The Trans-Mountain Tunnel: A Historic Feat of Engineering on the China-Bordering Highway

First Tunnel Branch Opened on the Dong Dang – Tra Linh Expressway

Recently, in the territory of Thuy Hung commune, in the heart of Tha An district, cheers and applause erupted from groups of officials, engineers, and workers deep within the mountains after a series of loud explosions, marking the official opening of the right branch of the Dong Khe Tunnel. This is the first tunnel to be completed on the entire Dong Dang – Tra Linh Expressway, three months ahead of schedule.

Responding to the Prime Minister’s call for “beating the sun and rain,” working “3 shifts and 4 crews,” and “working during the day and continuing through the night if necessary,” the project enterprise and contractors mobilized 1,091 personnel, 376 pieces of equipment, and deployed 27 simultaneous construction sites working 24/7, aiming for completion in 2025.

At the Dong Khe Tunnel, to complete the excavation of more than 493 meters of the right branch, the team of engineers and workers overcame numerous geological challenges, achieving an average construction speed of 2.86 md/day.

Mr. Pham Duy Hieu, Deputy General Director of the Deo Ca Corporation, representing the general contractor, shared: “This milestone is a testament to the commendable efforts of all the workers on the project. This achievement not only surpasses the schedule by three months but also brings joy and pride to all of us. The left branch is expected to be completed by early December, marking another significant step forward.”

The right branch of the Dong Khe Tunnel, a highlight of the Dong Dang – Tra Linh Expressway, is the first item to be completed in terms of excavation and reinforcement. Immediately following this milestone, the team of engineers and workers will proceed with the next steps, including foundation excavation, reinforcement, formwork installation for concrete tunnel lining, and installation of the ITS system.

The entire Dong Khe and That Khe Tunnel sections are expected to be substantially completed by June 2025, ensuring the project’s schedule and quality.

The moment the right branch of the Dong Khe Tunnel was cleared was marked by three loud explosions. Officials and workers from both the East and West entrances advanced into the tunnel, illuminated by the faint light of flashlights and the dusty haze of the million-year-old mountain. Through the smoke, the groups of workers gradually recognized each other, cheering and shaking hands in celebration, acknowledging the efforts made to reach this memorable moment.

Mr. Ma Thanh Long, a tunnel digger, could not hide his emotions as he participated in building the first expressway in his hometown of Cao Bang. Holding a small piece of rock he had picked up from the tunnel after the blast, he shared: “I want to take this memento home to keep this special moment alive.”

Like Mr. Long, the other tunnel diggers on the Dong Dang – Tra Linh project shared the same excitement when the final blast rang out. “At that moment, we advanced towards each other from both sides of the tunnel, shaking hands and beaming with joy. It was an indescribable feeling, and all the challenges we faced faded away in that moment of pride,” Mr. Long expressed.

Dong Dang – Tra Linh Expressway Receives Directives from the Prime Minister

Earlier, on November 14, the Prime Minister conducted a field survey and held a meeting, directing that the Dong Dang (Lang Son) – Tra Linh (Cao Bang) Expressway project be completed by 2025, contributing to the connectivity of the expressway from Cao Bang to Ca Mau in the same year.

The Prime Minister emphasized the significance of this expressway in connecting the two provinces, linking the Red River Delta and the capital region with northern mountainous areas, as well as connecting the nation and linking the Cao Bang – Lang Son expressway to Hanoi and the northern and southern expressways to Ca Mau in the south.

The Dong Dang (Lang Son) – Tra Linh (Cao Bang) Expressway project is invested in under the Public-Private Partnership (PPP) model, with a consortium of investors led by the Deo Ca Corporation. The project has a total length of 121 km and is divided into two phases with a total investment of over VND 23,000 billion.

Phase 1 involves the construction of over 93 km with a total investment of VND 14,114 billion, with more than 69% funded by the state budget. Phase 2 will involve the construction of the remaining 28 km.

Upon completion, this expressway will reduce travel time between Cao Bang and Hanoi from 6-7 hours to approximately 3.5 hours.

The Dong Dang – Tra Linh Expressway is expected to open up trade opportunities with China, soon establishing Cao Bang as a gateway connecting the southwestern provinces of China with neighboring provinces of Cao Bang, Lang Son, and Hanoi to Hai Phong, as well as connecting the southern provinces of Vietnam with the provinces of Bac Kan and Thai Nguyen to Hanoi, and linking with Ha Giang, Tuyen Quang, and other northern provinces of Vietnam.

Furthermore, it will form a southern transport route connecting ASEAN to the Guangxi Zhuang Autonomous Region, Chongqing, Sichuan, and Guizhou (China) to Central Asia and Europe. It will also ensure smooth trade, enhance the efficiency of infrastructure investment in general and connectivity in particular.

Additionally, the project will connect the horizontal axes in the network of the national expressway system, maximize the efficiency of completed and ongoing projects, and link economic centers, international border gates, and seaports in Quang Ninh and Hai Phong provinces. It will meet the transportation needs of the northern economic region, create opportunities and momentum for the development of the entire Northeast region, and provide modern and synchronized technical and social infrastructure.