The U.S. Army Corps of Engineers’ Nashville District awarded a $109,450,000 contract to American Bridge Company for the Wolf Creek Dam Spillway Gates Replacement Project.
Wolf Creek Dam on the Cumberland River in Jamestown, Ky., forms Lake Cumberland, which is 101 miles long and has 1,255 miles of shoreline. It also impounds water for a 270 MW hydroelectric powerhouse.
The Corps said replacement of the spillway tainter gates and lifting machinery equipment will not affect the operation of the six 45 MW hydroelectric generating units, which have an estimated annual energy output of 800,000,000 kWh. These units became operational in 1951 and 1952.
A Spillway Radial Gate Evaluation Design Document Report in 2016 revealed the 10 spillway tainter gates are subject to overstress due to trunnion friction issues. Trunnion friction is the force generated around the trunnion pin during gate lifting operation. It is caused by the bearing of the trunnion pin against the gates’ trunnion hub and bushing, which is the rotating point of the gate. In addition, the gates and lifting equipment have been in operation since the dam was completed use in 1952.
The project is fully funded by the Disaster Relief Supplemental Appropriations Act of 2022.
The scope of this contract includes fabrication of 10 new tainter gates; removal of existing gates and lifting machinery equipment required to operate the gates; and installation of the new gates and lifting machinery equipment.
Capt. Joseph R. Cotton, Nashville District project manager, said the contractor is limited to three inoperable gates, always leaving seven operable gates. As an additional risk-reduction measure, only one gate bay will be open at any given time during construction. Replacement of gates will occur between June and November each year, as this is considered the dry season and there is a lower lake level and less risk for flooding.
This replacement project will ensure the authorized flood-risk-reduction capabilities of this project will be realized for years to come. During construction, “Corps of Engineers’ water managers will maintain lake levels within current parameters agreed upon with the Southeastern Power Administration and the public will not experience significant drawdowns of the lake elevation,” Cotton said. “The most distinguishable change to reservoir levels during the construction period may be a lower peak summer pool from 723 feet to closer to 720 feet. This adjustment would lower project risk during construction while still falling within current operating targets.”
The contractor will have to modify the bridge substructure to accommodate replacement of the 10 spillway tainter gates, which are 37 feet high and 50 feet wide, and to access lifting machinery equipment. This includes wire rope and drum setup and replacement of high- and low-speed gear boxes, 10 hp electric motor, bull and pinion gears, and the machinery base on each gate pier.
American Bridge, part of the Southland Holdings LLC group of companies, specializes in construction of new bridges, bridge rehabilitation and maintenance, complex structures and marine construction.
