The Czechoslovakian diesel screw steam tug Oslava according to a CIA report dated 16 January 1952

An item reported that the Czechoslovak Oder Navigation Company (CSPO) possessed the diesel screw steam tug Oslava with a horsepower of 150hp.

Source
The report was published on www.archive.org, document number CIA-RDP82-00457R010000110009-3