The Plymouth CR-8 was a class of 4-axle B'B' centre cab locomotive, built by Plymouth Locomotive Works in the United States, several of which were used on industrial sites.

Ten units (CR-8b) were briefly operated in Thailand in the mid-1960s. During the Vietnam War they were operated by the US Army in South Vietnam, and afterward became entered Vietnam Railways service as class D10H. A second class of Chinese-built locomotives, classed DFH21, have operated as D10H in Vietnam from around 1980 onwards.

History and design The CR-8 class was available in weights from , with installed power ranging from using hydraulic twin engines via a cardan shaft final drive, in gauges from to .

The gauge American locomotives used in Vietnam used two General Motors 12V71 two stroke V12 engines.

The locomotives were originally thought to have been operated on the Royal State Railways of Siam (RSR) as numbers 2001-2010 beginning in 1963 or 1964. They were transferred to South Vietnam in the late 1960s during the US involvement in the Vietnam War, and operated as numbers 1988 to 1997 by the US Army. After the war's end in 1975 they were reclassified D10H and renumbered 31 to 40 by Vietnam Railways.

Several similar locomotives were used in the US by industrial operators, as well as MBTA and BART. A heavier model, the CR-8XT, was used by companies including Bethlehem Steel and the Jones and Laughlin Steel Company.

Known owners

Owner Variant Qty. Numbers NotesState Railway of ThailandCR-8102001-2010Metre gauge; later to US Army as 1988-1997; later used by Vietnam Railways as class D10 locomotives 31-40; presumed scrapped.Bay Area Rapid Transit25000, 5013Built to gauge; 5000 originally built in 1971 as L-1, and 5013 built in 1979; in service on maintenance-of-way trains.Massachusetts Bay Transportation Authority104443In use for maintenance-of-way trains on the Red Line of the MBTA subway.Maryland Transit Administration1801Formerly used to tow broken-down light rail vehicles the Baltimore Light RailLink, now used on the Baltimore Metro SubwayLink.Martin-Marietta147-0050Built in 1981 (serial number 7347) and formerly used in Woodville, Ohio; now owned by Stoneco and numbered 40.0001.Kaiser Sand and Gravel13707Built 1969 for various industrial operations in California, including in Radum and the Permanente Quarry.Ponce & Guayama Railroad340-42Meter gauge; #40 was built in 1963 (serial number 6199) and #41 - #42 were built in 1964 (serial numbers 6420 and 6421) for use on this sugar railroad in Puerto Rico. They operated on the railroad until its closure in 1990. All weighed 45 tonsJones & Laughlin SteelCR-8XT237-3837 built in 1967, and 38 built in 1975. Used in Aliquippa, PA. 37 later sold to LTV Steel.Bethlehem Steel171Built 1963 for use in Bethlehem, Pennsylvania, later renumbered 30 for use in Lackawanna, New York.Sungshin Cement26, 7Built in 1992 and 1993 for use on an industrial railroad in North Chungcheong Province, South Korea; used to haul cement and coal to Korail's Dodam junction

Notes

References