Athens Metro Line 4 has reached a defining construction milestone with the arrival of tunnel boring machine (TBM) “Athena” at the Evangelismos worksite. The breakthrough marks the successful completion of one of the project’s most technically demanding tunnel drives beneath the dense urban fabric of central Athens.

The arrival of “Athena” at Evangelismos represents more than the end of a tunnelling phase—it signals the transition toward the next critical stages of the project, including station structural works, systems installation, track laying, and architectural fit-out.

Engineering achievement beneath the city

Operating deep below some of Athens’ busiest districts, “Athena” excavated and simultaneously lined the tunnel with precast concrete segments, ensuring ground stability while maintaining progress in complex geological and urban conditions.

• Over the course of its drive, the TBM has:
• Excavated more than 5 km of twin-track tunnel
• Installed nearly 3,400 precast concrete lining rings
• Removed approximately 400,000 cubic metres of excavated material
• Advanced safely beneath major roads, utilities, and densely built neighbourhoods

Following the breakthrough, the TBM will be dismantled and removed from the shaft in accordance with manufacturer specifications, allowing construction teams to accelerate follow-on works within the completed tunnel section.

Tender & Award History for Athens Metro Line 4

Early Tendering Phase

The invitation to tender for the construction of the first phase of Athens Metro Line 4 (Alsos Veikou to Goudi) was issued in September 2018 by Attiko Metro S.A., the public authority responsible for the metro network.

During the tender process, multiple consortia were initially shortlisted as potential bidders. In September 2018, three groups were selected to compete for the contract:

• Terna / Vinci / Siemens
• J&P AVAX / Ghella / Alstom
• Aktor / Ansaldo STS / Hitachi Rail Italy

Award of Section A Contract

On 19 October 2020, Attiko Metro’s Tender Committee unsealed the financial offers for this major contract. The competition was based on the most economically advantageous tender, evaluated on technical merit and price.

The AVAX S.A. – Ghella SpA – Alstom Transport S.A. consortium emerged as the lowest bidder with a competitive discount on the base price. Their offer was declared provisionally successful, positioning the consortium to be awarded the project.

Shortly thereafter, on 5 November 2020, the consortium was formally selected as the winner of the tender by Attiko Metro’s Board of Directors, confirming the award for the construction and delivery of the first section of Line 4, valued at an estimated €1.3 billion+ including rolling stock and systems.

Contract Signing

The construction contract for Metro Line 4’s first section (Alsos Veikou – Goudi) was signed on 22 June 2021 between Attiko Metro S.A. and the AVAX – Ghella – Alstom consortium.

The signing ceremony was attended by Greek government officials including the Prime Minister and the Minister of Infrastructure and Transport, underscoring the national strategic significance of the project.

Components of the Award

The awarded contract covers:

• Full civil works for the Line 4 Section A underground tunnels and 15 stations.
• Rail systems, including electrification, signalling, power and communications.
• Rolling stock procurement: 20 fully automated 4-car Metropolis trains supplied by Alstom under the same consortium agreement.
• Construction of a new operations control centre and integration with Athens Metro’s existing network.

Context & Funding

The Line 4 project is one of Greece’s largest infrastructure investments and is part-funded by European Union and national programmes.

Click here for further information on tunnelling projects in Greece. 07/26.