Marmaray () is a commuter rail line located in Istanbul, Turkey. The line runs from Halkalı, on the East Thrace, to Gebze, on the Anatolia, along the north shore of the Sea of Marmara. Mostly using the right-of-way of two existing commuter rail lines, the Marmaray line linked the two lines via a Marmaray Tunnel under the Bosporus strait, becoming the first standard gauge rail connection between Europe and Asia (all prior connections ran through Russia and used the incompatible Russian broad gauge).[Keith Fender, "Standard gauge rail connection from Asia to Europe opens in Turkey", Trains (October 29, 2013).] The two existing sections of the line were rebuilt and expanded from two tracks to three tracks, to allow for higher capacity with intercity and freight rail. The name Marmaray is a portmanteau of the words Marmara and Ray, which is Turkic peoples for rail.
History
Construction started in 2004 and was originally intended to be completed by April 2009.
[ Rails under the Bosporus; , Railway Gazette International February 23, 2009] After multiple delays caused – among other things – by the discovery of historical and archaeological sites along the route as new stations were built, the first phase of the project was finally opened by president Erdoğan on October 29, 2013.
The second phase of the project was scheduled to open in 2015 but work once again stopped in 2014.
[Uysal, Onur. "Is Marmaray Project Behind the Schedule?", Rail Turkey, November 6, 2014][Uysal, Onur. "Completely False Facts About Marmaray", Rail Turkey, May 20, 2013] It was restarted in February 2017 and the line finally opened in its entirety on March 12, 2019.
The trains came with completely new
rolling stock, with carriages that can be walked through from end to end.
The line can carry 75,000 passengers per hour in each direction (PPHPD).[ Istanbul; , web page at urbanrail.net. Accessed on line September 24, 2007.] Travel time from Halkali to Gebze normally takes 104 minutes.
The Marmaray is integrated with other parts of the Istanbul public transport network, including the Metro and the Metrobus network, via a number of interchanges. It is also integrated with the YHT high-speed train network to Ankara, Eskişehir and Konya, as well as with the international trains to Sofia in Bulgaria which depart from Halkalı.
Project
The project involved building a tunnel under the
Bosphorus and upgrading of existing
commuter rail lines to create a high-capacity passenger line between Halkalı and Gebze, along with the provision of 440 electric multiple unit carriages.
First phase
The contract for the project was awarded to a Japanese-Turkish consortium led by Taisei Corporation in July 2004.
The consortium included
GAMA Endustri and
Nurol Holding.
The Bosphorus (Istanbul Strait) is crossed by a earthquake-proofed immersed tube, assembled from 11 sections – eight are long, two are , and one element is .[Smith, Julian. "The Big Dig" Wired Sept. 2007: pages 154–61.] The tube was placed below sea level, beneath of water and of earth.[" Norwegian technology in the world's deepest immersed tunnel" (in Norwegian) Teknisk Ukeblad, October 12, 2013. Accessed: October 13, 2013. Technical report: Claus K. Larsen. " Testing of fireproofing for concrete" Norwegian Public Roads Administration, 2007.]
Construction started in May 2004 and the Marmaray tunnel was completed on September 23, 2008,[ Final tubes sunk on Bosphorus Tunnel, International Railway Journal, November 2008.] with a formal ceremony to mark its completion on October 13.[ Marmaray tunnel completed; , Railway Gazette International October 20, 2008]
Second phase
The second phase of the project involved the renewal of the old suburban railway that ran between Halkalı and Kazlıçeşme on the European side of Istanbul and between Ayrılıkçeşmesi and Gebze on the Asian side. The work was meant to be completed at the same time as the first phase (the tunnel and underground sections), but was delayed until March, 2019.
A third line was added to enable the electric multiple unit (EMU) cars and other railway carriages to move separately.[ Facts and figures; , web page at the Marmaray web site. Accessed on-line September 24, 2007.][ Travel time and alignment; , web page at the Marmaray web site. Accessed on line, September 24, 2007.] Signalling was also modernised to allow trains to travel as close as two minutes apart (although in reality far fewer trains than that actually run).
The suburban-rail upgrade part of the project, known originally as CR1, was first awarded to the AMD Rail Consortium, comprising Marubeni of Japan, Dogus Insaat of Turkey and Alstom of France.
Freight
In February 2010,
Railway Gazette International reported that the tunnel's administrators were hiring consultants to analyse options for carrying freight traffic.
[ Contracts February 2010, Railway Gazette International February 9, 2010] The Prime Minister and other officials have suggested that the Marmaray will help to create a modern "Iron
Silk Road" by allowing freight trains to travel between
Europe and
China. Freight trains that are not carrying
dangerous goods will be able to use the tunnel when commuter services are not operating (between 1:00 a.m. and 5:00 a.m.).
[Uysal, Onur. "Is Marmaray Key for Europe-Asia Rail Connection?", Rail Turkey, November 12, 2013] At other times only passenger trains will be in the tunnels.
Financing
The Japan International Cooperation Agency (JICA) and the European Investment Bank (EBI) provided much of the financing for the project. By April 2006, the JICA had lent 111 billion yen and the EIB 1.05 billion euro for the work. The original cost was estimated at $4.5 billion
although it finally cost almost twice that.
Rolling stock
The Marmaray uses TCDD E32000 rolling stock manufactured by
Hyundai Rotem in ten- and five-car EMU configurations. The original contract called for 440 vehicles to be produced locally by
Eurotem, Hyundai Rotem's joint venture with Turkish rolling stock manufacturer TÜVASAŞ. Hyundai Rotem was chosen ahead of
Alstom, CAF, and a consortium of Bombardier,
Siemens, and
Nurol.
[ Marmaray train contract signed; , Railway Gazette International November 14, 2008]
There are two depot and maintenance yards on the line (one at each end) where the sets are stocked.
Archaeological discoveries during work on the Marmaray
The project was delayed by four years, largely due to the discovery of
Byzantine Empire-era and other 8,000-year-old archaeological finds on the proposed site of the European tunnel terminal at Yenikapı in 2005.
[ Tunnel links continents, uncovers ancient history CNN] Excavations then produced evidence of the city's largest harbour, the 4th-century Harbour of Eleutherios (originally known as the Harbour of Theodosius).
Archaeologists also uncovered traces of the city wall of Constantine the Great, and the remains of several ships, including what appears to be the only ancient or early medieval
galley ever discovered, preventing the project from proceeding as planned.
[; Nautical archaeology takes a leap forward, The Times, December 31, 2007] In addition, archaeologists uncovered the oldest evidence of settlement in Istanbul, with artefacts, including
, pottery fragments, shells, pieces of bone and horse skulls, and nine human skulls found in a bag, dating back to 6,000 BCE.
artefacts and fragments dating from the Hellenistic, Roman, Byzantine and Ottoman periods were also found during excavations at Sirkeci.
[Üzlifat Canav-Özgümüş. " Recent glass finds in Istanbul; " Doğuş University, September 2012. Accessed: October 13, 2013.]
Opening
On August 4, 2013, Prime Minister Recep Tayyip Erdoğan, test-drove the Marmaray from Ayrılıkçeşmesi station (originally İbrahimağa station)
on the Asian side under the Bosphorus and back again.
On October 29, 2013, the first stage of the Marmaray project, the underground tunnel between Europe and Asia, was inaugurated on the 90th anniversary of the Turkish Republic'.
On November 7, 2019, the first Chinese freight train to Europe ran through the tunnel. This demonstrated that the China to Turkey transportation time could be reduced from a month to 12 days as part of the Iron Silk Road concept.
Earthquake protection
The tunnel construction is only about away from the active North Anatolian Fault and has worried some engineers and seismologists. "Since AD 342, it has seen large earthquakes that each claimed more than 10,000 lives."
Some scientists have estimated a 77% probability that, at some time in the next 30 years, Istanbul will suffer an earthquake measuring 7.0 or more on the Richter magnitude scale. The waterlogged, silty soil on which the tunnel is constructed has been known to liquefy during an earthquake so engineers injected industrial grout to below the seabed to keep it stable.
The walls of the tunnel are made of waterproof concrete coated with a steel shell, each section independently watertight. The tunnel is made to flex and bend in the way that tall buildings are constructed to react if an earthquake hits.
at the joints of the tunnel are able to close and isolate water in the event of the walls failing.
Steen Lykke, project manager for Avrasyaconsult, the international consortium that oversaw the construction, summed the problems up by saying, "I can't think of any challenge this project lacks".
Marmaray in numbers
Some figures of the project are as follows:
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Overall length:
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Tunnel section:
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Immersed tube:
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Deepest point:
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Minimum curve radius:
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Maximum gradient: 1.8%
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Surface stations: 37
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Underground stations: 3
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Interchanges: 8
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Inter-city stations: 8
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Minimum platform length:
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Average station spacing:
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Maximum speed:
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Commercial speed:
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Headway: 2–10 minutes
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Passengers per hour and direction: 75,000
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Number of passenger cars: 440
See also
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Eurasia Tunnel
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Great Istanbul Tunnel, a proposed three-level road-rail undersea tunnel
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Public transport in Istanbul
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Rail transport in Turkey
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Turkish Straits
External links
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Overview of the Marmary history, justification, and construction process with pictures
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Marmaray Project:
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L. C. F. Ingerslev, 2005, " Considerations and strategies behind the design and construction requirements of the Istanbul Strait immersed tunnel", Tunnelling and Underground Space Technology 20: 604–08.
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Steen Lykke and Hüseyin Belkaya, 2005, " The project and its management", Tunnelling and Underground Space Technology 20: 600–03.
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Steen Lykke and Frits van de Kerk, 2005, " Marine operations, the Bosphorus Crossing", Tunnelling and Underground Space Technology 20: 609–11.
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Hideki Sakaeda, 2005, " Tunnels and stations in BC contract", Tunnelling and Underground Space Technology 20: 612–16.
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Istanbul Technical University Marmaray Laboratory web site
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Tunnelbuilder technical description
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Marmaray BC1 project and surveying works
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BBC article on the project
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Marmaray Durakları
