Super Deep Railway Tunnel Opens in Istanbul

Istanbul has long been considered a city that bridges both the continents and cultures of Asia and Europe. In a statement that further cements this idea, the city has announced the opening of the 13.6-kilometer Marmaray tunnel that will ferry passengers between Istanbul’s Asian and European sides.

The massive tunnel, which burrows under the Strait of Bosporus, isn’t just long; it claims to be the world’s deepest railway tunnel, bending 60.46 metres (198.4 ft) under the strait at its deepest point.

Beginning in 2005, Turkish engineers created the transcontinental tunnel using an “immersed-tube method”. This construction technique, which has been used in projects all around the world, sinks sections of the tunnel to the bottom of the strait to be linked together on-site.

According to the project plans, the Marmaray tunnel was scheduled for completion in 2009. The construction had to be halted, however, when engineers stumbled upon the ruins of a 4^th century Byzantine port filled with archeologically significant material.

Now that the tunnel has been completed, some critics have voiced skepticism that the span will be able to handle the seismic jitters that are a regular feature of any continental divide.

To assuage worries, Marmaray engineers used flexible joints when bonding the tunnel sections to one another; producing a structure so secure that Turkish Transportation Minister Binali Yildrim has gone on-record stating that it is “the safest place in Istanbul”.

Capable of accommodating some 1.5 million passengers a day, the Marmaray tunnel looks to play a big role in the future of Turkey’s growing metropolis. Regardless of the traffic it sees, however, I’m willing to bet that mega-project / civil engineering nerds (like me) will flock to Istanbul to experience the rush of their transcontinental-commute.

Source: The Hindu