Glendo Power Plant Fixed Wheel Gate Gets Facelift
Written by: Jay Dallman, WYAO
Illustration of fixed wheel gate in penstock.
On October 30, 2013, WYAO mechanical engineers traveled to Glendo Power Plant to assess the condition of the fixed-wheel gate.
This is a single leaf gate which controls flow to the main supply penstock which provides water from Glendo Reservoir to spin the turbines and generate hydroelectric power, and also supplies water to the outlet gates which provide an additional means of releasing water to the river.
The gate was lifted into the gate chamber by power plant staff. This was completed over the course of a couple weeks by lifting the gate with the hydraulic hoist, hanging the gate, removing a section of gate stem, re-attaching stem sections, and lifting the gate another stem length. A total of five stem sections were removed until the gate was fully up. At this point, the gate leaf was set on beams and could be thoroughly inspected.
The conclusion reached by the Centralized Mechanical Support Branch was that a complete refurbishment of this fixed-wheel gate should proceed. The work would consist of removal of the bulkhead hoist, stem and gate leaf, to perform the surface preparation and painting of the fixed wheel gate, stem and gate hoist. After the inspection, the gate was re-installed into its guides and placed back into service until refurbishment could be scheduled.
In FY 2014, Reclamation entered into an interagency agreement with Tennessee Valley Authority (TVA) to provide a feasibility level plan that included a cost estimate and schedule for performing the refurbishment.
TVA personnel performed a site visit during the week of February 24, 2014, to finalize project scope details. Reclamation reviewed the cost estimate and schedule provided by TVA and found it to be reasonable and economical and entered into a new inter-agency agreement to perform the refurbishment work.
Reclamation received upfront power customer funding from Western States Power Corp. (WSPC) which covered the entire cost of the gate refurbishment project. In late October, TVA personnel arrived at the Glendo Fixed-Wheel Gate house and began site preparation and mobilization. A crane from a local crane company was hired to perform all lifting tasks including the gate and all appurtenances. The gate was lifted into the gate chamber and over the next month, the gate was disassembled.
TVA's original plan was to lift the gate as one piece and to refurbish the gate on-site inside of a portable steel garage building. TVA mistakenly believed the gate to be 80,000 lb. (40-tons) but in reality, the weight of the gate is about 160,000 lb. (80-tons). This caused TVA to re-evaluate their plans. It became clear that the crane onsite was not large enough to lift the gate in one piece as planned. TVA also became aware of the difficulties in refurbishing the gate onsite due to local weather conditions. The decision was made to separate the gate into two sections andship the gate to their facility in Muscle Shoals, Alabama. The gate was split and loaded onto transport trucks and shipped to TVA’s power services shop in December.
At TVA's facility, the gate halves and all gate components were sand-blasted and recoated with an epoxy coating. All hardware was evaluated for continued service and hardware was replaced as appropriate. New wheels were fabricated as the existing wheels had worn beyond specifications. Other minor machining and welding repairs were made while at the Power Service Shop.
In mid-February, TVA personnel arrived back at Glendo to begin the process of re-installing the gate. The gate halves were hoisted into the fixed-wheel gate chamber and the halves were fitted together. The new wheels were installed into the gate and properly aligned with the gate. New seals were installed on the gate leaf and the hydraulic hoist was re-installed.
On March 19, 2015, the gate was lowered to its final position and was tested. It travelled through its range successfully with no binding or other undesirable issues. By taking advantage of the specialized skills of the TVA, WYAO was able to get a quality product in a reasonable timeframe. Since Glendo is a seasonally operated power plant, Reclamation was able to complete the work over the non-irrigation season without any impacts to power production or water deliveries.
Fixed wheel gate showing corrosion.
Crane lifting bottom leaf of fixed wheel gate.
Placing gate leaf section on truck for transport to Alabama.
Gate leaf sandblasted and ready for epoxy coating at TVA Shop.
Refurbished fixed wheel gate ready for re-Installation.
Published on March 30, 2015