[deelowe]

That demo is unrealistic. The entire end of the tube isn't going to open all at once. Instead, any realistic leak would be pretty small in comparison.

[Spooky23]

Forces of nature or other things never suddenly disrupt infrastructure.

See: http://whns.images.worldnow.com/images/22787728_SA.jpg

[Retric]

It's an elevated track so it really could be designed to deal with that kind of break. Water, Oil, and Gas pipelines for example have long dealt with those issues without breaking when designed correctly.

[mcguire]

Absolutely.

http://www.snopes.com/photos/accident/graphics/gasline2.jpg

[brianwawok]

How do oil pipes do this? Automatic cutoffs every mile?

[Retric]

There are a wide range of solutions: https://sfwater.org/modules/showdocument.aspx?documentid=577... http://www.pbs.org/wgbh/amex/pipeline/peopleevents/e_quakes....

Sliders https://www.quora.com/Why-do-oil-pipelines-that-transfer-oil...

Now doing this without bending the long pipe is going to be harder, but you really could design this thing so riders don't notice a magnitude 9 earthquake.

PS: In the end you get into cost benefit designing it to survive an aircraft impact is probably not worth it let alone a nuke, but predictable earthquakes are not that hard.

[Spooky23]

Big water infrastructure breaks too.

My wife was PM on an emergency project to replace a 72" main feeding a city that failed.

[UnoriginalGuy]

I don't understand why a tube section couldn't come away? What if a bomb went off, a truck hit a support beam, or an earthquake caused a section to topple over...

I don't think it is unrealistic at all.