Crews are pumping water out of the ship that sprung a leak Monday in the Duluth-Superior harbor. The Walter J. McCarthy's engine room flooded after the ship struck an unidentified object under water while docking in Superior. The ship's stern sank to the bottom next to the dock.
The McCarthy is one of the big ships - the 1,000-ft. carriers that haul coal and taconite across the Great Lakes. The McCarthy's stern has been sitting on the bottom in about 20 feet of water since Monday. It struck something while docking for the winter in Superior.
Jim Sharrow of the Duluth Seaway Port Authority, says the McCarthy isn't really sunk. One end of it, the stern, is what Sharrow calls down-flooded. The heavy engines are in the back, and with the engine room flooded, the stern has settled to the bottom. But the front still floats.
The McCarthy isn't entirely empty. It carries thousands of gallons of water ballast, and that ballast may be the key to refloating the stern. Sharrow says you can get the ship off the bottom by emptying the water out of its ballast tanks, which would then fill with air.
"I don't know exactly how much ballast might be aboard but it's probably about 30,000 tons of water ballast," says Sharrow. "When you create a hole that down-floods the engine room, then as you raise the ship just by pumping the ballast out, the water that's in the engine room would just seek its own level as the ship comes up."
That also releases water from the flooded engine room, which will flow back through the breach and into the harbor.
The most important thing, Sharrow says, is to get the water out of those ballast tanks before it freezes. The ship has no heat or power, and very cold weather is moving in.
"There is a real severe question about that. The big problem would be freezing up of the ballast tanks, and the piping systems to and from those tanks. That could create lots of damage," says Sharrow.
The ship is owned by the American Steamship Co., a division of GATX Corp. in Chicago. Corporate spokeswoman Rhonda Johnson says the Wisconsin Department of Natural Resources signed off on a permit late Tuesday that lets the company begin pumping water out of those ballast tanks.
"So we did begin doing that. That's a process that should probably take about a day or two to fully complete," explains Johnson. "They did do all kinds of testing on the water and determined that it was clean and not contaminated. So once the water's emptied from the tanks, we'll have a diver going down to inspect the damage and to begin repairs to close up the hole."
Depending on the extent of damage, divers could weld a patch over the tear with the ship in place.
But there's lots more to be done. Johnson says the ship's four 3,500-horsepower diesel engines are going to need a thorough going over.
"We're going to have to take the engines apart and basically rebuild the engines. You've got to see what kind of damage has been done, if there's any rust, if there's any issues at all with the engines. And that's going to take some time to figure out," says Johnson.
It's going to an expensive repair for the Walter J. McCarthy, and the work could keep the ship off the lakes for months, well past the resumption of lake shipping in March.
There's no doubt the owners will try to quickly return the McCarthy to service, since there's a limited number of the 1,000 foot ships on the Great Lakes and plenty of coal and taconite to keep the fleet busy.