AAC was contacted by the Army Corps of Engineers to assist with de-watering the Bonneville Dam Navigation Lock on September 4, 2019.  The USACE had been experiencing an issue closing the downstream gate and wanted to investigate the lower sealing surface.   On September 5, AAC mobilized to the site and installed the stoplogs on the downstream side.   After the navigation locks were de-watered, AAC and the USACE identified a complete failure in the downstream miter gate sill.

On September 7, the USACE awarded AAC a contract to start the demolition of the failed sill.  AAC mobilized crews and equipment to install safe access and begin the demolition process.  Demolition was completed on September 12.

AAC’s crews, combined with some key subcontractors worked around the clock to repair and install a new lower gate sill.  The new lower gate concrete sill damage was identified and replaced in 22 days (3 days early by contract). 

AAC and the USACE team both worked long hours and through many challenges to make the project successful and injury free.