The Athens Metro Line 4 project, the largest public infrastructure undertaking in Greece, is steadily moving towards its final phase. Despite initial delays in the original schedule, the two tunnel boring machines (TBMs) have already excavated more than 7 kilometers of tunnels, demonstrating significant advancement in the construction.
Tunnel Boring Machines Drive Progress
The journey of the TBMs beneath Athens continues relentlessly as part of the new Metro Line 4 construction. According to reports, the ‘Niki’ TBM has reached Kypseli Station, having already excavated over 2.6 kilometers of underground tunnel. Kypseli Station is anticipated to be one of the busiest on Line 4 due to the high population density of the area. The ‘Niki’ TBM, which commenced its journey from Veikou Shaft, has already passed through Alsos Veikou, Galatsi, and Helikonos stations.
Following essential technical maintenance, the ‘Niki’ TBM will proceed to the next station, Dikastiria (Courts), where it is expected to arrive by the end of February 2026. Subsequently, its route includes Alexandras, Exarcheia, Akadimia, and Kolonaki stations, with Evangelismos as its final destination by the end of 2026.
‘Athena’ TBM Nears Completion
Simultaneously, the second TBM, ‘Athena,’ has already covered 4.5 kilometers of its total 5.7-kilometer route. It has passed through Goudi, Zografou, Ilisia, and Panepistimioupoli stations, and is now in its final segment. After completing excavation at Kaisariani Station, it is heading towards Evangelismos, where it will be disassembled and removed from the project. In total, the two TBMs have excavated more than 7 kilometers of the new 12.8-kilometer ‘orange’ line.
It is worth noting that the consortium of ABAX S.A. – GHELLA SpA – ALSTOM TRANSPORT S.A., responsible for the project, procured both TBMs brand new from Germany. The machines started from opposite ends of the line, with Evangelismos Station serving as the common exit point.
In parallel, conventional mechanical means are being used to construct underground tunnels beneath Veikou Avenue and Katechaki Avenue, as well as to excavate the platform tunnel at Kolonaki Station.
Station Construction and Challenges
Construction work is currently underway at 11 of the 15 stations on Line 4, including Alsos Veikou, Galatsi, Helikonos, Kypseli, Dikastiria, Alexandras, Akadimia, Kolonaki, Kaisariani, Ilisia, and Zografou. Excavation is also in full swing at the Vivliothiki and Evangelismos shafts, along with the New Operation Control Center in Sepolia.
Kolonaki and Alsos Veikou stations are in a more advanced stage, with main construction having already commenced. Station excavations are also progressing at Galatsi, Dikastiria, Alexandras, Akadimia, and Kaisariani.
Regarding the remaining four stations: the Exarcheia construction site was recently handed over, requiring necessary installations. At Evangelismos, an appeal concerning Rizari Park is pending. Archaeological research continues at Panepistimioupoli, and at Goudi, the study is being revised due to the discovery of an unmapped EYDAP (Athens Water Supply and Sewerage Company) pipeline.
Greece’s Largest Public Project
Athens Metro Line 4 represents the largest purely public project in Greece, with a budget approaching 1.8 billion euros (including VAT). Funding began under the NSRF (National Strategic Reference Framework) 2014-2020 and continues into the NSRF 2021-2027.
For Elliniko Metro, this project is its biggest challenge, as its implementation has faced significant technical and institutional difficulties. Although initially slated for completion by the end of 2029, the timeline has shifted, with new official milestones awaited.
The new line will operate with a fully automated system, following the model of the Thessaloniki Metro, featuring platform screen doors at stations and driverless trains. According to studies, it will be able to serve up to 340,000 passengers daily, with train frequencies as low as every 90 seconds during peak hours.
Its operation is expected to contribute decisively to alleviating traffic congestion, as seven stations are located within the Municipality of Athens, while the others serve densely populated areas such as Galatsi, Kaisariani, and Zografou.
