The 1922 Locomotive Cyclopedia of American Practice, published by Simmons-Boardman, is the most recent Locomotive Cyclopedia to be in the public domain. At 1141 pages of main text, plus indexes, front matter, and other content, it is a substantial book. It was essentially a combined catalog for all the major builders of railroad locomotives and associated equipment in North America, who provided the information. It contains photographs and scale drawings of several hundred locomotive types as examples of the locomotives that North American builders could produce, with chapters on all manner of locomotive components, appliances and equipment.
Illustrations from the 1922 Locomotive Cyclopedia