Soo Locks poised for new chamber construction

The 1,200-foot lock will take seven years to complete, giving the Soo Locks a second lock to accommodate the Great Lakes' largest vessels.

The 1,000-foot Indiana Harbor at Soo Locks
The downbound 1,000-foot Indiana Harbor enters one of the Soo Locks in 2017.
Steve Kuchera / File / Duluth News Tribune
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SAULT STE. MARIE, Mich. — Construction of the third and largest phase of the newest Soo Lock will start this summer, the U.S. Army Corps of Engineers said this weekend, following the signing of a $1.068 billion contract.

The contract allows Kokosing Alberici Traylor LLC, a joint venture headquartered in Westerville, Ohio, to begin constructing the new 1,200-foot lock chamber and rehabilitate downstream approach walls.

Officials expect the newest phase of construction to take seven years.

“The Corps of Engineers looks forward to beginning construction on the new lock chamber later this summer, and we continue to work hard to maintain the pace and continue to make progress toward New Lock at the Soo total project completion in summer 2030,” said Project Manager Mollie Mahoney in the news release.

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The third construction phase is a milestone for the project. The project’s first phase to deepen the upstream channel began in spring of 2020 and is substantially complete. The project’s second phase to rehabilitate the upstream approach walls began in spring of 2021 and is scheduled to be complete in summer 2024.


A major cost increase led to a five-month contract award delay while the Corps of Engineers developed necessary reports to deliver a new cost estimate for reauthorization to Congress.

The cost increase root causes are changing market conditions, inflation, a nationwide labor shortage, design modifications and early estimate assumptions.

Project fully funded cost changed from $1.031 billion to $3.189 billion. The fully funded cost allows for escalation through the construction mid-point and anticipates what the project will cost.

“We recognize funding a larger amount for the new lock at the Soo is a challenge that could potentially result in schedule impacts,” said Deputy District Engineer Kevin McDaniels.

With continued funding, remaining work, valued at $803.95 million, may be awarded over the next three years.

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The Soo Locks are situated off the eastern end of Lake Superior on the St. Marys River at Sault Ste. Marie, Michigan, and allow vessels to transit the 21-foot elevation change at the St. Marys Falls Canal.

Over 88 percent of commodity tonnage through the Soo Locks is restricted by vessel size to the Poe Lock. The new lock project will construct a second Poe-sized lock (110 feet-by-1,200 feet) on the existing decommissioned Davis and Sabin locks site.

A 2015 Department of Homeland Security study estimates a six-month Poe Lock closure would temporarily reduce the U.S. gross domestic product by $1.1 trillion, resulting in the loss of 11 million jobs. The locks are essential to U.S. manufacturing and national security, according to the study.

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