Polish tug Los according to a CIA report dated 20 May 1954

An item reported the Polish tug Los with a gross register tonnage of 129 tons, a horsepower of 500 hp, built in 1941 and as homeport  Szcezecin, Poland. Also used as an icebreaker on the Oder river.

Source
The report was published on www.archive.org, document number CIA-RDP80-00810A004001050003-8