PITTSBURGH – The U.S. Army Corps of Engineers announces the award of a $5.6 million contract to continue critical dam gate work at an Ohio River navigation facility.
The contract award is the third of five contracts designed to replace two dam lift gates at Montgomery Lock and Dam on the Ohio River at Monaca, Pennsylvania, in Beaver County.
“The contract is necessary to avoid near term catastrophic gate failure, which could result in a potential loss of navigation and impact to utility and commercial water intakes on the upper Ohio River,” said David Heidish, project manager, Pittsburgh District.
The failure of the dam gates carries a low risk to loss of human life.
C.J. Mahan Construction Company, LLC of Grove City, Ohio, will execute the work, which includes removal of existing dam lift gates 2 and 3 and associated components. The contract also includes pier 2, 3 and 4 machinery housing modifications, track and sill modifications and miscellaneous pier concrete repair.
The Army Corps has previously performed temporary repairs and maintenance on the dam; however, the dam has remained in need of a more permanent solution.
“This contract will go a long way to providing that solution,” said Heidish.
An in-depth 2006 structural analysis of the dam concluded that all 10 of the dam’s gates were in an active state of failure under normal hydraulic load. To date, the Pittsburgh District has replaced four of the 10 gates. The fifth gate is currently being replaced under a separate contract.
The installation work of the two new gates is scheduled to begin fall of 2017 and complete in 2019.
The Montgomery Dam was built in 1934. Its gates were originally designed to meet the 1934 design standard for dead, hydraulic and vertical ice load; however, they were not designed for barge impact and horizontal ice load.
The 2006 condition inspection of the dam revealed that there were significant deterioration problems with the fracture critical structural members and riveted connections of the vertical lift gates.
In October 2006, a down bound tow barge struck the upstream guide wall. Three barges separated from the tow and were drawn into gates 4 and 8 of the Montgomery Dam.
Both gates were destroyed with the impacts. In 2008, gates 4 and 8 were replaced with new, state-of-the-art designed lift gates.
Gates 5 and 7 were replaced with a construction contract awarded in 2015 and Gate 6 of the same contract is in the process of being replaced.
For more information on the Lower Mon project, please visit www.lrp.usace.army.mil.