ST. PAUL, Minn. - The St. Paul District is investing more than $18 million in tow rail systems, vital pieces of equipment which assist tows locking through locks and dams when traveling upriver.Locks and Dams 6, 8 and 9 are the first locks benefiting from this upgrade, which have been completed in time for the 2020 navigation season. Locks and Dams 4, 5, 5A and 7 will be receiving similar upgrades in upcoming winters.“Overall, these much needed upgrades will make the locks more efficient for tows which are locking upriver and improve safety for the navigation industry as well as our lock and dam staff,” said Kim Warshaw, project manager.Tow rail systems at Locks and Dams 2 through 10 have been deteriorating over the past several years. Two failures at Lock and Dam 7 identified the need for a project to address serviceability and safety issues. Interim repairs at that lock were completed in 2014, however, the current project aims to repair each lock’s tow rail system with a design life-expectancy of 50 years. Repairing the system will be completed during the non-navigation seasons from 2019 to 2022.The repair work includes removing the existing tow rail system and making necessary repairs to the concrete before installing a new system. Replacing the concrete is necessary to provide sound material to anchor the new tow rail.Working in the elements provides its own set of challenges, as mechanical engineer Wade Carr explained. “Precision alignment of the new tow rail on the guidewalls during the winter months, combined with a condensed construction period, posed one of the greatest challenges the team faced,” Carr said.Lock and Dam 6 was designed in-house and awarded for construction in 2018. Locks and Dams 4, 5, 5A, 7, 8 and 9 are a design-build contract where the contractor completes the plans and specifications and constructs the project. It was decided to do the Lock and Dam 6 design in-house to prove the new continuous rail concept, as well as the new traveling mooring bitt design prior to the additional sites design work.Work at Locks and Dams 5 and 5A are planned for the 2020-2021 non-navigation season and Locks and Dams 4 and 7 are planned for the 2021-2022 non-navigation season.-30-