Perhaps overshadowed by more 'exotic' locos, the Class 31s nonetheless played a significant part in British Railways' Modernisation Plan. Intended for use on more lightly loaded and shorter-distance trains on routes away from the main lines, the 263 original Brush Type 2 locomotives were new between 1957 and 1962 and entered service on the Eastern Region. They could soon be found all across the country. Not long into their careers, they were renumbered into Class 31 under the TOPS system and, over time, four subclasses were developed. The most numerous was the steam heat boiler-fitted 31/1, examples of which were further modified with electric train heating (ETH) to produce the 31/4. Towards the end of the class's collective lifespan came two more developments, the 31/5 and 31/6. The fact that so many still survive after decades of sterling service is testament to their usefulness and versatility, and they are especially appreciated on the various heritage lines up and down the country. This volume includes more than 200 images showing these workhorses in action, mostly in the south of England.