BPU Approves Steam Turbine Maintenance
One of two steam turbine generators will be overhauled at the Jamestown Board of Public Utilities.
On Monday, the BPU approved contracting with S.T. Cotter Turbine Services of Clearwater, Minn., to perform a maintenance overhaul of steam turbine generator No. 5 in the amount of $1.9 million. According to the resolution approved by the BPU, S.T. Cotter Turbine Services was the lowest of seven bids, which ranged between $1.9 million and $4 million.
S.T. Cotter was the lowest bid, which included parts, rotor balance, diaphragm blade replacement of the double flow curtis rings and repairs to the remaining stages, replacement rotor blades from stage 1 through stage 12 and minor work on stages 13 through 19, replacement of all control valves and seats and various other repairs as identified in the inspection report. The cost for the majority of this work is included in the 2021 electric division budget overhaul reserve fund.
In December 2020, the BPU discussed the assessment report on steam turbine generator No. 5. Cory Allen, BPU power plant manager, said the assessment report was better than expected. He said the last overhaul of the generator was in 2003. He added the throttle valve end seats are pitted, but that is what is expected after 17 years between overhauls.
Allen said the nondestructive evaluation was completed for the rotor inspection and showed no cracks found on the shaft. He said blade damage was found, but there were no cracks
“No cracks on the rotor shaft is very good news,” he said. “This level of blade erosion is expected.”
Allen said the nondestructive evaluation completed for diaphragm halves showed multiple minor cracks and erosion patterns. He said minor cracks and erosion is expected.
“Overall, the findings are better than expected,” he said.
In other business, the BPU approved a Chadakoin River stabilization project agreement. According to the resolution, a portion of the steel retaining wall on the Chadakoin River is failing, and the Chautauqua Soil and Water District has provided the BPU with a proposal to remove the retaining wall and harden the shoring by filling, altering the course of the river flow, and stabilizing the banks of the Chadakoin River. The project is expected to cost $60,000.
BPU officials state the failing retaining wall has been a growing issue for some time, but the presence of the rail bridge made it costly to repair in the past. Now that the rail bridge has been removed, a stabilization project that will remove a portion of the failing wall, and replace it with a rip-rap slope and weirs in order to slightly widen the channel, enhance flood capacity of the channel, enhance habitats and prevent soil migration to the river.
The Chautauqua County Soil and Water Conservation District has offered to partner on the project with the BPU at no cost for their technical services and a dollar-for-dollar reimbursement for their excavation contractor on a time and materials basis.