BOATLOPNIK

The Way The U.S. Coast Guard Replaces Its Largest Ship's Motor Is Mind-Blowing

David Tracy
Tuesday 11:30AM • Filed to: BOATLOPNIK

A fire broke out on the United States Coast Guard’s largest ship last summer, destroying one of the vessel’s enormous electric motors. Now the Coast Guard, one of the five service branches of the U.S. military, is replacing that motor and documenting the entire process, which involves cutting a giant hole in the hull. The whole thing is fascinating. Check it out.

The USCGC Healy is the biggest and most advanced ship in the Coast Guard’s fleet, capable of breaking 4.5 feet of ice at three knots, and it’s equipped with over 4,000 square feet of laboratory space. On August 18, during an Arctic research mission, a fire broke out and ruined a propulsion motor, forcing the research ship to return to Washington State. The Coast Guard breaks down what happened in its memo:

The Healy was 60 nautical miles off of Seward, Alaska, en route to the Arctic when an electrical fire was reported at 9:30 p.m. A fire team disconnected the affected motor, and the fire was confirmed extinguished by 9:56 p.m. The cause of the fire is currently unknown.

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Due to the fire, Healy’s starboard propulsion motor and shaft are no longer operational, and the ship is transiting back to its homeport in Seattle for further inspection and repairs.

Luckily, there were no injuries reported, and there’s still no word on the cause of the fire. What is known is that the Coast Guard will have to replace that broken starboard propulsion motor. It is one of the electric motors that spin the propellers, powered by juice from generators spun by the ship’s diesel engines. “This Design,” the Coast Guard writes, “protects the engines from variations in shaft speeds inherent to ice operations.”

The Coast Guard’s Facebook page for Healy describes the research ship’s powertrain setup and why it uses 35,000 horsepower (combined) electric motors instead of the diesel engines to spin the props:

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