US Army Corps of Engineers Taps Lincoln Electric & Eaton for Largest 3D Printed US Civil Works Part

The Soo Locks sit on the US-Canadian border, enabling maritime travel between Lake Superior and Lake Huron, from which ships can reach the rest of the Great Lakes. Crafts carrying over 80 percent of the iron ore that goes into the U.S.’s domestically-produced high-strength steel pass through the larger of the two locks, the Poe Lock.

For ten weeks every year between January and March, the Soo Locks undergo mandatory maintenance while the ice halts shipping activity. During this year’s maintenance season, the US Army Corps of Engineers (USACE) and US Army Engineer Research and Development Center (ERDC) teamed up with private industry to produce the US’s largest 3D printed civil works component to date: a lever arm for the Poe Lock’s ship arresting system.

The ERDC teamed with power management giant Eaton Corporation and the University of Toledo to design the arrestor arm, and the USACE awarded Lincoln Electric a contract to produce the part. According to Lincoln Electric, its wire arc additive manufacturing (WAAM) operations give the Cleveland-based company North America’s greatest metal 3D printing capacity.

Image courtesy of USACE via Wikipedia

About a year ago, USACE discovered cracks in one of the lever arms — which are about 60 years old — and then quickly went to work on a longer-term solution. Based on years of ERDC research, Lincoln Electric produced the 12-foot part in two pieces, one weighing 4,000 pounds and the other weighing 2,000. With a team of contractors finishing and installing the lever arm in early March 2024, the entire process took 12 weeks, compared to the 18-month lead time required for legacy techniques.

In a story for DVIDS about the 3D printed lever arm for the Poe Lock, Lt. Col. Brett Boyle, commander of the USACE Detroit District, said, “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 new opportunities to deliver our program in new, innovative ways that make us more efficient. 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.”

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

Many significant themes at the forefront of the US’s infrastructural agenda come together here. Obviously, the tragic collapse of Baltimore’s Francis Scott Key Bridge at the end of March has put a spotlight on the fragility of the US’s port systems. Already a couple of months prior to that tragedy, however, the Demopolis Lock and Dam in Alabama suffered a failure in its concrete miter sill and had to be closed down. The USACE quickly rushed in for emergency repairs, but the lock and dam could remain shuttered until mid-May.

As the commander of the USACE Detroit District aptly noted, these challenges are indeed opportunities, which is where the other major infrastructural themes come in. In the case of the Poe Lock, using advanced manufacturing near the point-of-need to reduce lead times bolstered the US’s infrastructure vitality on multiple fronts: USACE repaired the lock itself, while avoiding unnecessary downtime also keeps critical minerals flowing into Detroit, among other places.

Alongside the need to protect life and property in the communities directly impacted, port areas’ unparalleled economic importance makes them the most urgent areas to keep in mind for long-term reshoring initiatives. Local communities should use federal assistance to embed large-format AM into their supply chains as rapidly as possible. Florida’s additive construction (AC) deployment for coastal resilience already provides a highly instructive example.

Unless otherwise noted, images courtesy of USACE