The Derby 4F is one of the unsung heroes of the locomotive world. No less than 530 of them were built to a Fowler design for the LMS in the 1920s. Stanier added 45 more in 1937.

Designed for medium freight working, anyone who lived in the steam age will remember this final version of the Midland 0-6-0 tender engine which kept working until the final years of steam. Three have survived into preservation with no. 4422 operational on the West Somerset Railway.

In live steam modelling, Don Young produced an excellent design in 3.5” in the 1970s complete with Joy valve gear, and incorporating many standard castings.  The model has a length of 40.75”, driving wheels 3.936” dia, cylinders 1.125’ bore, and a boiler 3.75” diameter.

This good example was shown by Stephen Forge at the Bristol exhibition in 2017.