The Explosion that Changed the Pipeline Industry

On the evening of September 9th, 2010, residents of a quiet neighborhood in San Bruno, California, were going about their evening when at 11 minutes past 6, the ground beneath them erupted. A huge fireball shot into the sky and set the neighborhood al light. Witnesses thought a plane taking off from the nearby airport must have

crashed, and it took responders almost an hour to realize what had actually happened. The culprit was a natural gas pipeline line 132 buried a few meters deep under the city owned and operated by utility company PG&D. The 30-in steel pipeline carried natural gas from Militus Terminal in Santa Clara County where gas is fed into the region's major

transmission lines to Martin Station on the San Francisco Peninsula, a distribution hub supplying energy to local communities. The pipe hadn't been overloaded. The pressure that night had stayed within its allowable operating limits, but somewhere inside the steel, a crack had been slowly growing, and that night it fractured with catastrophic results. Eight people were killed, dozens more

were injured, and 38 homes were destroyed. Could this have been predicted? Modeling how small defects grow and predicting when they'll become large enough to cause a structure to fail is one of the central challenges in engineering. One with life or death consequences, whether it's in pipelines, jet engines, or bridges. In this video, we'll dive into

the fascinating world of fracture mechanics, the field of engineering used to understand how cracks grow under load, and how engineers predict when materials will fail. If you take a plate and pull on it at both ends, a uniform tensile stress will develop within the material in response to the applied load. This stress is