An important component of the nation's Inland Waterways System, the New Braddock Dam was constructed with an innovative in-the-wet technique, used for the first time by the Army Corps of Engineers. Its signature feature, the fabrication, assembly and delivery of two football field-sized concrete segments, required floating the 11,000 and 9,500-ton pieces 27 miles upstream on the Ohio and Monongahela rivers. These two pieces combined to form the New Braddock Dam, which replaced the nearly 100-year-old fixed crest dam, allowing the Corps to replace the inefficient older locks upstream and completely eliminate the severely deteriorating dam 3 and the locks.
In only ten months, over 700 drawings and 3,000 contract pages were prepared, including unique design criteria for floating the dam structures, which, given that the Corps had no existing guidelines for such technology, had to be developed from scratch. The designs eliminated the need for conventional cofferdams to dewater the construction site, which reduced cost, allowed for concurrent construction of the foundations and dam structure, which reduced time, and called for pre-casting in a controlled environment, which increased quality. After a best value-trade off negotiated procurement was conducted by the Pittsburgh District, the $107.4 million contract was awarded to the joint venture of J. A. Jones Construction Company and Traylor Bros., Inc.
The dam, which helps sustain the $8 billion in annual commerce that travels through the Port of Pittsburgh and the 34,000 jobs directly linked to the local waterways, had a unique impact on the physical environment. Over 400,000 cubic yards of dredged and excavated foundation materials were reused as cap matter on the former U.S. Steel Duquesne Works Brownfield, saving millions of dollars and restoring an economic generator in the economically depressed Monongahela River steel valley. The construction methods also eliminated the need for cellular cofferdams, and the associated risk of increased flood levels during construction. The dam contains a water quality gate which sustains improved dissolved oxygen levels in the Monongahela River.
The project was selected by ASCE as a finalist for the 2004 Outstanding Civil Engineering Achievement (OCEA) Award.