Most British Rail diesel locomotive types are represented in preservation, though some classes are much more prolific than others (in particular the more recently withdrawn). Sadly, several early types were lost completely because they were withdrawn around the same time as steam traction finished on British Railways, a time when most enthusiasts had no interest in saving diesels. As a result, no North British locos survive, and of several other types there is just one survivor, for example Classes 15 and 28, both of which are under restoration. A number of types have also now spent longer in preservation than main line service, such as the hydraulic classes and the famous Class 55 Deltics. There are a large number of heritage railways running diesel locomotives today, some hosting special events bringing together several classes and operating intensive services, others using them to supplement steam traction, and many have locos under restoration for future use. Using his fantastic collection of photographs, Ross Taylor displays the surviving examples of a wide range of classes, including (TOPS classifications) 14, 20, 24, 25, 26, 27, 31, 33, 35, 37, 40, 42, 44-47, 50, 52, 55, 56, and 58. The sole surviving prototype HST power car is included as it was initially regarded as a Class 41 locomotive before the whole train became known as Class 252. The Class 73 Electro-Diesel is also shown, but none of the Class 74 version survive.

These locomotives are now based at many different heritage railways, including Barrow Hill Roundhouse, Bo'ness &Kinneil, East Lancashire, Ecclesbourne Valley, Embsay & Bolton Abbey, Gloucestershire Warwickshire, Great Central and Great Central North, Keighley & Worth Valley, Lakeside & Haverthwaite, Llangollen, Mid-Norfolk, Midland Railway - Butterley, North Norfolk, Nene Valley, National Railway Museum, North Yorkshire Moors, Peak Rail, Severn Valley, and Railway Age at Crewe.