Price Drops on Soo Locks Project

The latest cost estimate for the 10-year mega project in Sault Ste. Marie to build a new shipping lock has taken the price tag from nearly $3 billion down to about $2.62 billion―a nearly 13% reduction.

The U.S. Army Corps of Engineers announced the update Thursday during a stakeholder presentation about how construction is proceeding on the new lock, which officials said remains on track to be completed on time in the summer of 2030.

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The downward revision to the Army Corps’ certified cost estimate is due to eliminating contingency costs associated with different sub-phases of the project’s contracts that have now all been awarded, said Kevin McDaniels, the Corps’ deputy district engineer for planning programs and project management in the Detroit District.

“Being able to award all nine options on time meant that we were able to eliminate essentially $250 million worth of risk to the project,” McDaniels said Thursday.

A crane on a barge works on the Soo Locks in Sault Ste Marie, Michigan.

The project has received $2.321 billion in funding to date, with another $176 million in President Donald Trump’s budget proposal for the 2026 fiscal year. The Army Corps anticipates needing about $103 million to continue construction during the 2027 fiscal year, McDaniels said.

The Army Corps’ plans call for a new 1,200-foot-long lock to mirror the Poe lock, which is the only lock at the shipping complex big enough to handle the largest Great Lakes freighters that carry 88% of the tonnage that traverses the waterway connecting Lakes Superior and Huron.

The shipping complex is critical to the nation’s supply chain for steel, helping to convey iron ore mined along the shores of Lake Superior to mills along the lower Great Lakes, where it’s processed into high-strength steel.

An unscheduled outage of the Poe Lock could disrupt that supply chain, affecting automobile, appliance and heavy equipment manufacturing and, within six months, lead to 11 million lost jobs and $1.1 trillion in economic impact, the government says.

The new lock project is in its third phase, after earlier work on upstream approach walls and deepening of the upstream channel to a depth of 30 feet.

The current phase is focused on building the new lock chamber, with over $630 million worth of work completed to date. This includes constructing the downstream approach walls and building a new bridge to the complex’s existing power plant, as well as a new pump.

“Over the past year, several major milestones have been achieved on the project, and the site has really been transformed,” Project Manager Mollie Mahoney said during Thursday’s call.

Tower cranes make history

Mahoney referenced completion of the new bridge to the power plant in January and the demolition of the 100-year-old Sabin Lock structure, which was completed in July. The filling in of the Davis Lock to grade with bedrock and construction debris was also finished in July, as well as the construction of the third and last tower crane on site.

“The tower cranes really allow the contractor the ability to move materials wherever they need throughout the construction site,” Mahoney said, noting they’re each between 240 and 270 feet tall.

“Fun fact: They are the second-tallest structures in the Upper Peninsula of Michigan. The only taller structure is the (Copper Peak) ski jump at Ironwood at 469 feet high. That’s hard to wrap your mind around,” she added.

“We are almost certain that this is the first tower cranes ever constructed in Sault Ste. Marie, and potentially the first tower cranes ever constructed in the Upper Peninsula.”

A ship simulation study by the Army Corps in Vicksburg, Mississippi, virtually navigated the new lock design to check the length of the approach walls and the alignment of the chamber.

Mahoney said that, as a result of that exercise, the Corps lengthened the north upstream approach wall and added timber fenders on the south upstream approach wall ― a late addition to the design.

Timber fenders are massive chunks of wood that serve as bumpers so that a ship doesn’t rub up against the walls of the lock.

Bedrock excavation for the new lock has been a main focus of the contractors this year, with the bedrock being broken up using “hoe rams” or machines that use hydraulic power to “peck at,” hammer and break up the rock, Mahoney said. The exposed bedrock will serve as the base of the foundations for the new lock walls.

Mahoney compared building the walls of the new lock to building Lego blocks, which the Army Corps is calling monoliths. Eighty-one monoliths or giant Lego blocks are planned on the north and the south side of the new lock chamber to form its walls. Just over 50 of the monoliths have been started to date, with one of them complete, she said.

The concrete being used is very stiff and made with heavy 2- to 3-inch aggregate, which is “quite different” than most of the concrete that is used in construction to build the humongous retaining walls that will form the walls of the lock, Mahoney said.

“The workers that are helping to get the concrete in place wear snow shoes and can walk right on top of it,” she said. “It’s that stiff.”

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