David John Maidment was born in 1940. He became a British Rail: Western Region Management Trainee in 1960. Between 1964 and 1971 he undertook various South Wales operating posts. In 1972 he began working in Management Services Parcels at British Railways Headquarters until 1982. He then moved to British Rail: London Midland Region as Operations Manager between 1982 and 1986. He was appointed as the Reliability Manager at British Railways Headquarters in 1986 and between 1988 and 1989 was involved with the Clapham Junction Accident Public Inquiry. He worked in Safety Management for British Rail from 1990 to 1994 when he joined Railtrack as Safety Controller. Between 1996-2002 he worked as an independent consultant.