The Trans Anatolian Gas Pipeline Project (TANAP) is part of the Southern Gas Corridor, which aims to convey natural gas from the Caspian region via Turkey to Europe. It traverses the whole of Turkey in east-west direction.
The pipeline has a length of 1811 km where the pipe diameter is 56" for the first 1338 km and 48" for the remaining 455 km up to the Greek border. The Sea of Marmara is being crossed by 2x36” pipes.
Turkey is a country of significant contrasts in landscapes and geology which is reflected by numerous terrain types ranging from coastal plains to high altitude mountain ranges, with the pipeline highpoint reaching 2750m asl. In combination with geology, hydrogeology and climate wide spread geohazards are encountered along the TANAP route corridor including landslides, slope and river erosion, scour and karst. Furthermore some of the most active fault zones worldwide added additional challenges to the route selection process in the form of active fault crossings, areas of potential liquefaction and lateral spreading as well as areas of increased landslide risk in the vicinity of active faults.
Apart from the huge importance of geohazards route selection also had to take into account a multitude of other constraints. Consequently it was the main task to find a stable and safe route in the area of conflict between constructability, economic, social and environmental constraints and operation of the pipeline. Many years of experience in routing pipelines in Turkey and through challenging terrain adopting best industry practice as well as introduction of cutting-edge GIS technology were key factors for the successful completion of these tasks despite rigid time constraints.