New Orleans Canal Levee Failure

Reported post-Katrina safety factor of 1.3 — the lowest Tom knows of in a structural application. Personal connection: Tom's great-grandfather, a civil engineer, worked on the levees around 1880.

The New Orleans levees — around 1880 my great-grandfather was a civil engineer working on the levees — I read somewhere after Katrina that the safety factor on the levees was 1.3. That 1.3 is one of the lowest safety factors I know of. Typically safety factors are around 1.67 to 2. When you're hoisting equipment above someone's head, or someone's more than six feet off the ground, they'll go to 4. Some cases when you're working with castings and pressure vessels where the consequences of failure are pretty severe — blowing up a building or a city block — safety factor of five.

Safety factor 1.3. Tom emphasizes the levees did not fail by strength — they were overtopped. Personal note: Tom's grandfather built levees in New Orleans in the 1880s.

The New Orleans levees — someone may have mentioned that, because I pointed it out. Did he tell you what the safety factor on the levees is? It's 1.3. And frankly the levees didn't fail in New Orleans because the safety factor wasn't strong enough. They got breached over — they got washed away from the top. My grandfather in the 1880s was building levees in New Orleans.