ConstructioNews
Vol. 35 No. 3 (01-2026)
The Tung Chung Line Extension - Critical Turnout Installation for Track Diversion Works
The Tung Chung Line Extension project is the first to commence construction among several new railway projects. The proposed Tung Chung Line Extension comprises an approximately 1.3 kilometres extension of the existing Tung Chung Line, connecting it to a new station in the Tung Chung West area. Additionally, it involves the construction of a new intermediate Tung Chung East Station, necessitating railway line modifications spanning about 1.2 kilometres between the existing Sunny Bay Station and Tung Chung Station. The primary purpose of the Tung Chung Line Extension is to provide rail services for the Tung Chung New Town Extension. Construction for the two new stations and associated railway sections commenced in May 2023, with an anticipated completion date of 2029.
(I) Construction Works of Tung Chung East Station
The works for the Tung Chung East section of the Tung Chung Line Extension mainly include the construction of the Tung Chung East Station# in the Tung Chung East reclamation area, the construction of a new approximately 1.2 kilometres section of new track, and track diversion works to connect the new station to the existing Tung Chung line track. Part of the track works must be carried out on the operating Tung Chung Line.
The Tung Chung East section has seen notable progress with the completion of structural works for two exits to the north of the station, and the structural works for the station roof, installation of platform screen doors and assembly of two pedestrian bridges connecting the station exits are underway.
Major Track Diversion Works
The works of Tung Chung East Station involve the diversion of the existing 1.2 kilometres of operating track between the existing Sunny Bay Station and Tung Chung Station, including the construction of new railway sections, track bifurcation for connecting the new railway section to the existing tracks, installation of overhead lines as well as modification of part of the equipment of the existing signaling system.
The turnout installation is particularly critical in the track diversion works. Turnouts are important track facilities that allow trains to enter the new railway section. This works needs to be carried out on the operating Tung Chung Line tracks, and includes the following procedures that must be carried out uninterrupted:
• Installation of track components
• Track position adjustment and connection
• Installation of a point machine
• Testing of the signaling system and the various tests before train service resumption
The first and second critical turnout installation was successfully completed in the late night of 26 October 2024, and 19 April 2025, respectively. According to the current plan, the remaining turnouts will be installed between 2026 and 2027.
The turnout installation works are challenging and need to be carried out on the operating Tung Chung Line tracks. To minimise the impact on daily train services and accommodate railway maintenance work after the last train at night, the project and operations teams closely coordinated and planned in detail, breaking down the pre-procedures for installing the turnouts into hundreds of nights over two to three nights a week, within the “golden two hours”. Therefore, on the nights of the critical turnout installations, Tung Chung Line train service only needed to be slightly adjusted, with services between Tung Chung and Sunny Bay stations ending about two hours earlier to carry out the installation which requires a couple of continuous work hours.
To accommodate the new alignment after the Tung Chung East Section diversion, the existing Tung Chung Line tracks need to be gradually adjusted within tight timeframes during non-traffic hours. Track slewing both tracks requires about 300 nights. These procedures include adjusting the tracks’ angle and ballast precisely for comfortable train rides. The team made good use of technology, introducing an Austrian-made tamping machine to accurately detect track positions, adjust tracks, and tamp ballast.
Before installing the turnouts, the team spent about 20 nights in non-traffic hours replacing the original concrete sleepers with synthetic sleepers for turnouts, and co-designed with our design department a temporary welding base plate for the switch to streamline the installation process, shorten the time required, and hence reduce the impact on daily train services.
When formulating a detailed installation plan, each task was arranged with minute-by-minute precision. Rehearsals at the practice ground during the day and on-site drills at night were arranged to ensure preparedness. These enabled the teams to execute the tasks swiftly and accurately, avoiding any impact on passenger service the next day.
(II) Construction of Tung Chung West Station
The works of Tung Chung West section mainly include the construction of an approximately 1.3 kilometres westward extension from the existing railway tunnel of Tung Chung Station, and the construction of a new Tung Chung West Station near Yat Tung Estate, as well as the construction of an emergency egress point at Shun Tung Road. The tunnel between the existing Tung Chung Station and the future Tung Chung West Station will be constructed by Tunnel Boring Machine (TBM). To facilitate the construction, the project team set up a construction site for works including setting up a TBM launching shaft at the end of the existing Tung Chung Line tunnel, i.e., the public open space between the two phases of Tung Chung Crescent.
Prior to the commencement of construction works for the Tung Chung West Section Tunnel, a temporary noise enclosure was erected at the works site between the two phases of Tung Chung Crescent, to minimise any impact of the works on the nearby residents. Construction of the temporary noise enclosure began in the first quarter of 2024, noise mitigation measures were implemented.
Tunnel Construction Works Started
After a series of investigations along the alignment, such as the soil quality and construction space, the project team chose to use Tunnel Boring Machine for the construction of the Tung Chung West Tunnel. The works to be carried out by the TBM are underground, which is a more effective way to minimise the impact of dust and noise.
The TBM will also install the tunnel walls at the same time as the tunnels are being constructed, which is highly efficient. The tunnel walls serve to stabilise the ground level, prevent soil erosion and reduce the potential impact on the adjacent building structures.
The tunnel boring machine’s 16 components were transported in batches from the Tung Chung East barging point to the Shun Tung Road tunnel shaft site for assembly. Transportation of the last two batches was completed in the second quarter of 2025.
The TBM is 100 metres in length, 7.3 metres in height, and has a total weight of 1,000 tonnes. The red cutterhead is the most distinctive feature of the TBM, with 42 sets of cutter discs for excavation as the TBM moves forward. The TBM can drill in different types of rock layers when it is equipped with different cutter heads.
Behind the cutter head is a large body, consisting of different components including the screw conveyor, control room and tunnel wall precast component placement system, where professional engineers control the forward movement of the TBM, pressurisation and depressurisation, installation of the tunnel walls and replacement of the cutter head. While the TBM is drilling, the tunnel wall will be installed at the same time, which greatly improves the efficiency of the project.
Notable Progress
The structural works of Tung Chung East Station are making good progress, with the four turnout installations required for the future track diversion well on schedule.
The Tung Chung Line Extension project comprises the building of two new stations at the Tung Chung East reclamation area and in Tung Chung West near Yat Tung Estate, together with the associated new railway works. While tunnel boring works for the Tung Chung West section is ongoing, the Tung Chung East section has also seen notable progress with the completion of substructure works, and the main structural works for the station platform, concourse and two entrances are underway.
Source of Information and Pictures: Tung Chung Line Extension Website & New Railway Projects Website of MTR Corporation Limited
(I) Construction Works of Tung Chung East Station
The works for the Tung Chung East section of the Tung Chung Line Extension mainly include the construction of the Tung Chung East Station# in the Tung Chung East reclamation area, the construction of a new approximately 1.2 kilometres section of new track, and track diversion works to connect the new station to the existing Tung Chung line track. Part of the track works must be carried out on the operating Tung Chung Line.
The Tung Chung East section has seen notable progress with the completion of structural works for two exits to the north of the station, and the structural works for the station roof, installation of platform screen doors and assembly of two pedestrian bridges connecting the station exits are underway.
Major Track Diversion Works
The works of Tung Chung East Station involve the diversion of the existing 1.2 kilometres of operating track between the existing Sunny Bay Station and Tung Chung Station, including the construction of new railway sections, track bifurcation for connecting the new railway section to the existing tracks, installation of overhead lines as well as modification of part of the equipment of the existing signaling system.
The turnout installation is particularly critical in the track diversion works. Turnouts are important track facilities that allow trains to enter the new railway section. This works needs to be carried out on the operating Tung Chung Line tracks, and includes the following procedures that must be carried out uninterrupted:
• Installation of track components
• Track position adjustment and connection
• Installation of a point machine
• Testing of the signaling system and the various tests before train service resumption
The first and second critical turnout installation was successfully completed in the late night of 26 October 2024, and 19 April 2025, respectively. According to the current plan, the remaining turnouts will be installed between 2026 and 2027.
The turnout installation works are challenging and need to be carried out on the operating Tung Chung Line tracks. To minimise the impact on daily train services and accommodate railway maintenance work after the last train at night, the project and operations teams closely coordinated and planned in detail, breaking down the pre-procedures for installing the turnouts into hundreds of nights over two to three nights a week, within the “golden two hours”. Therefore, on the nights of the critical turnout installations, Tung Chung Line train service only needed to be slightly adjusted, with services between Tung Chung and Sunny Bay stations ending about two hours earlier to carry out the installation which requires a couple of continuous work hours.
To accommodate the new alignment after the Tung Chung East Section diversion, the existing Tung Chung Line tracks need to be gradually adjusted within tight timeframes during non-traffic hours. Track slewing both tracks requires about 300 nights. These procedures include adjusting the tracks’ angle and ballast precisely for comfortable train rides. The team made good use of technology, introducing an Austrian-made tamping machine to accurately detect track positions, adjust tracks, and tamp ballast.
Before installing the turnouts, the team spent about 20 nights in non-traffic hours replacing the original concrete sleepers with synthetic sleepers for turnouts, and co-designed with our design department a temporary welding base plate for the switch to streamline the installation process, shorten the time required, and hence reduce the impact on daily train services.
When formulating a detailed installation plan, each task was arranged with minute-by-minute precision. Rehearsals at the practice ground during the day and on-site drills at night were arranged to ensure preparedness. These enabled the teams to execute the tasks swiftly and accurately, avoiding any impact on passenger service the next day.
(II) Construction of Tung Chung West Station
The works of Tung Chung West section mainly include the construction of an approximately 1.3 kilometres westward extension from the existing railway tunnel of Tung Chung Station, and the construction of a new Tung Chung West Station near Yat Tung Estate, as well as the construction of an emergency egress point at Shun Tung Road. The tunnel between the existing Tung Chung Station and the future Tung Chung West Station will be constructed by Tunnel Boring Machine (TBM). To facilitate the construction, the project team set up a construction site for works including setting up a TBM launching shaft at the end of the existing Tung Chung Line tunnel, i.e., the public open space between the two phases of Tung Chung Crescent.
Prior to the commencement of construction works for the Tung Chung West Section Tunnel, a temporary noise enclosure was erected at the works site between the two phases of Tung Chung Crescent, to minimise any impact of the works on the nearby residents. Construction of the temporary noise enclosure began in the first quarter of 2024, noise mitigation measures were implemented.
Tunnel Construction Works Started
After a series of investigations along the alignment, such as the soil quality and construction space, the project team chose to use Tunnel Boring Machine for the construction of the Tung Chung West Tunnel. The works to be carried out by the TBM are underground, which is a more effective way to minimise the impact of dust and noise.
The TBM will also install the tunnel walls at the same time as the tunnels are being constructed, which is highly efficient. The tunnel walls serve to stabilise the ground level, prevent soil erosion and reduce the potential impact on the adjacent building structures.
The tunnel boring machine’s 16 components were transported in batches from the Tung Chung East barging point to the Shun Tung Road tunnel shaft site for assembly. Transportation of the last two batches was completed in the second quarter of 2025.
The TBM is 100 metres in length, 7.3 metres in height, and has a total weight of 1,000 tonnes. The red cutterhead is the most distinctive feature of the TBM, with 42 sets of cutter discs for excavation as the TBM moves forward. The TBM can drill in different types of rock layers when it is equipped with different cutter heads.
Behind the cutter head is a large body, consisting of different components including the screw conveyor, control room and tunnel wall precast component placement system, where professional engineers control the forward movement of the TBM, pressurisation and depressurisation, installation of the tunnel walls and replacement of the cutter head. While the TBM is drilling, the tunnel wall will be installed at the same time, which greatly improves the efficiency of the project.
Notable Progress
The structural works of Tung Chung East Station are making good progress, with the four turnout installations required for the future track diversion well on schedule.
The Tung Chung Line Extension project comprises the building of two new stations at the Tung Chung East reclamation area and in Tung Chung West near Yat Tung Estate, together with the associated new railway works. While tunnel boring works for the Tung Chung West section is ongoing, the Tung Chung East section has also seen notable progress with the completion of substructure works, and the main structural works for the station platform, concourse and two entrances are underway.
Source of Information and Pictures: Tung Chung Line Extension Website & New Railway Projects Website of MTR Corporation Limited