Editing Tattenham Corner line (section)

===Later 20th century developments===
Detailed plans for Smitham station (now Coulsdon Town) had been drawn up in 1898 and 1899, but it was not opened until 1 January 1904.{{sfn|Gray|1990|p=69}} It was very close to {{rws|Coulsdon North}} station on the [[Brighton Main Line]], which had opened on 5 November 1899 and closed on 1 October 1983.{{sfn|Quick|2023|p=145}}{{sfn|Mitchell|Smith|1993|loc=Figs 62, 64}} Reedham station opened on 1 March 1911 as a halt. It closed for two years between 1 January 1917 and 1 January 1919, and became a staffed station on 5 July 1936.{{sfn|Quick|2023|p=386}}{{sfn|Mitchell|Smith|1993|loc= Figs 56, 59}}

During the First World War, racing at Epsom Downs was suspended and the area was used for military training camps. The line was used extensively for transport of troops and supplies.{{sfn|Jackson|1978|p=146}} Following the end of the war, sidings at Tattenham Corner station were used to store surplus [[War Department (United Kingdom)|War Department]] locomotives.{{sfn|Jackson|1999|p=162}} During the Second World War, casualties from the [[liberation of France]] were transported to a field hospital at Epsom Downs Racecourse via the line.{{sfn|Jackson|1999|p=169}}

Electrification was first proposed in 1913 by the LBSCR. The company offered to install its overhead 6,700 V system, on the condition that it could lease the line from the [[South Eastern and Chatham Railway]] (SECR, the successor to the SER) and operate all services. Following the end of the First World War, the SECR engineer, [[Alfred Raworth]], recommended that the LBSCR scheme should be adopted.{{sfn|Brown|2009|pp=29-30}} The plans were not pursued and under the [[Railways Act 1921]], the Tattenham Corner line became part of the London Central Division of the [[Southern Railway (UK)|Southern Railway]] in 1923.{{sfn|White|1961|p=91}} A new proposal to electrify the line using the 750 V DC third-rail system was authorised in August 1926.<ref name=ES_electric>{{cite news |title= To Tattenham Corner by electric |date= 9 August 1926 |work= Evening Standard |issue=32187 |page= 4 }}</ref>{{efn|The 1926-1928 electrification scheme was part of a wider £3.75M programme to electrify lines leading to {{rws|London Victoria}}. As part of the same initiative, lines with overhead wires were converted to third rail electrification.<ref name=ES_electric/>}} Electric services started running between Purley and Tadworth on 25 March 1928 and the platforms at Reedham, Chipstead and Kingswood were lengthened to accommodate the new rolling stock.{{sfn|Oppitz|1988|p=95}} Initially the new trains used the same timings as their steam-hauled predecessors, but on 17 June 1928 a new, accelerated timetable was introduced, which also restored regular services to Tattenham Corner.{{sfn|Brown|2009|p=53}}

Woodmansterne station opened on 17 July 1932. Taking the form of an island platform, linked by a concrete bridge to both sides of the line, it served a new area of [[semi-detached]] and [[terraced house|terraced]] housing. The necessary land was donated by the developers, who also contributed around a fifth of the cost of construction.{{sfn|Mitchell|Smith|1993|loc=Fig. 66}}{{sfn|Brown|2009|p=73}} Woodmansterne signal box opened on 13 April 1932 and closed on 12 May 1963.{{sfn|Mitchell|Smith|1993|loc=Woodmansterne}} Kingswood signal box closed on 2 December 1962.{{sfn|Mitchell|Smith|1993|loc=Fig. 81}}

A major resignalling project, in which colour light signals were installed, was commissioned on in the second half of 1970.{{sfn|Jackson|1999|p= 230}} Smitham signal box closed on 16 August,{{sfn|Mitchell|Smith|1993|loc=Fig. 63}} followed by the box at Tadworth on 29 November that year.{{sfn|Jackson|1978|p=149}} 

[[File:Tattenham Corner station building - geograph.org.uk - 927728.jpg|thumb|right|{{rws|Tattenham Corner}} station building, opened in August 1994<ref name=Johnston_1994>{{cite magazine |last= Johnston |first= Howard |date= 17 August 1994 |title= Around the regions |magazine= RAIL |issue= 233 |page= 43 }}</ref>]]
The track layout at Tattenham Corner was altered in 1971, reducing the number of operational platforms to three.{{sfn|Mitchell|Smith|1993|loc=Fig. 113}} The redundant  land no longer required for the terminus was sold in 1979 and 1980 for housebuilding.{{sfn|Jackson|1999|p=174}} The original wooden station building was damaged beyond economic repair on 1 December 1993, when a train crashed through the buffer stops.<ref>{{cite news |title= Sacking upheld of rail driver gaoled after crash |date= 2 June 1995 |work= Croydon Advertiser |issue= 6600 |page= 2 }}</ref><ref>{{cite magazine |title= Crash caused by 'drink driving' |date= December 2013 |magazine= Rail Express |issue= 211 |page= 32 |url= https://issuu.com/mortons-digital/docs/redec_001 |access-date= 7 February 2024 }}</ref> The current single-storey ticket office was opened the following August.<ref name=Johnston_1994/>{{sfn|Jackson|1999|p=174}}