The London Midland and Scottish Railway (LMS) Fowler Class 4F is a class of 0-6-0 steam locomotive designed for medium freight work. They represent the ultimate development of Midland Railway's six coupled tender engines. Many trainspotters knew them as "Duck Sixes", a nickname derived from their wheel arrangement.

The Somerset and Dorset Joint Railway, also known as the S&D, SDJR or S&DJR, was an English railway line connecting Bath and Bournemouth, with a branch from Evercreech Junction to Burnham-on-Sea and Bridgwater. Strictly speaking, the main line ran from Bath Junction to Broadstone, as the line between Broadstone and Bournemouth was owned by the London and South Western Railway, while the line between Bath Junction and Bath was owned by the Midland Railway.