which had such inadequate dry-weather flow that their depth could be measured in inches. During several months in most years, Pittsburgh's steamboats, towboats and barges remained landlocked, unable to move until it rained and the rivers rose to boatable stages. Pittsburgh's mills during those months sometimes closed for want of raw materials and fuel, commercial shipments piled up at riverside, business languished and unemployment became the lot of workingmen. Those seasonal economic recessions often extended down the Ohio, for Cincinnati, Louisville and other downriver cities then depended upon shipments of Pittsburgh coal to fuel their industries.

It was during such a seasonal dry spell and accompanying economic recession in 1871 that Pittsburgh industrialists and businessmen launched their campaign to secure for the city a reliable harbor with a year-round depth for navigation. Pittsburgh should no longer, proclaimed one local newspaper, be dependent "upon the rain from Heaven for conducting our chief employment." The ironmasters of Pittsburgh also threw their substantial weight behind efforts to secure funding from Congress for the construction of a lock and dam on the Ohio providing Pittsburgh with a harbour and to initiate the building of locks and dams along the entire 981-mile length of the river. But as odd as it now may seem, rivermen and coal shippers of the Pittsburgh area vigorously opposed locks and dams, fighting the ironmasters over the issue in both the state legislature and Congress. Caught in the middle of that battle between the iron and coal titans of Pittsburgh was Colonel William E. Merrill, the Army Engineer officer in charge of the Ohio River.

Colonel William E. Merrill was the central figure in the history of the planning and construction of the first lock and dam on the Ohio. He personally designed the Davis Island project.

Intense opposition to the project prevented the start of its construction from 1871 to 1878, and building it required another seven years, 1878 to 1885, as a result of foundation difficulties, flooding and meager funding. Pittsburgh therefore did not have a harbor until 1885, and a second lock and dam on the Ohio was not completed until 1904 because Colonel Merrill and his successors in charge of the river delayed further work on the Ohio until the operation of the Davis Island Lock and Dam had proven successful and had allayed the opposition of rivermen.

Operating the giant lock and dam at Davis Island, with its many complex mechanisms devised by European engineers and by Merrill and his staff, proved to be a task as formidable as its planning and construction. Its operation revealed many design weaknesses, which Merrill and his successors remedied through the application of technology and improved operational procedures. For 37 years the engineers and operating personnel at Davis Island made the project work for Pittsburgh, redesigning, rebuilding and improving parts of the project each year. By the time it was removed to make way for the Emsworth Locks and Dams in 1922 few of the original parts of the structure remained.