The British Railways standard class 9F 2-10-0 tender steam locomotives were designed at Derby and Brighton Works under the oversight of R. A. Riddles for use on fast heavy freight trains. 251 built at Crewe Works (198) and Brighton Works (53) between 1954 and 1960, the most numerous and without doubt, the most successful of the BR standard classes. The 9Fs were numbered 92000 to 92250, the famous 92220 Evening Star, built at Swindon Works, was the 999th BR standard and the last steam locomotive to be constructed by British Railways.
The original concept was for a 2-8-2 but following the success of Riddles’ War Department 2-10-0, the latter wheel arrangement was chosen, the was flange omitted from the centre drivers allowing the engines to traverse curves of 400ft radius. Two outside cylinders and Walschaerts valve gear were fitted. The locomotives were coal fired and used BR1B, BR1C, BR1F, BR1G and BR1K tenders with varying capacities.
Some 9Fs were subject to experiments and modifications including 10 built with Franco-Crosti boilers (92020-29), 3 with mechanical stokers (92165-67) and 1 with a Giesel ejector (92250) none of which were successful. The modifications were subsequently removed but the Crosti versions retained their distinctive smoke boxes. Double chimneys however, did make an improvement and were fitted to several of the class.
In service the 9Fs proved very successful in the role that they were designed for, they could work key round trips within the crew’s 8 hour shift, making substantial savings. Surprisingly, they also proved very capable of hauling passenger trains at speeds of up to 90mph and in particular, could easily climb the challenging bank from Bath Green Park on the former Somerset and Dorset Joint Railway. However, the high rotational speed of the 5ft driving wheels caused excessive wear and tear on the running gear and passenger train operations ceased.
Having been introduced in 1954, the operational life of the class 9Fs was very short. Withdrawal began in 1964 and the last of the class was withdrawn in 1968. Nine have been preserved; 92134 (sole-surviving single chimney 9F), 92203 Black Prince, 92207 Morning Star, 92212, 92214, 92219, 92220 Evening Star, 92240 & 92245.
BR Standard class 9F 2-10-0 specification
Length: 66 ft 2 in (20.167m)
Width: 8 ft 10 1/8 in (2.695m)
Height: 13 ft 1 in (3.988m)
Gauge: 4 ft 8½ in (1.435m)
Driving wheel dia: 5 ft 0 in (1 524mm)
Boiler Pressure: 250 psi (1.72 MPa)
Cylinders: 20 x 28 in (510 x 711mm)
Loco weight: 86 tons 14 cwt (88.091 tonnes)
[Crosti version: 90 tons 4 cwt (91.647 tonnes)]
Tractive effort: 39,670 lbf (176.5 kN)
Last updated: 04/11/11