A group of crew of SK E&C celebrate the completion of the 3.34 km long section of the Eur-Asia Bosporus  Undersea Tunnel linking Asia(Istanble) and Europe on Aug. 22 with Turkish Prime Minister Ahmet Davutoglu attending leading Turkish government officials.(Photo:SK E&C)

SK Engineering and Construction Co. held a ceremony on Aug. 22 to celebrate the completion of a 3.34km-long section of the 14.6km-long Bosporus Eur-Asia Undersea Tunnel being built to link Asia (Istanbul, Turkey) and Europe, with Turkish Prime Minister Ahmet Davutoglu leading other Turkish government officials and construction company leaders.

From April this year, the Korean construction firm used a tunnel boring machine to pierce the undersea rocks to open the tunnel with around 100 25-ton dump trucks, which were mobilized to carry out the earth and rocks from the undersea jobsite daily. The company was able to advance seven meters a day to bore the tunnel during the 16 months project using the TBM. 

The machine is 13.7 meters tall, 120 meters long and weighs 3,300 tons. It’s the the largest mammoth-class TBM in the world.

SK E&C officials said the work was very hard, as the work was done 110 meters below the surface, which was made of sands, pebbles and mud, all mixed together with water to make the layer watery with very high pressure. There were huge risks: water and sand mixed with rocks could slip back into the tunnel, making the job very tough.

Chief Engineer Lee Jin-moo in charge of the jobsite for the company said they used high-tech monitoring equipment, because the company didn’t know the exact conditions undersea to check the quality of the geology where the TBM was used to bore the tunnel for 24 hours a day. 

“We also at the same time had to work to prevent water and sands slipping back into the tunnel with no time to relax throughout the work period,” he said. 

 SK E&C now has comparatively easier work ahead. 

The entire tunnel work is 62 percent complete and SK Construction is scheduled to finish its section of the project by March 2017. 

The project calls for the construction of an undersea tunnel with four double-layer lanes. Some 120,000 dump trucks will be used daily to complete the mammoth project.

This is the map showing the Eur-Asia Bosporus Undersea Tunnel being built which is 14.6 km long scheduled for completion in March, 2017.