Cengiz Holding constructs highways and railways as well as highway and railway tunnels. The Company completed the construction of Ilgaz and Ovit tunnels and the construction of Zigana tunnel is in progress. Zigana Tunnel, longest in Turkey with a total length of 14,5 km will also be the longest highway tunnel in Europe. Ovit Tunnel is the fourth longest in Europe with a total length of 12,6 km. These projects are managed by Turkish engineers employed by Cengiz İnşaat. Tunnels were built in Sarajevo in line with EU standards by Cengiz İnşaat.
- Karavanke Highway Tunnel Work
Completion date, April 2025
The total length of the eastern tunnel pipe is 7,948 m, of which the tunnel on the Slovenian side to the border with the Republic of Austria will be 3,546 m long (3,446 m of underground construction, 100 m of gallery).
The design speed through the tunnel will be 100 km / h after the establishment of one-way traffic in both pipes. The estimated design speed for two-way traffic is 80 km / h.
In the Slovenian part of the tunnel, 12 cross-sections will be built, namely cross-sections for pedestrians or cross-sections for intervention vehicles in the event of an accident or fire in the tunnel and two ventilation cross-sections in the upper part of the tunnel pipe. Four parking niches will also be built, each 112.50 m long.
The tunnel will also include a new underground catchment of Karavanke water and two drainage pipes from the water catchment to the water shaft in the southern portal area.
The tunnel will be equipped with modern electrical equipment.
The designed normal transverse profile of the tunnel is 10.00 m.
lane: 2 x 3.50 m
edge belt: 2 x 0.35 m
maintenance corridor: 2 x 1.15 m
light profile height: 4.70 m
- Zigana Tunnel
Completion date, June 2023
- 5C Corridor Highway Zenica Tunnel Work
Zenica, Bosnia -Herzigova
Completion date, May 2021
- Ovit Tunnel
Completion date, December 2018
- Çamlıca Tunnel,
Completion date, May 2018
- Ilgaz Tunnel,
Completion date, December 2016