Earlier this year, Elliniko Metro completed a 5.1‑kilometer tunnel as part of the Athens Metro Line 4, Section A project. Working around the clock, Elliniko Metro’s project team advanced a 100‑meter‑long tunnel boring machine (TBM) named Athena through some of the busiest and most historic neighborhoods in Greece’s capital city. The process excavated more than 400,000 cubic meters of material and installed more than 3,000 concrete lining rings to form the tunnel in the TBM’s wake.
As the leader of the project’s technical consultancy team, GISI Consulting Group firm Hill International, Inc. helped plan and execute the tunneling drive in accordance with Elliniko Metro’s requirements.
The TBM’s breakthrough at Evangelismos marked a major milestone on the Section A project, which will deliver an approximately 12.8-kilometer, underground, U-shaped rapid transit alignment from Alsos Veikou through the city center to Goudi, as well as 15 stations and additional tunnels linking the new line with Lines 2 and 3 of the Athens Metro and the train stabling and maintenance yard at Katehaki. Section A is the first phase of the overall Line 4 program, the largest public infrastructure initiative currently underway in Greece.
When complete, the brand-new, nearly 40-kilometer rapid transit line will enhance connections between central Athens and its northern and western suburbs with a reliable, sustainable, and safe public transit option.
Working in collaboration with technical consultancy partners NAMA Consulting and Concept, Hill is supporting the project by providing technical and procedural expertise across the project life cycle. For the new tunnel, Hill’s subject matter experts helped Elliniko Metro manage the multitude of technical interfaces involved in designing, excavating, and constructing the tunnel to overcome challenges associated with the city’s geotechnical conditions and dense network of underground infrastructure. This involved continuous coordination with Elliniko Metro, public agencies, consultants, contractors, and other stakeholders during planning and throughout the tunneling process. Hill’s timely inputs reduced the risk of quality and safety issues and contributed to the completion of the tunneling drive as planned.
“We are proud to support the expansion of the Athens Metro, one of the most significant public works underway in all of Europe,” says Hill President, Europe Manolis Sigalas. “The project’s recent tunneling milestone is proof of the team’s well-coordinated efforts and our shared commitment to delivering long-term value for the city. We look forward to maintaining the momentum with our client, Elliniko Metro, and our project partners. Congratulations to Elliniko Metro, our outstanding staff, the AVAX–Ghella–Alstom construction consortium, and everyone else involved with this important project!”
GISI Consulting Group CEO Derek Amidon says: “With Athena’s successful breakthrough, Athens moves one step closer to an enhanced public transit network system that will shape mobility for generations. We’re committed to helping public agencies around the world deliver a more sustainable, resilient future through well-planned, well-executed infrastructure projects like this one.”
Hill International provides program, project, and construction management and advisory services for clients in a range of sectors undertaking major construction projects across the world. Hill is the 3rd largest project and construction management firm in the U.S., as featured in Building Design + Construction magazine. Hill is also ranked as the 8th largest overall U.S. construction management firm by Engineering News-Record. The team has participated in more than 90,000 project assignments with a total construction value of over $1 trillion, and operates in more than 100 offices across 42 countries.