The Istanbul rail bypass project has entered the expression-of-interest stage for consultancy contracts. These contracts support the 127 km Istanbul North Rail Crossing Project. This is reported by the railway transport news portal Railway Supply.

Istanbul rail bypass project tender phase begins
Istanbul rail bypass project tender phase begins

Also, Turkey’s Ministry for Transport & Infrastructure has given advance notice of four construction tenders. They cover the planned rail bypass around the city.

The US$6.5bn INRAIL route is planned as a passenger and freight railway. It has a design speed of up to 160 km/h. The line would form a 127 km northern bypass of Istanbul. It would give Turkey’s Asian and European rail networks a direct connection. That link would avoid the Marmaray corridor in the city centre. At the same time, that corridor has capacity only for limited overnight freight movements.

In addition, the Yavuz Sultan Selim Bridge is a central part of the scheme. The northern road crossing over the Bosphorus was built with provision for a double-track railway. It could now form part of the planned passenger and freight bypass around the city.

Consultancy roles for the Istanbul rail bypass project

One consultancy role covers the Construction Supervision Consultant. This contract will involve supervision of four civil works and electrification contracts. It will also cover a separate signalling and telecoms package. The consultant will check compliance with contract requirements and technical standards. Applicants must have provided comparable consultancy services within the past 10 years.

Also, the Project Implementation Oversight Consultant will cover independent technical verification. This role will also cover quality assurance and risk management. Applicants must have operated as railway engineering consultants for at least 10 years.

INRAIL construction tenders and route scope

The first construction tenders for INRAIL are expected to be issued later this year. They will follow the conditions set out in the World Bank’s Standard Procurement Document.

The 127 km railway will require extensive structures. The planned works are set out by Turkey’s Directorate General of Infrastructure Investments. They include five twin-bore tunnels with a combined length of 36.2 km. In addition, they include 22 New Austrian Tunnelling Method tunnels totalling 23.3 km. The works also include 17 cut-and-cover tunnels with a total length of 3.7 km. The route will also include at least two viaducts and 40 bridges. Together, those bridges and viaducts will measure 22.1 km.

Separately, the construction programme is to be split into four geographical lots. Each lot will include the design and construction of civil and structural works. Also, each lot will cover track, electrification and electromechanical systems. Stations are included where relevant.

Four construction lots across Istanbul

Asian-side construction lots

Lot 1 covers Çayırova – Sabiha Gökçen Airport – Kurtdoğmuş. This section runs east to west on the Asian side of the Bosphorus. It includes about 27.8 km of double-track alignment and 916 m of single track. Much of the route will be in tunnel. In addition, the package includes a new underground passenger station serving Sabiha Gökçen airport.

Separately, Lot 2 runs from Kurtdoğmuş to Alibahadır. It includes around 25.6 km of double-track railway in Asia. The section involves extensive tunnelling and a large number of viaducts and bridges.

Bridge and European-side lots

Meanwhile, Lot 3 covers Alibahadır – Yavuz Sultan Selim Bridge – Mithatpaşa. This lot includes about 32 km of double-track alignment. It covers the Asian and European approaches to the Yavuz Sultan Selim Bridge. It also covers the bridge itself. The bridge was constructed with provision for a double-track railway. The section will include a series of NATM double-track tunnels. They will be on both sides of the bridge. It will also include several cut-and-cover tunnels, viaducts and bridges.

Lot 4 runs from Mithatpaşa through İstanbul Airport to Çatalca. It is on the European side of the city. It includes 37.8 km of double-track main line and about 2.0 km of single-track connections. The works include a large twin-bore tunnel to be excavated using TBMs. They also include NATM and cut-and-cover tunnel sections, viaducts and bridges.

Finally, signalling and telecoms for the full route will be procured under a separate contract.

News on railway transport, industry, and railway technologies from Railway Supply that you might have missed:

Don’t miss…Semmering Base Tunnel enters final works stage