How the Coast Guard’s ice breaker crushes through 21 feet of solid ice
The Arctic ice cap reached a new low in September 2012. In just six months last year, 4.5 million square miles of Arctic Ocean ice melted, according to a report by the United Nations.
While that may be hard to imagine, the commanding officer of the U.S. Coast Guard Cutter Polar Star says Arctic ice was the lowest he’s ever seen in all his ice breaking trips to the region.
After three years in a Seattle shipyard and a $90 million makeover, the Coast Guard’s heavy ice breaker just returned from trials in the Beaufort Sea and made a brief stop in Juneau.
“It’s capable of breaking over 21 feet of solid ice, with an inch and a quarter thick steel hull, and a design that allows it to ride up on the ice and crush it with its weight,” said MST1 Brian Carr, at the start of a Polar Star tour.
He is one of the 150 crew members and officers aboard the rebuilt ice breaker, 115 of them making their first trip to the Arctic.
Their commanding officer has spent much of his 30 years in the Coast Guard breaking ice.
“Pretty much the most fun job on the planet.”
Captain George Pellissier started his Coast Guard career as a naval engineer on an ice breaker.
“We pretty much get to live the Discovery Channel. I mean where they send us and where we get to go, most people only get to see watching TV or reading about it in a magazine.”
That includes deployments to both the Arctic and the Antarctic. It’s a toss-up as to which Pellissier likes best, though the trip south from the Polar Star’s Seattle home port is more diverse; such as crossing the tropics.
“Pulling an ice breaker into, say, Tahiti is always interesting,” he said.
Penguins greet the ship at the South Pole; polar bears and walrus at the North.
“Even the ice that you’re actually going through is a little bit different,” Pellissier said.
On this shakedown trip to the Arctic, the Polar Star found heavier ice than the captain anticipated.
“What we found was essentially first year ice where we went, although in the vicinity of Barrow it was all rafted together and piled on top of each other, so it was fairly tough ice,” he said.
The ship reached Barrow’s ice-choked shore on July 2nd.
“We did find that a couple weeks into the trip the ice was breaking up and receding rapidly,” he said. “So this trip there was less ice that we encountered than I’ve seen in years past.”
The Polar Star spent most of the time in the Beaufort Sea, reaching 78 degrees north latitude, “not terribly far, but enough to find some nice good ice to play around in for a while and do all of our testing.”
The rafted ice is some of the hardest to break, a good test for the ship’s rebuilt engine, propeller and navigation systems.
The propellers are driven by a diesel-electric or gas turbine power plant.
The diesel generators are capable of 18,000 horsepower, and the three turbines, more than 75,000 horsepower. The thickness of the ice determines which system to use.
Pellissier gets a real twinkle in his eye when he talks about testing his “new” ship on the piled-up ice.
“We kind of tested the full power by nosing up to a large pressure ridge and running the turbines one at a time and just running them all the way up through the whole horse power range, which was kind of neat,” he said.
So what does it feel like when the 13,000 ton Polar Star is breaking a mound of ice?
“We are one of the few ships on the planet that intentionally runs into things. It makes a fair bit of noise and everything shakes.”
The entire ship is an ice breaker. The trials also tested the Polar Star crew; some fresh out of basic training.
“You’ll be going through the ice and making good progress, if you hit a pressure ridge, or a little bit of thicker ice, all of a sudden the ship will lurch off to one side or the other with not a lot of warning for the folks. So they learn right quick to close or latch open the doors and hold on,” he said.
Pellissier said backing up in the ice is one of the more dangerous things to do. The ship draws 31 feet; the three propellers are 16 feet in diameter and sit about 15 feet below the water line.
“You know the spinning propeller will kind of knock the pieces of ice aside. You’ll feel it; it’s what we call milling ice and it does feel like all of a sudden your ship becomes a giant blender.”
The bigger concern is the rudder, so the key, he said, is taking it slow to make sure the rudder remains centered “so that it’s going directly back into the ice and not getting knocked over to the side and potentially wedged over to the side.”
He said backing up is always a bit tense. “You just take it nice and slow for the back and then you get a running start at the ice again.”
The newly rebuilt Polar Star is the only operating heavy ice breaker in the Coast Guard fleet. Pellissier says the Arctic ice trials show she’s a better ice breaker now than when commissioned in 1976.
He has a list of work to be done in home port over the next four months then the ship will head south to Antarctica.
Check out this footage from one of the Polar Star’s early journeys to Antarctica in 1998