After the first three volumes of this book series documented the Reichsbahn era up to the end of World War II, the fourth volume opens the main creative period of Bellingrodts, starting with the first recordings of the post-war period and extending deep into the Federal Railway era of the early 1970s. Particularly the 1950s and 1960s established Carl Bellingrodts' outstanding reputation. During this time, no one else documented the early years of the Federal Republic and its railways as comprehensively and at such a high technical level. The first volume about this Federal Railway era focuses on the express steam locomotives of the series 01, 01.10, 03, 03.10, and 05.