Coast Guard at the ready for oil spills
By Bob Kelleher
Minnesota Public Radio
DULUTH — It’s a spooky morning on Lake Superior. About two miles off Duluth’s Aerial Lift Bridge, the Coast Guard Cutter Alder is socked in by fog.
Superior is dead quiet and smooth as a swimming pool. These are perfect conditions for mopping up an oil spill.
Jeremy Mitchell directed a dozen guardsmen on deck. They’re pulling a three-armed metal pump and folded orange fabric from pickup truck-sized aluminum crates.
"Basically, it’s a system that’s installed in the ship," Mitchell said. "We have put it together, pull it out of the cargo hold, so that we can build the system as we’re en route to the oil spill."
If oil spills on Lake Superior, or even parts of Lakes Michigan or Huron, the Alder could be the first responder. Much of the oil spill equipment is newly developed, although it’s not all high tech.
It took three sailors and a sturdy rope to swing a 42-foot aluminum outrigger arm off the Alder’s port side. That arm will anchor a floating boom. It’s like an orange inflatable wall that forms into a horse-shoe shape on the water surface. Before it’s dumped overboard, the crew inflates the boom like an air mattress with a blast from a heavy duty leaf blower.
"You’re looking at about maybe a four hour max — four to five hour max — with a trained crew to set this system up," Mitchell said. "We’re fortunate enough to have it actually installed in a cargo hold on the ship, so it’s on the ship at all times."
With the floating orange boom open on one side, Mitchell said, the ship cuts through a slick, forcing oil into the open mouth of the boom.
"Our boom is set up in a "u" configuration, and it just turns it into a big funnel," Mitchell said. "And, as the oil comes in, you’re going to try and build up a nice pocket that surrounds that skimmer."
The skimmer is that three-armed contraption. It can suck more than 200 gallons a minute, separating the oil while chewing up floating debris like aluminum cans, vegetation or dead birds.
"You’re going to punch in your skimmer and try and drain that pocket down as the ship is going through it," Mitchell said.
On that day, there was no oil on the water. If there were, it would have been pumped through a wide rubber hose to something that looked like a floating orange blimp.
"They call them ‘sea slugs,"’ Mitchell said. "They’re a big bladder. While this vessel is out skimming, it will have the bladder on the side. Once that bladder gets filled up, a tug will come along side, gather that bladder, come in with a brand new one, and take that one to shore so we can off-load it."
The Alder has carried this system for four years, and so far, it’s never been pressed into real service. But Mitchell said there’s a lot of cargo on the Great Lakes and spills can happen.
What’s important, he said, is that the crew is trained and ready. That’s not easy to maintain as the crew turns over. Alder Captain Kevin Wirth said half the crew is new since last year.
"This is a mission we don’t typically do, but we’re capable of doing," Wirth said. "So we need to train on that, and we spend about a week a year as well as some time for individuals to go to schools away from the ship to learn how to do what we did today."
Wirth said the Alder was designed with the massive Exxon Valdez oil spill in Alaska in 1989 in mind.
"When the cutters were originally designed and built, it was the early ’90s," Wirth says. "After Exxon Valdez, they thought it would be a good capability for these ships to have would be to skim and recover oil. So that was one of the considerations in the design and building of this ship."
But there are limitations. If a leaking ship has grounded, there might not be enough water depth for the Coast Guard cutter to operate. Also, particularly rough seas can overwhelm the system.
"The deployment of that will depend on the event," Wirth said. "We’re training for a mission set that we wouldn’t know when we’ll need to use it. We just need to be ready to do it. So, true to the motto ‘Semper Paratus,’ right? We’re training to be ready to deploy pollution recovery gear when it’s ready, when it’s needed."
"Semper Paratus" is the Coast Guard motto. It means "always ready." And it’s true for the crew of the Alder.