The Trans-Alaska Pipeline System, commonly known as the Alaska Pipeline, transports oil 1287 km across Alaska from the oilfields in Prudhoe Bay by the Arctic Ocean, to Valdez on the Pacific coast.
The pipeline was built between 1974 and 1977 after the 1973 oil crisis made exploration of the Prudhoe Bay oil field economically feasible. The construction of the pipeline was one of the first large-scale projects to deal with problems caused by permafrost, and special construction techniques had to be developed to cope with the frozen ground.
The oil is pumped through the pipeline at a relatively slow speed of around 6 km/hour, and it thus takes more than 11 days for the oil to be pumped all the way from Prudhoe Bay to Valdez.
Much environmental, legal, and political debate has sorrounded the pipeline and the oil production in the sensitive northern wilderness areas and several notable incidents of oil leakage have occurred, caused by both sabotage, maintenance failures, and gunshot holes. The most significant oil spill associated with the pipeline was caused by the Exxon Valdez, but did not directly involve the pipeline itself.
The oil throughput has been steadily declining and will continue to decline unless additional sources of oil are developed in the northern regions. By law, Alaska is required to remove all trace of the pipeline after oil extraction is complete. No date has been set for this removal, but plans for it are being updated continuously.