The Pipeline Authorization Act required the pipeline to be able to withstand the maximum earthquake ever recorded in the area it was built. When crossing the Denali Fault, Teflon-coated sliders were designed to allow the pipeline to move side-to-side in an earthquake. To protect against forward-and-backward shocks and to allow for thermal expansion, the pipeline wasn't designed as a straight line. Instead, it was intended to be laid in an S-shape, and the bends would allow for expansion and movement without breaking