ENKA and its joint venture partners signed the contract to construct the first line between Taksim and Levent on the Line M2,with the Istanbul Metropolitan Municipality for Stage I, Section II works. Along this subway line, there are three stations (Taksim, Osmanbey, Şişli), each with a total length of 180 meters. The project was designed to accommodate heavy rail transport system, travelling along the double underground tunnels and accompanying facilities. Total length of tunnels is 10,250 meters. Diameters of tunnels range between 4.20 meters to 13.40 meters. The major diameter along the route is 6.20 m.

• The Istanbul Metro Project is the first deep excavation in the city centre and it was a challenge to construct metro stations in dense areas. Osmanbey and Sisli cut and cover stations are located under two major avenues of the city, Halaskargazi Caddesi and Buyukdere Caddesi, and engineers gave special attention during construction in order not to cause any traffic congestion.

The project scope of works consisted of the construction of 10,250 meters of metro tunnel and three stations, each with 180 meters of platforms. The “New Austrian Tunnelling Method” was employed in the construction of the tunnels. The project was completed in 1998.