When British Railways (BR) initiated its Modernisation Plan in 1954 it had little experience of diesel locomotives thus initiated a Pilot Scheme to trial combinations of the three elements comprised within a locomotive the engine, transmission and body. The initial orders for 174 locomotives were placed in November 1955, but even before the first locomotive had been delivered, changes in Government policy led to bulk orders for most designs being trialled. It was only in 1968, once steam traction had been removed from the network, that BR was able to review the success, or otherwise, of its diesel fleet and decide which designs to withdraw from service. The nascent preservation movement of the time was concerned to preserve steam locomotives whilst only buying diesel shunting locomotives for support roles on heritage lines and it wasn t until 1977 that any effort was made to preserve main line diesels. Once it was confirmed that diesel locomotives had an appeal to enthusiasts, further purchases were made that resulted in examples of most of the BR diesel classes being represented within the preservation movement.
Fred Kerr s book details those classes which are represented on heritage lines, identifies where possible their location as of December 2016, shows many of them at work and shows what is involved in the restoration, maintenance and operation of diesel locomotives by the volunteers whose efforts are vital but rarely acknowledged. Some of the preserved locomotives were bought for possible use on the national network and this was facilitated by the Railways Bill 1993\. A complementary album of preserved and heritage locomotives titled _Heritage Traction on the Main Line_ details the locomotive classes whose representatives are still in regular use on the national network as at December 2016 and follows a similar format to this album.
Fred Kerr was born in Edinburgh in 1948 where he gained an interest in railway locomotives from both the LMSR and LNER companies whose services permeated the local network. When his parents moved to Corby in 1956 the interest in railway locomotives continued and included the diesel locomotives that increasingly appeared at Kettering from the late 1950s. The sightings increased his interest and during the 1960s he travelled widely throughout the UK observing the various designs centred within specific areas. In the late 1970s his interest in Diesel Traction led to his involvement with the Diesel & Electric Preservation Group and its preservation of 'Hymek' Class 35 D7017 - the first diesel preservation scheme to be funded by public subscription. The subsequent growth of Heritage Lines and the preservation of diesel traction re-kindled his interest in the earlier diesel designs and during this century retirement has given him renewed opportunities to visit the many Heritage Lines where diesel traction can be both viewed and sampled.