Diesel locomotive were classified as DET 1 and DET 2 (). Due to shortage of petrol products during World War I, they remained unused for regular service in Germany. In 1922, they were sold to Swiss Compagnie du Chemin de fer Régional du Val-de-Travers (), where they were used in regular service up to the electrification of the line in 1944. Afterwards, the company kept them in service as boosters till 1965. Fiat claims a first Italian diesel–electric locomotive built in 1922, but little detail is available. A Fiat-TIBB diesel–locomotive "A", of 440CV, is reported to have entered service on the Ferrovie
Electro-diesel locomotive whose electricity source is overhead line include: In 2010, Bombardier had plans, apparently known as "Operation Thor" or "Project Thor", to convert 500 existing diesel multiple units (DMUs) into electro-diesel multiple units (EDMUs). Whilst exact details are unclear, one source specified that these would involve their Voyager family DEMUs, and entail the construction of additional intermediate cars with a pantograph and a transformer which would feed power into the traction motors of the existing diesel-electric cars when running off overhead lines. Several, primarily diesel locomotive types and a multiple-unit have been built to operate off a third rail into the