Accueil » Projets » Marmaray Railway Engineering Project

Marmaray Railway Engineering Project


he Marmaray Project in Turkey represents the first physical rail link between Europe and Asia. It consists of connecting Istanbul’s Asian and European sides through a 76.3 km subway-type railway tunnel under the Bosphorus Strait.

The project includes upgrading the 63 km lines of the commuter train to improve Gebze-Haydarpasa and the Sirkeci-Halkali suburban railway lines, and the 13.6 km submarine rail tunnel with two tracks under the Bosphorus.

With the opening of the tunnel, commuter trains started operating from the Ayrilikçesme station (Asia) to the Kazlicesme station (Europe).


  • The number of passengers: 12M travel by the center of Istanbul every day, 75000 passengers /hour.
  • Length of line: 76.3km of line in total
  • Length of the underwater railway tunnel under the Bosphorus: 13.6km
  • Number of stations: 37
  • Inauguration of the liaison: October 2013 for the 90th anniversary of the Turkish Republic.
  • Total project cost: estimated at $ 4.5 billion.
  • Line type: single phase 25kV, traction power supply system equipped with 36 stations (stops)

The Marmaray project included the construction of a tunnel under the Istanbul Strait. This tunnel is considered the deepest submerged structure in the world, 55m below sea level.

Its length is 13.6 km (8.5 miles) long with 9.8 km of the tunnel drilled, 2.4 km built using cutting and roofing methods and the remaining 1.4 km as a tube tunnel.

The submerged tunnel is connected to the coast by dug tunnels to produce separate holes for each running line, with frequent interval connections for emergency use.

The system also included the modernization of 63 km of existing suburban railway lines, the reconstruction and construction of 37 new three stations. The stations are based on metro-type activities, but are also served by heavy rail trains capable of traveling at 100 km / h with an average speed between stations of 45 km / h. The Marmaray project provides an east-west transportation corridor with connection to Yenkapi at the north-south subway line, also under construction.

Technical characteristics

The traction power supply for the electrification of catenaries for the design, installation, supply, testing of substations traction:

  • 6 x 154kV / 25kV 50Hz
  • 1 x 34.5kV / 25kV 50Hz (temporary station)
  • 5 x 25kV 50Hz, isolation and automation stations with IEC61850 protocol-based systems (standard design for automation electrical substations)

SDCEM provided disconnector switches, load break switches and control & monitoring solutions to EYM Instalaciones for the substation traction project in 2013-2014. SDCEM scope of supply :





Key data

Location Turkey
Industry Railway Electrification
Delivery date 2013-2014
 Network voltage  25 kV
 Rated voltage  52 kV
End-user Turkish State Railways (TCDD)
EPC EYM Instalaciones
Commissioning date 2018