Diesel Dawn 4: First Generation DMUs – A Pictorial Observation

During the 1950s and 1960s diesel traction slowly replaced steam on South Wales valley lines. The emphasis on hauling coal had started to decline while passenger traffic became increasingly important. Consequently, a new type of vehicle was introduced, the Diesel Multiple Unit (DMU).

Diesel Dawn 4: Diesel Multiple Units – A Pictorial Observation by Robert Carroll provides an overview of the classes of first generation DMUs. These had an operational life stretching from the mid-1950s right up to the early 2000s. It was published by Irwell Press and Mortons Books under their Gresley Imprint in September 2021 in Bookazine softcover format.

As befitting its title, the book is generously illustrated with photographs of the DMUs in various liveries carried across the UK in a long working life. This is not a history book as such, but each class of DMU is described in the annotations which accompany each photograph. The author clearly knows his subject well and comprehensively covers the topic, dealing with aspects of the trains not included in other publications.

First generation DMUs – modernising local passenger transport

Diesel railcars had been introduced on a small scale by all four post-grouping railway companies when internal combustion engines became powerful enough for practical use following World War 1. The most famous of these were probably the GWR railcars which were used on a fast scheduled service between Cardiff and Birmingham from 1933. Some of these units were to survive until the 1960s.

The trialling of lightweight diesel multiple units was recommended in a 1952 report and the first order for operational trains was placed in November 1952. This was for 21 2-car sets built at British Railways Derby Works, hence the name, Derby Lightweights! The 1955 Modernisation Plan required the manufacture of up to 4,600 diesel railcars, which needed the involvement of private carriage builders along with BRs works at Derby and Swindon. Power output varied from 150 to 230 hp (110 to 170 kW) depending on the diesel engines used and vacuum brakes were standard.

Class 116s – core South Wales vehicles for 30 years

Regular working in the Cardiff Valleys commenced shortly after with the service from Barry in January 1958. DMUs then steadily replaced steam trains as appropriate refueling facilities were added and within six months over 80% of Valleys services were DMU operated. Illustrated in the book is a Green livery set at Ferndale in 1964 and a later blue livery set at Barry.

Undergoing regular upgrades and livery changes, First Generation DMUs survived for over 30 years. Introduced to Cardiff In 1987, Second Generation Class 150/2 Sprinter units displaced the 116s, with the final power cars leaving Cardiff Canton Depot in 1992.

In Summary

A well produced book which will be of much interest to anyone keen on learning more about first generation DMUs. Very informative annotations with great illustrations. Recommended, especially for modellers

Outline Contents

• Progenitors – GWR Railcars
• Early Derby ‘Lightweight’ DMUs
• Early Metro-Cammell Units
• Early Swindon ‘Inter-City’ Units
• ‘Blue Square’ Low Density Types Gloucester Class 100
• Metro-Cammell — Classes 101 and 102
• Park Royal Class 103
• BRCW Class 104
• Cravens Classes 105 and 106 Derby Class 107
• Derby Class 108 Wickham Class 109
• BRCW Class 110
• Metro-Cammell Class 111
• Cravens Classes 112 and 113
• Derby Class 114
• ‘Blue Square’ High Density Units Derby Class 115
• Derby Class 116
• Pressed Steel Class 117
• BRCW Class 118
• Cross-Country Units Gloucester Class 119
• Swindon Class 120
• Single Units and Trailers Pressed Steel Class 121Gloucester Class 122
• Later Inter-City and Trans-Pennine Units Swindon Class 123
• Swindon Class 124
• Lea Valley Sets: Derby Class 125
• Later Scottish Region Inter-City Sets – Swindon Class 126
• St Pancras-Bedford Sets Derby Class 127
• Parcels Cars
• Four-Wheel Types

About the Author: Robert Carroll

A family holiday to Dawlish Warren in August 1972 sparked his interest in diesel multiple units, a type of train he had rarely seen prior to that week in Devon. The class of a unit forming the Kingswear service he travelled on that day bugged him for years afterwards. During that holiday, he also recalls seeing Derby suburban units (Class 116) amongst others. More recent railway modelling activities, and in particular the production of excellent models of several major classes, reinvigorated his interest in first generation DMUs.

(From Irwell Press/Mortons Books)

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