SAULT STE. MARIE — The Soo Locks' MacArthur Lock opened to marine traffic June 19, after completing a critical repair that took longer than expected.

The lock was set to reopen in late April, but replacing the almost 79-year-old tainter valve machinery — original to the lock, built in 1943 — caused a 59-day extension.

"The tainter valve machinery replacement contract was a very large task," said Soo Locks Construction Chief Nicholas Pettit. "The original machinery had to be cut into pieces and removed by crane out through a small access tunnel.

"The new machinery had to be fabricated in sections, lowered by crane in through the small tunnel and installed inside of the lock."

The installation took longer than scheduled, but this critical replacement means the MacArthur Lock will continue operating long into the future, according to Pettit.

The extended closure demonstrates how important the "New Lock at the Soo" project, currently under construction, and maintaining the current locks are to shipping in the Great Lakes. If the Poe Lock was closed for a similar repair, it would've halted nearly all shipping.

"The extended MacArthur Lock closure caused increased wait times for many vessels using the Soo Locks," said Area Engineer Kevin Sprague. "The maintenance team worked with the contractor to get the tainter valve machinery project completed as quickly as possible. Our locks crews also worked very hard keeping vessels moving through the Poe Lock as quickly and safely as possible."

The MacArthur Lock closed Dec.15, 2021, for seasonal maintenance, including the tainter valve machinery project. Every year, the Corps of Engineers uses the winter period to perform maintenance to keep the Soo Locks operating.

The Sault Ste. Marie Project Office works long hours in extreme conditions to complete a significant amount of maintenance during this annual closure period. The work they perform is unique, especially given the harsh northern Michigan conditions they work in.