Construction of the New Lock at the Soo in Sault Ste. Marie, Mich., has reached the halfway point, marking a major milestone in the U.S. Army Corps of Engineers' (USACE) effort to add a second Poe-sized lock to the Soo Locks complex.
According to the USACE, Detroit District, Phase 3 of the project reached 50 percent completion in September. The $3.219 billion project is being built in the footprint of the existing Sabin Lock and is designed to provide additional capacity and resiliency at the Soo Locks.
The project is being constructed in three phases. Phase 1, which involved deepening the upstream approach channel from 24 to 30 ft., was completed in August 2022. Phase 2, involving rehabilitation of the upstream approach walls, was substantially completed in September 2024.
Phase 3 is the major construction portion of the project and includes demolition of the existing Sabin Lock, infilling the Davis Lock, construction of a new pump well and construction of the new lock chamber, according to the Corps.
The Phase 3 base contract was awarded in July 2022 to Kokosing Alberici Traylor LLC (KAT) of Westerville, Ohio. The contractor has been working on bedrock excavation and construction of the new lock chamber, with concrete monoliths forming the walls of the new structure.
A Corps photograph from August shows the concrete monoliths taking shape. According to the Detroit District, 84 concrete monoliths, along with extensive reinforcing steel, will make up the new lock chamber.
The new lock will be the same size as the existing Poe Lock — 1,200 ft. long, 110 ft. wide and 32 ft. deep. The design will allow the new facility to accommodate the large vessels that currently are limited to the Poe Lock.
The Soo Locks are located on the St. Marys River and allow vessels to bypass a 21-ft. elevation change between Lake Superior and Lake Huron. Approximately 80 million tons of commercial commodities pass through the facility each year, according to the Corps. The agency also reports that 88 percent of commercial commodity tonnage moving through the Soo Locks is restricted by vessel size to the Poe Lock.
Adding another Poe-sized lock is intended to provide redundancy if the existing Poe Lock is unavailable for maintenance or an unplanned outage.
The Corps awarded additional Phase 3 options totaling $95.3 million in June 2025. Those options included downstream work, a hands-free mooring system and downstream ship arrestors. The project's current construction plan calls for completion in 2030, assuming efficient funding and favorable conditions.
Reaching 50 percent completion represents the latest step in a construction program that has already involved major excavation, demolition and concrete work. With the project now halfway through Phase 3, crews will continue construction of the lock chamber and associated infrastructure as the Corps works toward bringing the new lock into service.
The New Lock at the Soo is intended to strengthen the Soo Locks' ability to handle Great Lakes vessel traffic while providing another route for large vessels when the Poe Lock is unavailable.
