RAIL CASE STUDY: Marmaray tunnel in Turkey

Safety Assessment and inspection of the Marmaray Tunnel CONNECTING TWO CONTINENTS

FACTS AT A GLANCE

What was the challenge?

The Marmaray project is a 13.3 km long, 65 m deep underground tunnel, including 1.3 km immersed tunnel underwater running under the Bosphorus canal and links the Asian and European side of Turkey. The tunnel provides a vital connection between two densely populated areas of Istanbul within just four minutes.

To ensure the safety of the railway an independent judgement was needed to assess the entire metro system in the new rail tunnel.   

What was our solution?

TÜV SÜD Rail was involved in the safety assessment at system and subsystem level following EN 50126. Our experts carried out the Independent Safety Assessment for permanent way, substructure, understructure (geological and seismic), civil works (tunnels, stations, viaducts), power supply, signalling, telecommunication, SCADA, automatic fare collection, E&M, CR2 (ROTEM rolling stock) as well as the Federal Independent Safety Assessment (F-ISA) of the overall system including the related interfaces.

As Istanbul’s metro system operates during the day, our experts worked night shifts to monitor the safety of the rail lines. In doing so, they took note of every detail and possible problems with the track bed, ranging from loose fastenings and deformed rails to fire doors that did not shut properly. Besides reviewing the safety facilities, also the planes produced by the engineering company have been checked by our experts.

What was the customer benefit?

TÜV SÜD´s Independent Safety Assessor's role was to verify that the required level of safety and quality was achieved by all actors concerned to ensure a safe implementation of the project to the required safety standards.

Since October 2013, inner-city metro trains have been travelling through the tunnel (including the connecting tunnel) while in 2019, it was approved for intercity rail traffic. This ensured that the end customer TCDD could successfully meet their project goal to successfully connect the European side of Istanbul with the Turkish side via a high-speed rail network.