The Czechoslovakian CSPD motor tug Dumbier active on the Danube according to a CIA report dated 29 June 1955

An item dated 11 May 1955 reported the Czechoslovakian CSPD (Ceskoslovenska Plavda Dunajska) motor tug Dumbier on the Danube off Budapest, Hungary while towing loaded barges and tankers upstream.

Source
The report was published on www.archive.org, document number CIA-RDP80-00810A007200560007-7