Class 03 diesel shunters were once British Rail’s (BR) most successful 0-6-0 diesel-mechanical shunters and very common in yards all over the country due to their lightweight and short wheel base making them ideal for tight radius curves. 230 were built in the Doncaster and Swindon locomotive works between 1957 and 1962. Later as the need for these shunters diminished on the railway network, many continued useful working lives in Industry.