Chamber Wall Monoliths Option 1B Awarded for Soo New Lock

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U.S. Army Corps of Engineers, Detroit District’s New Lock at the Soo project in Sault Ste. Marie, Michigan, awards $213.8 million contract Option 1B (Chamber Wall Monoliths) to Kokosing Alberici Traylor, LLC (KAT) of Westerville, Ohio.  

Contract Option 1B includes construction of the lock wall monoliths, very large concrete wall portions that make up the sides of the chamber along the north and south side of the lock chamber. The chamber monoliths span between the Upstream wide wall monoliths and Downstream wide wall monoliths.   

“There are 21 chamber monoliths that make up the north wall and 21 chamber monoliths that make up the south wall,” Jeremy Nichols, Inland Navigation Design Center, New Lock at the Soo Design Engineer said. “The chamber monoliths are approximately 44 feet wide and 70 feet 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 New Lock at the Soo project is being built in 3 phases. Phase 1 (Upstream Channel Deepening) was completed in 2022, and Phase 2 (Upstream Approach Walls) is expected to be completed in summer 2024. The Phase 3 contract was awarded to KAT in July 2022 as a base contract at $1.068 billion. Awarding the base contract allowed the contractor to begin work in 2022 with the remaining work (contract options), to be awarded over the next three years.  

“The remaining options are required for a complete lock,” said Kevin McDaniels, Deputy District Engineer. 

“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, totaling $281.3 million,” said McDaniels. “The leadership team throughout the Corps of Engineers has made the New Lock at the Soo project a national priority and we have continued to see strong support every step along the way.” 

Four contract options, totaling $320 million, await to be awarded. These options are Option 3 (Lock Operational), Option 4 (Downstream Work), Option 5 (Hands-Free Mooring), and Option 6 (Downstream Ship Arrestors). The Corps of Engineers aims to award these options over the next two years. 

Phase 3 construction began in late 2022, and is expected to last seven years, given efficient funding and favorable weather. The New Lock at the Soo will be constructed in the footprint of the Sabin Lock and will be the same size as the Poe Lock (1,200 feet long, 110 feet wide and 32 feet deep). 

As of Dec. 4, 2023, KAT has completed over $240 million worth of work. Work to date includes Upstream cofferdam construction, cells are set and fill is being placed; Downstream cofferdam construction, cells are being set; abatement of hazardous materials; demolition of existing structures; partial construction of a new bridge to the hydropower plant; adding stability structures for the existing monoliths in preparation for dewatering and excavation; installing a grout curtain for upcoming dewatering and blasting/excavation for a new utility shaft.  

“Construction will continue over the winter season, to include hazardous waste abatement, concrete demolition, utility shaft excavation and electrical work,” said Mollie Mahoney, New Lock at the Soo Senior Project Manager.  

The Soo Locks 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 at the Soo project will construct a second Poe-sized lock. 

The Soo Locks are essential to U.S. manufacturing and National Security, the New Lock at the Soo project will provide resiliency for this critical node in the Great Lakes Navigation System. A 2015 Department of Homeland Security study estimates a six-month Poe Lock closure would temporarily reduce the U.S. gross domestic product (GDP) by $1.1 trillion, resulting in the loss of 11 million jobs.  

For more information about the New Lock at the Soo project, visit our website:


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