|Service type||Commuter rail|
|Locale||Sydney, New South Wales|
|Current operator(s)||Sydney Trains|
|Line used||Richmond railway line
Main Western railway line
Main Southern railway line
|Rolling stock||Sydney Trains K, S and C sets|
|Track gauge||1,435 mm (4 ft 8 1⁄2 in) standard gauge|
The Cumberland Line (numbered T5, coloured magenta) is a commuter rail line operated by Sydney Trains in Sydney, New South Wales, Australia. It connects Schofields and Campbelltown stations in the western suburbs. The line opened in 1996, following the construction of a 'Y-link' track between Harris Park and Merrylands stations. The intention of this link was to allow direct services to operate from Liverpool and Campbelltown to Parramatta and Blacktown without requiring a change of trains at Granville. The line takes its name from the Cumberland Plain on which much of Western Sydney was built.
Upon its opening in 1996, the line had a regular half-hourly service in each direction consisting of 38 journeys per day. Subsequent timetables saw its services significantly reduced to the point of running only during weekday peak hours, and from 2005 to 2013 the line only ran in one direction at a time: two services ran in the morning peak from Campbelltown towards Blacktown and three services ran in the opposite direction in the evening. Some services operated to or from Quakers Hill or Schofields on the Richmond line, but the line's official terminus on network maps and other material remained at Blacktown.
Prior to the Y-Link's opening, passengers travelling between the Western and South lines were required to change trains at Granville. With the reduction in services to peak hours only, this travelling strategy was resumed by most commuters.
In 2006, the then-Iemma Labor Government's NSW State Plan committed to re-introduce a regular half-hourly service to the Cumberland line during 2007 "subject to detailed timetable and train planning... and fleet delivery, availability and rostering". A CityRail news release on 15 December confirmed this intention, based on the gradual introduction of the then-new OSCAR (H set) trains, which would displace outer suburban Tangara G sets; the latter trains then reassigned to suburban service. This promise was not delivered, and the Cumberland Line remained a peak-hour-only service with 4 car trains.
Daytime half-hourly services were re-introduced on 21 October 2013. Services finish in the early evening and do not operate on weekends. At this time the line was also officially extended to Schofields, where most northbound services terminate.
The service also occasionally operates on weekends if trackwork affects the Western and South lines, particularly between Granville and Strathfield. Services from Glenfield and Liverpool are diverted to the Western Line and proceed beyond Blacktown, to either Penrith or Richmond, and vice versa. In the extremely rare circumstances, South line trains may divert to Parramatta, terminate there then reverse back to Granville and continue its trip as per the timetable.
During 2017, Cumberland Line services will be modified to no longer travel to and from Campbelltown, instead starting and terminating at Leppington. Combined with changes to the Airport, Inner West & South Line, this means commuters will need to change trains to travel from south of Glenfield to north of Glenfield or vice versa. The changes will also see late night and weekend services introduced on the Cumberland Line. 
The following chart shows the relative patronage of Sydney Trains' seven lines in the 2016-17 financial year.
Description of route
Physically, the line consists of the Richmond railway line from Schofields to Blacktown, the Main Western Line from Blacktown station to Harris Park, the 'Y Link' as described below, the "Old Main South" between Merrylands and Cabramatta, and the Main South Line between Cabramatta and Campbelltown.
The 'Y-link' was opened in 1996 as part of former Prime Minister Paul Keating's 'Building Better Cities' programme in recognition of Parramatta's place as the capital of Sydney's west. It cost $80 million to construct, and required the construction of a little over one kilometre of new track and no new stations. This track consists of the creation of a triangular junction at the junction of the 'Old Main South' and the 'Main Western Line by laying track between Merrylands and Harris Park stations. The work included a new flyover of the 'Up Old Main South' over these new tracks.
Cumberland Line stations
|Name||Code||Railway line||Serving Suburbs||Other lines|
|Schofields - Campbelltown|
|Schofields||SFS||Richmond||Schofields||■ North Shore, Northern & Western Line|
|Quakers Hill||QKH||Richmond||Quakers Hill|
|Blacktown||BAK||Richmond||Blacktown||■ North Shore, Northern & Western Line
|Seven Hills||SEV||Main Western||Seven Hills||■ North Shore, Northern & Western Line|
|Pendle Hill||PDH||Main Western||Pendle Hill|
|Westmead||WMD||Main Western||Westmead||■ North Shore, Northern & Western Line
|Harris Park||HRK||Main Western||Harris Park||■ North Shore, Northern & Western Line|
|Merrylands||MLN||Old Main South||Merrylands||■ Airport, Inner West & South Line|
|Guildford||GUD||Old Main South||Guildford|
|Yennora||YNR||Old Main South||Yennora|
|Fairfield||FFL||Old Main South||Fairfield|
|Canley Vale||CVE||Old Main South||Canley Vale|
|Cabramatta||CTT||Main South||Cabramatta||■ Airport, Inner West & South Line
■ Bankstown Line
|Warwick Farm||WKF||Main South||Warwick Farm|
|Casula||CSL||Main South||Casula||■ Airport, Inner West & South Line|
|Macquarie Fields||MQF||Main South||Macquarie Fields|
|Campbelltown||CAM||Main South||Campbelltown||■ Airport, Inner West & South Line
- New South Wales Government (2006). NSW State Plan: Appendices. Archived from the original on 23 October 2007. Retrieved 3 November 2011.
- Rail Corporation New South Wales (2006). The first Oscars are out and about. Press release. Retrieved 3 November 2011.
- Barr, Eliza (27 February 217). "Southwest Sydney train service to increase with new peak hour trains and north-south connection from Leppington to Parramatta and Blacktown". The Daily Telegraph. Retrieved 27 February 2017. Check date values in:
- O'Sullivan, Matt (27 February 2017). "Decision on rail link to new Sydney airport 'many years off', Transport Minister Andrew Constance says". Sydney Morning Herald. Retrieved 27 February 2017.
- Transport for NSW (27 February 2017), "More Trains, More Services for South Western Sydney" Retrieved 27 February 2017
- "CityRail: Have times changed?". Railway Digest, November 2005. ARHS NSW Division.
- - Sydney Trains timetable - Campbelltown to Schofields
- - Sydney Trains timetable - Schofields to Campbelltown