Built in 1940, by Ira S. Bushey and Sons Incorporated of Brooklyn, New York (hull # 473) as the Crusader for the Ira S. Bushey and Sons Company of Brooklyn, New York.
In 1940, the tug was acquired by the United States Navy. Where she was designated as YN-36 (Mahaska). And, allocated to the 3rd Naval District.
In 1941, the tug's conversion for Naval Service completed at the New York Navy Yard. Where she was allocated to the 5th Naval District at Norfolk, Virginia. At the Norfolk Naval Shipyard in Portsmouth, Virginia.
In 1942, the tug was redesignated by the United States Navy as the YNT-4 (Mahaska).
In 1945, the tug was redesignated by the United States Navy as the YTB-730 (Mahaska).
In 1946, the tug was redesignated by the United States Navy as the YTM-730 (Mahaska). It is unknown as to when the tug was placed out of service, and struck from the Naval Register.
In 1970, she was acquired by the Thames Towboat Company of New London, Connecticut. Where she was renamed as the Thameship.
Originally powered by a single, six cylinder, Fairbanks Morse diesel engine. Turning a single, fixed pitch, propeller. Rated at 1,800 horsepower. The Thames Towboat Company re powered the tug with a a single, EMD 16-645 diesel engine. Turning a single, fixed pitch, propeller. She is a single screw tug, rated at 2,000 horsepower.