3 ms·

Seems like there should be a separate competition for designing the tube. For example why should the radius of the tube be what it is, why have a center rail in

by soheil 10y ago

Seems like there should be a separate competition for designing the tube. For example why should the radius of the tube be what it is, why have a center rail instead of two rails or side tracks, should the tube have some sort of inner coating? What if it should be a double tube, a tube within a tube, for sound/temperature isolation and to reduce vibrations, and to reduce the risk of depressurization due to outside impact kinda like a double-haul oil tanker? Can it be made out of glass (that'd be kinda cool to look at/out of)? How close to vacuum the pressure and thick the walls of the tube should be? Can someone double check my work here: In the webcast they mentioned it will take 30mins to depressurize the tube. The length of the tube is 1mi. For example from LA to SF is roughly 400 miles if the final pump is twice stronger it'll take 6000mins or 4 days to depressurize, I'm assuming they will only need to do this once and have gates to maintain the main tube's pressure near areas of loading/unloading.

the8472 10y ago
a longer tunnel would likely have more pumps along the track. I don't think you should extrapolate from this small-scale model.
- smbullet 10y ago
  It definitely doesn't scale linearly. They had a section of the tube only several meters long for vacuum testing pods and that took 15 minutes to depressurize. It's likely bigger/more pumps would be used.
  - annerajb 10y ago
    Woudn't the need for depressuration be removed if using airlock since you only have to depressurize the airlock volume?
    - vidarh 10y ago
      To some extent, but part of the reason for having pumps is that it removes the need to make the tube fully airtight - the idea being that it's likely to be cheaper to build a tube that is largely airtight and use pumps to deal with leaks than to build one that can keep a vacuum over time.
nilstycho 10y ago
The tube design is not final. They included a variety of features to allow some flexibility in designing pods. The radius is smaller than a full-scale hyperloop. Depressurization is not catastropic, as it would be for an oil tanker, so there is no need for a double hull. In fact, some leakage is expected. The real tubes will have airlocks. The test track was originally going to have airlocks, but they were scrapped for complexity.

by soheil 10y ago

the8472 10y ago

a longer tunnel would likely have more pumps along the track. I don't think you should extrapolate from this small-scale model.

smbullet 10y ago
It definitely doesn't scale linearly. They had a section of the tube only several meters long for vacuum testing pods and that took 15 minutes to depressurize. It's likely bigger/more pumps would be used.
- annerajb 10y ago
  Woudn't the need for depressuration be removed if using airlock since you only have to depressurize the airlock volume?
  - vidarh 10y ago
    To some extent, but part of the reason for having pumps is that it removes the need to make the tube fully airtight - the idea being that it's likely to be cheaper to build a tube that is largely airtight and use pumps to deal with leaks than to build one that can keep a vacuum over time.

nilstycho 10y ago

The tube design is not final. They included a variety of features to allow some flexibility in designing pods. The radius is smaller than a full-scale hyperloop. Depressurization is not catastropic, as it would be for an oil tanker, so there is no need for a double hull. In fact, some leakage is expected. The real tubes will have airlocks. The test track was originally going to have airlocks, but they were scrapped for complexity.