According to the project management board, the progress of contract package CP03 for the underground section and stations of the metro line is 43.3 percent.

The main contractor is the joint venture Hyundai & Ghella (HGU), while FECON JSC is in charge of tunnel boring.

According to FECON deputy general director Nguyen Quoc Bao, the tunnel construction technology using TBMs on Metro Line 3 is among the most advanced technologies in the world.

These Earth Pressure Balance (EPB) machines also suit the city’s mixed soil geological conditions.

Alongside the tunnels, other elements of the underground section such as lowering slopes, underground stations, garages and transition lanes are also under construction.

Construction on the underground section of Hanoi Metro Line 3 is expected to be completed in 2027. The entire line is planned to be functional shortly after.

According to the blueprint, Metro Line 3 measures 12.5km in length with eight elevated and four underground stations.