The class 9F goods locomotive was built from 1954 as the last and most powerful of the standardized steam locomotives from British Railways. This was ordered when extensive electrification of the British railway network was still considered realistic and powerful steam locomotives were needed for the transitional period. After Robert Riddles had already developed the 2-10-0 wheel arrangement war locomotives for the War Department, he also developed the 9F. This wheel arrangement was chosen because of the greater adhesive weight after initially wanting to develop a locomotive with a 2-8-2 wheel arrangement.

No. 92151 in July 1961 in front of the “Pines Express” at Haresfield, Gloucestershire

Ben Brooksbank / Down 'Pines Express' passing Haresfield station.

A goal in the development was to realize the greatest possible power, taking into account the British loading gauge and a relatively low axle load. The five coupled axles were able to negotiate curves by designing the wheels of the middle coupled axle without a wheel flange and by providing the wheels of the second and fourth axle with weakened wheel flanges. It was soon found that the locomotives with this axle arrangement ran very well at higher speeds, despite the fact that the coupling wheels were only five feet in diameter and they had two cylinders. In the course of production, the output was further increased with a double chimney. Adaptations such as a Franco-Crosti boiler and mechanical stoker were less successful and were not used in large numbers.

No. 92203 “Black Prince” in 2010 at Toddington

Tony Hisgett / Black Prince 6

Like many more powerful British goods steam locomotives, the 9F also had to be used to pull express trains in heavy excursion traffic, especially on weekends. There are credible reports of runs where the locos hit just over 90 mph. A total of 251 examples were made by March 1960. Number 92220 “Evening Star” was the last steam locomotive built for British Railways and was also the 999th standard steam locomotive. This example was not decommissioned even after the steam ban in 1968 and was used without interruption for excursions until the 1980s. Today it is a static exhibit, while eight more of its sisters, which were retired until 1968, were also preserved and some are still running today. One of these, No. 92203 “Black Prince”, pulled the heaviest train in Great Britain ever hauled by a steam locomotive in 1982 at 2,178 tons.