Editing 4-4-0 (section)

===United Kingdom===
====Tank locomotives====
[[File:GWR bogie class Horace.jpg|thumb|[[GWR Bogie Class|''Bogie'' class]] 4-4-0ST ''Horace'' of 1854]]
4-4-0T classes began to appear on {{RailGauge|7ft0.25in}} broad-gauge lines in the United Kingdom from 1849. The Great Western Railway built its [[GWR Bogie Class|''Bogie'' class]] saddle tanks for the [[South Devon Railway Company|South Devon Railway]] in 1849, and others for its own use during 1854 and 1855. Between 1851 and 1876, the South Devon Railway acquired a further six [[South Devon Railway locomotives|saddle tank classes]], and the [[Vale of Neath Railway]] a [[Vale of Neath Railway 4-4-0ST locomotives|further nine.]] The [[Bristol and Exeter Railway]] introduced several [[Bristol and Exeter Railway 4-4-0ST locomotives|4-4-0ST classes]] after 1855.<ref>{{RCTS-LocosGWR-2|pages=B21–B23}}</ref>

[[William Adams (locomotive engineer)|William Adams]] built a series of standard gauge [[Locomotives of the London and North Western Railway#Locomotives of the North London Railway|4-4-0T]] classes for the [[North London Railway]] between 1863 and 1876. He went on to build the [[LSWR 46 Class]] for the [[London and South Western Railway]] in 1879. Other British 4-4-0T types included the [[Metropolitan Railway A Class|A Class]] of the [[Metropolitan Railway]], built by Beyer, Peacock & Company from 1864, and the [[Highland Railway O Class]] of 1878 and [[Highland Railway P class|P class]] of 1893–94. Also in 1864, [[John Lambie (engineer)|John Lambie]] of the [[Caledonian Railway]] built twelve Class 1 4-4-0T locomotives.

====Inside cylinder tender locomotives====
[[File:LBSCR B4 class.jpg|thumb|A [[LB&SCR B4 class]] c.1910 typical of the British inside frame/inside cylinder layout]]
Between 1876 and 1903, [[Samuel Waite Johnson|Samuel Johnson]] of the [[Midland Railway]] built 350 inside cylinder tender locomotives to various designs, notably the [[Midland Railway 483 Class]]. The type was particularly refined by [[John F. McIntosh]] of the [[Caledonian Railway]] with his [[Caledonian Railway 721 Class|''Dunalastair'']] and ''Breadalbane'' classes of 1896 to 1898. In addition, [[Wilson Worsdell]] of the [[North Eastern Railway (United Kingdom)|North Eastern Railway]] designed six classes between 1896 and 1909. Other notable classes included the [[London and South Western Railway]]’s [[LSWR T9 class|T9 class]] of 1899 and the [[London and North Western Railway]]’s [[LNWR Whale Precursor Class|''Precursor'' Class]] of 1904.<ref name="Poultney"/>

From the mid-1890s until after [[World War I]], the inside cylinder 4-4-0 was the standard type for British [[Express train|Express passenger trains]], although several classes were also used in [[mixed-traffic locomotive|mixed-traffic]] service in later years.<ref name="Poultney"/>

[[File:City of Truro 3717 Didcot (6).jpg|thumb|left|[[GWR 3700 Class 3440 City of Truro|''City of Truro'']]]]
The [[Great Western Railway]] (GWR) preferred to retain [[Locomotive frame|outside frames]] on their inside cylinder 4-4-0s. One member of its [[GWR 3700 Class|''City'' class]], the [[GWR 3700 Class 3440 City of Truro|''City of Truro'']], designed by [[George Jackson Churchward]] and built at the GWR's [[Swindon Works]] in 1903, was reputedly the first steam locomotive in Europe to travel in excess of {{convert|100|mph|km/h|abbr=off}}, reaching a speed of {{convert|102.3|mph|km/h|abbr=off}} on 9 May 1904 while hauling the ''Ocean Mails'' special from [[Plymouth railway station|Plymouth]] to [[Paddington railway station|London Paddington]].

Although the inside cylinder 4-4-0 had largely been superseded by larger locomotives for mainline express trains by 1920, the type remained in use in Scotland and East Anglia, where lines that could not support heavier or larger locomotives were common. Thus both the [[Great Eastern Railway]]’s [[GER Classes S46, D56 and H88|''Claud Hamilton'']] classes of 1900 to 1911 and the [[Great Central Railway]]’s [[GCR Class 11F|''Director'']] classes of 1920 were perpetuated by the [[London and North Eastern Railway]] in 1923. Until 1932, the [[London, Midland and Scottish Railway]] also continued to build its [[LMS Class 2P 4-4-0|Class 2P]] of traditional inside cylinder {{nowrap|4-4-0s}} for secondary passenger working.

====Three-cylinder tender locomotives====
[[File:440locomotivestowe.jpg|thumb|Southern Railway ''Schools'' class ''Stowe'', constructed in 1934]]
Experiments were conducted with three-cylinder [[compound locomotive]]s by Wilson Worsdell of the North Eastern Railway in 1898, [[Samuel Waite Johnson|Samuel Johnson]] of the [[Midland Railway]] in 1901 and [[Francis Webb (engineer)|Francis Webb]] of the [[London and North Western Railway]]. Of these, the development of Johnson's design by [[Richard Deeley]] of the Midland Railway into the [[Midland Railway 1000 Class|1000 Class]] was the most successful. This class continued to be built by the [[London, Midland and Scottish Railway]] (LMS) after 1905, until 1932 with the almost identical [[LMS Compound 4-4-0]].

British three-cylinder simple expansion (simplex) locomotives included [[Nigel Gresley]]'s [[LNER Class D49]] ''Hunt'' and ''Shire'' 4-4-0s of 1927–28. However, the most powerful and one of the most successful 4-4-0 designs ever constructed was the [[SR V class|''Schools'' class]] of the [[Southern Railway (UK)|Southern Railway]], designed by [[Richard Maunsell]] and built between 1930 and 1935. These were used on secondary express trains between London and South Coast towns, until their withdrawal in 1962.<ref name="Maunsell">{{Cite web |url=http://www.maunsell.org.uk/virtual%20shed/928/928profile.htm |title=Maunsell Railway Society {{nowrap|4-4-0}} locomotive "Stowe" |access-date=2006-02-18 |archive-url=https://web.archive.org/web/20160322133854/http://www.maunsell.org.uk/virtual%20shed/928/928profile.htm |archive-date=2016-03-22 |url-status=dead }}</ref>