USACE 3D Prints Largest Soo Lock Component


The Detroit District of the U.S. Army Corps of Engineers recently announced it has finished installing the largest U.S. civil works infrastructure component produced by a 3D printer on the Soo Locks Facility in Sault Ste. Marie, Michigan.

According to USACE, the 12-foot-long metal part for the ship arrestor system on the Poe Lock, one of the two active locks on the facility, was manufactured with a 3D printer for faster production times and a lower cost to maintain and improve the property.

About the Project

Using years of research by the U.S. Army Engineer Research and Development Center (ERDC), the part was built in 12 weeks, compared to a projected 18-month lead time for conventional manufacturing.

The part was reportedly installed, tested and commissioned during the Soo Locks’ winter maintenance cycle, which is a 10-week maintenance closure period set by federal regulation.

USACE stated that the rapid repair helped ensure normal operations at Poe Lock, a key transit point for domestic iron ore, where a random closure would be “catastrophic for the nation,” according to a 2015 study by the Department of Homeland Security.

“We secure our nation and energize our economy by operating, maintaining and preserving strategic water resources and infrastructure. That is a challenge as our infrastructure continues to age. These challenges are opportunities to deliver our program in new, innovative ways that make us more efficient,” said Lieutenant Colonel Brett Boyle, commander of the USACE Detroit District.

“The Poe Lock ship arrestor project has been one such opportunity for our team to work with ERDC researchers to harness existing 3D-printing technology in a way that safely delivered superior quality, while cutting through the extended lead times of today’s environment.”

The Soo Locks' mechanical ship arresting system reportedly protects the lock’s miter gates, an important system component, from an emergency impact with a ship. Each lock has two arrestors, each located upstream of the miter gates.

“The system is designed to safely and quickly halt a 100,000-ton vessel loaded with commodities over the course of 72 feet,” Detroit District Structural Engineer Clint Dougherty said.

The Poe Lock ship arresting system was reportedly rehabilitated by prime contractor OCCI, Inc. from early 2022 through the winter maintenance closure period of 2024. In February 2023, cracks were found in one of the 60-year-old lever arms that raised and lowered a large boom on the Poe Lock’s arresting system.

Temporary repairs were made before putting it back into service for the 2023 navigation season, and USACE stated that it needed new replacement lever arms to back up the long-term future use of this safety component.

After looking through several design alternatives, Detroit District engineers reportedly decided that 3D printing was the best option. During this process, they asked the ERDC for any knowledge it had in manufacturing, testing and procuring additive parts.

USACE had reportedly solicited and awarded the contract for the lever arms to construction equipment manufacturer Lincoln Electric.

Detroit District engineers reportedly built the arms and worked with Lincoln Electric to find the best print strategy to reduce distortion, get the desired surface finish and material mechanical properties and ensure strong quality control.

“Lincoln Electric and USACE developed an additive print strategy to print the part in two pieces, one approximately 4,000 pounds and the other 2,000 pounds, made from high-strength, low-alloy steel (HSLA), then weld them together at their Baker Industries facility located in metro Detroit,” Dougherty said.

Additionally, Dr. Zack McClelland, a research mechanical engineer at ERDC’s Geotechnical and Structures Laboratory, said the project was a collaboration of ERDC’s experience in additive manufacturing, the Detroit District’s knowledge of the Soo Locks and the application needs for the arrestor arm and Lincoln Electric’s experience with fabricating and welding large-scale components.

“There are only a handful of places in the world that can print a metallic part at this scale, and a lot of those parts tend to be cylinders,” McClelland said. “The Poe Lock arrestor arm really shows what can be done with the technology in terms of complex designs, and it signals a paradigm shift in how large parts can be manufactured.”

The lever arm was built, coated and installed by OCCI and their subcontractors (machining by Fulton Iron and coating by Coatings Unlimited) in early March 2024. The Soo Locks reopened for the navigation season on March 22, after OCCI commissioned the new lever arm.

Replacing Old Parts

USACE stated that replacing large vintage components is a current necessity, with much of the nation’s infrastructure now operating beyond its design life. Additionally, many of these parts are reportedly singular to individual projects, making their replacement more difficult.

If one was to suddenly break, that failure could shut down a facility for months, causing significant national economic damage. This is reportedly true for the Poe Lock, which was built in 1969 and still has most of its original parts.

“Roughly 88% of domestically produced high-strength steel used to manufacture products like automobiles and appliances is made with iron ore that transits the Soo Locks,” Detroit District Senior Project Manager Mollie Mahoney said.

Of the iron ore that transits through the Soo Locks, 95% is reportedly restricted to the Poe Lock because of vessel size. Because of this, a six-month Poe Lock closure could reportedly temporarily reduce the U.S. gross domestic product by $1.1 trillion, potentially causing the loss of 11 million jobs, according to the DHS study.

Advances in additive manufacturing offer transformative potential and can reportedly help when facing this challenge. As the technology has matured to support large-scale builds, ERDC has reportedly analyzed how it could be used by the U.S. Army and Department of Defense.

Now, it is reportedly working to apply the lessons learned from these military projects to modernize USACE infrastructure components and structures.

USACE stated that replacing large vintage components is a current necessity, with much of the nation’s infrastructure now operating beyond its design life. Additionally, many of these parts are reportedly singular to individual projects, making their replacement more difficult.

The ERDC has reportedly worked with electronics manufacturing company Eaton on military additive manufacturing research for over a decade, recently utilizing that partnership along with the University of Toledo on new research focused on civil works infrastructure, which resulted in the Poe Lock arrestor arm.

“This technology not only strengthens our national infrastructure, but also reinforces how the power of the collaboration is shaping the future of manufacturing and enabling the safety and efficiency of critical infrastructure," said Eaton Director of Government Programs Bryan Farrens.

The project reportedly utilized wire-arc additive manufacturing, a new process that supports complex, large-format metal builds.

“We found the researchers and industry partners shared our passion for solving problems in the field,” said Peter Dodgion, chief of the USACE asset management branch.

“Our field folks in Civil Works know where the problems with fabrication are. All we had to do was connect those researchers with our folks in the field and real-world solutions began to emerge.”

USACE stated that a key focus was ensuring that additive manufacturing met USACE requirements for reliability, utility and cost efficiency, especially given the intense stressors placed on civil infrastructure.

Research was reportedly conducted to understand material properties of existing vintage parts and to ensure the 3D-printed material could meet or exceed their performance.

“We have been trying to advance the scale and reduce the cost using new approaches for manufacturing,” said Dr. Robert Moser, ERDC Senior Scientific Technical Manager for Materials, Manufacturing and Structures.

“A lot of our research has gone into investigating the best parameters to produce some of the metals we want and to ensure we minimize any defects that would affect strength or fatigue. We have to validate the mechanical performance of those parts and ensure they are as good as or better than the parts we already have. In this case, it was at least 20- or 30-percent stronger than the metals that were previously being used.”

The effort is also expected to help build a digital USACE parts inventory to speed up the turnaround time for replacement components tenfold and cut out of the need to physically store large parts and molds for future use.

Research following this current study will reportedly look at the production of stainless-steel materials and the ability to incorporate multiple metals. At the moment, this option doesn’t exist with traditional manufacturing, but could allow for greater efficiency, like only placing a fatigue-resistant material where it is needed instead of using it as the only metal throughout the entire project.

The ERDC and its partners are reportedly also looking into how parts can be better designed with a modern understanding of structural loads.

In the past, parts had reportedly been “overdesigned” based on conservative assumptions, but today’s increased knowledge combined with emerging material research could potentially allow for improved performance with lighter weight, with parts scoped to meet actual needs.

Building on the success of the Poe Lock arrestor arm project, the research efforts will reportedly help advance USACE’s large-format additive manufacturing capability.

Ultimately, this could reduce the turnaround time to attain components from months to days, improving the reliability of critical flood risk management and navigation infrastructure to protect communities and preserve economic growth.


Tagged categories: 3D printing; 3D Printing; Design build; Environmental Controls; Equipment manufacturers; Health & Safety; Infrastructure; Infrastructure; Locks and dams; NA; North America; Ongoing projects; Program/Project Management; Research; Research and development; Ships and vessels; Technology; U.S. Army; U.S. Army Corps of Engineers

Join the Conversation:

Sign in to our community to add your comments.