Tuen Ma line
The Tuen Ma line is a commuter rail / rapid transit line that forms part of the Mass Transit Railway system in Hong Kong. It is in length, making it the longest line of the MTR network. It has a total of 27 stations, more than any other in the MTR system.
The Tuen Ma line is formed by a merger of two former MTR lines, the West Rail line and the Ma On Shan line via a new stretch of mostly underground railway known as the "Tai Wai to Hung Hom section" of the Sha Tin to Central Link project. It consists of of track and six new intermediate stations. The Tai Wai to Kai Tak section opened on 14 February 2020, while the Kai Tak to Hung Hom section opened on 27 June 2021, thereby completing the line.
During the planning and construction phase, this line was referred to as the "East West Corridor". On 25 May 2018, the operational name "Tuen Ma line" was confirmed by the MTR Corporation, reflecting the names of Tuen Mun and Ma On Shan, Tuen Mun being the terminal of the West Rail line and Ma On Shan being the namesake of the Ma On Shan Line. The full journey time is about 73 minutes.
Overview
The 56.2 kilometre long line starts at Tuen Mun station, Tuen Mun and ends at in Wu Kai Sha, Ma On Shan. There are ten interchange stations: and with the ; and with the ; with the ; with the ; Yuen Long, Tin Shui Wai, Siu Hong and Tuen Mun which connects to the Light Rail. The line has two maintenance depots at Tai Wai and Pat Heung.Like all MTR lines, the Tuen Ma line is entirely grade separated. It is mainly underground in the urban sections of Kowloon and Tsuen Wan, and at-grade or elevated in the rest of the New Territories.
Most of the original Ma On Shan line is built on a viaduct on a rail reservation that existed from the outset of the development of Ma On Shan New Town. However, the section between and is at ground level, located between the carriageways of the Tate's Cairn Highway, along with the section between Tai Wai to, which is also partially on an embankment running parallel with the. The line then enters Lion Rock Tunnel, which takes trains under Lion Rock Country Park. It continues underground through Diamond Hill station and Kowloon City before emerging into open air near Hung Hom station at ground level.
After Hung Hom, the line descends underground and around southern Kowloon Peninsula through and stations, before returning to ground level at Nam Cheong station. The line then continues northwest through a sealed box tunnel just to the north of and under the West Kowloon Highway through Lai Chi Kok Park into Mei Foo station. Bored tunnels traverse the densely populated Kwai Chung and under the Tsuen Wan line towards Tsuen Wan West station. It continues through a 5.5 km bored rock tunnel, the Tai Lam Tunnel, that takes trains through Tai Lam Country Park.
The line then emerges from the tunnel 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, then turns towards the south at Tin Shui Wai and continuing along the Tuen Mun River and eventually terminating at Tuen Mun station.
Construction methods predominantly include tunnel boring machines and cut-and-cover, though the Lion Rock Tunnel between Hin Keng and the Ma Chai Hang Recreation Ground was constructed using the drill-and-blast method.
While road and rail traffic in Hong Kong move on the left, the eastern section of the Tuen Ma line is an exception, as trains move on the right between Sung Wong Toi and Wu Kai Sha. This allows the southbound tracks of this line and the East Rail Line to run opposite each other at Tai Wai, facilitating cross-platform interchange there. This design was to speed up southbound passenger interchange between the East Rail line and Tuen Ma line during the morning commute.
Right-hand running is maintained as far as Sung Wong Toi, before the line goes into a stacked formation at To Kwa Wan, which has a split platform layout to allow the tracks to switch sides. Left-hand running is then used on the remainder section of the line.
As the section of the former Ma One Shan line opened as part of the KCR system, there are no ticket gates between the Ma On Shan Rail and East Rail platforms at Tai Wai. A trip between either lines counted as a single trip. There was no direct connection between these two lines and the West Rail while they were part of the KCR network.
Rolling stock
For much of its existence, the Ma On Shan line was, in the Hong Kong context, classified as a medium-capacity system. However, it is capable of passenger volumes of up to 32,000 passengers per hour per direction, which is comparable to the passenger capacity of a full rapid transit or "metro" system. Furthermore, the line has been upgraded to the standard of a full-capacity system in anticipation of the Sha Tin to Central Link, which will extend it to the heart of Kowloon and result in a merger with the full-capacity West Rail line.KCRC initially ordered 18 sets of 4-car SP1950 trains, built by Kinki Sharyo, running on the Ma On Shan line; they have all since been converted to eight cars. The train is the same model as the SP1900 sets used on the East Rail and West Rail lines, which runs on those lines with twelve-car and eight-car configurations respectively. They were the only trains in use until March 2017, when newly built eight-car Tuen Ma line trains, manufactured by CRRC Changchun Railway Vehicles, entered service on the Ma On Shan line. Both of these models have a maximum running speed of, but only reach a maximum service speed of on the long section between Kam Sheung Road and Tsuen Wan West stations. Unlike the trains on the East Rail line, there are no first-class compartments. All trains were serviced at Tai Wai depot and are equipped with the SelTrac IS moving-block signalling system for train protection, with provision for upgrading to the radio-based SelTrac CBTC at a later stage to increase capacity.
The first two converted 8-car SP1900 trains were introduced to the Ma On Shan line on 15 January 2017. During the transition period with both 4-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. Since December 2017, the Ma On Shan line has been run fully by 8-car trains and all stations retrofitted with automatic platform gates identical to those installed at elevated stations on MTR's other lines.
The former West Rail line was served by 33 eight-car SP1900 trains built by a Japanese consortium of Itochu, 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. 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. Beginning in January 2016, all 7-car trains on the former West Rail line were converted to 8-car trains in anticipation of the Sha Tin to Central Link; 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. They were the only trains in use on the line until March 2020, when a newly built eight-car EMU, manufactured by CRRC Changchun Railway Vehicles, entered service on the line.
History
Before the merger of the two major Hong Kong railway operators, the MTR Corporation and the Kowloon-Canton Railway Corporation rail networks in 2007, both the West Rail and the Ma On Shan Rail were operated by KCRC. Both railways were envisaged to be extended in the near future and platforms on the Ma On Shan line were built with reserved structures for extension at a later date.Both MTRC and KCRC independently submitted their own proposals to the Hong Kong government for developing the Sha Tin to Central Link by extending their own existing networks. After numerous revisions of their proposals, the government eventually approved the scheme by KCRC, which involved joining the West Rail and the Ma On Shan Rail via the Wong Tai Sin and Kowloon City districts, and extending East Rail line to Hong Kong Island's central business district.
After the 2007 network merger, operations of all transport services of the KCRC were leased to the MTRC for 50 years. The MTRC also rebranded the three commuter railways to East Rail line, West Rail line and Ma On Shan linetts like their own railways. Subsequently, the approved SCL schemes fall into the hands of the MTRC.
The construction of East West Corridor, which largely followed an alignment proposed by the MTRC in the 1970s as the East Kowloon line and later shelved, began in August 2016. At the time, it was unclear how MTRC would name the new lines or whether they would retain the provisional names "East West Corridor" and "North South Corridor"; the word "corridor" would set a precedent in the naming convention of MTR lines. Speculation of a "East West Line" arose when a photograph of an info plate printed with "EWL" at Ho Man Tin station while it was under construction surfaced. The plate was removed before the opening of the station that year as part of the Kwun Tong line extension to Whampoa. MTRC eventually announced on 25 May 2018 that the operational name was the Tuen Ma line.
Construction defects and delay
The Tuen Ma line was planned to be fully operational in 2019, but after the newly built platforms at Hung Hom station failed a safety inspection which occurred between December 2018 and January 2019, its full opening was postponed by about two years.The head contractor of the SCL construction, Leighton Asia, subsidiary of the CIMIC Group, was accused of covering up construction defects until a whistleblower from a subcontractor leaked photo evidence to the press. This led to more thorough investigations, hearings and inspections behind the set concrete for assessing if it would require demolition and rebuilding the structure from scratch. The Hong Kong government also expressed disappointment in the MTRC executives for their incompetent supervision.
Michael Tien, former KCRC chairman, suggested that it was technically feasible to have the Ma On Shan line be initially extended from Tai Wai to Diamond Hill station instead of delaying the opening of the entire line. This has the advantage of spreading the Kowloon bound traffic between Tai Wai and Kowloon Tong stations of the East Rail Line, which is overcrowded during peak hours. However, the then MTRC chairman, Frederick Ma, insisted that they aimed at inaugurating the whole line in mid-2019 to avoid the extra resources required for operating the line in separate phases.
On 18 July 2019, the Transport and Housing Bureau announced that the Tuen Ma line would open in two phases. On 14 February 2020, the Ma On Shan Line was extended from Tai Wai station to Kai Tak station because the latter has a crossover track which permits the operation of the station as a terminus. The extension, named Tuen Ma line Phase 1, was expected to alleviate significant congestion on the East Rail line between Tai Wai and Kowloon Tong stations in preparation for the shortening of trainsets as part of preparatory works for the cross-harbour extension of that line. The remaining section of the Tuen Ma line, from Kai Tak to Hung Hom, opened on 27 June 2021.