the british rail class 114 diesel multiple units were built by br derby from 1956 to 1957. forty-nine 2-car units were built, numbered 50001-49 for driving motors (later renumbered 53001-49) and 56001-49 for driving trailers (later renumbered 54001-49). the units were used on services in the west midlands, lincolnshire and humberside.