• 2 Posts
  • 21 Comments
Joined 1 year ago
cake
Cake day: July 5th, 2023

help-circle





















  • There’s so many flaws with a system like this, I can’t imagine how you could make it economical. I’m just gonna list a few that have popped up in my mind over the years

    1. Thermal expansion. Steel contracts and expands a lot depending on the temperature, railroads have regular expansion joints to account for this. But having expansion joints which withstand a vacuum in a 500+ km tube in a reliable way would be amazing. Imagine the maintenance cost just for those. Expanding, contracting, shifting left, right, up and down.
    2. Maintaining a vacuum. Maintaining a continuous vacuum over 500+ kilometers. There’s gotta be a lot of pumps using a lot of energy, considering it would be impossible to prevent leaks over such a humongous distance.
    3. Vacuum failure. With such a large distance, there’s bound to be failures along the hyperloop. The train can probably slow down along these sections, but they would need to be prepared. Reparation means many hours of downtime, for people who chose a vacuum train presumably to save travel time.
    4. Capacity. A regular long-distance train can take on hundreds of people, which makes the costs tolerable. All of the concepts show very short vehicles, with maybe a couple seats side-by-side. That’d make the cost/person very high.
    5. Embarking/Disembarking. The people have to enter the train somehow, either through pressurizing a very long section, or having very precise door section which the train mounts to.
      • In the case of pressurizing, it would take a long time for pressurize -> passengers move -> depressurize, adding long wait times at the station.
      • In the case of entrance doors, this hampers flexibility. There can’t be longer trains than what the station is designed for, the train design and length must always be the same, and any wear&tear on the train could potentially prohibit making a proper seal with the exit door.
    6. Related to the above point, long-distance railroads have many sub-destinations. Imagine having to pressurize->depressurize at every station, when a regular train just has to stop and open the doors.

    I believe all of the above points would make a vacuum train economically stupid and impossible.

    Just to escape the friction of air?