The Great Western Railway was always a little different to the rest of the railways, and that was still the position when in 1955 British Railways announced their Modernisation Plan that would see steam replaced by diesels and electrics. The rest of the railway regions opted for diesel-electric locos but the Western would be different, opting for diesel-hydraulics. The first entered service in 1957 and by 1964 six different classes were introduced. Unfortunately there were problems with them all, which were largely solved as experience was gained, but the BRB was in favour of standardisation using the diesel-electric type and they saw the Western hydraulics as non-standard, which resulted in their early withdrawal from service by 1977.

This book of mostly unpublished colour pictures taken by George Woods shows them in service from 1966 to 2019, and also includes the Class 50 locos that became their replacements.