Novelty 2026: Between 1897 and 1919, the Austrian locomotive factories delivered over 830 locomotives of the 170 series for heavy freight traffic. Due to the outdated saturated steam technology, a superheated version with a shortened boiler and a single steam dome was developed for higher efficiency, while retaining the proven frame and drive of the 170. Recipients of the new locomotives included Czechoslovakia, Italy, and Poland, where these machines became highly significant as the Tr12 series. Poland initially ordered 82 locomotives from the Floridsdorf Locomotive Factory (WLF) and two from the Wiener Neustädter Locomotive Factory. Due to the high demand for powerful freight locomotives, the Tr12 series was subsequently also produced domestically. The Polish locomotives received larger superheaters, extended chimneys, Westinghouse air brakes, and modified cabs. The Tr12 were mainly used in southern Poland, where their good steam performance and low axle load offered particular advantages. After 1945, only a few machines reached the PKP in operational condition. In total, 39 Tr12 locomotives were returned to Polish service, with the last Tr12 retired in 1969. The Polish Tr12 combined performance, maintainability, and economy, marking the transition from saturated to superheated steam technology. It was a milestone in European locomotive construction and had a lasting impact on heavy freight traffic in Poland. • Version with PKP cab and chimney • Additional air and feed pumps as well as generator according to Polish design • Fine steps, handrails, and many separate pipes • Metal wheelsets and delicate motion gear • Sound version with steam generator from the factory • In digital operation with switchable cab lighting • Brake hoses, protective pipes, and coupling hooks included for upgrading