The Plymouth CR-8 was a class of 4-axle B'B' centre cab locomotive, built by Plymouth Locomotive Works, USA Several locomotives of type CR-8 have been used in the USA on industrial sites. Ten units (CR-8b) were briefly operated in Thailand in the mid-1960s. During the Vietnam War the units were operated by the US Army in South Vietnam, and after the end of the war became the property of the Vietnam Railways as class D10H. A second class of Chinese-built locomotives of type DFH21 have operated as the type D10H on the railways of Vietnam from around 1980 onwards.