The British Railways Standard Class 9F 2-10-0 is a class of steam locomotive designed for British Railways by Robert Riddles. The Class 9F was the last in a series of standardised locomotive classes designed for British Railways during the 1950s, and was intended for use on fast, heavy freight trains over long distances. It was one of the most powerful steam locomotive types ever built for British Railways, and successfully performed its intended duties. The 9F class was given the nickname of 'Spaceship', due to its size and shape.^[2]

At various times during the 1950s, the 9Fs worked passenger trains with great success, indicating the versatility of the design, sometimes considered to represent the ultimate in British steam development. Several experimental variants were constructed in an effort to reduce costs and maintenance, although these met with varying degrees of success. They were capable of reaching speeds of up to 90 miles per hour (145 km/h).^[3][4]

The total number built was 251, production being shared between Swindon (53) and Crewe Works (198). The last of the class, 92220 Evening Star, was the final steam locomotive to be built by British Railways, in 1960. Withdrawals of the class began in 1964, with the final locomotives being withdrawn from service in 1968, the final year of steam traction on British Railways. Nine examples have survived into the preservation era in varying states of repair, including Evening Star.

They were generally thought of as very successful locomotives, O. S. Nock stating "The '9F' was unquestionably the most distinctive and original of all the British standard steam locomotives, and with little doubt the most successful. They were remarkable in their astonishing capacity for speed as well as their work in heavy freight haulage."^[5]

The British Transport Commission had proposed that the existing steam locomotive fleet be replaced by both diesel and electric traction. However the board of British Railways, which wanted the railways to be completely electrified, ignored the BTC and ordered a new fleet of 'standard' steam locomotive designs as a stopgap ahead of electrification.^[6] Freight was well catered for in terms of locomotive availability after nationalisation in 1948, with a number of heavy freight locomotives built to aid the war effort forming part of British Railways' inheritance. This consisted of 666 LMS 8F Class 2-8-0 and numerous Robert Riddles designed WD Austerity 2-8-0s and WD Austerity 2-10-0s.

It was the Eastern Region's Motive Power officer, L.P. Parker, who made the case for a new design of powerful freight locomotive, able to shift heavy loads at fast speeds in round trips between distant destinations within the eight-hour shift of the footplate crew.^[7] Riddles took up the challenge, initially designing a 2-8-2 locomotive, but settled upon the 2-10-0 wheel arrangement for the increased traction and lower axle load that five coupled axles can provide. The resultant design became one of the most successful, but shortest-lived, locomotive classes ever built in Britain.^[7]

The 9F was designed at both Derby and Brighton Works in 1951 to operate freight trains of up to 900 tons (914 tonnes) at 35 mph (56 km/h) with maximum fuel efficiency.^[6] The original proposal was for a boiler from the BR Standard Class 7 Britannia 4-6-2, adapting it to a 2-8-2 wheel arrangement ^[8] but Riddles eventually settled upon a 2-10-0 type because it had been used successfully on some of his previous Austerity locomotives. Distributing the adhesive weight over five axles gave a maximum axle load of only 15 tons, 10 cwt.^[6] The driving wheels were 5 feet 0 inches (1.52 m) in diameter. However, in order to clear the rear coupled wheels, the grate had to be set higher, thus reducing firebox volume. There were many problems associated with locomotives of such a long wheelbase, but these were solved by the design team through a series of compromises. The centre driving wheels had no flanges, and those on the second and fourth coupled wheels were reduced in depth. This enabled the locomotive to round curves of only 400 feet (120 m) radius.^[7] As on all other BR standard steam locomotives, the leading wheels were 3 feet 0 inches (0.91 m) in diameter.^[9]

Introduced in January 1954,^[10] the class comprised 251 locomotives, of which 53 were constructed at Swindon Works, and 198 at Crewe Works. The locomotives were numbered 92000-92250.^[7] The last member of the class was constructed at Swindon in 1960, the 999th "BR Standard" to be constructed, and the last steam locomotive to be built by British Railways. To mark the occasion, a competition was run within the Western Region of British Railways to choose an apt name, and the locomotive was given the name and number of 92220 Evening Star.^[7] Many of the class lasted only a few years in service before withdrawal when steam traction ended on the mainline in Britain. Withdrawals of the class from everyday service began in May 1964, and had been completed by June 1968.

The 9F was used as a proving ground for a variety of technical innovations intended to provide improvements in efficiency, power or cost.

The 9F turned out to be the best of the Standard classes, and one of the finest steam locomotives ever designed in Britain in terms of its capacity to haul heavy loads over long distances.^[7] It was highly effective at its designed purpose, hauling heavy, fast freight trains, and was used all over the British railway network. This was exemplified when in September 1982, preserved engine 92203 Black Prince^[19] set the record for the heaviest train ever hauled by a steam locomotive in Britain, when it started a 2,178-ton train at a Foster Yeoman quarry in Somerset, UK.^[20]

The 9F also proved its worth as a passenger locomotive, adept at fast running despite its small driving wheels, and for a time was a frequent sight on the Somerset and Dorset Railway,^[7] where its power and high proportion of adhesive weight were well suited to coping with the 1 in 50 ruling gradient on the Bath extension. On one occasion, a 9F was set to haul an express passenger train, in place of the normal LNER pacific, from Grantham to King's Cross. An enthusiast aboard the train timed the run and noted that twice the speed exceeded 90 mph. The driver was afterwards told that he was only supposed to keep time, "not break the bloody sound barrier!". He replied that the engine had no speedometer, and that it ran so smoothly at high speeds that he just let it run as fast as felt safe. Nor was this the only instance of 9Fs reaching high speeds. However, concerns that the high rotational speeds involved in fast running could cause excessive wear and tear to the plain-bearing running gear prompted the British Railways management to stop using 9Fs on express passenger trains.^[21]

In 1960, 9Fs from the Western Region's Cardiff Canton shed (code 86C) were also regularly made ready as 'standby' locomotives - in case of failure of the more usual Britannias - on the region's flagship Paddington-Cardiff/Swansea passenger express trains, the Red Dragon and Capitals United Express. Locomotives used on these duties included No. 92220 Evening Star, the only 9F to be given a name and to be painted in the express passenger livery of lined Brunswick green.^[22][23] On 8 September 1962 No. 92220 also hauled the last Pines Express to use the Somerset and Dorset route.^[24]

Like other primarily goods locomotives, British Railways' fleet of 9Fs also saw extensive passenger service in hauling Saturday 'Holiday Specials', especially in the North East and Western regions.^{[25][page needed]}

• On 19 November 1958, locomotive No. 92187 was hauling a freight train which overran signals and was in a rear-end collision with another at Hitchin, Hertfordshire. A third freight train ran into the wreckage.^[26]
• On 7 April 1964, locomotive No. 92161 was hauling a freight train that was derailed at Howe & Co's Signalbox, Cumberland due to a combination of defects on a wagon, excessive speed and minor track defects.^[27]

The class were painted British Railways Freight Black without lining. The British Railways crest was located on the tender side. Given the British Railways power classification 9F, the locomotives were numbered in the 92xxx series, between 92000 and 92250.^[1] Because of its status as the last steam locomotive constructed at Swindon, No. 92220 was named Evening Star and turned out in British Railways Brunswick Green livery, which was usually reserved for express passenger locomotives.^[1] Several locomotives allocated to the Western Region, including no. 92220, bore a blue spot on the cab side below the number, to denote the axle loading under the former GWR's system of weight classification.^[28]

Nine Standard Class 9F 2-10-0 tender locomotives survived withdrawal from mainline service into preservation: Evening Star became part of the National Collection; eight others were bought directly from BR or from Woodham Brothers scrapyard in Barry, South Wales. Only six members of the class have been restored to running order. 92240 was the first of the class to steam in preservation after restoration work in 1990. Engines from both builders have survived with three Crewe-built engines and six Swindon-built engines. The majority of the class have double chimneys but 92134 is fitted with a single chimney.

† In most cases, names are not historically accurate; i.e. they have all been applied in preservation except 92220 which, being the last steam locomotive to be built for BR, was named Evening Star during its unveiling in 1960. Some locomotives may also have names, but marked names indicate that the locomotive is not presently^[timeframe?] wearing them.

Of the nine surviving members of the class,^[timeframe?] two have run on the main line: nos. 92203 Black Prince & 92220 Evening Star. Due to the engines' flangeless centre driving wheels, there is a concern that the raised check rails on modern pointwork might cause a derailment, so the class (alongside other 2-10-0 locomotives) is currently^[timeframe?] prohibited from operating on the main line – including the Esk Valley Line from Battersby to Whitby, used by the North Yorkshire Moors Railway on their Grosmont to Whitby trains alongside the regular passenger services on the route.

Murdoch from Thomas & Friends is a BR Standard Class 9F locomotive.^[38]