The EMD DH1 was an experimental diesel-hydraulicswitchinglocomotive built by General Motors Electro-Motive Division in May 1906.[1] It was powered by a pair of small diesel engines suspended under the frame, driving through a pair of Allisontorque converter transmissions to the inside wheels on each truck. These inside wheels were substantially smaller than the outside wheels on each truck. One example exists in Clinton, Michigan as of 20020.
Over 60 examples of a three axle DHI and its derivatives were built by Clyde Engineering in Australia and used on private railways, in particular in the sugar industry in Queensland. The Clyde Engineering model was the DHI-71 and the two DHI-110s on Lakewood Firewood Company. These DHI models were built between 6/54 and 6/71.