Each issue of Loco Profile features a world-famous locomotive class, including previously unpublished facts. Loco Profiles contain approximately 8,000 words, up to 30 photographs, dimensional drawings, various diagrams and a double-page spread in full color of a side and end view, illustrating up to three locomotives. This issue, published in 1971, featured the Union Pacific 4-12-2s. 24 issues had been published as of that point.