Corps readies the main contract for a new 1,200-foot lock at Mississippi River Lock and Dam 25

Design work on the new 1,200-foot chamber wrapped up in June, and in July the Corps asked for proposals on the main lock contract, Bryan Dirks, the project's technical lead, told The Waterways Journal. More than 2,000 drawings went out with it. A Federal Compass listing for the St. Louis District solicitation, W912P926RA004, was last updated Oct. 21 and shows proposals due Dec. 9, with no set-aside.

The run-up has been a series of smaller advance contracts meant to shorten the main job and get long-lead items out of the way. G&G Steel in Alabama has built 17 of the 21 bulkheads that will dewater the new chamber once its wall monoliths are up, with delivery expected in January. Massman Construction has drilled the last of 10 shafts for a downstream guide cell and moves next to sheet pile and mass concrete, also aiming for January. A third package, Phase 2C, covers maintenance and storage buildings that keep the old lock running during construction.

J.F. Brennan Company, which holds the newest advance contract for foundation and site preparation, has started mobilizing. Its first job is dredging more staging room for the main lock contractor on a site Dirks described as crowded, then rebuilding the ground under the future lock using dredged fill held by a combination wall of sheet piles. With a completed Phase 1 contract on the existing intermediate wall, finished and active work totals about $100 million, Dirks said. Nothing unexpected has delayed the project yet.

Neither the Journal report nor the solicitation listing gives a value for the main contract. Once the 1,200-foot chamber opens, modern tows can lock through without being split, and the existing 600-foot chamber becomes the backup.