Hanoi completes tunneling for four underground stations of 2nd metro line

THE HANOI TIMES — The first Tunnel Boring Machine (TBM) used for the Nhon–Hanoi Station metro line has completed its entire tunneling route, marking a milestone in Vietnam’s urban underground construction.

According to the Hanoi Metropolitan Railway Management Board (MRB), TBM No.1, named Than Toc (Lightning Speed), reached Station S12 on December 1, completing its drive through the project’s first four underground stations.

Starting on July 30, 2024, Than Toc tunneled through a chain of four underground stations, beginning at Station S9 (Kim Ma), passing Stations S10 (Cat Linh) and S11 (Van Mieu) and ending at its final point, Station S12.

This is the first time Hanoi has used a TBM in its densely populated and historically sensitive city center. The journey marks a major step forward in building the nearly 4km underground section of the metro line.

A second TBM, Tao Bao (Bold), is continuing excavation on the remaining tunnel section and is moving toward Station S11. As of December 1, the contractor reported that Package CP03, which includes underground tunnels and stations, had reached more than 72% completion. 

Nguyen Ba Son, Deputy Head of the Hanoi Metropolitan Railway Management Board, said the breakthrough at Station S12 is a historic milestone and reflects the sustained efforts of engineers and construction teams.

“The tunneling was carried out under strict safety protocols and with support from international experts, helping overcome technical challenges. The successful performance of TBM No.1 gives confidence in the progress of TBM No.2,” Son said.

According to Park Young, Project Director for the Hyundai-Ghella joint venture, main contractor for urban railway line of Nhon - Hanoi Station, Hanoi’s geological conditions are complex and the surface environment includes a mix of new and old buildings as well as cultural and historical sites.

"The safe operation of TBM No.1 shows that Vietnamese engineers and contractors are increasingly capable of mastering advanced underground construction technologies," said Park Young.

He noted that the Nhon-Hanoi Station metro line is one of Hanoi’s key transport projects, expected to become a vital artery that helps alleviate congestion, promote public transit and improve urban environmental quality.

"Work on the underground section is being carried out with a focus on safety, quality and maintaining progress toward planned milestones," he said.

The TBMs were custom-designed for the Nhon-Hanoi Station urban railway project. Manufactured by German firm Herrenkecht, each machine stretches over 100 meters, weighs around 850 tons and has a rotating cutting wheel with a diameter of 6.55 meters. The machine is designed to drill 10 meters of tunnel per day.

Hanoi’s second metro line, the Nhon-Hanoi Railway Station route, will run 12.5 kilometers from the Nhon area in Tu Liem ward via Kim Ma Street to Hanoi Railway Station on Le Duan Street.

With a total investment of VND36 trillion (US$1.56 billion), the urban railway will run 8.5 kilometers on elevated tracks through eight stations and the remaining four kilometers underground.