Hanoi Pilot light metro line project - section Nhon-Hanoi railway station

Vietnam

The project for the Hanoi Pilot Light Metro Line 3 is part of the new transport system for the Vietnamese capital. The section that Ghella is working on, which is fully funded by the Asian Development Bank (ADB), is the longest and most important of the nine sections that the whole underground line is divided into. The overall railway network comprises eight lines of the underground and will be completed by 2050.

Situated in the north of Vietnam, Hanoi rises up on a floodplain on the Red River, about 130 kilometres from its mouth. It is called the “city of lakes” because of the numerous bodies of water that can be found there. Over the course of the twentieth century it had a dizzying rate of demographic growth, especially after the end of the war between North and South Vietnam in 1975. The demographic boom brought about a massive process of urbanization and industrialization: today Hanoi is a metropolis with a population of over 8 million, aged an average of 27 years. To these are added commuters who use motorcycles, buses, taxes and bicycles. The underground project is part of the general plan of the Vietnamese Ministry of Transport, which aims to reduce the use of private transport and to improve the urban environment. When it is finally completed, the line will provide transport for 200,000 passengers a day.

The Pilot Light Metro Line 3 is the first line of the Vietnamese capital excavated underground, extending for 12.5 kilometres from Nhon, in the Tay Tuu neighbourhood, flanking Kim Ma Street, in the western district of Nam Tu Liem, as far as Hanoi Station, in one of the city’s most populated areas. It runs for 8.5 kilometres on overhead tracks and 4 kilometres underground, and includes the construction of four underground stations: Kim Ma Station, Cat Linh Station, Van Mieuh Station, and Hanoi Station. The excavation of the stations has already been completed in preparation for the mechanized excavation, which will start early in 2021.

The contract includes the excavation of two twin tunnels, each one 2.6 kilometres long, which will be made using two Tunnel Boring Machines (TBMs), machines capable of excavating tunnels in a mechanized way and in complete safety. TBMs, commonly known as “moles”, excavate the rock with a rotating cutting wheel equipped with cutters. These remove the excavated material, and line the tunnel that was just made by installing prefabricated segments. In order to be able to excavate in a highly urbanized area the TBM Earth Pressure Balance (EPB) was chosen, a model aimed at preventing the collapse of the overlying surface. The moles working beneath Hanoi will be 6.60 metres in diameter.

Line 3 of the Hanoi Metro, also known as Văn Mieu Line (Temple of Literature Line), will be the city’s most used underground network. The project is part of a programme of integrated development for transport in Hanoi, offering a system of urban transport that is safe, efficient, and clean. As a whole, environmental benefits are expected, among which better air quality, a reduction in greenhouse gas emissions, and improvement in the community’s health and safety.

A staff of over 400 workers and technicians are involved in the project, most of whom are locals who will benefit from an important cultural transfer: indeed, one of the things that makes Ghella unique is that it implements engineering and technical competence to guarantee the highest international standards.