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
Diesel Locomotive Works plans to increase it to 275 based on the current demand.Since inception,DLW has produced total 8099 locomotives (up to 31st January, 2018) of various types. DLW now manufactures“More than one locomotive a day”. DLW manufactured 334 diesel-electric locomotives in last financial year 2016-17, which is the highest ever loco production by any loco manufacturing unit in India and bagged the “Best Production Unit Shield” for the second successive year. DLW locomotives have power outputs ranging from to . Currently DLW is producing EMD GT46MAC and EMD GT46PAC locomotives under license from Electro-Motive Diesels (formerly GM-EMD) for Indian Railways. Some of