Yugoslavian JRP steam tug Kralj. Tvrtko according to a CIA report dated 7 February 1949

An item referred to a list published by the Austrian Ministry for Property Control and Economic Planning dealing with the shipping on the Austrian Danube divided in kilometres on 8 May 1945. On kilometre 2195 was sighted the Yugoslavian JRP (=Jugoslavenska recna plovidba) steam tug Kralj. Tvrtko with a horsepower of 500hp.

Source
The report was published on www.archive.org, document number CIA-RDP83-00415R002100070001-9