Foundation Mechanics LLC conducted a dive of the Chicago Harbor Lock today to assess the condition of the walls on the western half for upcoming rehabilitation. The walls of the Chicago Harbor Lock have reached the end of design life and will be replaced in the fall with steel armor plating. The Chicago Harbor Lock, adjacent to Navy Pier, was the busiest in the nation last year for lockages and vessels. “In 2019 we had about 10,000 lockages, and saw an average of 1.16 million passengers and almost 62,000 vessels," Lockmaster Tyrone Valley said.