A lightering operation of a Keystone Shipping-operated self-unloading bulker has started a week after the ship ran aground off the US state of Michigan.

The 27,100-dwt bulker Philip R Clarke (built 1952) began taking a taconite cargo from the grounded 47,300-dwt Roger Blough (built 1972), the US Coast Guard said.

The operation is part of an effort to take the laker Roger Blough off Gros Cap Reef in Lake Superior's Whitefish Bay.

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