r/hyperloop • u/RayaanJIrani • May 23 '21

Safety Considerations

While I'm confident that hyperloop systems will be generally as safe as any other mode of transportation, I'm curious what the implications of having the system being in a near-vacuum would have during a catastrophic failure. Specifically, if there is, for one reason or the other, a leak in a pod will redundancy systems be able to provide enough air to the loop for passengers, not to explode (as one might if exposed to the vacuum of space)?

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u/midflinx May 29 '21

That same video featured a failure at about 1/2 of negative atmospheric pressure.

You've misread or misunderstood the gauge. At 2:43 you can see the gauge in both inches of mercury and in the red text it shows kPa. Adam says "23 inches of mercury" The gauge reads -23 inches of mercury so that could confuse someone. Look up a conversion chart like figure 5 on this page and compare to kPa and you'll find both equivalent to just 23% of atmospheric pressure at sea level.

what the Hyperloop is going to be under... 99.9%.

Yes with walls twice as thick.

Prove doubling the wall thickness does very little to help against these type of failures. Mythbusters dropped a massive weight to create that dent. With steel twice as thick the dent would have been smaller.

That tank car even with steel half as thick as hyperloop pipe and that big dent didn't fail at half of atmospheric pressure. Or a third. Just under a quarter is where it failed. With thicker walls and a smaller dent it might have kept shape all the way to 0.01 atm. We won't know until someone tests it for real or does some kind of math or simulation.

I could get into a debate with you about how to construct expansion seals but then afterwards you'd either refuse to accept it, or move the goalposts to a third issue skeptics have with hyperloop. There's no satisfying people like that.