The biggest ships you'll see on Lake Superior are eventually headed to the lower Great Lakes, with tons of taconite pellets or coal on board.
To get there, they pass through the locks on the St. Mary's River near Sault Ste. Marie, Michn. Those locks raise or lower ships to match Lake Superior's higher level with that of Lakes Michigan and Huron. But there's only one lock that can hold a 1,000 foot freighter: the 1,200-foot-long Poe lock.
"The first 1,000 footers started coming out in the early '70s," says Glen Nekvasil, with the shippers trade group, the Lake Carriers Association. "It was not long after that that the Lake Carriers Association started lobbying for a second Poe-sized lock."
Glen Nekvasil says the 1,000-foot-long ships carry 70 percent of the freight that moves on the Great Lakes. With those ships having to share a single lock, Nekvasil says disaster is just a breakdown away.
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"If anything was to happen to the Poe lock, the U.S.-flagged fleet on the lakes would basically go to anchor," Nekvasil says. "We would just not have anywhere near the capacity to meet the needs of commerce."
Duluth Seaway Port Director Adolph Ojard says the Poe lock is showing its age. It needs two months of heavy maintenance every winter.
If anything was to happen to the Poe lock, the U.S.-flagged fleet on the lakes would basically go to anchor.
"Our locks and our infrastructure are very old, and they're getting older," Ojard says. "It will take at least 10 years, if we move at break-neck speed, to build a lock at the Soo, at which point the existing lock will be 50 years old. And, of course, the adjacent MacArthur Lock, which is sightly smaller, is 70 years old. It will be 80 years old at the time."
Ojard says an additional lock prevents bottlenecks, but also opens up an extended shipping season.
"A second lock would resolve summer operation delay," Ojard says. "It would reduce the amount of out-of-service time during the winter. And it certainly would be one of the key items to set the stage for extended season and possibly year 'round shipping on Lake Superior and the Great Lakes."
That's an idea that gets more attractive, as Lake Superior's ice grows thinner in the warmth of global climate change.
The second lock isn't a sure thing. The bill passed by Congress over the president's veto authorizes the project, but the actual money must still be appropriated in a separate measure.