American diesel electric tug Limestone (1952) in 1966

Active on the Great Lakes system. Operated by the Michigan Limestone Operations-Ynited States Steel Corporation. Homeport Calcite, Michigan, USA. Built in 1952. Steel made. Net register tonnage 99 tons. Dimensions 82.3 (register)-95.5 (over all) x 24 (register)-25.5 (over all) x 12 (register)-13.5 (loaded) and as highest fixed point above water (=spar) 22 feet. Horsepower 1.000 hp.

Source

Corps of Engineers US Army. Transportation Lines on the Great Lakes System 1966. Transportation series 3.