The 4F was the final development of the long-used Midland Railway 0-6-0 design of various power classifications. The class eventually totalled 772, 197 were built by the Midland with the London Midland and Scottish Railway building a further 575 locomotives.
No. 3924 entered service in 1920 and of the 4 members of the class preserved, is the only built by the MR. It was numbered 43924 on nationalisation and was finally withdrawn by British Railways in June 1965, being sold to Woodham Bros. of Barry in South Wales.
After displaying much enthusiasm and persistence, a small band of enthusiasts finally gained permission to purchase the engine from Woodham’s scrapyard. 43924 has a special place in preservation history by becoming the first of over 200 locomotives to be rescued from the cutters torch at Woodham’s. lt arrived at Haworth in the summer of 1970 but after so many years out of traffic required and missing many parts, a complete overhaul was needed before being able to re-enter traffic. After a successful steam test, the engine started its preservation career in earnest in 1974 and was finally purchased by the KWVR from the original band of enthusiasts (The 4F Society) in 1990.
Withdrawn in 1987, the 4F returned to service after a thorough overhaul in 2011 and has been a regular and popular performer ever since.