The Mississippi River towboat the Patrick Gannaway pushes through downtown Minneapolis on its way to its last ride in the Upper St Anthony Falls Lock & Dam. Image courtesy of Minnesota Public Radio via NPR.
I guess it’s nautically correct to call boats like the Patrick Gannaway towboats but I prefer tugboat. Neither’s accurate anymore, not when what they’re moving are barges. Been a long time since they routinely towed or tugged barges. Mostly they push. The Patrick Gannaway had been pushing barges up the upper reaches of the Mississippi River and on into and through downtown Minneapolis for years. To do that, it had to push past the Mississippi’s only waterfall. That meant pushing into the Upper St. Anthony’s Falls lock and taking a ride five stories down. NPR reported yesterday that the Patrick Gannaway recently took its last ride.
To get its 2,400 tons of sand, gravel, and limestone past the river's only waterfall, the barges take a five-story vertical ride inside the Upper St. Anthony Falls lock.
Deckhands squeeze everything into the narrow chamber and use a winch to take up the slack in the boat's steel cables.
In a control room above, a lock operator closes the chamber's enormous gates before opening a valve and letting in 10 million gallons of rushing water.
The towboat and its fully-loaded barges rise quickly, 49 feet in just 10 minutes. Doors at the other end of the chamber open, and the Patrick Gannaway continues its journey upriver to a concrete plant.
That’s how it worked. But that’s done with. The lock’s closed. Closed to towboats. And it’s hoped closed to fish. A certain kind of fish, particularly.
Concerns about the spread of Asian carp led Congress to mandate the permanent shutdown of the Upper St. Anthony Falls Lock & Dam. It brought an end to 52 years of commercial barge navigation on the northernmost stretch of the Mississippi River.
Environmentalists and the tourism industry are hailing the move. Christine Goepfert with the National Parks Conservation Association says the carp — which can leap into boats —- pose a big threat to the food supplies of other fish.
"They have disastrous consequences," she says. "They out-compete our native fish populations like our prized walleye. They vacuum up everything in their path. So now we know that the waters north of that lock will be protected from that threat."
Like I said, this is the hope.
Goepfert concedes that invasive carp may still migrate upriver. The fish could bypass the lock entirely if a careless boater neglects to drain ballast water, or empties leftover fishing bait in an unaffected body of water.
You can read and listen to Matt Sepic’s whole story, After Waterway Closure, Minneapolis Sees An End To River Shipping, at NPR. Dull headline for an interesting story. There’s also a video. But you can watch that here.
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