Editing BR Standard Class 9F (section)

==Concept and Construction==
===Background===
The [[British Transport Commission]] had proposed that the existing steam locomotive fleet be replaced by both [[diesel locomotive|diesel]] and [[electric locomotive|electric]] traction. However the board of [[British Railways]], which wanted the railways to be completely [[railway electrification system|electrified]], ignored the BTC and ordered a new fleet of 'standard' steam locomotive designs as a stopgap ahead of electrification.<ref name=nrm>{{cite web | url=https://www.nrm.org.uk/OurCollection/LocomotivesAndRollingStock/CollectionItem.aspx?objid=1975-7024 | title=NRM - Collections - Locomotives - Evening Star | publisher=National Railway Museum | access-date=2007-09-23 | archive-date=10 March 2015 | archive-url=https://web.archive.org/web/20150310095024/http://www.nrm.org.uk/OurCollection/LocomotivesAndRollingStock/CollectionItem.aspx?objid=1975-7024 | url-status=dead }}</ref> 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 Stanier Class 8F|LMS 8F Class]] {{whyte|2-8-0}} and numerous Robert Riddles designed [[WD Austerity 2-8-0]]s and [[WD Austerity 2-10-0]]s.

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.<ref name="Herring">{{cite book |last=Herring |first=Peter |title=Classic British Steam Locomotives |year=2000 |publisher=Abbeydale |isbn=1-86147-057-6 |pages=190–191}}</ref> Riddles took up the challenge, initially designing a {{whyte|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.<ref name=Herring />

===Design features===
The 9F was designed at both [[Derby Works|Derby]] and [[Brighton railway works|Brighton Works]] in 1951 to operate freight trains of up to 900&nbsp;[[long ton|ton]]s (914&nbsp;[[tonne]]s) at 35&nbsp;mph (56&nbsp;km/h) with maximum [[fuel efficiency]].<ref name="nrm" /> The original proposal was for a boiler from the [[BR Standard Class 7]] ''Britannia'' {{whyte|4-6-2}}, adapting it to a {{whyte|2-8-2}} wheel arrangement <ref name="Walford">{{cite book |last1=Walford |first1=John |last2=Harrison |first2=Paul |volume=4 |title=The 9F 2-10-0 Class |series=A detailed history of British Railways Standard Steam Locomotives |publisher=[[Railway Correspondence and Travel Society|RCTS]] |location=Bristol |year=2008 |isbn=978-0-901115-95-9}}</ref>{{rp|52}} 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&nbsp;tons, 10&nbsp;cwt.<ref name="nrm" /> The driving wheels were {{convert|5|ft|0|in|m}} in diameter. However, in order to clear the rear coupled wheels, the grate had to be set higher, thus reducing [[Firebox (steam engine)|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 [[flange]]s, and those on the second and fourth coupled wheels were reduced in depth. This enabled the locomotive to round curves of only {{convert|400|ft|m}} radius.<ref name=Herring /> As on all other BR standard steam locomotives, the leading wheels were {{convert|3|ft|0|in|m}} in diameter.{{r|Walford|p=44,283-289}}

===Construction history===
Introduced in January 1954,{{r|Walford|p=76}} the class comprised 251 locomotives, of which 53 were constructed at [[Swindon Works]], and 198 at [[Crewe Works]]. The locomotives were numbered 92000-92250.<ref name=Herring /> The last member of the class was constructed at Swindon in 1960, the 999th "[[BR standard classes|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 [[BR Standard Class 9F 92220 Evening Star|92220 ''Evening Star'']].<ref name=Herring /> 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.

{| class="wikitable collapsible"
|+ Table of orders and numbers<ref>{{cite book| last=Bradley |first=Rodger P. |year=1984 |title=The Standard Steam Locomotives of British Railways |publisher=David and Charles |location=Newton Abbot |pages=44, 45, 48–50}}</ref>
! Numbers !! Year !! Builder !! Tender !! Notes
|-
| 92000–09 || 1954 || [[Crewe Works|Crewe]] || BR1G || 8 for [[Western Region of British Railways|WR]], 2 for [[London Midland Region of British Railways|LMR]]
|-
| 92010–14 || 1954 || Crewe || BR1F || for [[Eastern Region of British Railways|ER]]
|-
| 92015–19 || 1954 || Crewe || BR1C || for LMR
|-
| [[BR Standard Class 9F 92020-9|92020-29]] || 1955 || Crewe || BR1B || Franco-Crosti boiler; for LMR
|-
| 92030–44 || 1954 || Crewe || BR1F || for ER
|-
| 92045–59 || 1955 || Crewe || BR1C || for LMR
|-
| 92060–66 || 1955 || Crewe || BR1B || for [[North Eastern Region of British Railways|NER]]
|-
| 92067–76 || 1956 || Crewe || BR1F || for ER
|-
| 92077–86 || 1956 || Crewe || BR1C || for LMR
|-
| 92087–96 || 1957 || [[Swindon Works|Swindon]] || BR1F || for ER
|-
| 92097–99 || 1956 || Crewe || BR1B || for NER
|-
| 92100–18 || 1956 || Crewe || BR1C || for LMR
|-
| 92119–39 || 1957 || Crewe || BR1C || for LMR
|-
| 92140–49 || 1957 || Crewe || BR1F || for ER
|-
| 92150–64 || 1958 || Crewe || BR1C || for LMR
|-
| 92165–67 || 1958 || Crewe || BR1K || for LMR; tenders later BR1C
|-
| 92168–77 || 1958 || Crewe || BR1F || for ER
|-
| 92178–83 || 1957 || Swindon || BR1F || for ER
|-
| 92184–202 || 1958 || Swindon || BR1F || for ER
|-
| 92203–17 || 1959 || Swindon || BR1G || for WR
|-
| 92218–20 || 1960 || Swindon || BR1G || for WR
|-
| 92221–50 || 1958 || Crewe || BR1G || for WR
|}