In 1932, when William Stanier became the Chief Mechanical Engineer of the London Midland Scottish, most of the regions freight traffic was being hauled by ageing 0-8-0 engines, many of which dated from the pre-grouping period. By 1934, freight traffic accounted for 58% of the LMSs turnover and the only modern stock available for haulage were Beyer-Garrett and Austin Seven Class 7F locomotives. These locomotives had serious maintenance issues, as well as proving inadequate for the gradual acceleration of freight traffic as decreed by the Operating Department and so Stanier looked to the Great Western Railway for design inspiration for his new freight locomotive.
The influence came from the GWRs 28xx class, but Staniers chief draughtsman, T.F Coleman, removed any legacy of that locomotive from the final design, resulting in a typically balanced Stanier locomotive that was similar in appearance to that of the Black 5. The first locomotives left Crewe Works in June 1935 and initially were classified as 7F, although this was soon changed to 8F and the class quickly proved its worth on the whole range of freight duties, as well as express goods, parcels and occasional passenger traffic