Marmaray Commuter Railway CR3 Contract

Marmaray commuter railway project, constructed by Kolin - Kalyon - Cengiz Joint Venture, was tendered by the department of Infrastructure Works of Ministry of Transport, Maritime Affairs and Communications.

The project is currently the biggest transportation project of the world. The main purpose of the project is to provide a new, high-capacity railway system connecting Halkali at the European side to Gebze at the Asian side in Istanbul which is a fast-growing mega city, leading an increased demand for better transportation system.

Marmaray CR3 Contract covered the upgrading of existing 63 km long railway on both Asian and European shores to connect with the 14 km Bosporus tube crossing, creating a total of 77 km long cross-city commuter corridor connecting Gebze and Halkali. The CR3 contract also covered three new underground stations, 37 aboveground stations (renovation), operation control center, transformer buildings, ateliers, maintenance facilities, a new railway, existing railways (renovation), new electrical and mechanical systems and procurement of modern railway vehicles.

Within the scope of the project, Prota’s services include;

  • Track-way Alignment Engineering and Railway Design
  • Architectural and Finishing Works Design
  • Structural, Geotechnical and Tunnel Design
  • Electrical and Electromechanical System Design
  • Mechanical Engineering Design
  • Fire Safety Engineering and Control System Design
  • Emergency Exit and Ventilation Simulation
  • Acoustic and Vibration Design
  • Traffic Plan and Landscape Design
  • OCS and Traction Force Design
  • Infrastructure Evaluation and Displacement Studies
  • Excavation Support System Design
  • Design of Bridges, Tunnels, Underpasses, Culverts and Engineering Structures
  • Design of Storage Areas and Maintenance Facilities
  • Demolition and Dismantling Design


  • LocationIstanbul, Turkey
  • ClientKolin - Kalyon - Cengiz Joint Venture
  • Total Length77 km
  • Term of Contract2012 - 2018