Ok22 is the name for a Polish passenger steam locomotive used by PKP. It was the first locomotive designed in Poland after World War I, so the design work was done jointly with Hanomag, based on the German class P8 (Polish PKP class Ok1) The production lasted from 1923 when the first five engines were built in Germany Hanomag until 1928 when serial production was started in Fablok in Chrzanów. The first Polish-built locomotive (OK22-6) was ready on December 31, 1928. Polish versions of the locomotive bore some improvements and changes compared with German ones, and were similar to PKP class Ty23. OK22 locomotives were the first on the PKP to be equipped with electric lights. During wartime Ok22 bore German classification numbers 38 4501 - 38 4630. Only two examples have survived to this day. Ok22-23 in Jaworzyna Śląska and Ok22-31 in Wolsztyn. Ok22-31 is still operational. It ran until 1997, and after retirement became a stationary exhibit. In 2004 the machine was restored to the working order.