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Olmsted Locks and Dam

Posted Thursday, November 6, 2014 at 2:08 PM

Field Construction Engineer, URS Corporation

"The Olmsted dam, scheduled to be completed in 2016, will be the largest in-the-wet dam ever built."

Olmsted Locks and Dam

PostedThursday, November 6, 2014 at 2:16 PM

Olmsted Locks and Dam

 

The Olmsted dam, scheduled to be completed in 2016, will be the largest in-the-wet dam ever built.

Author:  Cindy Sheu

The Olmsted locks and dam project is a massive effort to replace current aging infrastructure on the Ohio River. The locks on the river were built to control the water level and allow river traffic to easily navigate and, among other things, to transport coal from upstream down to the power plant below for energy generation. However, Lock 52 and 53 were originally installed in the 1920’s, and they are currently in critical condition.   These locks must still be raised and lowered manually and can pose potentially life-threatening situations because they are old and do not always function properly. Since they rely on human power, it sometimes takes days before someone can correctly adjust the position of the locks which backs up traffic on the river and causes costly delays. The new locks and dam have the potential to reduce the time required to pass through significantly. 

What makes this project unique? 

In some ways the Olmsted Locks and Dam project has been an experiment. Traditionally most dams in the United States have been built using the coffer dam method where workers drive piles into ground to create an area where water will be temporarily kept at bay while they build the dam right on the river bed. The Olmsted Locks and Dam project is being built using the in-the-wet method. This is something like trying to build a large-scale Lego structure with concrete blocks completely underwater. In general this means that workers build most of the shells on land and use a custom-designed catamaran barge equipped with a 4,500 ton capacity gantry crane, to move and set each block in place. Only a handful of dams have ever been constructed in this fashion, and the Olmsted dam will be the largest of its kind. 

So why did the Army Corp of Engineers choose this method? 

Original estimates suggested that an in-the-wet dam would be completed in less time at decreased cost with less impact to river traffic. Over the course of the project however, a number of unexpected circumstances arose that made the project very time-consuming and expensive.  While no engineer wants a project to be behind-schedule or over-budget, big projects such as this one that use new or different methods serve as learning experiences that inform future projects, and the lessons learned from the Olmsted project will most-likely last even longer than the dam itself.