Construction of the Trans-Alaska Pipeline System for a fifth, should it become necessary. Holding tanks were planned that had a capacity equal to that of the pipeline, allowing the whole pipeline to be emptied if required. As required by the Pipeline Authorization Act, a ballast-water filtration system had to be designed as well. This system removes oil from tankers' ballast water so it is not released into Prince William Sound—something fishermen feared when the pipeline was proposed. Shortly after the permit was signed, convoys of equipment on snow tractors began heading north, using hardened snow roads and an ice bridge over the Yukon River to reach
Central Europe Pipeline System European countries, known as the Northern European Pipeline System (NEPS). The pipeline system was founded in the late 1950s by NATO being funded as part of the NATO Common Infrastructure Program, with the various participating countries already having some of the infrastructure and capabilities required to operate such a system. In the 1980s, the pipeline was attacked several times by terrorist organizations. The Belgian communist terrorist organisation Communist Combatant Cells carried out five bombings against the pipeline on 11 December 1984, and one more attack on 6 December 1985. Earlier that year, in April 1985, a bomb attack was carried