One of the largest transportation infrastructure projects, and the world's deepest underwater railway system tunnel, extends 76.6 km long and includes 43 stations, from Halkalı Station on the European side to Gebze Station on the Asian side of Istanbul, and penetrates the Bosphorus Strait with a depth of up to 60.46 meters Underwater.

Date

The idea of ​​a railway tunnel under the Bosphorus Strait first started in 1860 with Sultan Abdul Majid, and the most realistic step was the project presented by Sultan Abdul Hamid II in 1892, then a similar design was developed in 1902, but it was not possible to construct the tunnel according techniques of that time.

The desire for the tunnel gradually increased in the early eighties, and the first comprehensive feasibility study was carried out in 1987. The study concluded that the construction of the tunnel is technically feasible and cost-effective, and then the best path was chosen from among a number of paths.


In 1997, the project was again put on the agenda, and in 2000 a consultancy tender was launched, where specifications, contracts, drafts, feasibility, major projects and bid files were prepared. 9 years, and on October 29, 2013, work on it actually ended.

It was scheduled to be completed in 2009, but the work was delayed by 5 years. In 2005, archaeological sites dating back to the era of the Byzantine Empire were found, located in the place where excavations are taking place, in the areas of Uskudar, Sirkeci and Yenkapi, to place the excavations under the supervision of experts. Antiquities and archaeological museums.

The name "Marmaray" comes in relation to the "Marmara" Sea, added to the word "Ray", which means railway in Turkish.

Erdogan (center) and his wife with other political figures at the opening ceremony of the Marmaray Line in October 2013 (Reuters-Archive)

Project financing

The project was financed by the JICA Bank for International Cooperation, the Development Bank of the Council of Europe, and the European Investment Bank.

In 1999, a financing agreement was signed between Turkey and the Japan Bank for International Cooperation (JBIC). The agreement forms the basis for financing the part passing at the bottom of the Bosphorus, in addition to engineering and consulting services. Under the agreement, a loan of 12.464 billion yen was provided.

The Turkish government also signed an agreement with the European Investment Bank (EIB) in 2004, according to which it was granted a loan of 650 million euros.

The remainder of the cost, amounting to 217 million euros, was obtained under an agreement signed in 2008 with the Development Bank of the Council of Europe.

Erdogan and political figures on board the Marmaray Train during its inauguration in October 2013 (Reuters - Archive)

Its importance and features

The project is one of the largest transportation infrastructure projects in the world, as it has the deepest submerged tube tunnel used by railway systems, located at a depth of 60.46 meters under the waters of the Bosphorus, and at a distance of 1.4 km, connecting the two ends of the European and Asian city of Istanbul, the train travels in 4 minutes.

The upgraded and completely new railway system is about 76.6 km long, includes 43 stations, and has connections at various stations by metro, metrobus, city line ferries and tramway.

The Marmaray Line secures a trip every 2-10 minutes between Gebze Station on the Asian side and Halkali Station on the European side, with a capacity of 75,000 passengers per hour in one direction, and the train can transport 3056 passengers at one time.

A view from Uskudar Station in Istanbul, one of the stations through which the Marmaray train passes (Reuters)

The number of cars per trip is 10, and the Marmaray trains differ from other metro trains in that their cars are not divided, meaning that the passenger can move from the beginning of the train to the end without barriers.

Those responsible for the project attribute this to security considerations, especially at night when the number of passengers is low. The passengers will not be isolated from each other, and this strengthens their sense of safety, in addition to the fact that the other reason is to prevent overcrowding in vehicles without others.

The project offers many advantages for people working and residing in Istanbul, reduces the rapidly growing problems related to traffic congestion in the city, and works to connect different points of the city together, adding vitality to the city's economic life.

A scene from the works in progress in the Marmaray Tunnel in 2010 (European)

Among its advantages is that the tunnels within the scope of this project are designed to resist earthquakes of the highest intensity that can be expected in the region, and the tunnel is isolated from contact with sea water by a layer of special and strong cement at a distance of 10 meters, in addition to equipping it with safe corridors equipped with all measures for various emergency scenarios of earthquakes and fires.

Preserving the environment and historical monuments

The project is designed to provide an opportunity for urban transportation for citizens while preserving the healthy ecological life of the city, by using electric energy that does not pollute the environment, and then decreases the amount of gases polluting the air, thus reducing the percentage of diseases resulting from pollution, and this also has a positive impact on reducing global warming, reducing From negative environmental problems such as noise and dust.

Marmaray Tunnel connecting the European part and the Asian part of Istanbul (Reuters)

The excavations in the project preserved the historical monuments of the city. On an area of ​​58 thousand square meters, and under 3 meters of water, the excavations were conducted under the supervision of archaeologists and archaeological museums in Istanbul. Data were obtained from all stages of the archaeological layers in the early Ottoman, Byzantine and Roman eras. The modern stone age.

The discovered historical artifacts indicated a large village of 8,000 years old, in addition to other traces. The excavations changed the history of Istanbul and brought it back 2,500 years. The well-known history of Istanbul, which dates back to 6,000 years, has reached 8,500 years due to excavations.