Civil Engineering Association

National Geographic - Deep Sea Highway

Busan, one of the busiest cities around the world was running out of room. The only solution was Geoje only 8 kms away by sea but 140 km away by road. How did the Koreans solve this problem? By building a highway immersed into the sea connecting both the cities. The Busan-Geoje fixed link. Directed and produced by Marijke De Schepper and written by Gary Parker this Nat Geo Documentary film tells the story of these two cities only 8 kilometers away by sea. One is over flowing with population while on the other one it’s hard to find a person – Busan and Geoje.

It is a four-lane highway that runs almost fifteen meters beneath the sea then leaps along two colossal cable state bridges. This was one of the biggest infrastructure projects around the world. The tunnel is composed of 18 mammoth segments each as long as two football pitches and wide enough to carry two lanes of traffic each way. Each segment was first carefully towed into the right position then aligned within 35 mm of each other.

Measures had to be taken to ensure the safety of the fixed link. Thus concrete columns were borne into the sea bed to avoid earth quakes and provide a stable ground to the highway. Later, the entire tunnel was covered with thousands of tons of crushed rock to avoid collision with ships or tankers. On the other hand, the construction of the pile on bridges was also at its peak. The bridges were huge, and the curved design was very challenging to construct. Nonetheless, the teams tirelessly kept working on the design and finally managed to complete one of the world’s toughest structures ever. How they did it and what challenges they had to face? Watch all this and much more in this Nat Geo documentary.