(Contains some technical spec information on Thumpers ( 201 - 207))First introduced in the early 1950s, the diesel multiple-unit represented an attempt to produce a vehicle that would replace steam traction on the countrys branch lines and secondary routes at a time when the railway industry was in desperate need of a cheaper alternative to steam in order to improve the finances of these increasingly unremunerative lines. Initially introduced in areas such as the north west of England, the West Riding of Yorkshire and East Anglia, the arrival of the new and much cleaner Diesel Multiple Units (DMUs) undoubtedly helped to stem both the loss of passenger traffic and improve, at least briefly, the economics of the lines over which they operated. Between the early 1950s and the start of the following decade, several thousand of these units were produced by a variety of manufacturers for service nationwide. However, despite the cost savings that these units represented, the financial position of the railways continued to deteriorate with the result that many of the lines for which they were designed were closed in the wake of the Beeching Report. Following refurbishment from the early 1970s onwards, many first generation DMUs were to survive in service until the late 1980s or early 1990s. Indeed a handful can still be found in operation almost 50 years after the first of the type entered service
To the uninitiated, the reign of the Southern Region diesel-electric multiple-unit sets in public service - the fleet comprising the various 'Hastings', 'Hampshire', 'Berkshire', 'Oxted' and 'Tadpole' variants - lasted around 47 years, from their introduction in 1957 to their final demise in 2004. On the surface this was a creditable achievement, especially as they were conceived as little more than a stopgap, an interim stage of motive power between steam and the planned electrification. The Southern Railway had been slowly extending its electrified network to cover the various main routes throughout the 1930s and this was to continue during the 1950s and 1960s. Whilst this was cost effective on the heavily used main line and suburban services there were a number of lines that would not support the investment, or were under threat of closure such as the Mid-Hants line from Alton to Winchester and the Swanage branch. As with all generalisations there was an exception - the London to Hastings line. Heavily used, and requiring modernisation, it could not accommodate standard-size rolling stock - due to limited clearances along the route. The result was a 'slim line' DEMU, with slab-sided vehicles. As the routes over which they operated were either electrified or closed, the units gradually saw their duties change and the classes were gradually withdrawn. A number, however, survived into the era of Privatisation and into the 21st century. Acquiring cult status amongst enthusiasts, a number have survived into preservation (many courtesy of the generosity of Porterbrook who donated a number to preservation schemes
Publication Date: 15 Feb 2005
The distinctive growl of a Southern Region DEMU's 4SRKT engine has been a familiar sound across southern England for almost half a century. In the mid-1950s the SR opted for diesel-electric units that were similar in many respects to the region's existing electric rolling stock, and integrating the two fleets considerably simplified maintenance. The consistent reliability and remarkable longevity of the DEMU fleet provide ample justification for that decision. Using top quality images, this all-colour volume traces the history of the various DEMU types and also includes much previously unpublished historical and technical information.