B.08.03 Plans_21R0015_McDouble_amd0009.pdf

This document outlines a federal contract opportunity for construction work at the McNary Dam located in Umatilla County, Oregon. The project involves rehabilitation of the dam's intake gates and isophase bus systems.

For the intake gates portion, the contract will rehabilitate or replace 45 intake gates, 90 hydraulic cylinders, 45 support beams, the hydraulic power unit, header piping, flexible hoses, control consoles, accumulator tanks, hydraulic fluid, oil storage tanks, gate position indicators, gate dogs, and related electrical and control equipment. For the isophase bus systems portion, the contract will replace the existing 15kV and 2,500V copper bus with new aluminum bus, move generator step-up transformer banks, replace synchronizing potential transformer cubicles, replace cracked 230kV tubular aluminum bus segments, install seven new motorized group-operated disconnect switches with surge resistors and manual ground switches, provide related electrical equipment, and perform testing and commissioning. The estimated period of performance is from December 2021 to May 2030, with work occurring over multiple scheduled unit outages from 2023 to 2029. The estimated contract value is between $25-100 million.