Quote from: Ralph S on November 03, 2025, 02:13:56 AM...The definition from US Federal Railroad Admin and the Assoc. Of American Railroads is confusing. Can someone restate that in layman's terms (I have no experience in or on real railroads).
As best I can parse it, a train consist (locomotive and freight) may be powered by a single locomotive or by a "multiple unit control" (two or more locomotives connected to function in unison). Two or more locomotives connected to function in unison is a "locomotive consist".
"Rolling Stock" is the wheeled vehicles owned and used by a railroad, including locomotives, freight cars, and passenger cars. This definition is widely accepted in the rail industry and can be found in various Association of American Railroads (AAR) publications and resources and the US EPA website. (https://www.epa.gov/epcra/what-items-are-covered-term-rolling-stock.
A "Train Consist" is a specific arrangement of specific rolling stock, e.g.,locomotive and freight cars (http://www.railway-technical.com/trains/).
A "Locomotive Consist" is two or more connected locomotives. "Multiple Unit (MU) Control" for diesel electric locomotives is "a standard arrangement approved by the AAR and its member railroads and manufacturers, enabling each unit of a locomotive consist to function as one from the controls of any unit in the consist." (http://www.railway-technical.com/trains/rolling-stock-index-l/diesel-locomotives/us-locomotive-mu-control.html).
See also the definitions here: http://www.railway-technical.com/glossary/rail-lexicon-mk24.pdf