CHICAGO (CBS) — After weeks of speculation, the oldest freighter on the Great Lakes — and one with a special place in Chicago history — is unloading its last load of cement, before steaming to Sturgeon Bay, Wis., to be transformed into a barge.

The freighter known best to Chicagoans as the Medusa Challenger, now the St. Marys Challenger, arrived at the South Chicago Terminal in Lake Calumet around midnight Friday.

A number of the ship’s fans — and she has many — lined bridges along the Calumet River to get late-night photos of the 551-foot-long freighter close-up. The enthusiasts came from as far away as Massachusetts and New York.