The purpose of this work is to resurface the quoin and miter surfaces on the middle 30-feet of both miter gate leaves on the downstream navlock gate at McNary Dam. Work involves quoin and miter surface repairs to be accomplished during the 2016 Nav-Lock Outage.
This work will consist of welding up the deficient areas and machining down the surfaces to remove defects and to restore the surface plates to their original thickness. Welders Qualification will be in accordance with AWS D1.1/D1.1M or AWS D1.5/D1.5M Section 12. Welders and welding operators must pass the qualification tests prescribed by AWS D1.1/D1.1M or AWS D1.5/D1.5M within 12 months prior to performing work on this contract. All welding work will be inspected using a Nondestructive Testing (NDT) method. Once the metal work is finished there will be approximately 40 sq ft of touch up painting using Vinyl paint.
Work also includes the installation of GFP stiffener plates at 16 locations within the quoin and miter posts on the Miter Gate leaves. Stiffener plate installation will involve welding in accordance with AWS D1.5 requirements.
The contract requires completion of all work at the navigation lock within a finite work window, as stated above. Work must be completed within the specified work window in order to return the navigation lock to service in accordance with a coordinated Columbia/Snake River navigation system outage plan.