Olmsted Locks and Dam

The Olmsted project utilized a first-in-the US “in-the-wet” method to build two 110’ by 1200’ locks and a dam comprised of five tainter gates, 1,400’ of boat-operated wickets and a fixed weir. Concrete shells, weighing as much as 2,700 tons, produced at an on-site precast yard were attached to lifting frames. A 5,000-ton gantry crane then placed the lifting frame and the shell onto a cradle that moved on tracks down to the river. Once at the river, a 5,000-ton catamaran barge took over the lift and was then pushed by towboat to the shells permanent position in the dam. The shell was lowered into place on the river bottom which was previously prepped for the shell by proper grading and installation of a portion of approximately 3,300 24” diameter pipe piles which provide the foundation for the entire dam.

Hillsdale completed fabricated and erection of the steel for the complex lifting frames, the shells’ precast yard, the cradle and thousands of pipe pile. Different lifting frame configurations were used for each type of shell with frame dimensions such as 75’ long by 100’ wide and on average 45’ tall. The majority of our steel was delivered to the project by barge from our river facility on the Mississippi River in north St. Louis.