Editing British Rail (section)

=== InterCity 125 ===
{{Main|InterCity 125}}
[[File:Intercity 125 original logo.svg|thumb|InterCity logo 1978–1985]]
[[File:Intercity 125 2169045.jpg|thumb|left|An [[InterCity 125]] about to depart [[Manchester Piccadilly railway station|Manchester Piccadilly]] in 1986]]

The InterCity 125, or High-Speed Train, was a diesel-powered passenger train built by BREL between 1975 and 1982 that was credited with saving British Rail.<ref>{{Cite news |url = http://news.bbc.co.uk/2/hi/uk_news/england/berkshire/5407016.stm |title = High Speed Train marks 30 years |date = 4 October 2006 |access-date = 23 July 2018 |language = en-GB |archive-url = https://web.archive.org/web/20180723214328/http://news.bbc.co.uk/2/hi/uk_news/england/berkshire/5407016.stm |archive-date = 23 July 2018 |url-status = live}}</ref> Each set is made up of two [[British Rail Class 43 (HST)|Class 43]] [[power car]]s, one at each end and four to nine [[British Rail Mark 3|Mark 3]] carriages. The name is derived from its top operational speed of {{convert|125|mi/h|km/h|abbr=on}}. Key features of the Intercity 125 over predecessors include the high power-to-weight ratio of the locomotives (1678&nbsp;kW per ~70-tonne loco), high performance [[disc brake]] system (in place of the [[clasp brake]]s traditionally used), improved [[crashworthiness]], and [[push-pull train|bi-directional running]] avoiding the need to perform any run arounds at terminating stations.<ref>{{cite web |url=http://www.nrm.org.uk/OurCollection/LocomotivesAndRollingStock/CollectionItem.aspx?objid=1988-7000 |title=HST Power Car |publisher=[[National Railway Museum]] |access-date=18 May 2009 |archive-date=11 October 2013 |archive-url=https://web.archive.org/web/20131011100217/http://www.nrm.org.uk/OurCollection/LocomotivesAndRollingStock/CollectionItem.aspx?objid=1988-7000 |url-status=dead }}</ref><ref>{{cite book |last = Marsden |first = Colin |publisher = Ian Allan |year = 2001 |title = HST: Silver Jubilee |page = foreword |isbn = 0-7110-2847-8}}</ref><ref name="Semmens1990"/><ref name="CC125"/>

By 1970, the setbacks of the APT project had led the [[British Railways Board]] (BRB) to conclude that a stopgap solution would be desirably to reduce journey times in order to compete effectively with other modes of transport. At the instigation of [[Terry Miller (engineer)|Terry Miller]], Chief Engineer (Traction & Rolling Stock), the BRB authorised the development of a high-speed diesel train using tried and tested conventional technology, intended for short-term use until the APT was available.<ref>Marsden 2001, pp. 10–11.</ref> Within two years, a [[prototype]] trainset had been completed by BREL; it performed extensive trial runs between 1972 and 1976.<ref>Marsden, pp. 15–16.</ref>

Encouraged by the prototype's performance, British Rail chose to put the type into production. The production version had a substantially redesigned forward section; this change was primarily made by the British industrial designer [[Kenneth Grange]] who, after being approached by British Rail to design the livery, decided to redesign the body in coordination with an aerodynamic engineer and guided by [[wind tunnel]] testing.<ref>{{cite web |title=How we made the InterCity 125 |url=https://www.theguardian.com/culture/2013/sep/09/how-we-made-intercity-125 |work=The Guardian |access-date=1 June 2022 |date=9 September 2013}}</ref><ref>Channel 5 documentary ''Intercity 125'' episode 1, broadcast 15 May 2018</ref><ref>{{cite news |url= http://www.ft.com/cms/s/2/2221b178-87f6-11e0-a6de-00144feabdc0.html#axzz1VgPEvCdV |title= Everywhere and Nowhere |newspaper= Financial Times |location= London |date=27 May 2011 |access-date=21 August 2011}}</ref> A total of 95 Intercity 125 trainsets were ultimately brought into service.<ref name="Semmens1990">{{cite book |last1=Semmens |first1=Peter |title=Speed On The East Coast Main Line: A Century and a Half of Accelerated Services |date=1990 |publisher=Patrick Stephens Ltd |isbn=0-85059-930-X |pages=129–225}}</ref><ref name="CC125">{{cite web |title=Trackside Classic: 1976 British Rail Inter City 125 High Speed Train – Still Setting The Standard |date=18 October 2021 |url=https://www.curbsideclassic.com/trackside-classic/trackside-classic-1976-british-rail-inter-city-125-high-speed-train-still-setting-the-standard/ |publisher=Curbside Classic |access-date=30 March 2022}}</ref> British Rail enjoyed a boom in patronage on the routes operated by the HSTs and InterCity's revenues noticeably increased.<ref>{{cite book |last = Harris |first = Sim |publisher = Ian Allan |year = 2016 |title = The Railway Dilemma |page = 16 |isbn = 978-0-7110-3835-6 }}</ref>

Prior to the HST's introduction, the speed of British diesel-powered trains was limited to {{convert|100|mph|km/h|0|abbr=on}}.<ref name = 'EarlyHighspeedBR' >{{cite journal |title=High speed track on the Western Region of British Railways |last= Collins |first=R.J. |volume=64 |issue=2 |date=May 1978 |pages=207–225 |journal=Proceedings of the Institution of Civil Engineers |url=http://www.icevirtuallibrary.com/doi/abs/10.1680/iicep.1978.2755 |doi=10.1680/iicep.1978.2755 |publisher= [[Institution of Civil Engineers]] |access-date = 2 October 2015}}</ref> The prototype InterCity 125 (power cars 43000 and 43001) set the [[Land speed record for railed vehicles|world speed record]] for diesel traction at {{convert|143.2|mph|abbr=on}} on 12 June 1973.<ref name="proto">{{cite web |url = http://www.traintesting.com/HST_prototype.htm |title = Testing the prototype HST in 1973 |publisher = traintesting.com |access-date = 29 April 2009 |url-status = dead |archive-url = https://web.archive.org/web/20090915204316/http://www.traintesting.com/HST_prototype.htm |archive-date = 15 September 2009 }}</ref> This was succeeded by a production set reaching {{convert|148.5|mph|abbr=on}} in November 1987.<ref>{{cite magazine |title = World speed record smashed |magazine = [[Rail (magazine)|Rail]] |issue = 76 |date = January 1988 |page = 5 }}</ref>