DULUTH, MN (KDAL) - The U.S. Army Corps' cream-of-the-crop ice cutter made a trip to the harbor this weekend, and it's fire-engine red hull shone bright in the sun. That would be the Mackinaw, a 240-foot powerful cutter capable of taking out up to 32 inches of ice at 3 knots. Although the Duluth-based Alder has been doing its own ice-cutting recently, the ship's commanding officer, Tony Maffia, said the Coast Guard often sends other cutters to assist in the run-up to the shipping season. The Mackinaw came in from the Soo Locks Saturday, and will leave Sunday or Monday. Meanwhile, the Alder will ship out later this week to help break ice at Sault St. Marie. In relief of the Alder will be the Biscayne Bay, a smaller cutter that will continue clearing out ice. The first laker of the season, the Mesabi Miner, will leave the Twin Ports Tuesday with a load of coal bound for Presque Isle, Michigan. It's expected to return Friday to pick up a load of iron ore.