Green Peter Dam

Project Date: 2016
Customer: USACE, Portland District

Project scope:
The purpose of the Green Peter Dam Tainter Gate Repair project was to upgrade the two 90 ton spillway tainter gate structures to current structural standards, replace trunnion bushings, gate seals, gate hoist equipment, wire rope and wire rope connections, electrical system and controls.

USACE accepted two Value Engineering Cost Proposals (VECP) from KCS for a combined instant contract savings exceeding $400,000. The first proposal provided more efficient mechanical and electrical hoist equipment design, and the second simplified the gate stiffening structure. New hoist equipment and structure were designed, manufactured and installed while maintaining the original contract period.

The structural work required the replacement of the gate end frames with trunnions. Roughly 35 tons of steel was demolished and replaced on each gate. All shop and field welding was completed in accordance with AWS D1.5 fracture critical quality standards with independent inspection. Shop fabrication was completed by a Major Bridge AISC Certified fabricator. KCS completed all field welding and other field work except for inspection and painting.

Knight Const. & Supply, Inc. (KCS) performed as the prime contractor on this project, which involved the fabrication and repair of two spillway tainter gates to strengthen structures and upgrade equipment and controls. The USACE accepted KCS’s Value Engineering Cost Proposal to redesign the contract hoist and controls design, provide instant contract savings and improve equipment efficiency. KCS designed, manufactured, installed and commissioned the hoist equipment and controls while maintaining the original contract period.

Key features of work:
1. Shop and field fabrication to AWS D1.5 fracture critical quality standards
2. High precision trunnion pin alignment
3. Design/build Temporary gate support structures designed for 20’ of water head
4. Difficult access within spillway