Zigana, which is one of Turkey's giant projects, the longest tunnel in Turkey and Europe with a length of 14.5 km and the third longest tunnel in the world, will provide 30 minutes advantage in time and the road will be shortened by 10 kilometres.

Within the scope of the project contracted by Cengiz İnşaat, the ventilation problem in the Zigana Highway tunnel was solved by lining the vertical ventilation shafts with a diameter of 3.6 m - ranging from 150 m to 272 m in height - at two different points along the tunnel with specially designed SUPERLIT GRP composite pipes with a diameter of 3.1 m.

Thanks to its smooth inner surface, SUPERLIT GRP composite cladding pipes, which enable the required air flow to be realised in smaller sections compared to classical cladding methods, enable fast and safe installation thanks to their high strength properties and light weight. The project also stands out as an extraordinary project with its assembly methodology and assembly accessories designed on the coating pipes. With this feature, the accessory designs have been registered as a patented product of Superlit as a new invention in the technique.