Design Modes, Changes, and Construction Processes of the Alyeska Pipeline

There were three basic construction modes during the initial period of Alaska Pipeline design: conventional burial, special burial, and above ground berm or pile bent. The top depths of the conventionally buried pipeline varied from 0.9 to 2.7 m in accommodation to local topography and soil conditions. In the special burial, the mechanically controlled circulation of brine coolant or pile foundations equipped with thermosyphons were designed for removing the heat from operating crude oil pipeline to keep permafrost frozen. The above ground construction mode included elevated pile foundations, and above ground berms, for reducing or preventing the heat released by oil from entering into permafrost and subsequently thawing permafrost. From the start, pipeline owners demanded an 100% burial of pipeline. At the end of the construction, the pipeline was buried only at 57% of the total length. It is concluded that the experiences leading to the success of the Alyeska Pipeline include; 1) The keys to the successful construction and operation of the pipeline are detailed surveys, research and design; 2) Dynamic design with a continuous improvement of design plans according to the progress of the surveys, design and construction; 3) Democratic debates and resulted stern requirements on environmental issues facilitated the safety of pipeline; 4) Solving design and construction problems according to their practical situations based on the familiarity and clear understanding of stipulations governing the surveys, design, construction and operations of the pipeline; 5) Close cooperation among pipeline engineers, environmental research scientists, and project management personnel was critical; and 6) Non-profit organization forms of the Alyeska and Joint Alaska Pipeline Office, and their practical management styles were equally important.