2nd Generation
As a result of the 1955 Modernisation Plan, large numbers of Diesel Multiple Units (DMUs) were constructed for a variety of traffic requirements, eventually totalling some 4000 vehicles. These First Generation units are extremely well documented on The Railcar Association website.
Construction of the First Generation units lasted between 1955 and 1963 and took British Railways from nowhere to number one in the world for use of DMUs.
The problem caused by this, however, was that all of BR's existing fleet would become life-expired within the same eight year period in the future and a solution had to be sought. During the 1970s it was clear that a replacement program would be necessary and work commenced on designing new vehicles suitable for the services they were to work. This work took two distinct directions - vehicles for commuter services with the power and speed capability to work routes with many stops, and cross country and secondary routes with longer distances between stops and lighter loadings.
The specification for the commuter stock eventually resulted in the two Class 210 DEMU prototypes which amassed many miles on test, but were eventually deemed too expensive for many PTEs due to Mark 3 design bodies and large diesel engine mounted above the floor in a proper engine room with electric transmission, under-floor engines ultimately winning the day. Meanwhile the secondary route requirement resulted in the lightweight railbus concept coming into being, initially in the shape of the BR Research Department, Derby and Leyland Bus, Workington collaboration 'LEV1'. LEV stood for Leyland Experimental Vehicle and it's official number was departmental RDB975874.
These prototypes over the years developed into Class 150, 151, 153, 154, 155, and 156 Sprinter DMUs and Class 140, 141, 142, 143 and 144 Pacer Railbuses respectively.
Below: Prototype class 150 Sprinter no. 150001 at Blythe Bridge in August 1988
Further development of the Sprinter DMUs resulted in Class 158 and 159 Express Sprinters, 165, 166 and 168 Turbos, and more recently Classes 170, 171, 175, 180 and 185. The DEMU concept has made a resurgence again in the shape of Class 220, 221 and 222 Voyagers and Meridians.
The earliest Second Generation Multiple Units are now also quite old and some Class 142 railbuses have been taken off-lease with a possibly uncertain future.
Some Second Generation Multiple Units have also already been preserved - railbus prototypes LEV1 and RB004, the prototype class 140 two-car unit, plus there are four class 141 units in preservation as well as some exported for further use in Iran!
Find out about all these and much more - just choose from one of the tabs at the top of this page.