District awards bulkhead slots contractView Source
American Mine Services, Boulder, Colo., was awarded a $2.4 million contract by the St. Paul Engineer District to construct bulkhead slots on the intermediate wall and river wall upstream of the miter gates in the auxiliary chamber at Upper Mississippi River Locks and Dam 3.
The project consists of the demolition of a section of the existing concrete monoliths, wall armor, ladders, handrails and electrical conduits within the footprint of the new bulkhead slots. The wall armor, ladders and handrails are replaced upon installation of the bulkhead slot assembly, a one-piece steel fabrication to support the installation of temporary bulkheads during future replacement or maintenance of the auxiliary miter gates.
A localized cofferdam and dewatering system are necessary for the construction in the auxiliary lock and will not impact navigation, the St. Paul District said.
The project is expected to be completed in December 2024.