It’s construction marks a watermark for Turkish infrastructure that will significantly improve commuting times for citizens and businesses in Istanbul. The tunnel will allow vehicles to cross from Europe to Asia, and vice versa, simultaneously.
The Eurasia Tunnel, Avrasya Tüneli in Turkish, is an underwater road tunnel crossing the Bosphorus strait. The 14.5km tunnel connects Kazlıçeşme on the European side and Göztepe on the Asian side of Istanbul with a 5.4 km of the route under the Bosphorus.
Designed and built to help reduce Istanbul’s traffic problems the tunnel is about 1km south of the undersea train tunnel Marmaray. The new tunnel and route will reduce travel times by 85 minutes from 100 to 15 – not too shabby!
While its construction will reduce pressure on existing infrastructure it will also help reduce Turkey’s air and noise pollution. On opening the tunnel will be the shortest route between Kazlıçeşme and Göztepe. This will reduce fuel costs and by virtue exhaust gas release and the maintenance costs of vehicles.
Planning the tunnel
Building on this plan, a pre-feasibility study was undertaken in 2003 for the new Bosphorus crossing. A tunnel solution was recommended as the most realistic option.
Commissioned in 2005, Nippon Koei Company Limited for Turkey’s Transportation, Maritime and Communication Department, completed a study for possible routes. Environmental, Economic, Social and Cost Benefit analyses supported the 2003 recommendation.
The Eurasia Tunnel’s route has factored in the existing infrastructure, current bridges, to enable a balanced distribution of traffic across the Bosphorus. The planned route also needed to consider the shortest underwater route possible. Other factors such as sufficient space for construction and operation were considered (toll booths etc).
Paying the ferryman
Tolls will be $4 plus VAT for automobiles and $6 plus VAT for minibusses in one direction for the first year.
The tunnel was built by Eurasia Tunnel Operation Construction and Investment Inc. (ATAŞ). ATAS designed and constructed the tunnel and associated infrastructure. They will also operate the project for 24 years and 5 months. The tunnel will pass to public ownership after this time has elapsed.
ATAŞ is a company equally owned by prominent Turkish contractor Yapi Merkezi and SK E&C from South Korea.
As Istanbul lies in a seismically active region the tunnel has been designed to resist a 7.5 magnitude earthquake. Designers claim the tunnel would be undamaged in the event of a once-in-500-year earthquake. Operations can be resumed “with slight maintenance works” in the event of a once-in-2,500-year earthquake.
Designers claim the tunnel to be Tsunami resistant with potential use as an underground bunker (which is a nice thought).
The tunnel comprises of three sections:
Project design was a joint operation with Parsons Brinckerhoff, HNTB, ARUP, and Jacobs Engineering. Once operational responsibilities will pass to ATAS and Istanbul Metropolitan Municipality.
The tunnels excavated diameter is 13.7 meters with an inner diameter of 12m. The lining is 60cm thick. The tunnel’s lowest depth (under sea level) is 106 m while its maximum depth below the seabed is 61 meters.
But the authorities have settled on the far less politically-loaded Avrasya Tunnel, despite a high-profile campaign by officials for the public to submit names.
“In public consultations, many names came out but Avrasya really was the most ideal,” said Arslan.
Speed limits will be 80km/h (50mph) with 40 km/h (25 mph) at U-turn underpasses. Designers estimate that traffic flow will increase from an initial 80,000 to 130,000 vehicles per day by 2023.
Don’t stop me now
“I think the Eurasia Tunnel will hugely ease the lives of the residents of Istanbul,” says Turkish Transport Minister Ahmet Arslan. “But we are not just going to stop there.”
This scheme involves a new gigantic third airport for Istanbul, the first bridge across the Dardanelles and even a Suez-style shipping canal for Istanbul.