The distinctive and rugged Class 14, universally known to generations of railway enthusiasts as "Teddy Bears" because of a comment made by Swindon's works manager during their construction, was ordered in 1963 and built entirely at British Railways’ Swindon Works between 1964 and 1965. A compact fleet of 56 of these robust 0-6-0 diesel-hydraulic locomotives was produced, specifically designed to handle short-distance freight trips, local mineral workings, and heavy shunting across the Western Region. Powered by a 650-horsepower Paxman Ventura engine paired with a Voith hydraulic transmission, they featured a unique, center-cab design that afforded drivers superb all-around visibility.

Tragically, they arrived just as the wagon-load freight traffic they were built for was systematically eliminated by the Beeching cuts, leading to their premature withdrawal by BR after barely five years of service. However, their incredible low-speed pulling power saved them; nearly the entire class was sold into heavy industrial use at collieries, steelworks, and quarries, where they worked hard for another two decades. Thanks to this second career, a phenomenal 19 of these charismatic little workhorses survived to be preserved, making them an incredibly popular fixture on heritage lines today.