Although there had been experiments with diesel multiple-units from the 1930s onwards, it was not until the early 1950s that they came into their own. In the post-Nationalisation environment, particularly at a time when costs were rising inexorably and traffic as in decline as a result of the growth of road transport, the DMU offered a more attractive and cleaner form of rail travel for the passenger as well as a more cost-effective means of providing services for the railway industry when compared with steam traction. Drawing upon the work of many of the best-known photographers, the author has produced a comprehensive pictorial survey of these vitally important units.The 'In Colour for the Modeller and Historian' series has proved itself to be highly popular with enthusiasts and with modellers and preservationists in particular. This addition to an excellent series which already outsells most railway series on the market, a volume focusing on these popular if unsung heroes of BR's Modernisation Plan, is certain to sell extremely well.