Bay Shipbuilding in Sturgeon Bay has seen quite a bit of traffic over the past week. Late last week, Walter J. McCarthy Jr. departed from winter layup and headed to Lake Superior to begin her 2017 season. On Monday evening, Interlake’s Mesabi Miner departed from Bay Shipbuilding and headed towards the Soo Locks to load her first cargo of the season at Duluth. Over the winter, the Miner was outfitted with exhaust gas scrubbers, similar to those added to her fleetmates James R. Barker and Lee A. Tregurtha last winter. The Miner is Interlake’s fourth vessel to be fitted with the new system, which is designed to remove sulfur and other emissions from the ship’s exhaust. Also on Monday evening, Pathfinder/tug Dorothy Ann left the shipyard after spending the past two weeks there for some sort of unspecified repairs. She headed for Stoneport to load. Great Republic arrived soon after the Pathfinder’s departure, presumably also for repairs of some sort. John G. Munson remains docked, but is expected to begin her sea trials for her new engines within the next few days. Manitowoc, Calumet, and American Courage all remain in layup.