TERRATEC reports continued progress on the South Section of Bucharest’s Metro Line 6, where its refurbished 6.39m-diameter EPB TBM has advanced beyond the future Gara Băneasa station and reached roughly the halfway point of the 6.6km twin-tunnel drive.
The South Section, running from 1 Mai to Tokyo, is being delivered for network operator Metrorex by the Alsim Alarko–Makyol Joint Venture, which was awarded the contract in March 2022.
Metro Line 6 will extend 14.2km through twin tunnels and 12 new stations, linking Gara de Nord in central Bucharest with Henri Coandă International Airport. The South Section includes six stations: 1 Mai, Pajura, Expoziției, Băneasa, Washington and Tokyo.
Since launching in April 2025, the TBM has encountered a challenging mix of sand, clay, silt and gravel, along with a shallow water table and overburden as shallow as 10m in places.
One of the most technically sensitive sections took the machine beneath Herăstrău Lake, where the alignment passed within 2.5m of an adjacent tunnel and close to the foundations of a 1930s bridge. Careful control of face pressure enabled the TBM to pass without disturbing either structure.
TERRATEC’s field engineers have supported the machine throughout the drive, including a mid-drive cutterhead inspection and tool change near the Tokyo station launch point. The team replaced disc cutters with rippers to suit the changing ground conditions.
The TBM’s refurbishment before the project, based on its operating history, has also been central to its performance on the constrained urban alignment.
The joint venture is now preparing for higher groundwater flows in the remaining sections. Working with TERRATEC, it has introduced additional pressurised air at the cutterhead to help manage water ingress.
The final stretch will take the TBM to within 3.5m of the existing M4 tunnels as it connects beneath the existing 1 Mai station, requiring significant ground improvement works.
Civil works on the South Section remain scheduled for completion in 2027, with the full Metro Line 6 route to Henri Coandă International Airport targeted to open in 2028.
