Thousands of ships pass through the Soo Locks on a yearly basis, but the winter season happens to be one of the busiest times of year there for U.S. Army Corps of Engineers workers.

“We tried to cram a lot of work into the 10 weeks that were shut down,” said Tim Bartlett, a mechanical engineer for the Army Corps at the Soo Locks. “During the navigation season, we can’t exactly take our main locks down and perform long-term maintenance. When the locks close, we hit the ground running to take advantage of that short duration.”

Every year the Soo Locks close for maintenance on Jan. 15, reopening for traffic on March 25.

[ Soo Locks Live Cam ]

This year, anchorage components were replaced on the upstream gate, which is required to keep water in the lock. Bartlett said this repair is not typical for a year.

“Usually we de-water the lock right away, and most work is performed on the dry lock. This year we had to keep watering the lock to complete that work,” Bartlett said.

A miter gate is a pair of canal lock gates that swing out from the side walls and meet at an angle pointing toward the upper level. This year, the anchorage components on the upstream miter gate were replaced. If it were to fail, it could cause a long-term impact on commerce.

“There’s only one upstream miter gate, so if something happens with that, we’d have to take it down and completely stops traffic through that through that lock,” Bartlett said.

The upstream is the most critical lock since there’s just one lock for that direction of traffic. The anchorage components replaced original equipment from the mid-1960s. All parts are fabricated in-house at the machine shop and installed by workers on site.

After the work was completed in mid-February, the lock was pumped dry and other fixes were underway. In-depth inspections on the miter gates, structural repair to the downstream miter gate and repairing emptying belts were part of the process.

“We also perform routine tasks like cleaning debris from the lock floor and under the floor drain system,” Bartlett said. “The ships with the current bring in a lot of debris that accumulate on the lock floor. There’s lower sections below that lock floor that collect debris so that a ship won’t hit it when it’s being locked through. The majority of it’s stone and pieces of concrete.”

During this year’s clean-out workers found a large semi tire, a cellphone, glasses and various tools.

A lot of the work has inherent risk.

“We do a lot of overhead lifting with cranes working from heights working close to the water, electrical hazards, operating machinery and heavy equipment. Safety is absolutely No. 1 here at our facility. That allows us to identify the hazards with which each one of those work tasks and mitigate the risks as best we can,” Bartlett said.

The dive team also completes underwater inspections. Both scheduled and unscheduled maintenance continues year-round. Next year’s maintenance is already being planned.

How does the lock work?

If a ship approaches from either upstream or downstream, a set of miter gates controls the water on both the upper and the lower ends. As a ship approaches the lock chamber is equal elevation of water. The gates open, the ships come in, and the miter gates shut behind and lock them into that chamber. At that point, a series of valves 60 feet down from from the lock wall surface open up the waters move all through gravity. The lower valves open and allow water in the lock chamber to lower to 21 feet, the elevation of the river. Once down at equal level the other side of the gates open and the ship can leave. The process is reverse for ship coming upstream.

It takes about 20 minutes total for the ships to travel through.

For those not able to come to the Soo Locks opening, there will be a Facebook Live stream of the first ship. Find it on the District’s Facebook page on March 24 starting at 11:55 p.m.

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