The class 533A 2-10-2 is unique in RSR history in that it was built after its designer's retirement. In 1945, Tešlov was faced with the task of rebuilding the RSR's motive power from the ruins of the Second World War. A new heavy freight locomotive was high on the list of priorities, but finding a builder able to produce a machine of this size took time. It was well known that Breda, of Milan, had received a similar order for the Greek railways; however, the fact that Italy had generated no new experience of locomotive design since 1927 was not lost on the RSR's buyers. When Tešlov retired, in 1950, the order still had not been placed. Not until 1953 were the contracts with Krupp, of Essen, signed and work begun. The RSR was not disappointed in Krupp quality. The 533A was the only large post-war design not to receive poppet valves. The majority of the class remained in service until 1994, sharing duties with the newer 564B and 555A 4-10-4s, after which withdrawals were heavy and the last 533A was retired in 1996 and took its place in the Museum of Science and Technology in Bevice.