The Marmaray Project – the first transcontinental subway system in the world once completed – consists of upgrading the commuter rail system in Istanbul, connecting Halkalı on the European side with Gebze on the Asian side with an uninterrupted, modern, high capacity commuter rail system.
The total length of the project is approximately 76 km; the immersed tunnel section is 1.4 km, approaching tunnels are 12.2 km, and the surface to be upgraded is nearly 63 km. The project will also include the construction of three new underground stations, the upgrading and renovation of 38 existing surface stations. The project will have three tracks. While two of the tracks will serve as a high capacity commuter rail system, the third track will be used by intercity passenger and freight trains between the continents Asia and Europe. The tunnel will provide an uninterrupted railway connection for Asia and Europe. The project also plays a significant role in Turkey’s connection to the Trans European Network.
This project is one of the major transportation infrastructure projects in the world at present. When introducing major infrastructure projects such as the Marmaray Project, it is important to realise that it will influence not only the daily traffic pattern of Istanbul, but also the development of the city and the region. It is therefore imperative that the objectives of the projects are described in clear terms.
The most important objectives are to:
- provide a long-term solution to the current urban transportation problems of Istanbul;
- relieve existing operating problems on the mainline railway services;
- provide direct connection of railway system between the continents Asia and Europe
- increase capacity, reliability, accessibility, punctuality and safety on the commuter rail services;
- reduce travel time and increase comfort for a large number of commuter train passengers;
- reduce air pollution resulting from the exhaust gases and thereby improve the air quality of Istanbul;
- reduce adverse effects on historical buildings and heritage sites by offering a potential for reducing the number of cars in the old centre of Istanbul.
The total cost of the project is estimated at approximately 4.6 billion USD including the Engineering and Consulting Services and other costs such as land acquisitions, archaeological excavations etc.
Current status:
Engineering and Consultancy Contract: A loan agreement between the Japan International Cooperation Agency (JICA) and the Republic of Turkey has been signed under Official Development Assistance (ODA). The loan is to cover the costs for the Engineering and Consulting Services including supervision and the construction costs for the Istanbul Strait Crossing phase of the Project; i.e. the BC1 Contract which covers the tunnelling works, the deep stations and related electro-mechanical works.
The Consultancy Services started in 2001 and the Avrasya Joint Venture (Oriental Consultants of Japan, Yüksel Proje of Turkey and JARTS of Japan) was subsequently awarded the tender and started work in March 2002.
BC1 Contract;
TAISEI-GAMA-NUROL Joint Venture started work in August 2004.
Under the BC1 Contract, the dredging and ground treatment of the Strait were completed. The manufacturing and construction of eleven tube sections (“elements”) were carried out and all the elements were immersed into a trench. Furthermore, five Tunnel Boring Machines (TBM) were used during the construction work of the approach tunnels at both sides of the Immersed Tube Tunnel and all of them had finished their excavations. All the tunnel excavations from Yenikapı to Ayrılıkçeşme were thus completed.
For the 13.6 km between Ayrılıkçeşme and Kazlıçeşme, preparations of the alignment have been completed including the Immersed Tube Tunnel (IMT) under the Bosphorus and its approach tunnels.
On the Asian Side, track works have been completed and overhead catenary installation works have started except in the Ayrılıkçeşme Station Region and Asian Cross Over Area.
On the IMT and European Side, the laying of all the rails has finished, rail concreting and welding works are continuing except Kazlıçeşme Station Region and European Cross Over Area.
All structural works at Uskudar, Yenikapı and Kazlıçeşme Station have been completed. Building and electromechanical works are continuing in this section.
For the Sirkeci Station area all NATM excavation works at platform and cross over tunnels have been completed. Finally linings are continuing.
Additionally, passenger walkway tunnel excavations and structural works at North and South Entrances of Sirkeci Station are continuing.
CR1&CR3 Contract (Commuter Rail Upgrading Contract (Contract CR1/CR3); covers upgrading the existing commuter rail system on both ends of BC1 Contract including a new third track on the ground and installing of a completely new electrical and mechanical system for the whole of the project length including the BC1 part. Contract CR3 was originally bid and awarded (in June 2007) as Contract CR1 but that contract was terminated in April 2010 with little construction work having been completed. The new Contract CR3 was signed in late 2011 and this contract is currently in progress with phased completion from end 2013 until mid-2015. The contract is partially financed by the EIB (Euro 650 million) and the CEB (Euro 217 million).
Under Contract CR3, conceptual design has been completed in this section. Basic and detailed design preparations have continued.
Train operation between Gebze-Pendik section has ceased, the site has been handed over to the Contractor since 29 April 2011. For this section the removal and dismantling of cables, signals, overhead catenary poles, rails, sleepers and ballast works have been completed in the Gebze-Pendik Section.
Excavation, backfilling, structural works, retaining wall and construction works are continuing.
Additionally, construction work of depot yards at Gebze and Halkalı are ongoing.
CR2 Contract; (Procurement of Rolling Stock – Contract CR2) is also partially financed by the EIB (Euro 400 million) and the CEB (Euro 170.1 million). The tender of Rolling Stock Procurement was completed and the CR2 Contract was awarded to Hyundai-Rotem Company (HRC). The Contract CR2 was signed on 10 November 2008 and the contractor started work on 25 December 2008.
Producing the rolling stocks is going on both in Turkey and the Republic of Korea. 300 rail cars will be produced in Türkiye and 140 cars will be produced in the Republic of Korea. As of January 2013, totally 355 of 440 cars have been produced.
13 sets of 20 five-car emus which are planned to be used in BC1 section by 29 September 2013 have been handed over to TCDD and these rail cars are used on the existing commuter lines.
(Source: TCDD)
VIDEO explaining the tunnel’s construction
