Contractor wins $213.8m deal on Soo Lock project in Michigan

US-based construction contractor Kokosing Alberici Traylor (KAT) has won an option contract for Phase 3 of the ongoing Soo Lock project in Michigan, US, which will include the installation of concrete chamber wall monoliths for the Great Lakes waterway lock system.

The US$213.8 million contract (named “Option 1B”) is in addition to KAT’s base contract for the phase of construction. Announced in 2022, KAT is scheduled to receive roughly $1.1 billion for Phase 3 work.

Phase 3 is the planned final stage and is the largest segment of the project.

Soo Lock concrete chamber monoliths Concrete chamber wall monoliths line an engineering representation of the future New Lock at the Soo, in Sault Ste. Marie, Michigan. A $213.8 million contract, known as Option 1B, was awarded to Kokosing Alberici Traylor, LLC (KAT) of Westerville, Ohio on Dec. 21, 2023. Photo Credit: Carrie Fox

“There are 21 chamber monoliths that make up the north wall and 21 chamber monoliths that make up the south wall,” explained Jeremy Nichols, an engineer on the Soo project with the USACE (US Army Corps of Engineers) Inland Navigation Design Center. “The chamber monoliths are approximately 44 feet [13.41 m] wide and 70 feet [21.34 m] tall. Each monolith will be constructed by placing mass concrete in roughly five-foot-high lifts, with a total of 14 lifts per monolith.”

The chamber monoliths will span between the new lock’s upstream wide wall monoliths and downstream wide wall monoliths.

Additional options will be needed to complete the new lock, said Kevin McDaniels, an engineer with USACE, Detroit Division. The USCACE, Detroit Division, are the legal operators and managers of the Soo Locks.

“To date, Options 1A (upstream wide wall monoliths), 1C (new power plant bridge ramp), 2 (new pump well completion) and 7 (alligator’s mouth mooring area) have been awarded, totalling $281.3 million,” added McDaniels.

Four contract options totalling roughly $320 million of work are still to be awarded. These are Option 3 (lock operational), Option 4 (downstream work), Option 5 (hands-free mooring), and Option 6 (downstream ship arrestors). The Corps of Engineers hopes to award these options over the next two years.


KAT was also awarded a base contract for Phase 2 of the project, which largely rehabilitated the upstream approach walls.

For Phase 1, US-based Trade West Construction deepened the upstream canal. The beginning portions of that segment started in 2020 and wrapped in 2022. Phase 2 is winding down and expected to finish this year.

The “New Lock” at the Soo is being built in three phases. Phase 1 (upstream channel deepening) was completed in 2022, and Phase 2 (upstream approach walls) is expected to finish this summer. The Phase 3 contract was awarded to KAT in July 2022 as a base contract at roughly $1.07 billion. Awarding the base contract allowed the contractor to begin work in 2022 with the remaining work (contract options) awarded in the coming years.

As of last December, the project planned to work through the winter season, despite the potential for adverse weather in this section of the US.

“Construction will continue over the winter season,” confirmed Mollie Mahoney, a senior project manager.

She added that hazardous waste abatement, concrete demolition, utility shaft excavation and electrical work were among the tasks expected to commence in the coming weeks and months.

USACE, Detroit Division, stated the renovated three-lock Soo system should be open by 2030.

What are the Soo Locks?

The Soo Locks are a vital point in the Great Lakes Navigation System (GLNS) that allows ships to travel through a 21-foot (6.4 m) elevation change at the St. Marys Falls Canal on the St. Marys River, which borders the US and Canada.

Originally a four-lock system on the US side, the first federal lock at the sight was named the Weitzel Lock and built in 1881. The Weitzel was replaced by the MacArthur Lock in 1943, which remains today and is large enough to accommodate ocean-faring ships.

The Poe Lock was built in 1896, but reconstructed in 1968 to make way for larger vessels (following the opening of the Saint Lawrence Seaway between the US and Canada).

Currently, according to USACE, almost 90% of the river’s trade volume is directed through the Poe Lock, the larger of the two remaining locks.

The new lock – the third on the US side once completed – does not yet have a name. It’s been in development for more than two decades with initial groundbreaking taking place in 2009. The new lock will replace two underutilized locks (Davis Lock and Sabin Lock), which became obsolete in the last three decades. The Davis Lock had not been used since 2018, and the Sabin Lock has been inactive since 1989.

An artistic rendering of the future Soo Lock system An artist rendering of the future three-lock Soo Lock system. Photo Credit: USACE, Detroit Division

Another lock, owned and managed on the Canadian side of the St. Marys River, is used for recreational and tour boats, while major shipping traffic uses the US locks.

The locks are big business, not just locally in North America, but across the globe. According to a 2015 US Department of Homeland Security study estimate, provided by the USACE, a six-month Poe Lock closure would temporarily reduce the US gross domestic product (GDP) by $1.1 trillion, resulting in the loss of 11 million jobs.

Approximately 80 million tons of commercial commodities pass through the Soo Locks annually.

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