Editing Chiltern Main Line

{{Short description|British railway line}}
{{Use British English|date=May 2013}}
{{Use dmy dates|date=July 2024}}
{{Infobox rail line
|box_width   = 30em
|name        = Chiltern Main Line
|color       =
|logo        =
|logo_width  =
|image       = 68010 Chiltern Railways Hatton Bank 19-08-15 (20628237900).jpg
|image_width = 321px
|caption     = A Chiltern Railways London to Birmingham express near [[Hatton railway station (England)|Hatton]], hauled by a Class 68 diesel locomotive.
|type        = [[Commuter rail]], [[Heavy rail]]
|system      = [[National Rail]]
|status      = Operational
|locale      = {{ubl|[[Greater London]]|[[South East England]]|[[East Midlands]]|[[West Midlands (county)|West Midlands]]}}
|start       = [[Marylebone station|London Marylebone]]
|end         = {{rws|Birmingham Snow Hill}}
|stations    = 32
|routes      =
|daily_ridership =
|open        = 1910 (complete line)
|close       =
|owner       = [[Network Rail]]
|operator    = {{ubl|[[Chiltern Railways]]|[[West Midlands Trains]] (in part)|[[CrossCountry]] (in part)|[[Great Western Railway (train operating company)|GWR]] (in part)}}
|character   =
|depot       =
|stock       = {{ubl|{{brc|68}} & [[British Rail Mark 3|Mk 3 Coaches]]|[[Driving Van Trailer|DVT Mk 3]]|[[British Rail Class 153|Class 153 ''Sprinter'']]|[[British Rail Class 165|Class 165 ''Network Turbo'']]|[[British Rail Class 168|Class 168 ''Clubman'']]|[[British Rail Class 170|Class 170 ''Turbostar'']]|[[British Rail Class 172|Class 172 ''Turbostar'']]|[[British Rail Class 220|Class 220 ''Voyager'']]|[[British Rail Class 221|Class 221 ''Super Voyager'']]}}
|linelength  = {{convert|112|mi|4|chain|km|0|abbr=on}}
|tracklength =
|tracks      = 2
|gauge       = {{track gauge|uksg|allk=on}}
|speed       = {{convert|100|mph|km/h|abbr=on}} maximum
|map         = [[File:Chiltern Main Line.png|321px]]<br>([[:commons:File:Chiltern Main Line.png|Click to expand]])
|map_state   = uncollapsed
}}
{{Chiltern Main Line|collapse=y}}
The '''Chiltern Main Line''' is a [[railway]] line which links [[London]] ({{stn|Marylebone}}) and [[Birmingham]] ([[Birmingham Moor Street railway station|Moor Street]] and [[Birmingham Snow Hill railway station|Snow Hill]]) on a {{convert|112|mi|km|adj=on}} route via [[High Wycombe]], [[Bicester]], [[Banbury]], [[Leamington Spa]] and [[Solihull]] in England.

It is currently one of two main line railway routes between London and Birmingham; the other is the [[West Coast Main Line]] between [[Euston railway station|London Euston]] and {{rws|Birmingham New Street}}, which is the principal [[Inter-city rail|inter-city]] route between the two cities. A third main line, [[High Speed 2]], is currently under construction.

The name ''Chiltern Line'' was invented as a marketing name for the line by [[Network SouthEast]] in 1985,<ref>{{cite web|title=NSE CHRONOLOGY Jan 1982 to May 1986 |url=http://www.networksoutheast.net/jan-1982-to-may-1986.html |publisher=Network SouthEast Railway Society |access-date=22 April 2014 |url-status=dead |archive-url=https://web.archive.org/web/20131104151947/http://www.networksoutheast.net/jan-1982-to-may-1986.html |archive-date=4 November 2013 }}</ref> with reference to the [[Chiltern Hills]] that the route passes through near its southern end. The route was originally part of the [[Great Western Railway]]'s main line from [[Paddington railway station|London Paddington]] to [[Birmingham Snow Hill railway station|Birmingham Snow Hill]], {{rws|Wolverhampton Low Level}} and {{rws|Birkenhead Woodside}}. Most main line services between London and Birmingham on this route were discontinued in 1967  after the West Coast Main Line was electrified, and Snow Hill station was closed.<ref name=warwickshirerailwayssnowhill>{{cite web |title=Birmingham Snow Hill Station – A brief overview |url=http://www.warwickshirerailways.com/gwr/birminghamsnowhill.htm |publisher=Warwickshire Railways |access-date=5 June 2016}}</ref> 

Services were resumed between London and the reopened Snow Hill in 1993; however, they were routed into Marylebone, formerly the London terminus of the now-closed [[Great Central Main Line]], instead of the historic terminus at Paddington.<ref name="NSE1993">{{cite web |title=The History of Network South East 1993 |url=http://www.networksoutheast.net/jan-1993-to-dec-1993.html |publisher=Network South East Railway Society |access-date=5 June 2016 |url-status=dead |archive-url=https://web.archive.org/web/20131103135422/http://www.networksoutheast.net/jan-1993-to-dec-1993.html |archive-date=3 November 2013 }}</ref>

Since the [[privatisation of British Rail]] in the 1990s, the main [[Train operating company|operator]] has been [[Chiltern Railways]], which has continued to develop the route and services. In the early 2010s, the line [[#Project Evergreen 3|underwent a major upgrade]] which saw much of the line cleared for 100&nbsp;mph (160&nbsp;km/h) running, resulting in significant reductions in journey times from 2013. The line is not [[Railway electrification in Great Britain|electrified]], although electrification is an aspiration.<ref name="shooter"/>

The line forms part of the [[Urban rail in the United Kingdom|suburban rail networks]] in both cities. The majority of towns towards the London end of the route are prosperous suburbs or commuter-belt towns, such as [[Ruislip]], [[Gerrards Cross]] and [[Beaconsfield]]; these have a journey time of 30 minutes or less to London Marylebone. In the [[West Midlands (region)|West Midlands]], it is one of the [[Snow Hill Lines]]. Commuter trains operated by [[West Midlands Trains]] run between Birmingham Snow Hill, {{rws|Solihull}} and {{rws|Leamington Spa}}, also to [[Stratford-upon-Avon railway station|Stratford-upon-Avon]].

==History==
===Early history and construction===
What is now the Chiltern Main Line was built in three key phases by the [[Great Western Railway]] (GWR) between 1852 and 1910:
* The first phase was the [[Birmingham and Oxford Junction Railway]] opened in 1852. The route ran from {{Stnlnk|London Paddington}} to Birmingham Snow Hill; in 1854, it was extended to [[Wolverhampton Low Level railway station|Wolverhampton Low Level]] and, connecting with other GWR lines, became the southern leg of a longer distance route to {{rws|Shrewsbury}}, {{rws|Chester}} and [[Birkenhead Woodside railway station|Birkenhead]]. It ran via the [[Great Western Main Line]] to {{stnlink|Didcot}} and then via {{Stnlnk|Oxford}}, {{rws|Banbury}} and Leamington Spa. This route was circuitous and was {{convert|16|mi|km}} longer between London and Birmingham than the rival [[London and North Western Railway]]'s [[Euston railway station|Euston]]-[[Birmingham New Street railway station|New Street]] route via {{rws|Rugby}}, meaning that the GWR could not compete on journey times.<ref>{{cite book |last=MacDermot |first=E.T.|year=1927 |title=History of the Great Western Railway, volume I 1833–1863 |location=London |publisher=Great Western Railway; Reprinted 1982, Ian Allan |isbn=0-7110-0411-0 |page=327, 336}}</ref><ref>{{cite book |last1=Boynton |first1=John |title=Main Line to Metro: Train and tram on the Great Western route: Birmingham Snow Hill – Wolverhampton |date=2001 |publisher=Mid England Books |isbn=978-0-9522248-9-1 |page=18}}</ref>
* The second phase was completed in 1906. In order to create a more direct route, the GWR collaborated with the [[Great Central Railway]] (GCR) to create a new railway known as the [[Great Western and Great Central Joint Railway]] between Northolt (in north-west London) and Ashendon Junction (west of [[Aylesbury]]) via {{rws|High Wycombe}}.<ref name="Jenkins">{{cite book |last=Jenkins |first=Stanley C. |title=The Great Western and Great Central Joint Railway |date=20 July 2006 |publisher=The Oakwood Press |isbn=9780853616535}}{{Page needed|date=May 2023}}</ref>
* Thirdly, as a final development, the GWR opened the ''Bicester cut-off line'' in 1910; this was an {{convert|18+1/4|mi|km|abbr=on}} connection between the Great Western and Great Central Joint Railway at Ashendon Junction, via {{rws|Bicester North}}, to Aynho Junction on the Birmingham line south of Banbury. This shortened the route between London and Birmingham by {{convert|18+1/2|mile|km}}, compared to the original Oxford route, and reduced the fastest London-Birmingham journey times by 20 minutes (from 140 to 120 minutes). Most of the through trains were immediately transferred to the new route, although the original route via Oxford continued in use and is now known as the [[Cherwell Valley line]].<ref name="Jenkins"/>
{{multiple image
 | width=250
 | direction=horizontal
 | align=none
 | image1 = B&ojr.png
 | caption1 = The Birmingham and Oxford Junction Railway as built in 1852. Prior to the construction of the Bicester cut-off line in 1910, London to Birmingham trains had to run on the [[Cherwell Valley line|circuitous route]] via [[Oxford]].
 | alt1 =
 | image2 = Gw&gc-overview.png
 | caption2 = The Great Western and Great Central Joint Railway (red) and the Bicester cut-off line (yellow) opened in 1906 and 1910 respectively. This completed the route of what is now the Chiltern Main Line.
 | alt2 = 
 | footer = 
}}

===GWR era===
Once the route between Birmingham and London was completed in 1852, the GWR introduced its first expresses between the two cities, timed at 2 hours 45 minutes, however this was soon revised to three hours, which matched the timings of the rival LNWR service. There was relatively little improvement for the rest of the 19th century, and three-hour expresses remained the standard timing of both companies until 1905, when the LNWR introduced new, more powerful [[LNWR Whale Precursor Class|Precursor Class]] locomotives, which allowed them to introduce two-hour expresses. The GWR could not compete with this, and it spurred the shortening of its route, as detailed above, which allowed them to introduce a matching timing of two hours once the works were completed in 1910.<ref>{{cite book |last1=Boynton |first1=John |title=Main Line to Metro: Train and tram on the Great Western route: Birmingham Snow Hill – Wolverhampton |date=2001 |publisher=Mid England Books |isbn=978-0-9522248-9-1 |pages=12-18}}</ref>

===Heyday, decline and rationalisation===
{{More citations needed section|date=June 2011}}
[[File:Seer Green geograph-2456422-by-Ben-Brooksbank.jpg|thumb|right|An ''Ex-''GWR [[GWR 6000 Class|King Class]] locomotive 6008 ''King James II'' hauling a Paddington to Birkenhead Woodside express in 1950]]
[[File:Seer Green station geograph-2400005-by-Ben-Brooksbank.jpg|thumb|right|A {{brc|52}} hauling an express from Paddington to Birkenhead Woodside near {{rws|Seer Green}} in 1962]]

During the heyday of the route, many prestigious trains ran from Paddington to the north-west of England, via the Joint Line; these reached Wolverhampton, {{rws|Shrewsbury}}, {{rws|Wrexham General}}, Chester and Birkenhead Woodside. Various through services from Marylebone to the GCR network also ran via the Joint Line between London and Ashendon Junction.

At [[Transport Act 1947|nationalisation in 1948]], the line passed to the [[Western Region of British Railways]], which continued to operate Paddington-Birmingham-Wolverhampton-Birkenhead fast trains through the 1950s in competition with the [[London Midland Region of British Railways|London Midland Region's]] (LMR) from Euston via the West Coast Main Line (WCML).

The Paddington-Birmingham-Wolverhampton-Birkenhead fast service was increased sharply in frequency to up to 15 trains a day each way from the 1959–60 timetable to compensate for the withdrawal of most London Midlands Region trains during electrification of the WCML.<ref>{{cite news |title=The winter timetables of British Railways: Western Region|work=[[Trains Illustrated]] |publisher=[[Ian Allan Publishing|Ian Allan]] |location=Hampton Court |date=December 1959 |page=584}}</ref> For the same reason, the Chiltern line was used by many trains between Paddington and Birkenhead from 1965.

All local trains were diverted to Marylebone in 1963 and operated by four-car [[British Rail Class 115|Class 115]] [[diesel multiple units]] (DMUs) and the main-line platforms at Greenford, on the New North route between Old Oak Common and Northolt Junction, were closed.

After the GCR main line was closed between {{rws|Calvert}} and {{rws|Rugby Central}} in September 1966, some trains from the South Coast were diverted north of Banbury via the route.  These became the forerunners of today's [[CrossCountry]] services between Birmingham and {{rws|Bournemouth}}.

[[File:Train, Marylebone station, London 3224106.jpg|thumb|right|Class 115 DMUs operated Marylebone – Banbury local services between 1960 and 1992]]

On 6 March 1967,<ref name=rcw>{{cite book |last=Collins |first=Paul|title=Rail Centres: Wolverhampton |publisher=Ian Allan |location=[[London]] |year=1990 |isbn=978-0-7110-1892-1}}</ref> after completion of the WCML electrification, express trains from Paddington to Birmingham/Wolverhampton/Birkenhead were discontinued under ''[[Beeching Axe|The Reshaping of British Railways]]''. The route was downgraded to secondary status, with all but one of the main-line services between London and Birmingham diverted via Oxford. In 1968, the line between Princes Risborough and Aynho Junction was reduced to single track and only a basic two-hourly DMU service between Marylebone and Banbury remained to serve Bicester.<ref name="BLHS">{{cite web |title=Railways |url=https://www.blhs.org.uk/index.php/transport/railways |publisher=Bicester Local History Society |access-date=21 October 2021}}</ref> Through lines were removed from most of those stations which had them, including Denham in 1965, Beaconsfield in 1973 and Gerrards Cross in 1989; the relief lines were lifted between Lapworth and Tyseley. The tunnel between Birmingham Moor Street and Snow Hill was closed on 2 March 1968.<ref name=rcw/> Local services from Leamington and Stratford terminated at Moor Street; the remaining services from Paddington and the South Coast were diverted into New Street. Snow Hill closed completely, along with most of the line to Wolverhampton, on 4 March 1972.<ref name=rcw/>

On 24 March 1974, the line from Marylebone to Banbury transferred from the Western Region to the [[London Midland Region of British Railways|London Midland Region]]; all stations between South Ruislip and Bicester were also transferred to LMR, giving LMR the responsibility of all passenger services out of Marylebone.

In 1977, the Parliamentary Select Committee on Nationalised Industries recommended considering [[Railway electrification in Great Britain|electrification of more of the rail network]] and, by 1979, BR presented a range of options to electrify numerous routes by 2000.<ref name="BR-CPU">{{cite book |author=Anonymous |title=Railway Electrification|date=Winter 1979 |publisher=[[British Railways Board]] (Central Publicity Unit) |pages=0–2, 8}}</ref> Some of these options included the Banbury–Birmingham section of the line, plus the [[Cherwell Valley Line]] and the [[Coventry to Leamington line]].<ref name="BR-CPU"/> Under the [[Premiership of Margaret Thatcher|1979–90 Conservative governments]] that succeeded the [[Callaghan ministry|1976–79 Labour government]], the proposals were not implemented.

The route was considered for partial closure between Marylebone and Northolt Junction in the early 1980s. All services would have run to Paddington, via the New North route; Marylebone station, and all lines leading to it, would have been closed and converted into a bus station. Services to and from Aylesbury would have been taken over by [[London Underground]] and run into [[Baker Street tube station|Baker Street]]. However, these proposals proved impractical and Marylebone was formally reprieved in 1986 (with a press announcement made on 30 April 1986) and the closure proposals rescinded.<ref name=Almostterminal>{{cite web |title=Almost Terminal: Marylebone's Brush With Destruction |url= http://www.londonreconnections.com/2014/near-terminal-case-saving-marylebone-rail-road-conversion/ |website=London Reconnections |access-date=15 September 2015 |date=20 February 2014}}</ref>

===Rejuvenation===
[[File:165027 at Kings Sutton.jpg|thumb|right|Class 165 DMUs were introduced to the Chiltern Main Line by Network SouthEast]]

With the sectorisation of British Rail in the mid-1980s, operations south of Banbury fell under the control of [[Network SouthEast]] in 1986, under the ''Thames & Chiltern'' sub-sector; this was split later into two constituent parts. In 1987, a new station was opened at [[Haddenham & Thame Parkway railway station|Haddenham & Thame Parkway]]. Birmingham Snow Hill reopened in 1987, on a much smaller scale than the original, beneath a [[multi-storey car park]]; its tunnel was reinstated and new platforms added to the through lines at Moor Street, where the terminus was taken out of use. Leamington/Stratford services were diverted to Snow Hill.

The opening of the extension of the parallel [[M40 motorway]] from Oxford to Birmingham in 1991 spawned development in towns along the northern section of the route, notably Bicester, Banbury, Leamington Spa and Warwick. This generated additional patronage for train services in the corridor.<ref name="OM">{{cite news |title= 100-year-old rail station steams into the future |url= https://www.oxfordmail.co.uk/news/8247619.100-year-old-rail-station-steams-future/ |work=Oxford Mail |access-date=21 October 2021 |date=1 July 2010}}</ref>

Between 1988 and 1992, British Rail used the Chiltern Line as a test bed for [[total route modernisation]]; this included resignalling from Marylebone to Aynho Junction, and both Marylebone to Aylesbury routes, from the new Marylebone [[Integrated Electronic Control Centre|Integrated Control Centre]], with full [[Automatic Train Protection]] provided. The track was renewed and Marylebone was refurbished. Much of this work was funded by selling part of Marylebone for development, which meant that the station lost two of its platforms; the central cab road at Marylebone was removed and two replacement platforms inserted in its place.<ref name=Almostterminal/> 

New {{brc|165}} ''Turbo'' trains were introduced in 1991, replacing the ageing 1960s diesels.<ref name=Almostterminal/> These improved passenger comfort and enabled journey times to be reduced; frequencies were increased, with an hourly stopping service to/from High Wycombe and hourly semi-fast service to/from Banbury. In 1993, Marylebone-Banbury services were extended to Snow Hill, calling at Leamington Spa, Warwick, Solihull and Moor Street, initially on a two-hourly frequency; these were increased to hourly in the following year. In 1995, the [[Birmingham to Worcester via Kidderminster Line|Jewellery Line]] was reopened, to allow Worcester line services to be diverted from New Street to Snow Hill; this resulted in some of Chiltern's weekday peak-period services to be extended beyond Snow Hill, first to Stourbridge Junction and then to Kidderminster.<ref>{{cite book |last1=Boynton |first1=John |title=Main Line to Metro: Train and tram on the Great Western route: Birmingham Snow Hill–Wolverhampton |date=2001 |publisher=Mid England Books |isbn=978-0-9522248-9-1 |page=70}}</ref>

===Chiltern Railways era===
Upon railway privatisation in 1996, the [[Chiltern Railways]] franchise was won by [[Chiltern Railways#History|M40 Trains]], a consortium of a management buyout, Laing Rail (a subsidiary of construction company and [[Private finance initiative|PFI]] specialist [[John Laing plc]]) and venture capitalist [[3i]]. In 1998, the line between Princes Risborough and Bicester North was redoubled by the company; this included the total reconstruction of [[Haddenham and Thame Parkway railway station|Haddenham and Thame Parkway]] at platform level, with two side platforms instead of the single platform constructed in 1987, and a new down platform at Princes Risborough, together with the raising of the speed limit. Also in 1998, the first Class 168 ''Clubman'' trains, with a maximum speed of {{convert|100|mph|kph|adj=on}}, were introduced to reduce journey times.

[[File:168107 A London Marylebone.JPG|thumb|right|upright=1.13|Chiltern Railways ordered 19 Class 168 DMUs for its Marylebone–Birmingham services]]

In 2000, Chiltern Railways opened a new station at [[Warwick Parkway railway station|Warwick Parkway]], to the west of the town next to the [[A46 road|A46]] and close to [[M40 motorway|M40]] Junction 15. This was intended to be a railhead for nearby towns without a station, such as [[Kenilworth]], and for towns south of Birmingham close to the [[M42 motorway|M42]] with no direct rail link to London, such as [[Redditch]] and [[Bromsgrove]]. Construction was funded by Chiltern Railways, with some support from [[Warwickshire County Council]]. At first, only Chiltern services called there but it is now also served by London Midland.

In 2002, after Chiltern won its 20-year [[exclusive right|franchise]], the line between Bicester North and Aynho Junction was also redoubled. Chiltern took over Hatton to Stratford-upon-Avon services from [[Thames Trains]] and [[Central Trains]], with direct services between Marylebone (rather than Paddington) and Stratford. Also at this time, Chiltern took over the operation of [[Leamington Spa railway station|Leamington Spa]], [[Warwick railway station|Warwick]], [[Hatton railway station (Warwickshire)|Hatton]] and [[Lapworth railway station|Lapworth]] stations from Central Trains, as the latter's services (now operated by London Midland) no longer operated beyond Dorridge except during weekday peak periods.

John Laing plc acquired 84% ownership of M40 Trains in 1999, buying out 3i; it was itself bought out by [[Henderson Group|Henderson Investments]] in 2006, resulting in the sale of Laing Rail to the German national railway operator [[Deutsche Bahn]] in 2007.

The [[Cherwell Valley]] line between Banbury and Leamington Spa was resignalled during 2004, with the closure of [[Fenny Compton]] signal box and the removal of its remaining semaphore signals. The new signalling and the existing signalling in the Leamington Spa station area is controlled from the box at Leamington via a new Westcad workstation.  More recently, the Leamington to Birmingham section has been resignalled and is controlled from the new [[West Midlands ICC]] at [[Saltley]] (taking over the old signalling centre at Saltley), with new 4-aspect LED signals throughout. But the manual signal boxes at Banbury North and South remained, along with some GWR lower-quadrant signals controlling the bay platforms and sidings at the station. In 2016, the station was remodelled and resignalled, being incorporated into the West Midlands ICC take over control as Oxford (exclusive) in 2016.<ref>{{cite web |url= https://www.networkrail.co.uk/feeds/orange-army-upgrades-railway-and-keeps-customers-moving-in-2016/ |title=Orange army upgrades railway and keeps customers moving in 2016 |publisher= Network Rail |access-date=19 May 2017 |date=2017 |archive-url= https://web.archive.org/web/20170402081301/https://www.networkrail.co.uk/feeds/orange-army-upgrades-railway-and-keeps-customers-moving-in-2016/ |archive-date=2 April 2017 |url-status=dead}}</ref>

Most of the route from Birmingham Snow Hill to Wolverhampton is now used by the [[Midland Metro]] light-rail system, which diverges from Network Rail's Jewellery Line at The Hawthorns.

The route between Marylebone and Leamington/Bordesley was used by [[open access operator]] [[Wrexham & Shropshire]]'s services from London to Wrexham, via Tame Bridge, Wolverhampton and Shrewsbury; this consisted of three [[British Rail Mark 3|Mark 3 coaches]], powered by [[British Rail Class 67|Class 67]] [[diesel locomotives]]. Since these were neither [[Sprinter (British Rail)|Sprinters]] nor [[InterCity 125|High Speed Trains]], they were restricted to lower line speeds, e.g. {{convert|60|mph|kph}} between Princes Risborough and Bicester, and {{convert|70|mph|kph}} between Leamington and Bordesley; they were permitted to travel at {{convert|85|mph|kph}} between Bicester and Aynho. Wrexham & Shropshire had negotiated with Network Rail to allow its trains to travel at higher speeds on these sections, which required it to show that they had sufficient brake force to stop from such speeds within the signal spacings.

Only the little-used line from Northolt Junction to Paddington has not been improved.

In September 2006, Chiltern completed its ''Evergreen 2'' upgrade project, carried out by [[Carillion]], which realigned the track through [[Beaconsfield railway station (Buckinghamshire)|Beaconsfield]] to increase non-stop speeds from {{convert|40|to|75|mph|kph}}, installed additional [[Railway signal|signals]] between High Wycombe and Bicester North and between Princes Risborough and Aylesbury, and added two platforms (Nos 5 and 6) at Marylebone, on the site of the daytime carriage sidings, replaced by the new Wembley Light Maintenance Depot, just south and west of [[Wembley Stadium station]]. The new platforms and partial resignalling of the station throat made it possible to run 20 trains per hour in and out of the station.

At weekends during 2008, when major engineering works were taking place on the WCML, the line was used by [[Virgin Trains]]' London Euston – {{Stnlnk|Birmingham International}} ''Blockade Buster'' service via Willesden, {{rws|Acton Main Line}}, {{rws|Ealing Broadway}}, {{rws|Greenford}}, High Wycombe, Banbury and {{rws|Coventry}}, using pairs of five-car Class 221 ''Super Voyager'' sets.

== Infrastructure ==

=== Tunnels and viaducts ===
[[File:Give Peas a chance! (geograph 2391585).jpg|thumb|The "Give Peas a Chance" viaduct is a landmark on the M25]]
There are several major civil engineering structures along the route of the Chiltern Main Line.<ref name=":0">{{cite book |title=Railway Track Diagrams Book 3 Western |last=Bridge |first=Mike |publisher=Trackmaps |year=2010 |isbn=978-0-9549866-6-7 |location=Bradford on Avon |pages=13, 18 19}}</ref><ref name=":1">{{cite book |title=Railway Track Diagrams Book 4 Midlands & North West |last=Bridge |first=Mike |publisher=Trackmaps |year=2013 |isbn=978-0-9549866-7-4 |location=Bradford on Avon|pages=14, 15}}</ref>

The viaduct ([[Chalfont Viaduct|Chalfonts No. 1 (Misbourne) Viaduct]]) crossing the M25 between Denham Golf Club and Gerrard's Cross is especially noted as a local landmark, as for many years it has borne a [[graffiti]] slogan, "{{smallcaps|give peas a chance}}" painted in large white letters on the south-facing parapet.<ref name="bbc-peas">{{cite news |last1=Winterman |first1=Tom de Castella and Denise |title=Campaigning by graffiti |url=https://www.bbc.co.uk/news/magazine-13524208 |access-date=20 September 2018 |work=BBC News |date=25 May 2011 |archive-url=https://web.archive.org/web/20180920153837/https://www.bbc.co.uk/news/magazine-13524208 |archive-date=20 September 2018|url-status=live}}</ref> The graffiti was partially removed in 2018.<ref name="es-peas">{{cite news |last1=Clifton |first1=Katy |title=Motorists devastated as iconic 'Give Peas a Chance' graffiti is erased |url=https://www.standard.co.uk/news/uk/motorists-devastated-as-iconic-give-peas-a-chance-m25-graffiti-is-erased-a3941311.html |access-date=20 September 2018 |work=Evening Standard |date=20 September 2018 |archive-url=https://web.archive.org/web/20180920154003/https://www.standard.co.uk/news/uk/motorists-devastated-as-iconic-give-peas-a-chance-m25-graffiti-is-erased-a3941311.html |archive-date=20 September 2018|url-status=live}}</ref>

{| class="wikitable"
|+Tunnels and viaducts on the Chiltern Main Line
!Railway Structure
!Length
![[Engineer's Line Reference|ELR]]
!Location
|-
|[[Snow Hill Tunnel (Birmingham)|Snow Hill Tunnel]]
|{{convert|635|yard|m|0|lk=in}}
| rowspan="6" |DCL
|South of [[Birmingham Snow Hill railway station|Snow Hill station]]
|-
|Bordesley Viaduct
|{{convert|38|chain|m|-1|lk=in}}
|South of [[Birmingham Moor Street railway station|Moor Street station]]
|-
|Goods Yard Approach & Corporation Yard Viaducts
|{{convert|18|chain|m|-1}}
|[[Bordesley railway station|Bordesley station]]
|-
|River Avon Viaduct
|{{convert|3|chain|m|-1}}
|Between [[Warwick railway station|Warwick]] and [[Leamington Spa railway station|Leamington Spa stations]]
|-
|Leamington Viaducts / Neilson Street Viaduct
|{{convert|18|chain|m|-1}}
|East of Leamington Spa station
|-
|[[Harbury|Harbury Tunnel]]
|{{convert|70|yard|m|0}}
|Between Leamington Spa and [[Banbury railway station|Banbury stations]]
|-
|Aynho Flyover (Down line)
|
| rowspan="5" |NAJ3
|Between [[Kings Sutton railway station|Kings Sutton]] and [[Bicester North railway station|Bicester North stations]]
|-
|Souldern No. 2 Viaduct
|{{convert|400|yard|m|0}}
| rowspan="3" |Between [[Aynho Junction|Aynho junction]] and Bicester North station
|-
|Souldern No. 1 Viaduct
|{{convert|580|yard|m|0}}
|-
|Ardley Tunnel
|{{convert|1155|yard|m|0}}
|-
|Brill Tunnel
|{{convert|191|yard|m|0}}
|Between Bicester North and [[Haddenham & Thame Parkway railway station|Haddenham and Thame Parkway stations]]
|-
|River Thame Viaduct
|{{convert|4|chain|m|-1}}
| rowspan="11" |NAJ2
|North of Haddenham and Thame Parkway station
|-
|Saunderton Tunnel (Up line)
|{{convert|83|yard|m|0}}
|South of [[Princes Risborough railway station|Princes Risborough station]]
|-
|Hughenden Road Viaduct
|{{convert|77|yard|m|0}}
|North of [[High Wycombe railway station|High Wycombe station]]
|-
|Gordon Road Viaduct
|{{convert|47|yard|m|0}}
| rowspan="3" |Between High Wycombe and Beaconsfield stations
|-
|Sir Philip Rose's Viaduct
|{{convert|66|yard|m|0}}
|-
|Whitehouse Tunnel
|{{convert|352|yard|m|0}}
|-
|'Tesco' Covered Way (also known as [[Gerrards Cross Tunnel]])
|{{convert|350|yard|m|0}}

|South of [[Gerrards Cross railway station|Gerrards Cross station]]
|-
|Chalfonts No. 2 Viaduct
|{{convert|165|yard|m|0}}
| rowspan="2" |Between Gerrards Cross and [[Denham Golf Club railway station|Denham Golf Club stations]] 
|-
|[[Chalfont Viaduct|Chalfonts No. 1 (Misbourne) Viaduct]] (also M25 under)
|{{convert|114|yard|m|0}}
|-
|River Colne Viaduct
|{{convert|121|yard|m|0}}
| rowspan="2" |South of [[Denham railway station|Denham station]]
|-
|Grand Union Canal Viaduct
|{{convert|198|yard|m|0}}
|-
|South Harrow Tunnel
|{{convert|204|yard|m|0}}
|NAJ1
|West of [[Sudbury Hill Harrow railway station|Sudbury Hill Harrow station]]
|-
|Kilburn Viaduct
|{{convert|23|chain|m|-1}}
| rowspan="3" |MCJ1
| rowspan="3" |North of Marylebone station
|-
|Hampstead Tunnel
|{{convert|694|yard|m|0}}
|-
|St John's Wood Tunnel
|{{convert|1606|yard|m|0}}
|}

=== Oxford Connection ===
{{Main|East West Rail}}
A quarter of a mile (about 0.3&nbsp;km) of double track has been constructed joining the [[Oxford to Bicester Line]] at [[Bicester Village railway station|Bicester Village]] to the Chiltern line, allowing a new Oxford to London Marylebone service to operate, calling at Bicester Village and High Wycombe. The track between Wolvercote Tunnel (on the outskirts of Oxford) and Bicester Village has been rebuilt and a new station constructed at [[Water Eaton, Oxfordshire|Water Eaton]], named {{stnlnk|Oxford Parkway}}.<ref>{{cite web |url=http://www.chilternrailways.co.uk/chilternmainline/ |publisher=Chiltern Railways |title=Chiltern Mainline |access-date=23 January 2010|archive-url=https://web.archive.org/web/20100415213504/http://mainline.chilternrailways.co.uk/about |archive-date=15 April 2010|url-status=dead}}</ref><ref name=CRpress20130920>{{cite press release |title=Chiltern Railways names new Oxfordshire station Oxford Parkway |date=20 September 2013 |publisher=Chiltern Railways |url=http://www.chilternrailways.co.uk/news/chiltern-railways-names-new-oxfordshire-station-oxford-parkway |access-date=20 September 2013 |archive-url=https://web.archive.org/web/20130921060403/http://www.chilternrailways.co.uk/news/chiltern-railways-names-new-oxfordshire-station-oxford-parkway|archive-date=21 September 2013 |url-status=dead}}</ref> The scheme includes additional platforms at Bicester, [[Islip railway station|Islip]] and Oxford. The Oxford line was reopened in stages during 2015 and 2016; services from London Marylebone to Oxford Parkway began in October 2015. Services through to Oxford started on 11 December 2016.<ref>{{cite news |url= https://www.bbc.com/news/uk-england-oxfordshire-38286727 |title=Oxford to London Marylebone railway line opens |date=12 December 2016 |work=BBC News |access-date=12 December 2016}}</ref><ref>{{cite news |url= https://www.railtechnologymagazine.com/Rail-News/chilterns-oxford-city-centre-london-services-pushed-to-december |title=Chiltern's Oxford city centre-London services pushed to December |date=20 January 2016 |website= www.railtechnologymagazine.com}}</ref><ref>{{cite web |url= http://www.chilternrailways.co.uk/oxford-london |publisher=Chiltern Railways |title=Oxford to London line |access-date=13 April 2015}}</ref> The delay to the full service was due to works in the Wolvercote tunnel, which were specifically scheduled to minimise disruption to roosting bats. The upgraded track has two bi-directional tracks and headroom in the tunnel for overhead electrification to be installed at a later date.<ref>{{cite web |url= http://www.bicestertooxfordcollaboration.com/in-your-area/wolvercote-tunnel.html |publisher=Bicester to Oxford collaboration |title=Wolvercote Tunnel |access-date=13 April 2015}}</ref>

{{anchor|Project Evergreen 3}}

==Main Line upgrade==
The second part of the project upgraded the line to {{convert|100|mph|kph}} running on {{convert|50|mi|km}} more of track, with junctions at Neasden, Northolt and Aynho rebuilt to permit higher speeds. The ''up'' through track was restored at Princes Risborough and signalled for bidirectional use, the existing 'up' line becoming a bidirectional platform loop. A new turnback siding was provided at [[Gerrards Cross railway station|Gerrards Cross]] and a new 'down' through track built from Northolt Junction to Ruislip Gardens, running alongside the ''up'' line to the east of the waste transfer station; the ''down'' line will continue to serve [[South Ruislip railway station|South Ruislip]]. Speed restrictions through Bicester North were raised to permit {{convert|100|mph|kph|adj=on}} running, with a new ''up'' alignment and platform. Two of the original terminal platforms at Birmingham Moor Street were reopened for Chiltern services in December 2010. Accelerated services started in September 2011,<ref>{{cite web |url=http://www.chilternrailways.co.uk/mainline/faqs |title=Chiltern Mainline FAQ |publisher=Chiltern Railways |access-date=13 April 2015 |archive-url=https://web.archive.org/web/20150412013542/http://www.chilternrailways.co.uk/mainline/faqs|archive-date=12 April 2015|url-status=dead}}</ref> after being postponed due to concerns about whether the works would be completed in time.<ref>{{cite news |url=http://www.railnews.co.uk/news/business/2008/08/29-chiltern-railways-upgrade.html |title=Chiltern Railways plan to make Bicester well connected |work=RailNews |location=Stevenage |date=29 August 2008 |access-date=7 September 2008}}</ref><ref>{{cite web |url=http://www.chiltern-evergreen3.co.uk|title=Project Evergreen 3 |year=2010 |publisher=Chiltern Railways |url-status=dead |archive-url=https://web.archive.org/web/20090828064814/http://www.chiltern-evergreen3.co.uk/ |archive-date=28 August 2009}}</ref>

Thanks to the speed increases, journey times have been reduced significantly. From Marylebone, the fastest journey time to Birmingham Moor Street is now 94 minutes instead of 117 minutes.<ref>{{cite web |url=http://www.chilternrailways.co.uk/mainline |title=Chiltern Railways Mainline is Here |publisher=Chiltern Railways}}</ref> The table below outlines the originally proposed peak timetable improvements as indicated by [[Network Rail]].<ref>{{cite web |url=http://www.networkrail.co.uk/browseDirectory.aspx?dir=%5CTrack%20Access%5C2%20Completed%20Consultations%5C2009%5C2009.10.27%20Chiltern%20Railways%2073rd%20Supplemental%20Agreement%20-%20consultation%20closed%2023%20November%202009&root=&cd=1 |title=73rd Supplemental Agreement |publisher=Network Rail}}</ref> This compares to roughly 85 minutes for the fastest Euston-Birmingham New Street trains, via the West Coast Main Line.

Chiltern Railways chairman [[Adrian Shooter]] said, "This is the biggest passenger rail project for several generations not to call on the taxpayer for support. Working closely with Network Rail, we are going to create a new main line railway for the people of Oxfordshire and the Midlands. This deal demonstrates that real improvements to rail services can be paid for without public subsidy by attracting people out of their cars and on to trains."

Network Rail said its investment will be reimbursed by a 'facility charge' over the next 30 years, by Chiltern Railways, whose franchise expires in December 2021, and then by the future franchisee. The infrastructure upgrade was carried out by main contractor [[BAM Nuttall]], in partnership with [[Jarvis plc|Jarvis]] and [[WS Atkins]].

{| class="wikitable"
|+ Fastest Peak Time from London (mins)
!
! Width="100"|Previous
! Width="100"|Evergreen 3
|-
! Gerrards Cross
| align=center|21
| align=center|'''18'''
|-
! High Wycombe
| align=center|34
| align=center|'''23'''
|-
! Princes Risborough
| align=center|41
| align=center|'''32'''
|-
! Bicester
| align=center|56
| align=center|'''44'''
|-
! Banbury
| align=center|67
| align=center|'''50'''
|-
! Leamington Spa
| align=center|85
| align=center|'''67'''
|-
! Solihull
| align=center|107
| align=center|'''84'''
|-
! Birmingham Moor Street
| align=center|117
| align=center|'''92'''
|}

==Passenger services==
While Chiltern Railways is the main operator of the route, parts of the line carry services by other operators:
* [[West Midlands Trains]] operates local services in the West Midlands area between Birmingham, {{rws|Dorridge}} and Leamington Spa, as part of the [[Snow Hill Lines]]
* [[CrossCountry]] operates some services from either Birmingham (joining the line at Bordesley junction) or Leamington (joining from the [[Coventry-Leamington line]]) and running as far as [[Aynho Junction]] where they diverge towards {{rws|Oxford}}
* [[Great Western Railway (train operating company)|Great Western Railway]] also operates a few services to Banbury via Oxford.

===Weekday off-peak service pattern===
At May 2011:
{| class="wikitable"
! Service 
! Type
! Trains per hour
! Notes
|-
! colspan="4" style="background:#ffffcc"|Chiltern Railways,<ref>{{cite web |url=http://www.chilternrailways.co.uk/sites/default/files/May%202011%20Timetable%20booklet.pdf|title=Chiltern Railways May 2011 timetable |date=22 May 2011 |access-date=25 June 2011}} {{Dead link|date=May 2017}}</ref> over the whole line
|-
|| [[London Marylebone]] – [[Birmingham Moor Street railway station|Birmingham Moor Street]] || Fast || 2 || 1 extended to [[Birmingham Snow Hill railway station|Birmingham Snow Hill]]
|-
|| London Marylebone – [[Kidderminster railway station|Kidderminster]] || Fast/Semi-Fast (Birmingham Snow Hill to Kidderminster) || Peak ||
|-
|| London Marylebone – [[Banbury railway station|Banbury]] || Semi fast|| 1 || Extended to [[Stratford upon Avon railway station|Stratford upon Avon]] every 2 hours
|-
|| London Marylebone – [[Bicester North railway station|Bicester North]]  || Semi-fast || 1 || 
|-
|| London Marylebone – [[Princes Risborough railway station|Princes Risborough]]  || Semi-fast || 1
|-
|| London Marylebone – [[High Wycombe railway station|High Wycombe]]  || local || 1
|-
|| London Marylebone – [[Gerrards Cross railway station|Gerrards Cross]] || local || 1
|-
|| [[Leamington Spa railway station|Leamington Spa]] – [[Birmingham Moor Street railway station|Birmingham Moor Street]]  || local || 1
|-
|| {{rws|Stratford-upon-Avon}} – Leamington Spa || Slow to Leamington Spa, then semi-fast || 1 || Most extended to London Marylebone
|-
! colspan="4" style="background:#ffffcc"|West Midlands Trains,<ref>{{cite web |url=http://www.londonmidland.com/download/52907.4/stratford-upon-avon-shirley-birmingham/ |title=London Midland Stratford-Birmingham May 2011 timetable |date=22 May 2011 |access-date=25 June 2011 |archive-url=https://web.archive.org/web/20111002091940/http://www.londonmidland.com/download/52907.4/stratford-upon-avon-shirley-birmingham/ |archive-date=2 October 2011 |url-status=dead}}</ref><ref>{{cite web |url=http://www.londonmidland.com/download/52934.7/worcester-kidderminster-birmingham-snow-hill/ |title=London Midland Worcester-Birmingham May 2011 timetable |date=22 May 2011 |access-date=25 June 2011 |archive-url=https://web.archive.org/web/20111002091954/http://www.londonmidland.com/download/52934.7/worcester-kidderminster-birmingham-snow-hill/ |archive-date=2 October 2011 |url-status=dead}}</ref> between Birmingham Snow Hill and Dorridge, with some services extended to Leamington Spa
|-
|| [[Dorridge railway station|Dorridge]] – [[Worcester Foregate Street railway station|Worcester Foregate St]] || local (semi-fast between Birmingham Snow Hill and [[Stourbridge Junction railway station|Stourbridge Junction]]) || 1 || Occasionally extended to [[Great Malvern railway station|Great Malvern]]
|-
|| Dorridge – Kidderminster || local (semi-fast Kidderminster to Birmingham Snow Hill (in this direction only)) || 1 ||
|-
|| Dorridge – Stourbridge Junction || local (semi-fast Birmingham Snow Hill to Stourbridge Junction (in this direction only)) || 1 ||
|-
|| [[Whitlocks End railway station|Whitlocks End]] – Kidderminster || local (semi-fast Kidderminster to Birmingham Snow Hill (in this direction only))|| 1 ||
|-
|| Whitlocks End – Worcester Foregate St/[[Worcester Shrub Hill railway station|Shrub Hill]] || local (semi-fast between Birmingham Snow Hill and Stourbridge Junction)|| 1 || Occasionally extended to Great Malvern
|-
|| Stratford-upon-Avon – Stourbridge Junction || local (semi-fast Birmingham Snow Hill to Stourbridge Junction (in this direction only)) || 1 ||
|-
! colspan="4" style="background:#ffffcc"|Cross Country,<ref>{{cite web |url=http://www.crosscountrytrains.co.uk/SiteImages/Assets/3/South_Coast_to_Manchester_the_North_East_and_Scotland.pdf |title=CrossCountry South Coast – Manchester/North East May 2011 timetable |date=22 May 2011 |access-date=25 June 2011 |archive-url=https://web.archive.org/web/20120323205710/http://www.crosscountrytrains.co.uk/SiteImages/Assets/3/South_Coast_to_Manchester_the_North_East_and_Scotland.pdf |archive-date=23 March 2012 |url-status=dead}}</ref> between Bordesley South Junction/Leamington Spa and [[Aynho Junction]]
|-
|| [[Bournemouth railway station|Bournemouth]] – [[Manchester Piccadilly railway station|Manchester Piccadilly]] || [[Inter-city rail|Inter-city]] || 1 || Calls at Banbury and Leamington Spa
|-
|| [[Reading railway station|Reading]] – [[Newcastle railway station|Newcastle]] || Inter-city || 1  || Calls at Banbury and Leamington Spa
|-
! colspan="4" style="background:#ffffcc"|GWR,<ref>{{cite web |url=http://www.firstgreatwestern.co.uk/Documents/Custom/TTs%20Apr%20%2711/GW11M_TT18_WEB_V1.pdf |title=First Great Western Banbury – Oxford May 2011 timetable |date=22 May 2011 |access-date=25 June 2011 |archive-url=https://web.archive.org/web/20110518165517/http://www.firstgreatwestern.co.uk/Documents/Custom/TTs%20Apr%20%2711/GW11M_TT18_WEB_V1.pdf|archive-date=18 May 2011 |url-status=dead}}</ref> between Banbury and Aynho Junction
|-
|| Oxford – Banbury || local || 1 every 2/3 hrs || Some extended to [[London Paddington]]
|}

===Rolling stock===
Passenger trains are operated by: 
{| class="wikitable"
|-
! colspan="7"  |[[Chiltern Railways]]
|-
|----- bgcolor=#f9f9f9
! rowspan="2" |Class
! rowspan="2" |Image
! rowspan="2" |Type
! colspan="2" |Top speed
! rowspan="2" |Cars per set
! rowspan="2" |Built
|----- bgcolor=#f9f9f9
!mph
!km/h
|-
|[[British Rail Class 165|Class 165/0<br>''Network Turbo'']]
|[[File:165001 B London Marylebone.JPG|115px]]
|[[diesel multiple unit]]
|75
|120
|2 or 3
|1990–1992
|-
|[[British Rail Class 168|Class 168/0 ''Clubman'']]
|[[File:168003 London Marylebone.jpg|115px]]
|Diesel multiple unit
|100
|160
|4
|1998
|-
|Class 168/1 ''Turbostar Clubman''
|[[File:Class168Banbury.jpg|115px]]
|Diesel multiple unit
|100
|160
|3 or 4
|2000
|-
|Class 168/2 ''Turbostar Clubman''
|[[File:Chiltern at Marylebone.jpg|115px]]
|Diesel multiple unit
|100
|160
|3 or 4
|2004
|-
|Class 168/3 ''HybridFlex''
|[[File:Chiltern at Marylebone.jpg|115px]]
|Diesel/battery multiple unit
|100
|160
|3 or 4
|2021
|-
|[[British Rail Class 172|Class 172/1 ''Turbostar'']]<ref>{{cite press release |title=Angel Trains orders 'green trains' for the UK rail market |url=http://www.angeltrains.co.uk/press/release.aspx?Id=692 |date=31 January 2008 |publisher=Angel Trains}} {{Dead link|date=May 2017}}</ref>
|[[File:172104 London Marylebone.jpg|115px]]
|Diesel multiple unit
|100
|160
|2
|2011
|-
|[[British Rail Class 68|Class 68]]
|[[File:Marylebone - DRS 68010.JPG|115px]]
|[[Diesel Locomotive]]
|100
|160
|N/A
|2013–2014
|-
|rowspan=2|[[British Rail Mark 3|Mark 3 Coach]]<ref>{{cite web |title=Passenger Board Annual Report 08/09 |archive-url=https://web.archive.org/web/20091229050940/http://www.chilternrailways.co.uk/downloads/29624.4/passenger-board-report-2008-2009.pdf |url=http://www.chilternrailways.co.uk/downloads/29624.4/passenger-board-report-2008-2009.pdf |archive-date=29 December 2009 |date=24 June 2009 |publisher=Chiltern Railways |url-status=dead}}</ref><ref>{{cite news |title=Coaching Stock Design Contract for Chiltern Railways |url=http://www.railway-technology.com/contractors/signal/delta-rail/press7.html |date=21 July 2009 |work=Railway Technology |access-date=26 June 2011 |archive-date=7 June 2011 |archive-url=https://web.archive.org/web/20110607001220/http://www.railway-technology.com/contractors/signal/delta-rail/press7.html |url-status=dead}}</ref>
|[[File:BR Mk.IIIa TSO No.12604 (8074749189).jpg|115px]]
|[[Passenger car (rail)|Passenger Coach]] 
|125
|200
|N/A
|1975–1984
|-
|[[File:Chiltern DVT Wrexham and Shropshire.JPG|115px]]
|[[Driving Van Trailer]]
|125
|200
|N/A
|1988
|-
! colspan="7"  |[[West Midlands Railway]]
|-
|----- bgcolor=#f9f9f9
! rowspan="2" |Class
! rowspan="2" |Image
! rowspan="2" |Type
! colspan="2" |Top speed
! rowspan="2" |Cars per set
! rowspan="2" |Built
|----- bgcolor=#f9f9f9
!mph
!km/h
|-
|[[British Rail Class 153|Class 153 ''Super Sprinter'']]
|[[File:153365 Nuneaton.jpg|100px]]
|Diesel multiple unit
|{{convert|75|mph|km/h|0|disp=table}}
|1
|1987–1988
|-
|[[British Rail Class 170|Class 170/5 ''Turbostar'']]
|[[File:170506 at Worcester Foregate.jpg|100px]]
|Diesel multiple unit
|{{convert|100|mph|km/h|0|disp=table}}
|2
|1999–2000
|-
|Class 170/6 ''Turbostar''
|[[File:170631 at Shrewsbury - DSC08281.JPG|100px]]
|Diesel multiple unit
|{{convert|100|mph|km/h|0|disp=table}}
|3
|1999–2000
|-
|[[British Rail Class 172|Class 172/2 ''Turbostar'']]
|[[File:LondonMidlandClass172.JPG|100px]]
|Diesel multiple unit
|{{convert|100|mph|km/h|0|disp=table}}
|2
|2011
|-
|Class 172/3 ''Turbostar''
|[[File:172337 Birmingham Moor Street.jpg|100px]]
|Diesel multiple unit
|{{convert|100|mph|km/h|0|disp=table}}
|3
|2011
|-
! colspan="7" |[[CrossCountry]]
|-
|----- bgcolor=#f9f9f9
! rowspan="2" |Class
! rowspan="2" |Image
! rowspan="2" |Type
! colspan="2" |Top speed
! rowspan="2" |Cars per set
! rowspan="2" |Built
|----- bgcolor=#f9f9f9
!mph
!km/h
|-
|[[British Rail Class 220|Class 220 ''Voyager'']]
|[[File:CrossCountry Class 220.jpg|100px]]
|[[Diesel multiple unit#Diesel-electric|Diesel-electric multiple unit]]
|125
|200
|4
|2001
|-
|[[British Rail Class 221|Class 221 ''Super Voyager'']]
|[[File:CrossCountry SuperVoyager.JPG|100px]]
|Diesel-electric multiple unit
|125
|200
|4 or 5
|2001
|-
! colspan="7"  |[[Great Western Railway (train operating company)|Great Western Railway]]
|----- bgcolor=#f9f9f9
! rowspan="2" |Class
! rowspan="2" |Image
! rowspan="2" |Type
! colspan="2" |Top speed
! rowspan="2" |Cars per set
! rowspan="2" |Built
|----- bgcolor=#f9f9f9
!mph
!km/h
|-
|[[British Rail Class 165|Class 165/1 ''Network Turbo'']]
|[[File:165117 at Royal Oak 13-4-07.jpg|100px]]
|Diesel multiple unit
|90
|145
|2 or 3
|1992
|-
|[[British Rail Class 166|Class 166 ''Network Turbo'']]
|[[File:166218 London Paddington.JPG|100px]]
|Diesel multiple unit
|90
|145
|3
|1992–1993
|}

===Connections===
These are available at: 
* [[Birmingham Snow Hill railway station|Birmingham Snow Hill]], to {{stnlnk|Kidderminster}} and [[Worcester Shrub Hill railway station|Worcester]], and [[Midland Metro]] to [[West Bromwich Central tram stop|West Bromwich]] and [[Wolverhampton St George's tram stop|Wolverhampton]].
* [[Birmingham Moor Street railway station|Birmingham Moor Street]], to {{stnlnk|Stratford-upon-Avon}}
* [[Leamington Spa railway station|Leamington Spa]], to Stratford-upon-Avon, {{stnlnk|Coventry}}, {{stnlnk|Birmingham International}}, and The North
* [[Banbury railway station|Banbury]], to {{stnlnk|Oxford}}, [[Reading railway station|Reading]], and {{stnlnk|Southampton Central}}
* [[Princes Risborough railway station|Princes Risborough]], to {{stnlnk|Aylesbury}}
* [[West Ruislip station|West Ruislip]]/[[South Ruislip station|South Ruislip]], to the [[Central line (London Underground)|LU Central line]] to [[Oxford Circus tube station|Oxford Circus]]
* [[Marylebone station|London Marylebone]], to Aylesbury and the [[Bakerloo line|LU Bakerloo line]] to [[Oxford Circus tube station|Oxford Circus]]

Birmingham New Street, the city's main station, is a five-minute walk from Moor Street; [[Baker Street tube station|Baker Street]], where several London Underground lines call, is a five-minute walk from London Marylebone.

==Future==
===Battery/diesel trains===
In September 2021, Class 168/3 ''HybridFlex'' battery/diesel trains were introduced, with lower emissions.<ref>{{cite web |date=22 July 2021 |title=Chiltern's first diesel-battery hybrid train makes passenger debut |url=https://www.railjournal.com/fleet/britains-first-diesel-battery-hybrid-train-makes-passenger-debut/ |website=railjournal.com}}</ref>  The trains operate on batteries, giving zero emissions when in stations or sensitive urban areas. However, the trains were removed from service in September 2023 as the diesel engine emitted high pollutants in stations.<ref>{{cite web |url=https://www.standard.co.uk/business/disappointment-as-chiltern-railways-scraps-hybrid-train-plans-b1105834.html |title=Disappointment as Chiltern Railways scraps hybrid train plans |first=Simon |last=Hunt |date=8 September 2023 |website=Evening Standard |access-date=15 July 2024}}</ref>

===Electrification===
No section of the line is electrified but, in 2010, the then chairman of Chiltern Railways, Adrian Shooter, indicated that electrification was being considered, though not in the immediate future. He added: "We could do some very interesting things with high-acceleration [[electric multiple units]] and possibly some further infrastructure work."<ref name=shooter>{{cite magazine |last=Broadbent |first=Steve |title=Happy Ever After |magazine=[[Rail Magazine]] |issue=643 |date=5 May 2010|page=16 |location=Peterborough}}</ref>

===Other plans===
There are several proposals:
* The restoration of the quadruple track between [[South Ruislip station|South Ruislip]] and [[West Ruislip station|West Ruislip]], allowing trains to call at both stations without blocking the line.{{citation needed|date=December 2012}} Triple track currently exists at West Ruislip, with the up platform loop still in situ, and at South Ruislip, with the [[rail directions|''Down'']] Main through line in situ. This would involve the reconstruction of the ''down'' platform at West Ruislip, the reconstruction of the ''up'' platform at South Ruislip and the demolition of West Ruislip [[signal box]].
* Building of a new combined [[West Hampstead Interchange]], bringing together what are currently three close by, but physically separated stations to allow easy interchange with the [[London Overground]] (Mildmay Line), [[London Underground]] ([[Jubilee line]]) and [[Thameslink and Great Northern|Thameslink]] ([[Thameslink (route)|Thameslink line]]) and Chiltern Railways, with new Metropolitan line platforms possible.<ref>{{cite web |url=http://www.camden.gov.uk/ccm/cms-service/download/asset/?asset_id=564194|title=Planning Framework for West Hampstead Interchange Area Appendix 2 |publisher=London Borough of Camden |date=19 April 2005 |access-date=29 July 2008 |page=25 |archive-url=https://web.archive.org/web/20110611231733/http://www.camden.gov.uk/ccm/cms-service/download/asset/?asset_id=564194|archive-date=11 June 2011|url-status=dead}}</ref>

==References==
{{Reflist|30em}}

==External links==
* [https://web.archive.org/web/20090828064814/http://www.chiltern-evergreen3.co.uk/ Chiltern Railways Evergreen 3 project]

{{Railway lines in London}}
{{Railway lines in South East England}}
{{Railway lines in the East Midlands}}
{{Railway lines in the West Midlands}}
{{Transport in Buckinghamshire}}

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