After more than six months of excavation, the tunnel boring machine (TBM) has officially reached Cat Linh Station (S10) as part of the Nhon – Hanoi Railway Station metro project.

The TBM began its journey from Kim Ma Station (S9) on July 30, 2024, as part of Contract Package CP03, which covers the construction of underground stations and tunnels. Over the past six months, it has safely excavated and installed tunnel linings across a 1,338-meter stretch, culminating at Cat Linh Station (S10).

According to Nguyen Ba Son, Deputy Head of the Hanoi Metropolitan Railway Management Board (MRB), a second TBM began operations from Kim Ma Station on February 3, 2025. Both machines are expected to complete all tunneling work by the end of 2025.

Once excavation reaches Hanoi Railway Station (S12), the TBM’s cutterhead will be dismantled at that location, while supporting equipment will be withdrawn through Kim Ma Station (S9).

Son highlighted that the TBM reaching Cat Linh Station is a critical milestone for the project, bringing it closer to completing the underground section. As of March 2, 2025, overall progress on Contract Package CP03 -which includes tunnels and underground stations - has reached 55.38% completion.

The Hanoi Metropolitan Railway Management Board has reaffirmed its commitment to collaborating with all stakeholders to accelerate construction and put the entire metro system into operation as soon as possible.

According to the current timeline, the underground section will be completed in 2027, allowing for the full operation of the Nhon – Hanoi Railway Station metro line.

The project is expected to redefine Hanoi’s public transport system, enhance connectivity across the city, and contribute to sustainable urban development.

The TBMs used for this project were custom-built for the Hanoi Metro’s Line 3, specifically designed to handle the capital’s geological conditions.

Each TBM measures over 100 meters in length and weighs approximately 850 tons. More than 150 engineers and workers are involved in the tunneling process.

The TBMs operate in a fully enclosed system, with a maximum drilling speed of 60mm per minute. The machine immediately installs tunnel linings using a robotic arm after excavation.

The tunnel lining process takes 30–35 minutes per segment, with each segment consisting of six pre-cast concrete pieces. This cycle of excavation and tunnel reinforcement continues seamlessly.

The Nhon – Hanoi Railway Station metro line spans 12.5 kilometers, featuring eight elevated stations and four underground stations.

The elevated section from Nhon to Cau Giay covers 8.5 kilometers, while the underground section from Cau Giay to Hanoi Railway Station extends 4 kilometers.

Construction of the project began in 2009, with the elevated section opening for operation in 2024.

By 2030, Hanoi plans to develop a 10-line metro system covering 417 kilometers, including 342 kilometers of elevated tracks and 75 kilometers of underground tunnels. Currently, only the Cat Linh – Ha Dong line (13 kilometers) is operational, having taken 10 years to complete.

The Nhon – Hanoi elevated section (8.5 kilometers) was completed after 15 years, while the remaining 4-kilometer underground segment is expected to be operational by 2027.

The other eight planned metro lines have yet to begin construction.

N. Huyen