Kwu Tung Station on the East Rail Line is situated in the town centre of the future Kwu Tung North New Development Area, located between the Lok Ma Chau Station and Sheung Shui Station on the East Rail Line. It will be the major public transportation hub in the area. Kwu Tung Station is an underground station and is the first new station in Hong Kong to be built on top of an operating railway tunnel, which involves highly complex construction procedures. Kwu Tung Station commenced construction in September 2023 and is set to be topped out in the fourth quarter of this year with target construction completion maintained in 2027, making it the earliest station to be commissioned in this wave of new railway projects.


Excavating above existing tunnel structure

The challenges for constructing Kwu Tung Station include carrying out works on the operating East Rail Line, such as modifying the existing tunnel for station use while maintaining normal train operations. Before the commencement of the relevant works, the project team needs to first carry out protection works for the existing railway facilities, as well as carefully plan and closely monitor the excavation process given the high groundwater table in the works area to ensure the East Rail Line operation will not be affected.

In addition, in view of the need to keep the existing emergency vehicular access and evacuation routes near the proposed Kwu Tung Station clear, the spaces available for carrying out works, placing construction equipment and project staff access are extremely limited. Also, part of the Kwu Tung Station construction requires works to be carried out during non-traffic hours in the nighttime, which may be less than several hours per night on several nights per week, considering the time needed for the daily inspection and maintenance for operations.

As the tunnel at Kwu Tung Station on the East Rail Line is a box structure that extends approximately 20 metres (about 6-storeys in height) underground, there must be sufficient weight from the soil above the structure to counteract the groundwater buoyancy to maintain the stability of the tunnel structure. A new automated groundwater pressure control system has been adopted. This system automatically detects water pressure and regulates valves based on a pre-set level for more effective and accurate control of groundwater levels. In the 500-metre-long Kwu Tung Station tunnel section, the project team has installed the Automatic Deformation Management System (ADMS) with more than 200 monitoring points tracking the conditions of the tunnel structure in real time.

The new station is constructed using the "cut and cover" construction method, during which the project team is required to excavate and remove the soil above the existing tunnel structure. While excavating, the project team has to install a lateral support system to support the weight of soil on both sides to stabilise the ground, control groundwater levels precisely, as well as conduct continuous monitoring of the condition of the tunnel structure to ensure the operation of existing railway facilities is not affected. After the relevant construction works are completed, the ground will be backfilled to cover the tunnel.

The bulk excavation works commenced in March 2024 and were completed in October in the same year. The project team excavated the soil in three layers to a depth of approximately 10 metres, with the volume of soil removed equivalent to the size of 40 standard swimming pools. During the excavation, 28 metal struts, which weigh 20 tonnes each, were installed laterally to support the weight of the soil on both sides.

After the completion of bulk excavation works, the main construction of the station has commenced, making use of the non-service hours at night for installation of platform screen door and platform modification works etc.


Station structural works

Since the completion of large-scale excavation works, the projects team has been progressively removing the temporary metal struts supporting the surrounding soil during construction. The station structure is rising layer by layer, with construction teams working around the clock to ensure steady progress.

To enhance the efficiency of the structural work, the team utilised cutting-edge construction methods such as Design for Manufacture and Assembly (DfMA) and use of precast components. This allowed them to complete the construction of all floor slabs in an impressive timeframe of less than 300 days, with the final ground-level slab successfully finished this past June.

The completion of the floor slabs is a critical milestone in civil engineering, signifying that the main structural work of the station is now largely complete. The remaining work, including the construction of the station entrances and exits, is also proceeding at full speed in preparation for the official “topping out” in the fourth quarter of this year.


Platform transformation works

The platforms of Kwu Tung Station are located within the operational tunnels of the East Rail Line, with portions of infrastructure laid during the construction of the Lok Ma Chau Spur Line. To advance the project without compromising passenger safety and service of the next day’s trains, the projects team has to make good use of the limited time after train services to perform a series of platform transformation works. This requires precise planning and rigorous execution to transform parts of the existing structure into the Kwu Tung Station platforms, making the work extremely challenging.

To free up space in the relevant tunnel section for the platform modification works, the team successfully relocated approximately 300 metres of the emergency walkway on each side of the East Rail Line tunnels during non-operational hours. Subsequently, a series of trackside components were installed in that space, including the header control boxes that manage the opening and closing of the platform screen doors, as well as the platform fixed panels and platform screen doors. Installation of the platform screen doors on both platforms is expected to be completed by the end of this year.

The box structure located behind the platform screen doors was originally built with about 90 columns to stabilise the tunnel structure, which sits approximately 20 metres deep underground. To create space for platform facilities, the team removed 19 of these columns. The columns, weighing a total of about 60 tons, were then upcycled and transformed into a part of the platform level floor, using their weight to help maintain the stability of the box structure.


Striving towards the 2027 completion target

Station structural work and platform transformation are progressing smoothly with zero disruption to the East Rail Line’s daily operations, and numerous critical milestones have already been achieved. Following the anticipated topping out ceremony in the fourth quarter of this year, the project will shift from civil engineering to the electrical and mechanical (E&M) phase.

The E&M stage will see the installation of essential E&M systems, interior fitting-out, and associated works. A series of testing and commissioning works will then be conducted as the project advances steadily toward its targeted completion in 2027.



Source of Information and Pictures: Northern Link Project and New Railway Projects Website of MTR Corporation Limited