The ship in question was the Mesabi Miner. There are quite a few ships that hold a place in my heart. This was the first ship I caught when I went to opening day at the Soo Locks a couple of years ago. She's also appeared on my blog a few other times.
She's kind of like the Tregurtha in that she makes several visits to the St. Clair Power Plant but I think she will carry other cargo.