American diesel tug S.M. Dean (1949) in 1966

Active on the Great Lakes system. Operated by Oglebay Noroton Company Fringle Barge Line. Homeport Detroit, Michigan. Built in 1949. Steel made. Net register tonnage 99 tons. Dimensions 110.3 (register)-115 (over all) x 27 (register)-27.8 (over all) x 12.5 (light)-13.6 (loaded) and as highest fixed point above water (=aft mast) 48.5 feet. Horsepower 1.600 hp.

Source

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