A heritage unit or commemorative locomotive is a railroad locomotive painted in an honorary paint scheme; usually the paint scheme is that of a now-defunct railroad that merged with or was acquired by the locomotive's owner.
Heritage units are popular among North American railroads. As of 2023, all major Class I railroads have official heritage units, except for BNSF Railway.[a][1][2]
The Union Pacific Railroad painted six EMD SD70ACes in stylized paint schemes of six of its predecessors between 2005 and 2006.[3] The Norfolk Southern Railway did the same in 2012 with 20 of its locomotives for its 30th Railroad Anniversary.[4] 10 of them are EMD SD70ACes, while the others are GE ES44AC units. For its 40th anniversary in 2011, Amtrak painted four GE P42DCs, a P40DC, and an EMD F40PH converted to an NPCU into its older paint schemes. Several more were painted for its 50th anniversary in 2021.[5] In 2019, the Canadian Pacific Railway (now Canadian Pacific Kansas City) painted nine EMD SD70ACU units in a maroon and gray paint scheme with a different font style. In late 2020, the Canadian National Railway revealed five new heritage units after they had been first spotted a month earlier. These included four GE ET44ACs and one EMD SD70M-2. They were painted in honour of the 25th anniversary of CN's initial public offering.[6][7] Beginning in 2023, CSX revealed its first of many heritage units, ES44AH 1827 with a Baltimore & Ohio paint scheme.[8]
Below is a list of heritage units in active service by various railroads.