Location Athens, Greece
Client Attiko Metro S.A.
Services Program Management
Project Value €5.3 billion
Hill International is providing program management support to Attiko Metro S.A. for current and future metro and tramway projects in the Attica Region. Hill provides expert input and advice to support Attiko Metro at every stage of project execution, including design, cost consulting, tendering, construction, testing, and commissioning.
One of the key projects in which Hill International is providing specialized consultancy services is the Athens Metro Line 4, Section A. Line 4 is a groundbreaking infrastructure undertaking that will connect the Northwest of Athens to the city center and other vital locations. Section A, known as Alsos Veikou – Goudi, spans approximately 12.8 kilometers and includes a tunnel linking Line 4 with Lines 2 and 3, as well as an access tunnel to the train stabling and maintenance yard at Katehaki. The project, with a budget exceeding €1.5 B, encompasses the construction of 15 underground stations and 9 intermediate and/or terminal shafts.
The underground work for Line 4 Section A is extensive, with complex geological formations such as Athens Schist, Sandstone-Marl Series, Ultrabasic Rocks, Crest Limestone, and Alepovouni Formation. The main tunnel, constructed to the standard Athens diameter observed in Lines 2 and 3, will be double-tracked with an internal diameter of approximately 8.5 meters and an external diameter of approximately 9.5 meters (31.17 feet). The excavation of the tunnels will be performed using state-of-the-art earth pressure balance tunnel boring machines (EPB-TBMs) equipped with advanced technology to handle the anticipated geological, hydrogeological, and geotechnical conditions.
Athens Line 4 Section A introduces a range of innovative features that distinguish it from other underground metropolitan systems of similar scale. To overcome the challenges posed by limited above-ground space and alignment, the project includes underground stabling sheds, maintenance tracks, a new Operations Control Center (OCC) building in the existing Sepolia Depot, and an Emergency Control Center (ECC) located in the GNA shaft. Moreover, the system will operate 20 fully automated 4-car trains without the need for drivers or attendants. The implementation of advanced Communication-Based Train Control (CBTC) technology enables an operational headway of 90 seconds. Energy-saving measures are also incorporated, including the recovery of energy generated during train braking, which is fed back into the city’s high-voltage network if not utilized by other accelerating trains, resulting in improved overall energy efficiency.
Hill is also supporting commissioning and closing out phase of Athens Metro Line 3 extension to Piraeus the Athens Tram extension projects, the production of tender designs and specifications for the new extensions of Line 2 of Athens Metro, and the procurement of a new series of metro rolling stock.