Braddock Locks & Dam

Braddock Locks & Dam (previously named Monongahela Locks and Dam No. 2) is one of nine navigational structures on the Monongahela River between Pittsburgh, Pennsylvania and Fairmont, West Virginia. Built and maintained by the U.S. Army Corps of Engineers, the gated dam and the lock form an upstream pool that is for 12.6 mi, stretching to Elizabeth, Pennsylvania.

Description
Braddock Locks and Dam consists of the locks located on the right bank and the newly gated dam, that replaced the nearly 100-year-old fixed-crest dam. The older structure in turn had replaced a lock and dam facility opened in 1841 at Port Perry, slightly upriver from Braddock.

Locks
Built in 1953, the locks consist of two side-by-side chambers. The land chamber is 110 feet wide by 720 feet long and the river chamber is 56 feet wide by 360 feet long.

Dam
Construction of new Braddock Dam, started in 1999, was completed in May 2004 using innovative in-the-wet construction techniques. Two prefabricated hollow concrete segments were constructed at an off-site dry-dock and floated into place and set down on a prefabricated foundation system of sheet-pile cut-off walls and large diameter drilled shafts socketed into bedrock. The float-in segments were built with precast wall panels and cast-in-place bottom and top slabs. Weight of the first 333 feet by 104 feet segment was 11,600 short ton. Dam segment two, at 9000 short ton, measures 265 feet by 104 feet.

The 517 foot spillway was equipped with three 110 foot by 21 foot Standard Tainter gates and one 110 foot by 11 foot Water Quality Tainter gate. Each gate is operated by two hydraulic cylinders. All gates were fabricated and assembled in one piece by G&G in Alabama and were barge shipped to the project site. Weight of the Standard Gate and the Water Quality Gate is 438 kips and 286 kips, respectively.

The construction cost of the new dam was approximately $107.4 million.