Four vessels will winter in the Twin Ports as the 2020-21 shipping campaign draws to completion Friday with the end-of-day closure of the Soo Locks connecting lakes Superior and Michigan.

During winter layup, the Soo Locks are repaired and maintained. Lake freighters go into the shop, too, sometimes requiring significant work. Hulls banged up by a season of sailing can see their steel repaired and painted.

“It is a difficult time in terms of weather to complete this work, but it keeps this important national infrastructure project operating during shipping season,” Soo Area Office engineer Kevin Sprague said in a U.S. Army Corps of Engineers news release this week.

The four ore boats wintering in the port of Duluth-Superior:

  • Hon. James L. Oberstar and Lee A. Tregurtha will dock at Fraser Shipyards in Superior.

  • Paul R. Tregurtha will move around the harbor and settle at the Midwest Energy Resources Co. terminal Sunday.

  • Burns Harbor will take up the Enbridge dock in Superior.

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The season reopens March 25.

The Great Lakes operating season is fixed by federal regulation and is driven in part by the feasibility of vessels operating in typical ice conditions, the Army Corps said.

The American Mariner loads with iron ore pellets at the BNSF Taconite Facility in Superior on Thursday morning. (Jed Carlson /
The American Mariner loads with iron ore pellets at the BNSF Taconite Facility in Superior on Thursday morning. (Jed Carlson /

The American Mariner was expected to be the final boat out of the Twin Ports, with an estimated departure through the Superior entry on Thursday afternoon.

None of the Great Lakes fleet of vessels, which are based in Duluth, will be wintering in the Northland.

Both Tregurthas and the Oberstar belong to Interlake Steamship Co., based outside Cleveland, Ohio, while Burns Harbor belongs to American Steamship Co., based outside Buffalo, New York.

While wintering in the Twin Ports, Paul R. Tregurtha will undergo a continuous hull survey as well as improvements to the self-unloading system, ballast tanks and main engine repairs, the company said.

The Oberstar will also undergo a continuous hull survey, repairs to the self-unloading system and refrigeration replacements, Interlake said. The Lee A. Tregurtha will have cargo hold repairs and renovations to crew rooms and common areas, Interlake said.

The concluding campaign was hampered by the COVID-19 pandemic. The resulting economic downturn saw blast furnaces slow down, and some mines close temporarily, slowing the transit of taconite iron ore.

It created a wide gap when comparing tonnage figures to the previous season.

Mark Barker, president of Interlake Maritime Services, which manages the steamship company, described the season as "one of the most dynamic in recent history."

“It wasn’t necessarily a banner year for cargoes carried," Barker said, "but I’m extremely proud of the resourcefulness and responsiveness of our entire industry and especially the women and men onboard our ships in keeping the American economy moving forward these last 10 months.”

Latest figures from the Duluth Seaway Port Authority showed a 25% tonnage gap through December between 2019-20 and 2020-21, 32.9 million tons compared to 24.7 million this season.

The overall tonnage gap did shrink as the season wore on, from 31% late in the summer, down to 27% through November, and then 25% in December.

“There were highs and lows, but we’re recovering well,” Kate Ferguson, the Port Authority’s director of trade and business development, said earlier this month.

The industry did well to prevent COVID-19 from infecting the workforce. At the beginning of the campaign, the specter of outbreaks on vessels was a major concern, Ferguson said.

“We had minimal reports on any of that kind of situation on lakers or salties, according to the U.S. Coast Guard,” Ferguson said. “You have to declare that an absolute success.”

Barker agreed, saying the companies worked together through the Lake Carriers' Association to establish protocols intended to mitigate the risk of infection.

"(W)e were able to keep our merchant mariners safe and healthy throughout a very unpredictable time," Barker said. "And at the same time (we) continued to deliver millions of tons of cargoes for our customers around the region.”

Off the eastern end of Lake Superior, on the St. Marys River, the Army Corps of Engineers uses the winter period to perform maintenance which keeps the Soo Locks operating. Often the work takes long hours in extreme conditions to complete during the closure period.

The Corps of Engineers has several projects this offseason, it said.

“The first step is to place the bulkheads then our dive team goes into the freezing water to seal the bulkheads and prepare the locks for dewatering,” he said. “Most of the maintenance projects will take place on the dewatered Poe Lock, the only lock large enough for the 1,000-foot freighters to transit.”

The Corps is also in the process of building a second Poe-sized lock to provide resiliency in the Great Lakes Navigation System. The second Poe-size lock will be 1,200 feet long, and the current project cost is estimated to be $922 million.

The Corps’ contractor wrapped up the first year of upstream channel deepening in mid-December, excavating between 2 and 6 feet of sandstone to deepen a canal enough for the 1,000-foot ships that will use it.

The deepening work will resume in April 2021. The project’s second phase, to stabilize the existing upstream approach walls, will also begin in April.

The project’s final phase is construction of the new lock chamber. The Corps’ Detroit District officials anticipate phase three construction will begin in spring 2022.

Ice floats in the Superior Bay as the American Mariner loads with iron ore pellets at the BNSF Taconite Facility in Superior on Thursday morning. (Jed Carlson /
Ice floats in the Superior Bay as the American Mariner loads with iron ore pellets at the BNSF Taconite Facility in Superior on Thursday morning. (Jed Carlson /