Marmaray
| File:Building the Marmaray tunnel.jpg Marmaray, the world's deepest immersed tube tunnel | |
| Overview | |
|---|---|
| Location | Bosphorus strait |
| Status | Under construction |
| Start | Fatih, Istanbul, Turkey |
| End | Üsküdar, Istanbul, Turkey |
| Operation | |
| Work begun | 9 May 2004 |
| Technical | |
| Length | 1.4 km |
| Line length | 76.3 km |
| Operating speed | 100 km/h |
The Marmaray tunnel is an undersea rail tunnel being constructed to link the European and Asian sections of Istanbul, running under the Bosphorus strait. When completed, it will be the world's deepest undersea immersed tube tunnel. The name Marmaray (Marmarail) comes from combining the name of the Sea of Marmara, which lies just south of the project site, with ray, the Turkish word for rail.
The project
The project includes a 13.6 kilometres (8.5 mi) Bosphorus crossing and the upgrade of 63 kilometres (39 mi) of suburban train lines to create a 76.3 km high-capacity line between Gebze and Halkalı.
The Bosphorus (Istanbul Strait) will be crossed by a 1.4 kilometres (0.87 mi)-long earthquake-proofed immersed tube, assembled from 11 sections, each as long as 130 metres (430 ft) and weighing up to 18,000 tons.[1] The sections will be placed down to 60 metres (197 ft) below sea level: 55 metres (180 ft) of water and 4.6 metres (15 ft) of earth.[1] This underwater tube will be accessed by bored tunnels from Kazlıçeşme on the European side and Ayrılıkçeşme on the Asian side of Istanbul. New underground stations will be built at Yenikapı, Sirkeci, and Üsküdar.[2] 37 other above-ground stations along the line will be rebuilt or refurbished.[2][3] The station at Yenikapi will connect with Istanbul Metro and Istanbul LRT.[4] The upgrade of the suburban lines requires the addition of a third parallel track, to increase capacity to 75,000 passengers per hour in each direction. Signaling must also be modernized to allow trains to be as close as two minutes apart.[5] The predicted travel time Gebze to Halkalı is 104 minutes.[2]
Construction of the Marmaray project started in May 2004. The Marmaray tunnel was completed on the 23rd of September 2008,[6] with a formal ceremony to mark completion of the tunnel on October 13.[7]Completion of the project is expected to occur 2012.[1] Revenue services are expected to commence in either 2012 or 2013.[7]
After completion, the usage of rail transportation in Istanbul is predicted to rise from 3.6% to 27.7%, which would see Istanbul's percentage rate of rail transportation usage as the third highest in the world, behind Tokyo (60%) and New York City (31%).[3]
Hyundai Rotem announced on November 11 2008, that it had signed a €580m contract to supply the rolling stock for the Marmaray cross-Bosporus tunnel project in Istanbul. The Korean firm saw off competition from shortlisted bidders Alstom, CAF and a consortium of Bombardier, Siemens and Nurol for the 440-vehicle contract which was placed by the Ministry of Transport's General Directorate of Railways, Harbours & Airports.[8]
The 22 m long stainless steel cars will be formed into 10 and five-car EMUs. Some production will be carried out locally by Eurotem, Hyundai Rotem's joint venture with Turkish rolling stock manufacturer TÜVASAŞ. The cars will arrive in three batches, the first 160 cars by 2011, the last by June 2014.
Delays
The project is currently four years behind schedule, largely due to the discovery of a Byzantine-era archaeological find on the proposed site of the European tunnel terminal in 2005. [9] The excavations produced evidence of the city's largest harbour, the 4th-century Port of Theodosius.[1] There, archaeologists 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 at full speed.[10] In addition, the excavation has uncovered the oldest evidence of settlement in Istanbul, with artifacts, including amphorae, pottery fragments, shells, pieces of bone, horse skulls, and nine human skulls found in a bag, dating back to 6000 BC.[1]
Tunnel construction is only about 18 kilometres (11 mi) from the active North Anatolian Fault, worrying engineers and seismologists. "Since AD 342, it has seen large earthquakes that each claimed more than 10,000 lives."[1] Scientists calculate the chances of the area being hit by a quake of 7.0 or greater may be as high as 77 percent. The waterlogged, silty soil on which the tunnel is being constructed has been known to liquefy during an earthquake; to solve this problem, engineers are injecting industrial grout down to 24 metres (79 ft) below the seabed to keep it stable.[1] The walls of the tunnel will be made of waterproof concrete coated with a steel shell, each independently watertight. The tunnel is made to flex and bend similar to the way tall buildings are constructed to react if an earthquake hits. Floodgates at the joints of the tunnel are able to close and isolate water in the event of the walls' failure.[1]
Steen Lykke, project manager for Avrasyaconsult, the international consortium that's overseeing the construction, sums it up saying, "I can't think of any challenge this project lacks".[1]
Financing
The Japan Bank for International Cooperation and the European Investment Bank have provided major financing for the project. As of April 2006, JBIC had lent 111 billion yen and EIB 1.05 billion euros. The total cost of the project is expected to be approximately 2.5 billion dollars.
See also
References
- ^ a b c d e f g h i Smith, Julian. "The Big Dig" Wired Magazine. Sept. 2007: pages 154–61.
- ^ a b c Facts and figures, web page at the Marmaray web site. Accessed on-line September 24, 2007.
- ^ a b Travel time and alignment, web page at the Marmaray web site. Accessed on line, 24 September 2007.
- ^ Istanbul Metro and LRT, web page at the Marmaray web site. Accessed on-line September 24, 2007.
- ^ Istanbul, web page at urbanrail.net. Accessed on line September 24, 2007.
- ^ Final tubes sunk on Bosphorus Tunnel, International Railway Journal, November 2008.
- ^ a b Marmaray tunnel completed, Railway Gazette International 2008-10-20
- ^ Marmaray train contract signed, Railway Gazette International 2008-11-14
- ^ Tunnel links continents, uncovers ancient history CNN
- ^ Rose, Mark. "Under Istanbul". Archaeology.org. Archaeological Institute of America. Retrieved 2008-10-27.
{{cite web}}: Unknown parameter|coauthors=ignored (|author=suggested) (help); Nautical archaeology takes a leap forward, The Times, 31 December 2007
External links
- Marmaray project official website
- Marmaray Project:
- 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.
- Steen Lykke and Hüseyin Belkaya, 2005, "The project and its management," Tunnelling and Underground Space Technology 20: 600-03.
- Steen Lykke and Frits van de Kerk, 2005, "Marine operations, the Bosphorus Crossing," Tunnelling and Underground Space Technology 20: 609-11.
- Hideki Sakaeda, 2005, "Tunnels and stations in BC contract," Tunnelling and Underground Space Technology 20: 612-16.
- Istanbul Technical University Marmaray Laboratory web site.
- Tunnelbuilder technical description.
- Template:Tr icon Marmaray BC1 project and surveying works
- BBC article on the project.