Why the Alaska Pipeline Zigzags on Stilts

In Alaska, an 800-mile steel pipe refuses to touch the ground. For more than half its length it floats on stilts, and instead of running straight it zigzags left and right, over and over. Straight lines are cheaper and faster, so why would anyone build it this way? The answer is frozen ground, hot oil and one of the most dangerous faults in North America. This is how the Trans-Alaska Pipeline survives the cold, the heat of its own oil and an earthquake that moved the ground 18 feet in seconds. In this video: • Why this pipeline can't be buried like a normal one • How heat pipes full of ammonia keep the ground frozen with no power at all • Why a straight pipe here would tear itself apart, and how the zigzag fixes it • The day the Denali Fault slid 18 feet sideways right under the pipe If you had to design a pipeline across Alaska today, would you build it the same way? Tell me in the comments. 🔔 Subscribe for more giant things explained simply. CHAPTERS 0:00 An 800-mile pipe that won't touch the ground 0:52 Meet TAPS 1:44 1968: oil at the top of the world 3:06 Secret #1: why stilts 5:33 Secret #2: why the zigzag 7:28 The $8 billion choice 8:04 The Denali Fault 9:45 The new problem: cold oil 11:02 Zooming out Sources: Alyeska Pipeline Service Company (pipeline facts, throughput and 2002 earthquake report); U.S. Geological Survey (Denali Fault, 2002); Bureau of Land Management; University of Alaska Fairbanks (permafrost). #TransAlaskaPipeline #Alaska #Engineering