Гонконгтың бұрынғы батыс темір жол желісі

Former Hong Kong railway line
the RTD (Denver, Colorado, U. S.) light rail line known as the West Rail line during construction

The West Rail line was a rapid transit line that formed part of the Mass Transit Railway (MTR) system in Hong Kong until 27 June 2021. Coloured magenta on the MTR map, the line ran from Tuen Mun to Hung Hom, with a total length of , in 37 minutes. and intercity services to Mainland China, although the latter role was ultimately superseded by the Guangzhou–Shenzhen–Hong Kong Express Rail Link Hong Kong section as part of the China Railway High speed network. After KCRC's merger of operations with the MTR Corporation on 2 December 2007, the West Rail line was operated as part of the MTR network. Along with the Ma On Shan line, the line was integrated into the Tuen Ma line in June 2021 upon the completion of Phase 1 of the Sha Tin to Central Link.

A railway to the northwestern New Territories from the urban area in Kowloon was recommended as early as 1978 in a Tuen Mun Transport Study by Scott Wilson Kirkpatrick & Partner; by the early 1990s, the surge of commuter towns in Yuen Long and Tuen Mun had frequently brought road networks to a standstill, as urban populations spilled over to the bedroom communities while keeping their jobs in Kowloon and Hong Kong Island. The 1994 Hong Kong Government Railway Development Strategy report envisaged a domestic passenger service between the Northwestern New Territories (NWNT) and urban Kowloon, a cross boundary passenger service for passengers travelling between Hong Kong and Mainland China, and container freight transport between ports in Mainland China and Hong Kong. The first phase of construction included a double track commuter railway connecting Tuen Mun station and Nam Cheong station in newly reclaimed West Kowloon, at a cost of HK$46.4 billion later reports cite $51.7 billion in money of the day prices.

Originally, the KCRC expected the West Rail to have a daily ridership of about 340,000 upon commissioning and 500,000 by 2011. Actual figures hovered around 100,000 by April 2004, however, and rose to 170,000 by the end of the year following a series of discounts. Frequent breakdowns (by local standards: 24 incidents in 2004 caused a delay of eight minutes or more) led KCRC Chairman Michael Tien to announce that he would consider resigning if service performance failed to improve. Some 30,000 flats were originally planned to be built along the route between 2006 and 2011, only to be put on hold when the property market crashed. The commuter line was built after the new towns in north west New Territories, along with road based transport networks, were nearing completion. Attempts to boost patronage were made by cutting longstanding bus services, which in turn necessitated government compensation to private bus operator Kowloon Motor Bus.

On 16 August 2009, the Kowloon Southern Link from Nam Cheong to East Tsim Sha Tsui station was opened. At the same time, the existing segment between East Tsim Sha Tsui station and Hung Hom station was transferred from the East Rail line to the West Rail line, and both services now terminated in the south and interchanged at Hung Hom.

Like all MTR lines, the West Rail line is grade separated throughout its entire length and includes a combination of underground, at grade, and elevated sections. Running from southeast to northwest, it starts at Hung Hom station at ground level and initially heads southwest into a tunnel and descending underground through East Tsim Sha Tsui and Austin stations (the former having originally being served by the East Rail line, and the track heading northwards through the latter), before returning to ground level (though still fully covered) at Nam Cheong station. The track then runs northwest through a sealed box tunnel just to the north to and under the West Kowloon Highway through Lai Chi Kok Park into Mei Foo station, which has a ground level/underground hybrid design. Bored tunnels traverse densely populated Kwai Chung and under the Tsuen Wan line towards Tsuen Wan West station on reclaimed land, after which a bored rock tunnel, the Tai Lam Tunnel, takes trains through Tai Lam Country Park. The line emerges into open air just south of the train depot at Pat Heung and initially runs at grade, and later on an embankment, as it approaches Kam Sheung Road station. The rest of the line is fully elevated and constructed on a continuous viaduct, running in a westerly direction through the new towns of Yuen Long and turning towards the south at Tin Shui Wai, before taking a bend towards the Tuen Mun River and eventually terminating at Tuen Mun station.

The West Rail line was served by 33 eight car MTR SP1900 EMUs built by a Japanese consortium of Kinki Sharyo and Kawasaki Heavy Industries, of which 22 were originally ordered by KCRC as seven car trains for the initial opening of the line (the same model was ordered in 12 car and 4 car variants for the East Rail and the original Ma On Shan line, respectively). Up to 26 sets run during the morning peak service with a 171 second headway; MTRC specifies capacities of 52 seated and 286 standing passengers per car. They were the only trains in use until March 2020, when a newly built eight car East West line train, manufactured by CRRC Changchun Railway Vehicles, entered service on the line. Both of these models have a maximum running speed of and travel at an average speed of on the West Rail line. Unlike the trains on the East Rail line, there are no first class compartments. All trains are serviced at Pat Heung depot and are equipped with the SelTrac IS moving block signalling system for train protection; this was among the earliest applications of the technology on a high capacity, heavy rail line worldwide. Beginning in January 2016, all 7 car trains were converted to 8 car trains in anticipation of the Sha Tin to Central Link (see ); this was completed in May 2018. During the transition period with both 7 car and 8 car trains in service, passengers had to pay attention to the platform LCD screens and announcements to queue at the right part of the platforms.

At 9:15am on 14 February 2007, a passenger train broke down when one of the voltage transformers mounted on the train roof exploded. This incident occurred in the southbound direction in the tunnel between Kam Sheung Road and Tsuen Wan West, about north of Tsuen Wan West. Around 650 passengers had to evacuate through the dark tunnel to the station, while around 340 people returned to the ground through a ventilation shaft at Chai Wan Kok. Eleven people were sent to hospital. Train services returned to normal after 4 hours. It was suspected that the overheated transformer caused its insulating oil to vaporise, thus causing the explosion. The train borne circuit breaker, which was connected in parallel to the voltage transformer to the train pantograph, was not designed to isolate this kind of fault. After the incident, all SP1900 EMUs had their voltage transformers replaced. The new voltage transformers are German made dry type transformers, which will not catch fire, even if they fail. As an apology, the West Rail was opened for free rides on 21 February 2007, the first working day after the Chinese New Year holiday.

On the night of 21 July 2019, during ongoing protests in the territory, Yuen Long station was stormed by armed men, and 45 people were injured.

Current proposals tabled under the Railway Development Strategy 2014 plan by the Hong Kong Government include the Northern Link, a spur line from Kam Sheung Road station to Lok Ma Chau station and a future Kwu Tung station, both on the Lok Ma Chau Spur Line of the East Rail line; and two new stations on the current West Rail line route in Hung Shui Kiu and Tuen Mun South. Hung Shui Kiu may house 160,000 in a new town, whereas Tuen Mun South is already home to 90,000 residents.