Construction of the Trans-Alaska Pipeline System with the Denali Fault, a major cause of earthquakes, and with large amounts of permafrost. In 1969, the unincorporated Trans-Alaska Pipeline System group drilled a series of core samples north of the Brooks Range that demonstrated how ubiquitous the permafrost was along the route. This forced the design of an elevated pipeline, which was tested in a loop built near Barrow. This elevation required the pipeline to be insulated, since extreme cold temperatures caused the metal to become brittle, even when hot oil was being pumped through the pipeline. After ecological objections forced subterranean pipeline crossings (in order to allow
Central Asia–Center gas pipeline system Balkanabat. It continues via Uzen in Kazakhstan to the Beyneu compressor station, where it meets the eastern branch of the CAC. South of Hazar, the western system consists of diameter pipeline, and between Hazar and Beyneau diameter pipeline. On 20 December 2007, Russia, Turkmenistan and Kazakhstan agreed to construct a new Caspian pipeline parallel to the existing CAC-3 pipeline. The pipeline is planned be built between Belek compressor station in Turkmenistan and Alexandrov Gay compressor station. Capacity of the new pipeline will be 20–30 bcm per year and it would be supplied from the planned East–West pipeline. Construction of the